cessna aircraft company aircraft division wichita, kansas … · 1997. 6. 1. · the cessna...

CESSNA AIRCRAFT COMPANY

AIRCRAFT DIVISION

WICHITA, KANSAS 67277

A SUPPLIER’S GUIDE TO ACCEPTABLE DATA SUBMITTALS

REPORT NO: GEN-96-002

REPORT DATE: June 1, 1997

APPROVED BY: _____________________

R. Phillips

APPROVED BY: _____________________

R. Held

APPROVED BY: _____________________

L. Van Dyke

APPROVED BY: _____________________

L. Bitker

APPROVED BY: _____________________

P. Hughes

TEXTRON AVIATION, INC. PROPRIETARY INFORMATION

Printed On 2/1/2017 GEN-96-002.pdf

The Cessna Aircraft Co. Page i

P.O. Box 7704 A Supplier’s Guide to Acceptable Data Submittals

Wichita, KS 67277 Report Number: GEN-96-002 Rev. C

REVISIONS

LETTER DATE DESCRIPTION APPROVED

A 11-30-2000 FMECA replaced by SSA

Rev Date By: Approved By:

B 3/10/2015 See Separate Electronic

Signature Sheet

See Separate Electronic Signature

Sheet

ECR No: 099985

Section Description

Global Updated document format and fonts, and corrected spacing.

Table of

Contents

Updated page numbers and titles.

§1 Is “General Formatting - Reports…,” was “General Formatting…”

Is “Supporting Report/Data Submission Information…,” was “Support Report

Information…”

Is “…in nearly every data submittal or report…,” was “…in nearly every

report…”

§2 Added “- Reports” to section title.

Under ‘Binding,’ added “Electronic report submission is preferred. Reports

should be provided in a single electronic file. If paper submission is

necessary, …”

Under ‘Margins,’ added “Standard margins of 3/4" to 1 1/4” are acceptable.

For paper submissions, …”

Under ‘Page Numbering,’ added “…, with the exception of the title page,…”

Under ‘Page Size,’ added “…is preferred, but it is understood that some over-

sized pages may be necessary. For paper submissions,…”

§3 Added “/data submission” following “report” in the section title and in two

other locations.

Is “Section 3.1 describes the information that should be submitted with any

type of data. Sections 3.2 through 3.7 describe required components of

reports.” Was “These general sections include the information sheet, title

page, contents, and revisions page.”

§3.1 Added “/data submission” following report in two locations.

Is “The information shall include the following items:..,” was “The

information sheet shall include the following items (ref. Fig. 3.1–1):...”



The Cessna Aircraft Co. Page ii



Deleted “Document Type – identify as one of the following types:

ATP Acceptance Test Procedure, DTA Damage Tolerance Analysis

FAT Fatigue Analysis, QSR Qualification by Similarity, QTP Qualification

Test Procedures, QTR Qualification Test Results, RSP Reliability

Substantiation Plan, RSR Reliability Substantiation Results, SAR Stress

Analysis, SSA System Safety Assessment.”

Added “14. ECCN, 15. Model, 16. Notification of Change (Major or Minor).”

Added “Figure 3-1 shows Cessna Form 2473, which can be completed and

returned with electronic or paper data submissions. For electronic

submissions, suppliers may have the option of providing the required

information via electronic template. If an electronic template is not available,

the information must be provided as a separate sheet during the transmission

of data.”

Revised Figure 3.1-1 and caption.



The Cessna Aircraft Co. Page iii



Rev Date By: Approved By:

C Sept. 1,

2015

See Separate Electronic

Signature Sheet

See Separate Electronic Signature

Sheet

ECR No: 099985

Rev. C

Section Description

QSR Title

(Now) "QUALIFICATION BY SIMILARITY REPORT (QSR)",

(Was) "QUALIFICATION BY SIMILARITY (QSR)"

Purpose of this Document

(Remove) " This report does not present information on the procedures

required for the report—it is not a Qualification by Similarity Methods

guide."

Purpose of a Qualification by Similarity Report

(Now) "A Qualification by Similarity Report (QSR) is a report that shows

similarity of a new or modified part to a previously …"

(Was) "A Qualification By Similarity Report (QSR) is a report that seeks to

establish viable similarity to a previously …"

(Add) "A QSR may also include additional … has adequately been defined."

Overview of a Qualification by Similarity Report

(Now) "To minimize the qualification test effort, a QSR should be pursued

when it is determined that a valid similarity exists between the part being

proposed and an existing qualified part or component. This generally means

that the form, function, materials, and manufacturing methods, are the same.

Operating loads and environmental operating conditions may be no more

severe for the new part than for what the previously part was qualified to."

(Was) "A QSR may be pursued when it is determined that a viable similarity

exists between the part being proposed and an existing qualified part or

component. This generally means that the form, function, materials,

manufacturing methods, operating loads, and environmental operating

conditions between the two parts are similar."

(Add) "Analysis and design review are … to some other previously tested

part."

QSR 1.1 (Now) "This section is required to include …"

(Was) "This paragraph should include …"



The Cessna Aircraft Co. Page iv



Rev. C

Section Description

QSR 1.2 (Now) "This section is required to include a brief description of the end

product being analyzed for this QSR including the Supplier and Cessna part

numbers of both the qualified part(s) and the part being qualified."

(Was) "This paragraph should include a brief description of the end product

being analyzed for this QSR including the contractor and Cessna part numbers

of both the qualified part and the part being qualified."

QSR 1.3 (Now) "This section is required to summarize …"

(Was) "This paragraph should summarize …"

QSR 2.0 (Now) "Summarize the report and include a brief …"

(Was) "Summarize the report and include an brief "

(Now) "If a requirement has been waived by Cessna Engineering, explicitly

state this."

(Was) "If a requirement has been waived, explicitly state this."

(Now) "Specify the military, federal, or industry specifications and standards

to which testing of the new part would be required …"

(Was) "Specify the military, federal, or industry specifications and standards

to which the testing is required …"

(Now) "Specify the military, federal, or industry specifications and standards

to which the testing is required … shall be summarized and included."

(Was) "A list of any tests still required to compensate for differences between

the two components or new tests required for qualification shall be included."

QSR 2.1 (Now) "This section shall document what is identical …

(Was) "This paragraph shall document the similarities …"

(Now) "… section …", (Was) "… paragraph …"

QSR 2.2 (Now) "… section …", (Was) "… paragraph …"- 2 places

(Now) "Provide either the justification that the difference does not invalidate

previous qualification data or state what additional qualification (analysis or

qualification testing) of the difference will be required."

(Was) "Describe how the differences affect the qualification criteria."



The Cessna Aircraft Co. Page v



Rev. C

Section Description

QSR 3.0 (Now) "This section shall document the rationale, data, analysis, and

justification for qualification by similarity analysis."

(Was) "This section shall document the rationale for qualification by

similarity."

(Remove) "Include any field service history that the unqualified component

may have, including any flight–time on preproduction aircraft as well as any

tests that the component has undergone. If possible, compare the results of

any similar tests between the two components."

(Add) "This section of the QSR is required … with any RTCA DO-160

qualification requirement."

QSR 4.0 Title

(Now) " QUALIFICATION TESTING",

(Was) "QUALIFICATION TEST"

QTP Purpose of this Document

(Remove) "This report does not present information on the procedures

required to setup or conduct a test—it is not a Qualification Test Procedures

Methods guide."

Purpose of a Qualification Test Procedure Report

(Now) "A Qualification Test Procedure (QTP) …"

(Was) "A Qualification Test Procedures (QTP) …"

(Now) "… provides test setup and instrumentation … show …"

(Was) "… seeks to establish …"

(Add) "… applicable …"

Overview of a Qualification Test Procedure Report

(Now) "… is required to …", (Was) "… should …"

(Now) "… shall …", (Was) "… must …"

QTP 1.1 (Now) "This section is required to …", (Was) "This paragraph should …"

QTP 1.2 (Now) "This section is required to …", (Was) "This paragraph should …"

(Add) "… that are applicable to this … shall be described and justified."

QTP 2.0 (Add) "A brief description of the component or system … definition of the

Test Article."

QTP 2.2 (Now) "… is required to …", (Was) "… should …"

(Now) "State if …", (Was) "It should be clear if …"

(Now) "… these are also required to be described."

(Was) "… these should be made clear."



The Cessna Aircraft Co. Page vi



Rev. C

Section Description

QTP

2.2.1.1

(Now) "… are also required to …", (Was) "… should …"

QTP

2.2.1.2

(Now) "This section is required to present …"

(Was) "This section presents …"

QTP

2.2.2

(Now) "This section is required to present …"

(Was) "This section presents …"

(Add) "… Engineering …"

QTP 3.0 (Now) "The number of Test Articles … in the test report."

(Was) "Each test should be … criteria of each test should be clearly stated."

QTP 4.0 (Add) "In order to facilitate … and other data in the QTP."

(Now) "The test facilities, equipment, and instrumentation shall be …"

(Was) "The test facilities should be …"

(Now) "… is required to be tabulated or listed."

(Was) "… should be tabulated."

(Now) "This table is required to include equipment, and instrumentation

descriptions and model numbers or identification."

(Was) "This table should include description and model number or

identification."

(Now) "The QTP is required to … in the test procedures and not here."

(Was) "It is not necessary to identify the serial numbers of the equipment in

this report."

QTP 5.0 (Now) "If a Cessna ODA conformity inspection is required it shall be clearly

stated."

(Was) "If an FAA conformity is being performed it must be clearly stated."

(Now) "Test setups and instrumentation shall … the conformity status."

(Was) "The procedures to handle deviations to the design definition should be

identified."

QTP 6.0 (Now) "The test procedures are required … for performance of the tests."

(Was) "The individual tests should be … procedure should be listed."

(Add) "Any special calibration or adjustment … included in the test report."

(Remove) "Any special equipment … for using that equipment."

(Now) "Pass/Fail criteria shall be …", (Was) "Pass/Fail criteria should be …"

(Add) "For example, if the acceptance … specific scope of the QTP."



The Cessna Aircraft Co. Page vii



Rev. C

Section Description

QTR Purpose of a Qualification Test Results Report

"A Qualification Test Results (QTR) defines the required testing needed to

establish that a vendor component meets all requirements specified in the

controlling engineering documents."

"A Qualification Test Results (QTR) is a report that documents the test results

which were the result of performing the test procedures defined in the QTP.

These results are used to establish that a vendor component meets all

requirements specified in the controlling engineering documents."

Overview of a Qualification Test Results Report

(Now) "The Qualification Test Results report is required to …"

(Was) "The Qualification Test Results should …"

QTR

Table of

Contents

(Add) " Scope and Objective

Requirements"

QTR 1.1 (Add) "1.1 Scope and Objective"

(Now) "This section shall …", (Was) "The introduction shall …"

QTR 1.2 (Add) "1.2 Requirements"

(Add) "This section is required to … to the following regulations:"

QTR 4.0 (Now) "… where the testing was accomplished and what equipment …"

(Was) "… where the testing was accomplished, what equipment …"

(Remove) ", and the name of a person to contact that can answer questions

regarding facilities, equipment, and how tests were run"

QTR 6.0 (Now) "Following is a list of typical data … passed each test section."

(Was) "If FAA conformity was required … 8100–1 if applicable."

QTR 7.0 (Add) "Even though it may be obvious … the Test Article with retest."



Report: GEN–96–002, Rev C

A supplier’s guide to acceptable data submittals

TABLE OF CONTENTS

SECTION TITLE PAGE

1. INTRODUCTION....................................................................................................... 2

2. GENERAL FORMATTING - REPORTS .................................................................. 3

3. SUPPORTING REPORT/DATA SUBMISSION INFORMATION .......................... 4

3.1 Information Sheet ................................................................................................. 4

3.2 Title Page .............................................................................................................. 6

3.3 Revisions Page ..................................................................................................... 6

3.4 Table of Contents Page ........................................................................................ 6

3.5 References ............................................................................................................ 6

3.6 List of Abbreviations and Symbols ...................................................................... 6

3.7 List of Definitions ................................................................................................ 6

4. ACCEPTED REPORT FORMATS ............................................................................ 7

Acceptance Test Procedure (ATP) .......................................................................... 7

Damage Tolerance Analysis (DTA) ...................................................................... 10

Fatigue Analysis (FAT) ......................................................................................... 16

System Safety Assessment (SSA) ......................................................................... 21

Qualification By Similarity (QSR) ........................................................................ 28

Qualification Test Procedure (QTP) ..................................................................... 33

Qualification Test Results (QTR) ......................................................................... 39

Reliability Substantiation Plan (RSP) ................................................................... 43

Reliability Substantiation Results (RSR) .............................................................. 47

Stress Analysis (SAR) ........................................................................................... 51



The Cessna Aircraft Co. Page 2



1. INTRODUCTION

A wide range of engineering documents supporting supplier parts and equipment is

regularly received and reviewed by Cessna’s engineering department. In the absence of

any pre–defined format requirements, the review process can be cumbersome and

inefficient for both Cessna as well as the submitting supplier. This report presents

acceptable formats for the more common document types.

While certain content requirements cannot be avoided—and indeed, formatting and

content go hand–in–hand—it is the primary intention of this report to define only the

layout and formatting needs of submitted data. The specific subjects to be covered, and

the data to be included, will generally be defined in the specification control documents

provided by Cessna. These specifications will always take precedence over any

requirements contained in this document.

Many companies have report formatting standards that have been accepted by Cessna in

the past and strict compliance with this standard is not required for data to be approved.

Nonetheless, compliance will ensure uniformity with data submittals from other sources

and will aid Cessna in our evaluation. To avoid conflicts, it is suggested that deviations

from this standard be approved by Cessna prior to document submittal.

This report divides the formatting requirements into three categories:

General Formatting - Reports (Section 2) defines the very basic formats of page size,

margins, font size, and so on.

Supporting Report/Data Submission Information (Section 3) defines the report sections

that would be expected in nearly every data submittal or report, i.e. Information Summary

Sheet, Reference Page, Table of Contents, and the like.

Acceptable Report Formats (Section 4) is the principal source for the specific format

requirements for each document covered in this report.






2. GENERAL FORMATTING - REPORTS

General Formatting affects the overall “look” of the report. The goal is to provide an

easy–to–read document in which data can be presented clearly and uniformly from one

document to the next.

Binding Electronic report submission is preferred. Reports should be

provided in a single electronic file. If paper submission is

necessary, there is no preference towards any single binding

method. It is acceptable (and most common) to submit reports in

standard loose–leaf, three–ring folders

Character Fonts For the general narrative, fonts smaller than 10 pt are discouraged.

Fonts smaller than 10 pt may still be used for figures, tables, or

other areas if their use improves readability by condensing

information that would otherwise be split across several pages to be

printed on a single page. Hand–written report sections are

sometimes inevitable (e.g., as in recorded data sheets from tests).

For these cases, the document should be legible and of adequate

quality for subsequent copies. In any case, the document must be

readable after being reproduced on typical photocopy equipment.

Figures and Tables Any figure or table reference in the report text must be numbered

and labeled. The preferred orientation is portrait.

Headers Each page shall include the supplier name, as well as the document

number.

Language English

Line Spacing Double–spaced typed

Margins Standard margins of 3/4" to 1 1/4” are acceptable. For paper

submissions, at least 1 1/4” margin at the binding and 3/4” margins

along all other edges. The margin at the binding shall be sufficient

to allow photocopying of permanently bound documents.

Page Numbering Each page, with the exception of the title page, shall be numbered.

Page Size 8 ½” x 11” is preferred, but it is understood that some over-sized

pages may be necessary. For paper submissions, all fold–outs

should be such that they fold within the standard page size.

Page Color White






3. SUPPORTING REPORT/DATA SUBMISSION INFORMATION

Certain sections of a report/data submission are required regardless of the report/data

submission content. Section 3.1 describes the information that should be submitted with

any type of data. Sections 3.2 through 3.7 describe required components of reports.

3.1 Information Sheet

A report/data submission information page shall be included with each report/data

submission. This single sheet defines all relevant information about the report to ensure

proper coordination with the reviewing engineers and other project support personnel.

The information shall include the following items:

1. Company Name – The name of the submitting supplier—this may not be the same as

company that actually wrote the report.

2. CAGE – Commercial and Government Entity code of the controlling supplier. If not

known, enter N/A.

3. Document Number – As defined by the supplier.

4. Document Revision

5. Document Title – As defined by the supplier

6. Part Number – List the supplier part number(s) that are associated with this report

7. Associated Cessna Part Number(s)

8. Reference Cessna Documents – List any documents that have been referenced.

9. Purchase Order/Contract No.

10. Authors – point of contact for possible questions

11. Phone/Address

12. Date Submitted

13. Abstract – contains a brief summary of the report contents

14. ECCN

15. Model

16. Notification of Change (Major or Minor)

Figure 3.1-1 shows Beechcraft Form 900-33769, which can be completed and returned

with electronic or paper data submissions. For electronic submissions, suppliers may

have the option of providing the required information via electronic template. If an

electronic template is not available, the information must be provided as a separate sheet

during the transmission of data.






FIGURE 3.1–1 Summary Information Sheet






3.2 Title Page

The Title Page shall include, as a minimum, the following information:

1. Company Name and CAGE

2. Document Name

3. Document Number

4. Purchase Order/Contract No.

3.3 Revisions Page

All report revisions shall be detailed on the revision page. In addition, a brief description

of the nature of the revision may be helpful.

3.4 Table of Contents Page

Each of the major sections along with most of the minor subsections shall be included in

the table of contents. The specific formats for each report–type (as given in Section 4)

present a general guideline to be followed.

3.5 References

Any source used in the report shall be listed on the reference page. In most cases this

would include the relevant federal regulations, any Cessna documents used, the source for

material properties, and any in–house documents used.

3.6 List of Abbreviations and Symbols

All symbols and abbreviations used throughout the report shall be listed. Exceptions can

be made when the abbreviation used is either obvious within context, or is in common

usage (such as FAA or NASA).

3.7 List of Definitions

It is anticipated that for most reports this section will not be required; however,

sometimes words are used with a specific meaning that might otherwise be

misinterpreted. For instance; in certain usage the word “Flight” can mean any number of

takeoffs and landings from engine start to shut–down, whereas in a fatigue usage, the

word “Flight” encompasses only a single takeoff and landing, each touch–and–go is

therefore a “Flight.” This section shall contain a list of those items that have specific or

peculiar meaning in the context of the report.






4. ACCEPTED REPORT FORMATS

This section presents report outlines or skeletons that define an acceptable report layout

for the more common report-types. These outlines are intended to be general in nature so

as to allow the supplier the flexibility needed to meet the special needs of individual

reports. Each outline is preceded by a brief description of the purpose of the report, an

overview of the report content, and a document outline presented in the form of a typical

table of contents.

The reports presented, and their respective report codes are as follows:

ATP Acceptance Test Procedure

DTA Damage Tolerance Analysis

FAT Fatigue Analysis

QSR Qualification by Similarity

QTP Qualification Test Procedures

QTR Qualification Test Results

RSP Reliability Substantiation Plan

RSR Reliability Substantiation Results

SAR Stress Analysis Report

SSA System Safety Assessment

ACCEPTANCE TEST PROCEDURE (ATP)


This document presents acceptable format and minimum content requirements for an

Acceptance Test Procedure. This document does not present information on the

procedures required for any test procedures—it is not an Acceptance Test Procedures

Methods guide.

Purpose of an Acceptance Test Procedure Report

An acceptance test is performed on components to verify that the production components

fulfill the requirements of the design activity and/or certifying agency under which it is

being purchased. The parameters being measured should include physical dimensions

and weight of the component as well as operational performance. An Acceptance Test

Procedure (ATP) is a document that establishes the procedures used to determine that

production components meet those requirements specified in Cessna’s Source Control

Document including all referenced Federal Aviation Regulations.

Overview of an Acceptance Test Procedure Report

An acceptable Acceptance Test Procedures report will identify all parameters that are to

be tested and the manner in which the test will be performed. The level of performance

(pass/fail criteria) for each individual test must be clearly stated.






How to use this Document

The following pages are organized as a full Acceptance Test Procedure. The

accompanying text for each section describes the expected content along with notes on

formatting. The pages are listed sequentially; however, in an actual report a page

numbering system that makes reference to the Section number (i.e., 3.1, 4.1, 4.2, ...) is

usually preferred.

Document Outline

The figure below (presented as a Table of Contents) gives the general outline of an

Acceptance Test Procedure.

TABLE OF CONTENTS (TYPICAL)

REFERENCES

LIST OF ABBREVIATIONS AND SYMBOLS

LIST OF FIGURES

LIST OF TABLES

1.0 INTRODUCTION

Scope and Objective

Requirements

2.0 REFERENCE DOCUMENTS

Government Documents

Non–Government Documents

3.0 SUMMARY OF TESTS

4.0 TEST FACILITIES AND EQUIPMENT

5.0 INSPECTION AND CONFORMITY

4.0 TEST PROCEDURES

1.0 INTRODUCTION

1.1 Scope and Objective

This paragraph should include a brief description of the scope and objective of this

document. This should include identifying the component being tested and the

specification requirements to which it is being tested.






1.2 Requirements

This paragraph should clearly state to what specification control document the component

is being tested.

2.0 REFERENCE DOCUMENTS

This section should tabulate all applicable documents. The criteria for determining the

applicable revision levels of the documents should also be clearly stated.

2.1 Government Documents

This section should list all applicable government standards.

2.2 Non–Government Documents

This section should list all applicable Cessna and supplier documents.

3.0 Summary of Tests

Each test should be tabulated. The objective and the passing criteria of each test should

be clearly stated as well as the passing criteria.


The test facilities should be identified in this section. This includes outside laboratories

and their available equipment. All equipment used in the testing should be tabulated.

This table should include description and model number or identification. It is not

necessary to identify the serial numbers of the equipment in this section of the document.

If necessary, any applicable equipment serial numbers may be listed on the data sheets.

Additionally, there should be a clear statement as to how the recorded data will be

maintained and for what length of time the data will be maintained.

5.0 INSPECTION AND PART CONFORMITY

This section shall clearly state that the part or system has been inspected and conforms to

the design definition. All deviations to the design definition should be documented in the

appendix on the appropriate forms.

6.0 TEST PROCEDURES

The individual tests should be fully described here along with the step–by–step procedure

for each. Any special equipment required during a test should be clearly stated, as well as

any instructions for using that equipment. Sample data sheets should also be included for

the approval phase of this document. Pass/Fail criteria should be clearly stated in the text

as well as on the face of the data sheet.






DAMAGE TOLERANCE ANALYSIS (DTA)


This document presents acceptable format and minimum content requirements for a

Damage Tolerance Analysis report. This report does not present information on the

procedures required for the analysis—it is not a Damage Tolerance Methods guide.

Purpose of a Damage Tolerance Analysis

A Damage Tolerance Analysis (DTA) is a structural analysis done to identify and

substantiate the inspection intervals required to ensure adequate safety. This guide is

applicable to a crack growth analysis supported by a residual strength analysis for the

critical crack (flaw) length. The Damage Tolerance Analysis is separate from a Fatigue

Analysis—generally associated with a safe–life, or life–limited part.

Overview of a Damage Tolerance Analysis

The general steps for a DTA include

1. Selection of critical locations

2. Stress history from load spectrum

3. Crack growth analysis

4. Residual strength (critical crack length)

5. Inspection requirements


The following pages are organized as a full Damage Tolerance Analysis report. The

accompanying text for each section describes the expected content along with notes on


numbering system that makes reference to the Section number (i.e., 3.1, 4.1, 4.2, ...) is

usually preferred.

Document Outline

The figure below (presented as a Table of Contents) gives the general outline of a

Damage Tolerance Analysis report. Depending on the specific requirements of each

analysis, some modifications would be appropriate. For instance, if two independent and

unrelated assemblies were being covered in the same report, with several analysis

locations on each assembly, then it might make sense to repeat sections 3.0 through 7.0

for each assembly. In any event, the outline presents the major topics that are expected in

all reports.







REFERENCES


LIST OF FIGURES

LIST OF TABLES

1.0 INTRODUCTION

Locations Analyzed

Certification Requirements

2.0 SUMMARY OF INSPECTION REQUIREMENTS

3.0 PART DESCRIPTION

4.0 SPECTRA

Operation Spectrum

Load/Stress Spectrum

Limit Load

5.0 MATERIAL PROPERTIES

6.0 ANALYSIS METHOD

Stress Intensity Solutions

Initial Flaw Assumptions

Spectrum Manipulations

Crack Growth Computer Code Used

7.0 CRACK GROWTH AND RESIDUAL STRENGTH

ANALYSIS

Location #1

Location #2

Location #3

1.0 INTRODUCTION

The introduction should include a brief summary of what the part is, why it is being

analyzed, what area of the part is analyzed, and what the final results are. The minimum

inspection interval should be listed along with the inspection method assumed in the

analysis.






1.1 Locations Analyzed

This section shall present a summary of each of the locations with a brief description of

each one. It is often helpful to include an overall picture of the part with locator arrows to

the analyzed locations. Section 3 will present a description of the overall part being

analyzed. A full detail description of the analysis locations will be presented in Section 7

including the reasons for selections.

1.2 Requirements

If the part is to be certified to particular Damage Tolerance requirements, then the

applicable paragraph numbers shall be listed—i.e., FAR 25.571(b). If additional

requirements are being met, including Cessna requirements, then those shall be listed

also.

2.0 SUMMARY OF INSPECTION REQUIREMENTS

At least two types of inspection are expected—initial and recurring. These inspection

times are dependent on the inspection method assumed, and when appropriate, the

inspection intervals for different inspection techniques should be presented as well. In

some cases, the time to initial inspection may be found to be extremely long (no crack

growth) and may be stated as such.


It is helpful to include a reasonably thorough description of the part being analyzed

including its relationship to the surrounding area of the aircraft. Illustrations clearly

showing part orientation should be included.

4.0 SPECTRA

The spectra refers to the history of cyclic loads or stresses that the analyzed part

undergoes during its assumed lifetime. The stress intensity history used for the crack

growth analysis is defined by the global operational profile, the load spectrum, and the

local stresses.

4.1 Operation Spectrum

The operational spectrum is defined by the usage of the aircraft—flight length, altitude,

speed, etc., and will usually be defined by Cessna. Except in a few special cases, the

flight profiles that any single aircraft, or fleet of aircraft, will fly can only be generally

approximated. In many cases, a single general flight profile can be assumed using the

expected hours per flight as the basis, while in other cases several distinct flight profiles

may be combined according to their expected number of occurrences.

4.2 Load/Stress Spectrum

The load spectrum defines the cyclic loading that the aircraft sees during flight and

ground operations. The stress spectrum derives directly from the load spectrum, but is in






terms of stress, not load. The load spectrum is often defined in terms of a load

exceedance curve. For instance, the maneuver load spectrum may be given in terms of an

exceedance curve of aircraft center–of–gravity load factor. If a continuous exceedance

curve has been converted to a few discrete steps, the procedure used should be defined

here.

For analyses with multiple locations, it is sufficient to present only an overview of the

load spectrum here, and to present the detailed stress spectrum in Section 7 for each

location. In any case, the actual stress spectrum used for the analysis shall be presented

either in the report body, or in an attached appendix. Any manipulations made to the

stress spectrum shall be covered in Section 6.

4.3 Limit Load

The critical crack length will be defined by the limit load case. The limit load level will

probably be greater than the largest spectrum load case, although in some cases the

maximum spectrum load will also be the limit load. As the critical case for residual

strength does not necessarily correspond to the critical case for static strength, the actual

case used should be clearly noted.


A complete listing of the relevant material properties used in the analysis along with their

source is required here. A typical list would be expected to include:

Fty yield strength

Ftu ultimate tensile strength

Kc plain–stress fracture toughness

Kic plain–strain fracture toughness

da/dN vs. ΔK crack growth rate data. Depending on the method of analysis used,

this information may be in the form of coefficients for any of several

possible equation forms, or in the form of tabular data for different R–

ratios.

ΔK Threshold

Constants

threshold below which there is no further crack growth.

R–cutoff stress ratio value, R, beyond which there is no further effect on crack

growth from changes in stress ratio.

If load interaction is accounted for in the analysis, or if further modifications to the crack

growth rate are used, then the applicable values shall be listed here as well.






6.0 ANALYSIS METHODS

An overview of the analysis method shall be presented here. It is likely that in most

cases, linear fracture mechanics will be used (LEFM) along with widely accepted stress

intensity solutions and analytical techniques. Even so, it is important that these methods

be stated up–front to avoid any confusion with the final results.

Initial Flaw Assumptions

The initial flaw size can be dependent on several factors including manufacturing

procedures, part size, and type of part. However, typically, an initial flaw size of 0.05” is

used for edge cracks. An explanatory drawing is especially helpful when presenting the

initial flaw sizes used.

Load Interactions and Spectrum Manipulations

A wide range of load interaction models are available. The specific one used (if any)

must be presented along with any additional assumptions used in its use. The stress

spectrum loading order can have a significant effect on the final outcome. The method

used (range–pair, rain–flow, etc.) must be referenced as well. If the techniques used are

generally well known (Willenborg load interaction for instance), there is no need to go

into further detail.

Stress Intensity Solutions

An overview of the stress intensity solutions used in the analysis is presented here.

Virtually any stress intensity solution involves a series of assumptions and

approximations. If a compounding approach has been used, the compounded, individual

solutions should be referenced. Any in–house or commercial software used should be

listed.

Crack Growth Computer Code Used

The specific crack growth computer code shall be listed here. Since most of the available

crack growth software packages have very similar names, to avoid confusion the principle

authors of the software along with the release date (or version) should be listed as well.

7.0 CRACK GROWTH AND RESIDUAL STRENGTH ANALYSIS

This Section contains the actual detailed analysis of each location. The specific details of

the general methods listed in Section 6.0 should appear here. Additionally, the following

items would be expected in every analysis:

1. Logic used to select the critical locations analyzed. Some of the factors that would

cause a particular location to be chosen include high stresses, high stress

concentration factors, high load transfer, or field experience.






2. The technique used to develop the stress distribution—Finite Element, Hand

Calculations, Strain Gauges, Photo Elastic, etc. The stress distribution has a direct

affect on the stress intensity solution.

3. Crack Growth Curves. These curves should clearly show the assumed initial flaw

size, the critical flaw size, various phases of crack growth (ligament, back side of

hole, etc.), and inspection times.

4. Inspection limits, including the minimum inspectable crack length and the inspection

technique used. These limits can usually be shown on the crack growth curves.

5. Critical Crack Length. Residual strength curves may be helpful in showing this.






FATIGUE ANALYSIS (FAT)



Fatigue Analysis report. This report does not present information on the procedures

required for the analysis—it is not a Fatigue Analysis Methods guide.

Purpose of a Fatigue Analysis

A Fatigue Analysis is a structural analysis done to identify and substantiate the safe–life

(or replacement life) required to ensure adequate safety. The Fatigue Analysis is separate

from a Damage Tolerance Analysis—generally associated with the determination of

inspection intervals.

Overview of a Fatigue Analysis

A fatigue analysis investigates the reduction in strength of a part, through the onset of

cracks, over the life of repeated load cycles. The general steps for a Fatigue Analysis

include:

1. Selection of critical locations

2. Stress history from load spectrum

3. Selection of appropriate life curves and scatter factor

4. Fatigue life analysis using the accumulation of damage (or other theory of fatigue

damage)


The following pages are organized as a full Fatigue Analysis report. The accompanying

text for each section describes the expected content along with any other notes on


numbering system that makes reference to the Section number (i.e., 3.1, 4.1, 4.2,...) is

usually preferred.

Document Outline

The figure below (presented as a Table of Contents) gives the general outline of a Fatigue

Analysis report. Depending on the specific requirements of each analysis, some

modifications would be appropriate. For instance, if two independent and unrelated

assemblies were being covered in the same report, with several analysis locations on each

assembly, then it would make sense to repeat sections 3.0 through 7.0 for each assembly.

In any event, the outline presents the major topics that are expected in all reports.







REFERENCES


LIST OF FIGURES

LIST OF TABLES

1.0 INTRODUCTION

Locations Analyzed


2.0 SUMMARY OF FATIGUE LIFE


4.0 SPECTRA

Operation Spectrum

Load/Stress Spectrum


Ultimate and Yield Strength

Fatigue Life Properties

6.0 ANALYSIS METHOD


Fatigue Analysis Computer Code Used

7.0 FATIGUE ANALYSIS

Critical Location Selection Criteria

Location #1

Location #2

Location #3

1.0 INTRODUCTION

The introduction will include a brief summary of what the part is, why it is being

analyzed, what area of the part is analyzed, and what the final results are. Any calculated

safe–life limitations should be listed. The final numbers should be presented so as to

avoid any possible misinterpretation concerning the presence or lack of scatter factors.







This section shall present a summary and brief description of each of the locations. It is

often helpful to include an overall picture of the part with locator arrows to the analyzed

locations. Section 3 will present a description of the overall part being analyzed. A full

detail description of the analysis locations will be presented in Section 7 including the

reasons for selections.

1.2 Requirements

If the part is to be certified to particular fatigue–life requirements, then the applicable

paragraph numbers shall be listed—i.e., FAR 25.571(c). If additional requirements are

being met, including Cessna requirements, then those shall be listed also.

2.0 SUMMARY OF FATIGUE SAFE–LIFE

The final fatigue safe–life will generally be defined by the mean fatigue life divided by an

appropriate scatter factor. The values listed in this section are summarized from the

calculations given in section 7.


It is helpful to include a reasonably thorough description of the part being analyzed

including its relationship to the surrounding area of the aircraft. Illustrations clearly

showing part orientation should be included.

4.0 SPECTRA

The stresses used for the fatigue analysis are defined by the global operational spectrum,

the load spectrum, and the local stresses.

4.1 Operation Spectrum

The operational spectrum is defined by the usage of the aircraft—flight length, altitude,

speed, etc., and will usually be defined by Cessna.

4.2 Load/Stress Spectrum

The load spectrum is often defined in terms of a load exceedance curve. For instance, the

maneuver load spectrum may be given in terms of an exceedance curve of aircraft center–

of–gravity load factor. If a continuous exceedance curve has been converted to a few

discrete steps, the procedure used should be defined here. For analyses with multiple

locations, it is sufficient to present only an overview here, and to present the detailed

stress spectrum in Section 7 for each location. In any case, the actual stress spectrum

used for the analysis shall be presented either in the report body, or in an attached

appendix. Any manipulations made to the stress spectrum shall be covered in Section 6.








source is required here. A typical list would be expected to include:

Fty yield strength

Ftu ultimate tensile strength

σ/n , ε/n. stress–life or strain–life (s–n) curves that define the cyclic fatigue life

for the material analyzed.

As it is unlikely that the geometry and material used to generate the fatigue–life curves

will be identical to the analysis location, it is important that the test coupon definition

used to develop the material data be listed. All s–n curves used in the analysis should be

presented in this section, or in an Appendix.


An overview of the analysis method shall be presented here. It is likely that in most

cases, some form of Miner’s rule of accumulated damage in combination with s–n curves

will be used. However, as there are a wide variety of variations on this method in use, it

is important that the full procedure be presented.


Unless the spectrum consists of a simple constant amplitude cyclic loading, it is likely

that some modifications will need to be made to the stress spectrum prior to the analysis.

The stress ranges for each cycle are often re–arranged (cycle–counting) to ensure that the

analysis more closely reflects the true loading. Additionally, the Ground–Air–Ground

(GAG) cycle is typically identified as a separate load cycle in the spectrum.

Stress Concentration Factors

For most cases, s–n curves for a given material are presented for specific stress

concentration (Kt) values. The method used to determine the Kt used should be

presented as well as the rationale for using a particular s–n curve.

Fatigue Analysis Computer Code Used

For all but the simplest cases, the fatigue analysis will require the use of computer

programs. Whether an in–house program is used, or commercial software, a description

of the code should be included here.

7.0 FATIGUE ANALYSIS

This Section contains the actual detailed analysis of each location. The specifics of the

general methods listed in Section 6.0 should appear here. Additionally, the following

items would be expected in most every analysis:






1. Logic used to select the critical locations analyzed.

2. The technique used to develop the stress distribution — Finite Element, Hand

Calculations, Strain Gauges, Photo Elastic, etc.

3. Stress Concentration (used in the selection of s–n curves)

4. Any additional factors

5. Scatter Factor justification or other method to account for variability.






SYSTEM SAFETY ASSESSMENT (SSA)



System Safety Assessment (SSA) report. Although information is given concerning the

content of a SSA, this report does not present the complete procedures required for the

analysis—it is not a SSA Methods guide.

Purpose of a System Safety Assessment Report

The System Safety Assessment (SSA) as required by Cessna is a procedure by which the

systematic, comprehensive evaluation of the implemented system (component) is

accomplished to show that relevant safety requirements are met. The SSA is to be

accomplished in accordance with the requirements and format of SAE ARP 4761,

Guidelines and Methods for Conducting the Safety Assessment Process on Civil Airborne

Systems and Equipment. The supplier prepared SSA integrates the results of the various

supplier prepared analyses to verify the safety of the overall system and to cover all the

specific safety considerations identified in those analyses.


The following pages are organized as a full SSA report. The accompanying text for each

section describes the expected content along with notes on formatting. The pages are

listed sequentially; however, in an actual report a page numbering system that makes

reference to the Section number (i.e., 3.1, 4.1, 4.2,…) is usually preferred.

Document Outline

The figure below (presented as a Table of Contents ) gives the general outline of a System

Safety Assessment report.








LIST OF FIGURES

LIST OF TABLES

1.0 INTRODUCTION

2.0 REFERENCES

3.0 DESCRIPTION SUMMARY

4.0 SYSTEM SAFETY REQUIREMENTS AND

EVALUATION

4.1 System Safety Requirements and Evaluation

4.1.1 System Safety Design Requirements Source

Data

4.1.2 System Safety Design Requirements

Compliance Evaluation

4.1.3 Failure Condition Classification Validation

4.1.4 Verification of Safety Requirements

Compliance

4.1.5 Verification of CCA Safety Requirements

Compliance

4.2 SSA Documentation

5.0 SAFETY REQUIREMENTS VERIFICATIONS

(CONCLUSTIONS)

1.0 INTRODUCTION

This section contains a short description of the purpose of the document, what it is

intended to accomplish, and the system being analyzed.

2.0 REFERENCES

This section lists the documentation which will be used to form the basis of the analysis

to be accomplished. It includes, but is not limited to, the Cessna provided Source Control

Drawing (SCD); component Fault Tree Analyses (FTA), Dependence Diagrams (DD), or

Markov Analysis (MA); component Failure Modes Effects Analyses (FMEA) or Failure

Modes Effects Criticality Analysis (FMECA); SAE ARP 4761, SAE ARP 4754, RTCA






DO-160D, RTCA DO-178B; the appropriate FAR/JAR sections (i.e., 25-1309) and the

appropriate FAA Advisory Circulars (i.e., AC 25-1309B), etc.

3.0 DESCRIPTION SUMMARY

This section consists of a detailed description (including the purpose) of the system(s)

being analyzed. It will include system block diagrams, input and output signal

descriptions, physical size (dimensions and weight), environmental conditioning

requirements, etc.

4.0 SYSTEM SAFETY REQUIREMENTS AND EVALUATION

These sections consists of the listing of the safety requirements being satisfied. The SSA

accomplishes the following:

a. Verification that the system safety design requirements established in the

component SCD are met.

b. Validation that the hazard classifications established by the supplier

analyses for the aircraft level effects are justified.

c. Verification that the design requirements identified in the supplier

accomplished Common Cause Analyses (CCA) are met.

4.1 System Safety Requirements and Evaluation

This section will discuss the sources of the system safety requirements which are to be

documented in this section of the SSA. Also discussed is the method suggested for

evaluation of the failure condition and requirements source data.

4.1.1 System Safety Design Requirements Source Data

This sub-section consists of a listing of the source data required accomplish the

evaluation required to be documented in the SSA. The types of source data to be

obtained include, but are not limited to, the following:

a. System architecture description and the associated design rationale.

b. Systems interfaces and their interactions with the items of the adjacent

systems.

c. Requirements and failure conditions identified in the component SCD.

d. List of functions and the associated rationale from the component SCD.

e. Common Cause Analyses results (as applicable):

(1) Zonal Safety Analysis (ZSA) results.

(2) Particular Risk Analysis (PRA) external threats.

(3) Common Mode Analysis (CMA) results.

f. Results of all the supplier developed supporting materials and lower level

studies required to accomplish the SSA. (Failure Mode Effects Analysis






(FMEA)/Failure Modes Effects Summary (FEMS)/Failure Mode Effect

Criticality Analysis (FMECA), Fault Tree Analysis (FTA), etc.)

4.1.2 System Safety Design Requirements Compliance Evaluation

This sub-section lists each failure condition and documents how the safety design

requirements for that condition are complied with. Examples of the techniques which

may be used to accomplished the required evaluation are as follows:

a. Show, using Fault Tree Analysis (FTA), Dependence Diagrams (DD) or

Markov Analysis (MA), how items failures combine to lead to the

considered failure condition.

b. Show, using FTA, DD, or MA that qualitative and quantitative

requirements and objectives associated with the failure condition are met.

c. Notify Cessna Project Engineering of the “Not to Exceed” interval for

maintenance tasks driven by latent failures considered in the FTA, DD, or

MA which are required to be included in the appropriate drawings and

maintenance manuals. (Not all latent failures drive “Not to Exceed”

maintenance intervals.)

d. Verify that the development assurance level of items derived from the

FTA, DD, or MA have been met.

e. Test the condition to assure compliance with the requirements.

f. Demonstrate that the component performs as expected with the given

failure condition.

4.1.3 Failure Condition Classification Validation

This section lists the traceability between the requirements established in the component

SCD and the documentation which specifies the requirements to the design organizations.

The documentation includes but is not limited to the following:

a. Aircraft design requirements and objectives documentation.

b. System requirements documentation (if developed).

c. Test plans (ground tests, flight test, etc.).

d. Aircraft maintenance and flight manual inputs.

e. Common Cause Analyses documents.

4.1.4 Verification of Safety Requirements Compliance

This section defines how the system safety requirements identified in the component SCD

are complied with. The component SCD contains all the aircraft design requirements

along with the FAR/JAR requirements. The verification of compliance is accomplished

by one or more of the four standard means (i.e., test, analysis, demonstration and

inspection).






4.1.5 Verification of CCA Safety Requirements Compliance

This section defines how the safety requirements developed by the CCA tasks (if

accomplished) are complied with. Examples of CCA requirements are as follows (list is

not all inclusive);

a. System and component separation and segregation (from the ZSA).

b. External threats (from the PRA).

c. Common mode failures (from the CMA).

The verification of compliance is accomplished by one or more of the four standard

means (i.e., test, analysis, demonstration and inspection).

4.2 SSA Documentation

This section defines the documentation which is required to be generated as part of the

SSA process. This is required in order to preserve the traceability of the steps taken in

the development of the SSA. The following data (list is not all inclusive) should be

preserved in order to maintain the required linkage between the source data used and the

SSA generated report:

a. Update failure condition list which includes the rationale showing

compliance with safety requirements (qualitative and quantitative).

b. Documentation showing how requirements for the design of the system

item’s installation (segregation, protection, etc.) have been incorporated.

These may include drawings, photographs, test reports, etc.

c. Materials used to validate the failure condition classification.

d. Safety maintenance tasks and associated “Not to Exceed” times.

e. Documentation showing how the system and items (including hardware

and software) have been developed in accordance with assigned

development assurance levels.

5.0 Safety Requirements Verifications (Conclusions)

This section consists of a table which indicates how each safety requirement was verified.

The first table below is an example of one approach for depicting the System Safety

Assessments results. The second table represents an alternate approach for depicting the

desired results.

System Safety Assessment

Item Number (1) Safety Requirement (2) Results (3) Verification Method &

Remarks (4)






(1) The item number will be assigned by the supplier.

(2) This column is a copy of the Safety Requirements from the component

SCD. It will list the failure condition and the required level of safety.

(3) This column will show the level of safety the system is designed to meet

through analysis and testing. It will also show if the system design passes

or fails the required level of safety outlined in the Safety Requirements

column.

(4) Types of testing, analysis and all other necessary documentation numbers

that are used to show compliance to the safety requirements for that system

failure. This column will include reference to FTA or an FMEA that is

included in the body of the document. Component, and system testing

documents may be referenced in this column.

SYSTEM SAFETY ASSESSMENT SUMMARY – APPROACH ONE

Aircraft Function

Being Analyzed

(1)

1

Function

(2)

2

Item

No.

(3)

3

Failure

Condition

(Hazard

Description)

(4)

4

Phase

(5)

5

Effect of Failure

Condition on

Aircraft/Crew (6)

6

Classification (7)

7

Reference to

Supporting

Material (8)

8

Verification

(9)

(1) Title of the Component Level Function being analyzed (e.g., Component

Provides False Data).

(2) Description of the Function being analyzed (e.g., Component Provided

False Data Causes Aircraft to Fly in Hazardous Manner).

(3) An item number will be assigned to each functional failure condition

entry. This item number will serve as a means to correlate functional

failure conditions between reports.

(4) Description of the resulting hazard (e.g., Aircraft Flight Path Results in

Aircraft Crash).

(5) Phase of aircraft operation for the specific condition being analyzed (e.g.,

Landing or Rejected Takeoff (RTO)).

(6) Description of the effect the failure has on the aircraft/crew and the

resulting crew action to counteract the effects.

(7) The failure condition classification resulting from the occurrence of the

risk being analyzed (e.g., Minor, Major, Hazardous, Catastrophic).

(8) Listing of the reference material used to substantiate the action taken to

mitigate the failure effects.






(9) The documentation used to verify the correctness of the analysis.

SYSTEM SAFETY ASSESSMENT SUMMARY – APPROACH TWO






QUALIFICATION BY SIMILARITY REPORT (QSR)



Qualification by Similarity Report.

Purpose of a Qualification by Similarity Report

A Qualification by Similarity Report (QSR) is a report that shows similarity of a new or

modified part to a previously certified or qualified part or component for the purpose of

reducing redundant and/or unnecessary testing requirements and expediting the

qualification effort.

A QSR may also include additional analysis or design review. The means of showing

compliance to each qualification requirement, design review, similarity analysis, or other

general form of analysis shall be clearly stated in the applicable QSR section. For the

purposes of this document, similarity means identicallity. Any design feature that is not

identical to that on the previously approved part shall be qualified by additional analysis

and/or test.

A QSR may be combined with a QTP, since the QSR is required to define the

qualification requirements for which similarity analysis is not valid and will require

testing. However, the QSR will be required to be submitted to Cessna at least in draft

form along with any supporting test data prior to Cessna Engineering approval of the QTP

for the new part. This is to ensure that any claim of similarity is valid and that the scope

of the test program has adequately been defined.

Overview of a Qualification by Similarity Report

To minimize the qualification test effort, a QSR should be pursued when it is determined

that a valid similarity exists between the part being proposed and an existing qualified

part or component. This generally means that the form, function, materials, and

manufacturing methods, are the same. Operating loads and environmental operating

conditions may be no more severe for the new part than for what the previously part was

qualified to.

Analysis and design review are strongly encouraged in lieu of qualification testing for

requirements where compliance is evident by review of design data or simple,

conservative analysis can be provided. For example, compliance with the Fluid

Susceptibility, Salt Fog, and Fungus Resistance requirements can be shown by review of

the materials and finishes used in construction of the component and by providing

handbook data or industry specifications showing the materials and finishes will not be

adversely affected by these threats. For most electromechanical components, compliance

with many of the electrical environment requirements can be addressed by design review

and analysis as equivalent means of satisfying the intent of electrical environment test

requirements. Explosion Proof qualification for an electrical component can be






demonstrated if design review shows it has no commutation or arcing in normal operation

and analysis shows that any electrical heating can readily be dissipated so that surface

temperature limits are not exceeded at the highest approved operating temperature and

altitude.

With Cessna Engineering concurrence, analysis may also be provided to demonstrate that

a qualification requirement is not applicable to the particular design of the equipment.

Qualification test data for a previous similar part may be used if it meets the criteria of

FAA Order 8110.4C, Paragraph 2-6.k.(3). The data is required to show sufficient

evidence that the data was FAA approved, which may include conformity inspection

records, FAA or designee witnessing records, and/or other correspondence showing the

data was approved by a prior applicant. The QSR is also required to show that the data is

applicable to the new design. If the previously approved test data requires redacting of

proprietary data, the redacting cannot remove so much content that it is then not possible

to determine that the data is applicable to the new design.

Qualification by similarity analysis based on test data for a previously qualified part may

be shown only to a tested part. It is not acceptable to show similarity to a previous part

which was qualified only by being shown similar to some other previously tested part.


The following pages are organized as a full QSR. The accompanying text for each

section describes the expected content along with any other notes on formatting. The

pages are listed sequentially; however, in an actual report a page numbering system that

makes reference to the Section number (i.e., 3.1, 4.1, 4.2,...) is usually preferred.

Document Outline


Qualification by Similarity Report.







REFERENCES


LIST OF FIGURES

LIST OF TABLES

1.0 INTRODUCTION

Scope and Objective

Part Description


2.0 SUMMARY OF SIMILARITY

3.0 RATIONALE FOR QUALIFICATION

4.0 QUALIFICATION TESTING

1.0 INTRODUCTION


This section is required to include a brief description of the scope and objective of this

document.

1.2 Part Description

This section is required to include a brief description of the end product being analyzed

for this QSR including the Supplier and Cessna part numbers of both the qualified part(s)

and the part being qualified.

1.3 Certification Requirements

This section is required to summarize all the qualification and certification requirements

listed in the contract, purchase order, control drawings, or governing regulations that are

applicable to this QSR. Cessna Engineering concurrence with the validity of similarity

claims and acceptability of any previously approved test data is required prior to QTP

acceptance to ensure the scope of the testing has been adequately defined. Cessna

Engineering will then provide the list of applicable regulations and their amendment

levels, which are required to be included in this section of the QSR with the statement:

"The data in this document is provided to support Cessna showing of compliance to the

following regulations:"

.






2.0 SUMMARY OF SIMILARITY

Summarize the report and include a brief overview describing why this part should be

qualified by similarity. For each of the requirements listed in paragraph 1.3, describe in

detail how the test results for the previously qualified component will be similar/different

to the anticipated results for the unqualified component. If a requirement has been

waived by Cessna Engineering, explicitly state this. Specify the military, federal, or

industry specifications and standards to which testing of the new part would be required

to be performed and compare these with the specification/standards that the original

qualified component was tested. Provide justification why testing performed on the

previously qualified component meets the requirements of the specifications and

standards applicable to the new part. FAA AC 21-16G provides guidance for comparison

of the requirements of different revisions of RTCA DO-160. The means of showing

compliance to each qualification requirement, design review, similarity or other general

form of analysis, or new qualification testing shall be summarized and included.

2.1 Similarities

This section shall document what is identical between the new component and the

previously qualified component. This and the following section may be combined into a

single comprehensive table or section.

2.2 Differences

This section shall document the differences between the new component and the

previously qualified component. Provide either the justification that the difference does

not invalidate previous qualification data or state what additional design review, analysis,

or qualification testing of the difference will be required. This and the preceding section

may be combined into a single comprehensive table or section.

3.0 RATIONALE FOR QUALIFICATION

This section shall document the rationale, data, analysis, and justification for qualification

by similarity analysis. This section of the QSR is required to show that the previous part

has been reliable in its previous application. To state that there is no evidence of

unreliability does not show the part has been reliable and may only indicate poor keeping

of reliability data records. Even if similarity can be shown based on review of previously

approved qualification data, if a component has not demonstrated adequate reliability in

the previous similar application it will not be accepted for the new application without

redesign and additional qualification (test, analysis, and/or design review).

While review of service history is required to establish that the previously qualified part

has been reliable in service, use of service history alone is not acceptable for compliance

with any RTCA DO-160 qualification requirement.






4.0 QUALIFICATION TESTING

Reference and briefly summarize the qualification test procedures and results for the

original part.






QUALIFICATION TEST PROCEDURE (QTP)



Qualification Test Procedure report.

Purpose of a Qualification Test Procedure Report

A Qualification Test Procedure (QTP) is a report that provides test setup and

instrumentation requirements, conformity inspection requirements (if for certification),

clear and concise step-by-step test procedures, and unambiguous, objective test result

acceptance criteria that will provide test data to show that a supplier component meets all

applicable requirements specified in the controlling engineering documents.

Overview of a Qualification Test Procedure Report

The QTP is required to identify all parameters that are to be tested and the manner in

which the test will be performed. The level of performance for successful passage of

each individual test shall be clearly stated.


The following pages are organized as a full Qualification Test Procedures report. The

accompanying text for each section describes the expected content along with any other

notes on formatting. The pages are listed sequentially; however, in an actual report a

page numbering system that makes reference to the Section number (i.e., 3.1, 4.1, 4.2,...)

is usually preferred.

Document Outline


Qualification Test Procedures Report.







REFERENCES


LIST OF FIGURES

LIST OF TABLES

1.0 INTRODUCTION

Scope and Objective

Requirements

2.0 COMPONENT/SYSTEM DESCRIPTION AND

OPERATION



5.0 INSPECTION AND CONFORMITY

6.0 TEST PROCEDURES

1.0 INTRODUCTION


This section is required to include a brief description of the scope and objective of this

document.

1.2 Requirements



applicable to this testing. Cessna Engineering concurrence with the validity of similarity

claims and acceptability of any previously approved test data is required prior to QTP

acceptance to ensure the scope of the testing has been adequately defined. Cessna

Engineering will then provide the list of applicable regulations and their amendment

levels, which are required to be included in this section of the QTP with the statement:



The basis for the testing, such as an industry standard or general test specification, such as

RTCA DO-160 or MIL STD 810 shall be defined. Any deviation from the requirements






of a general test specification on which the testing is based shall be described and

justified.

2.0 COMPONENT/SYSTEM DESCRIPTION AND OPERATION

A brief description of the component or system and its operation is required. It is not

necessary to provide detailed descriptive data in the QTP if reference is provided to other

documents where the detailed data can be found.

The QTP shall state the Part Number of the Test Article and the Assembly Drawing

number that defines it. It is not necessary to include revision level of the drawing, unless

the configuration of the test article can be determined only by reference to the particular

drawing revision level. An example of need to include a top Assembly Drawing revision

level is if significant changes are made during the testing to the design of the part by top

Assembly Drawing revision without change to the part number. If multiple Test Article

configurations are being tested or if changes occur during the testing and the differences

are defined only on lower level drawings that are not denoted on the top Assembly

Drawing, the differences in the design and in the lower level drawings shall be described

in this section as part of the definition of the Test Article.

2.1 Component/System Description

The physical characteristics of the component shall be described along with a summary of

its function.

2.1.1 Sub–Component Description

If the subject is a complex system it may be necessary to provide sub–component

descriptions. Additional sub-sections shall be added as needed.

2.2 Component/System Operation

This section presents a description of all operational aspects of the components. The

discussion is required to be written such that a person with minimal technical expertise

can understand how the component operates. State if there are manual and automatic

modes of operation. If the component has unique normal and abnormal operation modes,

these are also required to be described.

2.2.1 Normal Operation

2.2.1.1 Manual Operation Modes

This section presents a discussion of all manual operation modes. While automatic

operation modes would not be discussed here, any internal operations that are initiated

manually are also required to be discussed.

2.2.1.2 Automatic Operation Modes

This section is required to present a discussion of all automatic operation modes.






2.2.2 Abnormal Operation

This section is required to present a description of any secondary or backup operational

features. It is acceptable to make reference to an existing document (and to supply to

Cessna Engineering) that discusses failure modes and other abnormal system operations.


The number of Test Articles and the particular tests to be performed on each one shall be

defined. It is not necessary to identify the particular Test Article serial numbers, unless

different Test Article configurations will be required for different tests (for example,

assembly or adjustment to an extreme tolerance limit). It is generally undesirable to

identify Test Article serial numbers in a QTP, in case it becomes necessary to substitute a

different equivalent conformed part at the time of the test. Test Article serial numbers are

required to be recorded in the conformity records in the test report.


In order to facilitate preparation of the Conformity Inspection Request, the definitions of

the setup and instrumentation are required to be identified and segregated from test

procedures and other data in the QTP. The test facilities, equipment, and instrumentation

shall be identified in this section. This includes outside laboratories and their available

equipment. All equipment intended to be used in the testing is required to be tabulated or

listed. This table is required to include equipment, and instrumentation descriptions and

model numbers or identification. The QTP is required to either fully define the test

setups and instrumentation, or list drawings, layouts or specifications that define them. If

multiple tests are to be performed and each one requires a different setup, each setup

definition shall be identified and segregated from each other. Definition of test setup and

instrumentation shall be to the degree necessary to ensure that the intended function of

the setup and instrumentation can be verified by visual inspection during the Conformity

Inspection. The definition of the setup and instrumentation shall be sufficiently detailed

that their function could be duplicated based only on the definition in the QTP and

produce the same test results at any suitable test facility, without prior knowledge of the

intended results or reference to post test data or photographs.

The QTP shall specify the type, range, accuracy, sampling rate and any other significant

parameters required for the instrumentation. The QTP shall specify which parameters are

required to be recorded electronically and which ones may be hand recorded. Specifying

particular instrument part numbers should be avoided, since this would prevent

substitution of a suitable equivalent instrument at the time of the test. Specifying only the

part number of the instrument also impedes the ability of the Organization Delegation

Authorization (ODA) Unit Member (UM) witness and inspector to verify that the chosen

instrument is of suitable type, range, and accuracy at the time of the test without access to

manufacturer's data for the instrument. All instrumentation shall have current traceable

calibration and the calibration records are required to be available at the time of the






Conformity Inspection. The locations and details of attachment of instrumentation taps

and probes can be defined by written description, but are required to be clear and precise.

All instrumentation shall include an allowable tolerance and that tolerance is required to

be accounted for in the specification of required test conditions.

Schematics shall be provided for test setup plumbing and wiring and shall reflect the

general layout required for the setup. Plumbing sizes and wire gauges shall be specified

if they are critical to function of the setup. Otherwise, at least the range of acceptable

sizes shall be specified. If particular locations of components in the setup are critical,

such as requiring a pressure gauge be plumbed as close to the test article as practical, that

should be noted on the schematic. Specific part numbers of components used in

construction of the setup, such as plumbing fittings, wire, switches, fasteners, etc…,

should not be specified, unless use of that particular part is essential to the required

function of the setup, as this may prevent substitution of another suitable part at the time

of the testing.

If multiple tests are to be performed and each one requires a different setup, each setup

definition shall be identified and segregated from each other.

The QTP shall include a statement that all instrumentation is required to be calibrated

prior to testing. Reference to the standard company QA procedures pertaining to

instrumentation calibration is normally acceptable. Reference to an industry standard

without defining means to accomplish it normally will not. Any special calibration

procedures that are required to be accomplished during the testing (such as zeroing

settings or selection of particular instrument range settings) shall be specified in the test

procedures and not here.


This section shall clearly state the level to which the part or system is being conformed.

If a Cessna ODA conformity inspection is required it shall be clearly stated. Test setups

and instrumentation shall be conformity inspected prior to performing the test. Any

deviation from the test setup and instrumentation definition in the QTP is required to be

approved by the Cessna ODA UM witness before the testing can begin. Any significant

change to the test setup and instrumentation may also require update to the conformity

record. Any special calibration or adjustment procedures that are required to be

accomplished during the testing (such as zeroing settings or selection of particular

instrument range settings) shall be specified in the test procedures rather than in the test

setup and instrumentation definition so that the changes required to be performed during

the testing will not affect the conformity status.

6.0 TEST PROCEDURES

The test procedures are required to be detailed to the degree that the procedure could be

successfully performed by any suitable test facility by any qualified personnel without

prior experience with the particular QTP or prior knowledge of the desired results. It is






not acceptable to define test procedures solely by reference to a general test specification,

such as RTCA DO-160 or MIL STD 810. RTCA DO-160 defines general test

requirements and includes many options for performance of the tests.

Any special calibration or adjustment procedures that are required to be accomplished

during the testing (such as zeroing settings or selection of particular instrument range

settings) shall be specified in the test procedures. If the QTP specifies a particular setting

be used such as setting a power supply voltage, the actual setting used shall be recorded

with the data and included in the test report. Sample data sheets should also be

included. Pass/Fail criteria shall be clearly stated in the text as well as on the face of the

data sheet. For example, if the acceptance criteria for a proof pressure test is "There shall

be no detrimental permanent deformation", the QTP needs to define quantitatively how

much deformation is acceptable and how it is to be measured. Qualitative acceptance

criteria may also be used as long as they are unambiguous. If the QTP purpose is only to

take data for use in a subsequent analysis, the acceptance criteria shall be "Data shall be

taken."

All test conditions shall specify a bottom and top tolerance for each test parameter

(pressure, temperature, altitude, time, voltage, etc…). The test tolerances shall assume

worst case instrumentation tolerances. Additional tolerances may be required, depending

on the precision of the controls expected to be used for the test. For example, a pressure

transducer may have an accuracy of ±10 PSI, but the pressure regulator available for

performing the test may have a controllability of no better than ±50 PSI.

If the QTP contains additional "company" test requirements that are not required for

certification, they shall be suitably identified and segregated from the certification test

procedures. If additional certification testing is being performed that is in excess of that

necessary for the present certification program but is intended for use for certification of

future development airplanes, those procedures shall be identified as optional and

segregated from the procedures for the present certification program. Acceptance criteria

for additional, optional certification testing shall be specified as "Data shall be taken."

This is to ensure that if the optional test is failed or cannot be completed, it does not

interfere with the current certification program.

The QTP shall list the specific data required to be provided in the QTR. A typical data

requirements list is included in the QTR section of this document. That list may be

modified to match the specific scope of the QTP.






QUALIFICATION TEST RESULTS (QTR)



Qualification Test Results report. This report does not present information on the

procedures required for reducing test data—it is not a Qualification Test Results Methods

guide.

Purpose of a Qualification Test Results Report

A Qualification Test Results (QTR) is a report that documents the test results which were

the result of performing the test procedures defined in the QTP. These results are used to

establish that a vendor component meets all requirements specified in the controlling

engineering documents.

Overview of a Qualification Test Results Report

The Qualification Test Results report is required to identify all parameters that have been

tested and the manner in which the test was performed. The level of performance for

successful passage of each individual test must be clearly stated.


The following pages are organized as a Qualification Test Results report. The


notes on formatting. The pages are listed sequentially; however, in an actual report a



Document Outline


Qualification Test Results Report.







REFERENCES


LIST OF FIGURES

LIST OF TABLES

1.0 INTRODUCTION

Scope and Objective

Requirements

2.0 PART (OR SYSTEM) DESCRIPTION




6.0 QUALIFICATION TEST RESULTS

7.0 CONCLUSION

1.0 INTRODUCTION


This section shall include a brief summary of the scope and objective of this document

regarding the applicable qualification testing.

1.2 Requirements



applicable to this testing. Cessna Engineering will provide the list of applicable

regulations and their amendment levels, which are required to be included in this section

of the QTR with the statement:



2.0 PART (OR SYSTEM) DESCRIPTION

This section shall include a brief definition of the part or system and its operation.







This section shall summarize the testing and include an overview of the main problems, if

any, detected during or after the completion of the testing.


This section shall include a description of where the testing was accomplished and what

equipment was used for the testing.


This section shall provide a statement that the part or system has been inspected and the

part or system conforms to the design definition. If there are any non–conforming items,

they need to be listed with documentation supporting how they were approved for use in

the test.

6.0 QUALIFICATION TEST RESULTS

This section shall provide the results of each test, listing the test by controlling

engineering document paragraph number and Supplier qualification test procedure

paragraph number.

Following is a list of typical data requirements that are required to be provided in a QTR.

If there were multiple test sections each having different setups and conformity

documentation, the following data shall be organized in the Test Report according to each

section of the Test Procedure and clearly labeled as to which section of the Test

Procedure it applies to.

a) Photographs of each test setup, including any changes or adjustments made during

the testing.

b) Photographs of the Test Article before and after each test.

c) Results of physical examination of the Test Article and description of its

condition before and after each section of the testing, taking care to note any

conditions that may have existed prior to the testing.

d) Photographs of instrumentation locations.

e) Descriptions and photographs of any failures (if any).

f) Part numbers, serial numbers, range, nominal accuracy, and inspection dates of

instrumentation for each section of the testing.

g) List of witnesses for each section of the testing.

h) Times, dates and locations for each section of the testing.






i) Cessna data approvals on FAA Forms 8100-9 and Conformity Inspection

Requests on FAA Forms 8120-10 for the Test Articles and Test Procedure, if the

testing was performed for certification purposes.

j) Conformity Inspection Records for the Test Articles, Test Setups, and

Instrumentation. These shall be organized according to each section of the Test

Procedure, if the testing was performed for certification purposes.

k) Recorded data, as specified in the Test Procedure. Typically:

1. Pressures, temperature, humidities, voltages, etc attained after required

elapsed times.

2. Actual durations at each test condition specified by the Test Procedure and as

applicable to the particular test.

3. Any instrument or control settings required to be set and verified in the Test

Procedure. Include the actual values, not just verification that they were set.

4. Ambient conditions in the lab at time of testing.

5. Observations of the test witnesses, even if recording them was not required by

the Test Procedure.

6. Any other data specified by the Test Procedure as required to be recorded.

l) List of deviations (if any) from required test setup, instrumentation or procedures.

If there were no deviations, this shall be stated. If the deviations were recorded by

"redline" markup to the QTP rather than being incorporated into the QTP by

revision, the redlines shall be included in the QTR.

m) Test failures and resultant corrective actions, if any.

n) Summary and conclusions as to whether the Test Article passed each test section.

7.0 CONCLUSION

This section shall state the justification for the part or system meeting the engineering

requirements. Even though it may be obvious from the test results, state the obvious.

The reader should not have to draw any conclusions of their own.

It will not be acceptable for any portion of the testing to have been failed and justification

provided that the failure was acceptable. Any test failures should have been coordinated

with Cessna Engineering and suitable disposition provided prior to completion of the

testing. Suitable dispositions that are required to be documented in the QTR would

include revision or redline deviation to the test procedure such that the Test Article

passed the changed QTP or corrective action and design change to the Test Article with

retest.






RELIABILITY SUBSTANTIATION PLAN (RSP)

Purpose

This document presents an acceptable format and minimum content requirements for a

Reliability Substantiation Plan. This report does not present information on the

procedures required for the analysis—it is not a Reliability Methods guide.

Purpose of a Reliability Substantiation Plan

A Reliability Substantiation Plan (RSP) is part of a reliability program that the supplier

uses to propose a method for demonstrating that their components meet the required

reliability values prior to the first delivery of an aircraft with the specified equipment.

Overview of a Reliability Substantiation Plan

The general steps for a RSP include:

1. List agreed to reliability values/requirements

2. Describe system and environment

3. Selection of substantiation method

4. List components of final report

5. Provide schedule


The following pages are organized as a full Reliability Substantiation Plan report. The


notes on formatting. The pages are listed sequentially; however, in an actual report, a

page numbering system that makes reference to the Section number (i.e., 3.1, 4.1, 4.2, ...)


Document Outline


Reliability Substantiation Plan report.







REFERENCES


LIST OF FIGURES

LIST OF TABLES

1.0 INTRODUCTION

Scope and Objective

Reliability Values

2.0 SUMMARY


4.0 ENVIRONMENT

5.0 DATA COLLECTION AND ANALYSIS

Field History

Testing

Schedule

1.0 INTRODUCTION



document.

1.2 Reliability Values

This paragraph should include the reliability goal as listed in the Product Support

Agreement along with a brief description of how the goal was derived.

2.0 SUMMARY

Summarize the method you plan to use to substantiate reliability. This paragraph should

include the method used to demonstrate reliability. This could be field history or

reliability testing. Field history is the preferred method (assuming the design,

environment, and usage duty cycle are the same). If that information is often not

available, endurance testing and Highly Accelerated Life Testing (HALT) are two

effective methods for demonstrating reliability. Whatever method is selected, it must be

detailed in this plan and approved by Cessna Engineering before any reliability testing is

initiated.







This section describes the operation of the system and contains the details about the Line

Replaceable Unit (LRU). This may include block diagrams or any other information

pertaining to system or component description.

4.0 ENVIRONMENT

If testing is the means of substantiation, describe the test environment that the component

or system will be subjected to (as negotiated and agreed to with Cessna Engineering and

the Quality Engineering Reliability Department). This will include all testing parameters

that may include mission profile, environment, time, and units tested. If Highly

Accelerated Life Testing (HALT) is the method of substantiation, all stimuli shall be

described.

5.0 DATA COLLECTION AND ANALYSIS

5.1 Field History

Field history will be reported to Cessna Engineering to substantiate the reliability level

required. The initial report shall provide, but not be limited to, the following:

Part and Serial Number

Chart (Pareto) of Failure Modes

Identify Corrective Action Implemented

Service Bulletins

Modifications

Dates

Follow–up

Note: This substantiation report will be sent to Cessna Engineering within sixty days after

the design engineer’s request. This will give the Cessna sufficient time to determine if

any additional testing is required.

5.2 Testing

Failures will be reported to Cessna Engineering within 24 hours of failure occurrence.

The initial report shall provide, but not be limited to, the following:

Test log date

Part and Serial number

Test environment

Test elapsed time and number of cycles

Method of failure detection

Description of any other symptoms

Test Engineer name/signature






Note: A written failure report will be sent to Cessna Engineering within 10 working days

of the occurrence.

5.3 Schedule

If testing is the means of substantiation, a test schedule shall be included with all major

milestones documented. Included with the schedule shall be a time period for

incorporating test induced corrective action.






RELIABILITY SUBSTANTIATION RESULTS (RSR)

Purpose

This document presents an acceptable format and minimum content requirements for a

Reliability Substantiation Results report. This report does not present information on the

procedures required for the analysis—it is not a Reliability Methods guide.

Purpose of a Reliability Substantiation Results

A Reliability Substantiation Results (RSR) is part of a reliability program that a supplier

uses to demonstrate that their components have met the required reliability values prior to

the first delivery of an aircraft with the specified equipment.

Overview of a Reliability Substantiation Results

The general steps for a RSP include:

1. List agreed to reliability values

2. Describe system and environment

3. Selection of substantiation method

4. Provide final report

5. List engineering analyses and corrective action


The following pages are organized as a full Reliability Substantiation Results report. The


notes on formatting. The pages are listed sequentially; however, in an actual report, a



Document Outline


Reliability Substantiation Results report.







REFERENCES


LIST OF FIGURES

LIST OF TABLES

1.0 INTRODUCTION

Reliability Values

Substantiation Method

2.0 SUMMARY


4.0 ENVIRONMENT

5.0 FAILURES AND CORRECTIVE ACTIONS

Field History

Testing

1.0 INTRODUCTION



document.

1.2 Reliability Values

This paragraph should include the agreed to reliability value as listed in the Product

Support Agreement along with a brief description of how the goal was derived.

1.3 Substantiation Method

This paragraph should include the method used to demonstrate detailed in the Reliability

Substantiation Plan and be approved by Cessna.

2.0 SUMMARY

Summarize the level of component reliability substantiated. Provide an explanation if the

level of reliability substantiated is different from the value agreed to in the Product

Support Agreement (PSA). Discuss any prediction or testing anomalies that may have

occurred. Describe any changes to the original plan that may have taken place. Include

an overview of any failures. Describe any corrective actions taken. The summary shall

include conclusions and all recommendations based on the substantiation results.







This section describes the operation of the test system and contains details about the Line

Replaceable Unit(s) (LRU). This may include block diagrams or any other information

pertaining to system or component description.

4.0 ENVIRONMENT

If testing is the means of substantiation, describe the test environment the component or

system will be subjected to as negotiated and agreed to with Cessna Engineering and the

Quality Engineering Reliability Department. This will include all testing parameters that

may include mission profile, environment, time, and units tested. If Highly Accelerated

Life Testing (HALT) is the method of substantiation, all stimuli shall be described.

5.0 FAILURES AND CORRECTIVE ACTIONS

5.1 Field History

This section will include any failure modes and corrective actions taken place in the

component's history if this is the means of substantiation. This shall include, but not be

limited to, the following:


Chart (Pareto) of failure modes

Identify corrective action implemented

Service Bulletins

Modifications

Dates

Follow–up

5.2 Testing

If testing is the means for substantiation, all failures encountered during the reliability

testing shall be listed along with any corrective action required to reduce or eliminate

each failure mode encountered. This should include, but not be limited to, the following:

TEST

Test log date


Test environment

Test elapsed time and number of cycles

Method of failure detection

Description of any other symptoms

Root cause of failure

Test Engineer name/signature






ANALYSIS

Analysis procedure

Root cause of failure

Other findings/secondary failures

Analysis Engineer name/signature

CORRECTIVE ACTION

Design change description

Process change description

Completion/implementation on product hardware






STRESS ANALYSIS (SAR)



Stress Analysis report. This report does not present information on the procedures

required for the analysis—it is not a Stress Analysis Methods guide.

Purpose of a Stress Analysis

A Stress Analysis is a structural analysis done to identify and substantiate critical parts

and/or part locations for adequate strength.

Overview of a Stress Analysis

The general steps for a stress analysis include:

1. selection of critical locations

2. application of external loads

3. development of stress model

4. calculation of internal stresses/loads

5. gathering of material properties (allowables)

6. calculation of strength margins


The following pages are organized as a full Stress Analysis report. The accompanying

text for each section describes the expected content along with any other notes on


numbering system that makes reference to the Section number (i.e., 3.1, 4.1, 4.2,...) is

usually preferred.

Document Outline

The figure below (presented as a Table of Contents) gives the general outline of a Stress

Analysis report. For most cases, in which a single part or component is being analyzed,

this outline will correspond to the general work flow. For those reports that present stress

analyses for widely different locations, and using different analysis techniques, it may be

more appropriate to repeat Sections 3 through 7 for each analysis.







REFERENCES


LIST OF FIGURES

LIST OF TABLES

1.0 INTRODUCTION

Locations Analyzed


2.0 SUMMARY OF MARGINS


4.0 LOADS

Load Development

Critical Load Cases

Critical Loads



7.0 STRESS ANALYSIS

1.0 INTRODUCTION

The introduction should include a brief summary of what the part is, why it is being

analyzed, what area of the part is analyzed, and what the final results are (is the part

substantiated?). The minimum margins of safety should be presented.


Include a summary of each of the locations analyzed along with a brief description of

each one. Section 3 will present further details of the part.

1.2 Requirements

If the part is to be certified to particular strength regulations, then the applicable

paragraph numbers shall be listed. If additional requirements are being met, including

Cessna requirements, then those shall be listed also.






2.0 SUMMARY OF MARGINS

A summary (usually in the form of a table) of each analyzed location and its margin of

safety. When appropriate, the nature of the failure should also be present—shear tear out,

crippling, inter–rivet buckling, etc.


A description of the structure or parts analyzed will be given here. Sufficient figures

should be included in order to avoid any confusion of part location or orientation.

4.0 LOADS

A listing of the analyzed loads cases is given here. At its simplest, a singe load value or

G load may be sufficient. For others, a full accounting of shear, moments, and torques

will be needed. In any case, the loads used must be fully referenced and it must be clear

if any additional factors (such as 1.5) have been included. The loads development

process must be fully described. In most cases the applied loads will be supplied by

Cessna, in which case the full reference should be made.



source is required here. A typical list might include:

Fty yield strength

Ftu ultimate strength

E Elastic Modules

n Ramberg–Osgood Number

Beyond these basic material properties, allowables for rivets, bolts, cables, bonds, etc.

would also be appropriate here.


This section will contain an overview of the analysis methods, assumptions, and tools

used. Primarily this involves the technique used to take the external, applied loads and to

calculate internal stresses or loads. The structure may be assumed to be linearly elastic,

with small deflections, or the non linear, elastic and plastic deflections may all be

accounted for. In many cases, a finite element model will be used. For these cases, a

description of the extent of the model along with a general discussion of the assumptions

made in its construction should be included. Depending on the model size, it may be

appropriate to include the full model definition in an appendix.






7.0 STRESS ANALYSIS

This section will contain the actual analysis for each part or location. Each analysis

should:

1. Identify the specific load case used.

2. Explain why this location was selected (nature of criticality).

3. List any specific assumptions made (it may not be necessary to state the assumption

that plane regions remain plane, but if fasteners are assumed to carry loads

proportional to their capabilities, for instance, then that should be noted).

4. Identify the mode of failure (crippling, shear failure, etc.).

5. Clearly identify the final margin of safety.

6. Ensure the clear use of such terms as “ultimate”, “limit”, “factored”, etc.

