operator e-jets news rel 15

Issue No. 15 – February 2008

Issue No. 15 February 2008

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From the Editor

E-JETS NEWS is a publication that presents EMBRAER 170/190 aircraft technical items. This newsletter, compiled by EMBRAER Fleet Technical Center (EFTC), brings the latest developments and shares in-service knowledge and maintenance best practices. It also provides troubleshooting tips to optimize aircraft utilization and efficiency in daily operation.

E-JETS NEWS addresses Operators concerns with maintenance support and dispatchability of EMBRAER 170/190 aircraft. It has relevant information to be shared with the technical departments, such as Engineering and Maintenance. Recipients are encouraged to distribute this newsletter to EMBRAER Customers.

Earlier editions of E-JETS NEWS publication can be found at CIS / Aerochain at

http://www.aerochain.com

- Login (enter username and password);

- Select “Technical Services” and then “EMBRAER Customer Services”;

- Select “Maintenance Support”;

- Select “E-JETS NEWS;

- Click on desired E-JETS NEWS.

If any additional information regarding the in-service items covered in the E-JETS NEWS is needed, please contact the local EMBRAER Field Service Representative. General questions or comments about the E-JETS NEWS publication can be addressed to:

E-JETS NEWS

Tel: +55 12 3927 7075

Fax: +55 12 3927 5996

E-mail: [email protected]

PROPRIETARY NOTICE

The articles published in E-JETS NEWS are for information only and are an EMBRAER S/A property. This newsletter must not be reproduced or distributed in whole or in part to a third party without EMBRAER’s written consent. Also, no article published should be considered authority-approved data, unless specifically stated.


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Removal of Engine Driven Pump Pressure Attenuators – Update

Effectivity: EMBRAER 170

As informed in release No. 9 of E-Jets NEWS, after the first reports of EDP quick disconnect coupling leakages, EMBRAER confirmed that the high pressure ripple level at that region was causing these failures.

During investigation, it has been found that the removal of pressure attenuators reduced the ripple level.

Thus, SB 170-29-0020 was issued on July/2007 instructing how to remove these attenuators from No.1 and No.2 hydraulic systems.

Recent tests performed by the quick disconnect supplier confirmed that the current design is in accordance with ripple levels found after attenuator removal.

Additionally, investigation of EDP leakages concluded that one root cause for the failures was also associated with the high pressure ripple level, which once more justifies the incorporation of this SB.

Based on exposed above, EMBRAER expects a reduction of EDP leakages for aircraft without pressure attenuators and recommends operators to consider the accomplishment of this SB at the next opportunity.

For EMBRAER 190, the reduction of pressure ripple is also being developed, and since the removal of the attenuator did not lead to a satisfactory result, an installation redesign is under development in order to achieve the required ripple levels.

MLG Downlock Harness Damage – Update


E-Jets NEWS Release No.11 issued in October/2007, brought information about occurrences of MLG downlock sensor harness failure caused by fatigue stress during normal operation of the MLG. These events have occurred because the heat-shrinkable sleeve is not flexible enough to allow the harness to curve smoothly during MLG retraction.

As a consequence, the stress is concentrated at the heat-shrinkable tip, causing fatigue to the metal braid and wires. An incorrect installation of the clamps that attach the harness to the structure may contribute to this scenario, once it can increase the stress in that region.

This scenario is usually identified through the “LG NO DISPATCH” warning CAS message associated with “RIGHT/ LEFT MLG DOWNLOCK1/2 SNSR / WRG FAULT” maintenance message. There are two possible solutions under analysis:

1. Harness inspection to confirm its integrity. In positive case, the heat-shrinkable sleeve is removed and the harness is re-routed through a new bracket that separates the harness from the LG structure. It will avoid shafing and stress. The harness manufacturer is analyzing if there is a positive way to inspect and confirm that the harness is still in a good condition to be kept in operation.

2. Complete harness replacement and introduction of the same bracket above mentioned.

The defined solution will be informed soon.

As previously informed, EMBRAER has required operators to report any new event that occurs in the fleet.


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CF34-8E TR Spring Retainer Interference with Engine Hydraulic Tubes – Update


As presented in E-Jets NEWS Release No. 13, EMBRAER was informed of the occurrence of spring retainer chafing against engine hydraulic and fuel tubes. The spring retainer has been introduced by GE SB 78-0024 to avoid interference between left central thermal blanket PN EME335602D or EME335602E (EIPC 78-33-01), installed inside the left thrust reversers, and engine fuel tube PN 2161M26P01 or 4187T10P01.

Figure 1 – Damaged Suction Line

The root cause was identified as a batch of parts with an improper orientation marking (arrow marked on the flat surface, associated with an “UP” indication). The arrow marking had been inverted and this condition can lead the mechanics performing part installation to rotate the part and install it in an incorrect position, upside down, thus creating interference with the tubes.

Figure 2 - Incorrect and Correct Installation

MHD (Thrust Reverser manufacturer) issued a Service Letter (MHD 78-33-582) informing the operators to inspect the thrust reversers to make sure that the spring retainers are correctly installed and to identify damaged tubes.

GE Service Bulletin CF34-8E-AL S/B 78-0047 was released in December 2007 to support these inspections and SB 78-0024 R01 (Spring Retainer Introduction) was revised to highlight the need to have the correct orientation during installation.

Pack Air Cycle Machine (ACM) Contamination – Update

Effectivity: EMBRAER 170 / 190

As an update of E-Jets NEWS No. 8 and No. 12, EMBRAER informs that a new AMM task for the dual heat exchanger on-wing cleaning will be released in March 2008.

Regarding the two RH contaminated heat exchangers removed from revenue service operation for sampling purposes, EMBRAER and Hamilton Sundstrand confirmed that their performance degradation was caused by liquids disposed in the forward galley sink plus atypical gravels incrustation.

It is always important to highlight that disposal of liquids different from water in the forward galley sink is not recommended, as per SNL 170-25-0004 / 190-25-0007.

Autopilot – Operational Test


EMBRAER would like to inform that a new Autopilot operational test will be available in the next AMM Part II scheduled revision (Task 22-11-00-710-802-A). This task was created aiming at simplifying and reducing the time required to perform the current autopilot functional test (Task 22-11-00-720-802-A).


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LOAD 21.2 Side Effects


EMBRAER has released revision 1 of Service Newsletters 170-00-0032 and 190-00-0028. This new revision provides information about the side effects found in Load 21.2.

Pylon Heat Shield Improvements


Pylon heat shield damage due to high temperature and vibration has been reported since the beginning of the EMBRAER 170 operation.

Service Bulletins SB170-54-0004 and SB170-54-0005 were issued to replace portions of the inboard skin and trailing edge of the pylon aft fairings (which were initially made from composite or aluminum) with new ones made from stainless steel.

These service bulletins also give instructions to apply a thermal insulation protection and perform a structural re-design of the aft pylon fairing shields.

After small corrections, Revision 01 of SB170-54-0004 and SB170-54-0005 are available for application.

Fire extinguishing bottles removals under investigation – Update


Pacific Scientific, the manufacturer of the fire extinguishing (firex) bottles that equip the E-Jets, updated EMBRAER with more results of the investigation concerning the reason of firex bottles removals increase in the fleet, as reported on E-Jets NEWS Release No. 14.

Deeper inspections confirmed the initial suspicion on the TCPS conducting to erroneous low pressure indications. Such erroneous indications were caused due to liquid, maybe moisture, contamination of the TCPS contacts, reducing the impedance between pins A and C (see figure above), which conducted to transient low pressure signals.

Figure 1. Contamination Traces – local


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Figure 2. Contamination Traces

In order to avoid future occurrences, Pacific Scientific decided to improve the quality of the TCPS sealing in their production line, adding more room-temperature vulcanizing silicone rubber (RTV – the white material shown in the picture above) on a cleaner Kaizen process that may guarantee a better sealing for this component. Besides that, they also implemented a new production test to verify the insulation resistance of the TCPS wiring, which detects contamination possibilities before bottle installation in the aircraft.

Pacific Scientific is providing spares of the better sealed TCPS to the authorized repair shops, reducing the downtime to replace this device, when necessary. Some Pacific Scientific sites are also provided with rotable firex bottles for emergencies. EMBRAER is closely following up the actions to solve the events of low pressure in the firex bottles that are affecting E-Jets operators.

A new update may be issued in the following E-Jets NEWS edition and, when the final solution concerning the TCPS improvement is defined, a service letter with dispositions is also intended to be issued.

SPDA Block 11.1


EMBRAER released Service News Letters 170-24-0026 and 190-24-0020 to inform the Operators about the contents and improvements of the new Secondary Power Distribution Assembly (SPDA) - Block 11.1 Software.

Passenger Address/ Cabin Interphone Controller (PACIC) Improvement


The PACIC modification consists in the enhancement of the flight attendant microphone gain level, thus raising the microphones volume.

No circuitry is affected by this product improvement and, after the change; the PNs will receive MOD level A (for PN 5682-1-2) and MOD B (for PN 5682-1-1) designation on the front panel of PA/CIC.

This modification can be performed at the operator’s discretion, contacting either Avtech or Avtech’s authorized representative. For additional information, EMBRAER issued SNLs 170-44-0001 and 190-44-0001 in January 14th, 2008.

Commanded IFSD due to Erratic Engine Parameters


EMBRAER has recently been informed about an event involving one EMBRAER 190 aircraft which resulted in a commanded engine shutdown during flight.

The report indicated that while cruising at 36,000 ft, the number one engine N1, N2 and fuel flow indications became erratic. The engine presented two compressor stalls and thereafter the caution message "ENG 1 CONTROL FAULT" was displayed on the EICAS. The crew decided to shutdown engine one and landing occurred without further incident.

Initial investigations point out to a fault of the engine one T1.2 sensor as the root cause for the event. The sensor fault was duplicated in lab tests. The exact root cause for the abnormal sensor reading is still unknown. A full tear down of the component is being carried out.

EMBRAER and GE will continue to analyze all available data and keep operators updated on the progress of the investigation.


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EMBRAER 190 MLG Internal Nitrogen leakage


EMBRAER has received some reports from the field regarding the MLG “H” dimension (visible chrome length) out of specified in the servicing charts. After analysis, a damaged seal on the floating piston was revealed. The purpose of the floating piston seal is to isolate the nitrogen bottom chamber from the oil chamber in the MLG shock absorber. If the seal does not isolate properly, the nitrogen flows from the nitrogen chamber to the oil chamber and the MLG ‘H’ dimension will be out of the dimension specified in the servicing chart.

EMBRAER is evaluating some actions to mitigate the impact in the fleet, such as: issuing AMM tasks for replacement of the MLG seal and inspection for nitrogen internal leakage, and providing a kit of main components for the shock absorber to reduce aircraft down time for MLG seal replacement on wing.

The final solution under evaluation is a new type of seal that is being tested in the rig (endurance test). The tests are expected to be finished by the end of March/2008. The implementation plan will be informed after the accomplishment of the endurance tests. EMBRAER would like to ask the operators to report any new occurrence of the E190 MLG ‘H’ dimension out of specified by means of the servicing chart. This will ensure continued monitoring of the events in the worldwide fleet.

Forward Lavatory harness interference


An event was reported by an EMBRAER 190 operator in which the forward lavatory flush system was found inoperative. Troubleshooting indicated that the event could be related to the wiring. During inspection, evidence of arcing was found in one wire bundle located behind the forward lavatory ceiling panel, which can be reached through the smoke detector access panel.

Figure 1 – Interference between harness and smoke detector installation.

Investigations showed that one of the bolts of the smoke detector assembly could interfere with the mentioned wire bundle, causing friction and potentially leading to this kind of event.

Production line and in-service aircraft will be modified as necessary. EMBRAER will shortly issue a service bulletin to inspect and rework the affected components.


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Emergency Light System – One Minute Test


EMBRAER has released SNLs 170-33-0017 and 190-33-0023 about the alternative procedures for the emergency light system test on the forward FAP (Flight Attendant Panel).

Investigations indicated a malfunction on the circuit board of the ELPU (Emergency Light Power Unit) for the daily test performed by the FAP test button.

The alternative procedures will avoid possible events of emergency lights remaining ON for more than one minute or not being turned OFF after the test. The test can be accomplished either by turning the cockpit switch or by pressing the FAP ON/Armed button. For detailed information, please refer to the mentioned SNLs.

Figure 1 – Emergency Light Switch Locations

The definite solution will be available by the second quarter of 2008.

Potable Water System Leakage and Freezing


An EMBRAER 170 operator reported an event of Potable Water System leakage and ice formation under the forward cargo compartment floor panels along the aileron cable route, which led to stiffness of aileron movement.

The leakage can be caused either by the clamshell being out of position or cracked T-fitting due to freezing cycle of water kept in the Potable Water System lines when the aircraft is parked outside under freezing temperatures.

The AMM will be updated to include ice formation check on the forward fuselage (underneath the forward cargo compartment) through the fuselage drains (TASK 10-30-01-500-802-A SUBTASK 580-002-A item 10).


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Refer to SNL 170-38-0014 and 190-39-0015 for maintenance action recommended for aircraft exposed to extreme cold weather operation.

“FLT CTRL FAULT” CAS Message after Engine Shutdown


EMBRAER received some field reports from operators concerning the occurrence of FLT CTRL FAULT, GROUND SPOILERS FAIL, RUDDER LIMITER FAIL and ELEV THR COMP FAIL CAS Messages appearing in the EICAS after engine shutdown.

During aircraft engine shutdown, the FADEC resets automatically when N2 is below 5%, providing invalid data for approximately 2.5 seconds when the aircraft is on the ground. This behavior makes the following messages to be temporarily displayed on the CAS:

• GROUND SPOILERS FAIL

• RUDDER LIMITER FAIL

• ELEV THR COMP FAIL

• FLT CTRL FAULT

Final solution is already available in Primus EPIC LOAD 19.

Load 21.2 - Flight level limited to FL 370 due to a/c power cycle before loading new APM


EMBRAER has released SNL 170-00-0034 and 190-00-0030 to inform about the Flight Level setting limitation, if an a/c power cycle is done prior to the complete loading.

CMC LDI x FADEC Sofware Versions


EMBRAER has released new LDIs to implement the compatibility between the recent Load and FADEC versions. The table below provides a quick reference guide about LDI versions released for Load 4.3/17.3 and on.

EMBRAER 170/175

Load Pre FADEC v5.40 FADEC v5.40

21.x 170LDI21V17.7-X-V08 170LDI21V17.7-X-V08.1

19.x 170LDI19.3V17.6-X-V06

170LDI19.4V17.6-X-V07.1

17.x 170LDI17.5V17.1-X-V05.1

170LDI17.5V17.1-X-V05.2

EMBRAER 190/195

Load Pre FADEC v5.32 FADEC v5.32

21.x 190LDI21V17.7-X-V08 190LDI21V17.7-X-V08.1

19.x 190LDI19.4V17.6-X-V06.1

190LDI19.4V17.6-X-V07.1

4.x 190LDI4.5V17.1-X-V05.1

190LDI4.5V17.1-X-V05.2

Note: X means the customized configuration (A, B, C, etc.).


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EMBRAER 190/195 - FADEC Software v5.32


EMBRAER has issued Service Bulletin 190-73-0010 related to the new FADEC software version 5.32 applicable to the EMBRAER 190/195 fleet.

This software brings relevant corrections and improvements that have direct impact on aircraft dispatchability, such as improved logic for engine start in cold weather and high altitudes.

Therefore, EMBRAER recommends the accomplishment of this Service Bulletin.

Regarding the software implementation, it is important to observe that it has always been an obligatory dispatch condition to have the same FADEC software version installed in both engines.

However, in the FADEC software version 5.20 and prior, there was no CAS message associated to a disagreement in the FADEC software versions of both engine. With FADEC software version 5.32, if this scenario is detected, an ENG NO DISPATCH CAS message will be annunciated, correlated to an ND XENG SOFTWARE VERSION DISAGREE message on the CMC, and the proper software will need to be uploaded in both FADECs to allow aircraft dispatch.

Tail Strike Avoidance


As introduced in SNL 190-00-0023, EMBRAER would like to stress that the PRIMUS EPIC LOAD 19.3 and higher versions introduce the TSA (Tail Strike Avoidance) function in order to limit the maximum pitch angle when the aircraft is close to the ground for preventing tail strike occurrences.

This function is only available during takeoff and landing, under the following conditions:

TAKEOFF

1. The AOA Limiter function is available;

2. The estimated altitude is less than 200 ft;

3. The single sensor altitude rate at the CG position is valid OR the calibrated airspeed is less than 60 knots;

4. At least three weight-on-wheel sensors are valid.

LANDING

1. The AOA Limiter function is available;

2. The estimated altitude is equal to or greater than 200 ft;

3. The dual sensor compensated radar altitude is valid.

The TSA function is enabled when all the following conditions are satisfied:

1. The TSA function is available;

2. The estimated altitude is less than 20 ft OR

The estimated altitude is greater than or equal to 200 ft AND

The radio altitude at the landing gear position is less than 70 ft;

The TSA function is disabled when one of the available conditions is not satisfied, and the message TAIL STRIKE PROT FAIL is displayed.

If the TSA is unavailable (failed) and the conditions for available are found again, the TSA function turns back to available state. The TSA function is unavailable (failed) for the rest of the flight when the function fails (becomes unavailable) seven times. The failure counter resets when the aircraft is ON-GROUND and the calibrated airspeed is less than 60 knots. In addition, the EMBRAER DDPM 34-31-00 will be reviewed to inform that TAILSTRIKE PROT FAIL Advisory EICAS message will be displayed during flight when one of the Radar Altimeter Systems is inoperative.

Also, EMBRAER would like to inform that the delivered aircraft with PRIMUS EPIC


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LOAD 19.3 and higher versions installed have already had the TSA (Tail Strike Avoidance) functionality enabled on the applicable APM Options, but aircraft that have incorporated Load 19.3 or 19.4 through Service Bulletin, do not have this functionality enabled. SB 190-31-0017 (APM Options - TSA Installation) is already available enabling TSA functionality for aircraft equipped with Load 19.3 or 19.4. The released SB 190-31-0015 (LOAD 21.2 Upload) already has the TSA functionality enabled on the applicable APM Options.

EMBRAER 190/195 Engine Thrust Reverser (T/R), Ground Maintenance Override Switch (GMO) improvement

Effectivity: EMBRAER 190/195

EMBRAER 190/195 fleet has been experiencing the occurrence of ENG 1 (2) REV TLA FAIL EICAS message due to GMO failure in the closed state or during T/R functional test using GMO (covered by EMBRAER SNL 190-73-0010, issued on May/2007).

GMO manufacturer’s investigation has revealed a potential moisture ingression into the switch body could result in an electrical short.

The manufacturer made improvements to the switch which will prevent, from now on, this kind of contamination. Goodrich released a field recommendation in All Operators Letter, AOL EMB/190/195/ CF34-10-03, issued on January 2008.

EMBRAER recommends customers in the field to follow the above mentioned AOL for maintenance action and material support.

Copy of Goodrich, All Operators Letter, AOL EMB/190/195/ CF34-10-03 can be requested to your local EMBRAER Representative or Goodrich Technical representative by e-mail to [email protected]. Also, the AOL can be requested to EMBRAER at [email protected]

AMS Processor Failures


EMBRAER has recently helped troubleshooting an aircraft with failed AMS Processor Boards. In such event, the ECS synoptic display shows some valves intermittently opening and closing, and flow lines going gray and green; and not-correlated RECIRC SMK DET FAIL CAS message is displayed on the CAS during the aircraft power-up.

Afterwards, some aircraft have presented the same faults during production and delivery flights, in which one or both AMS processor boards were declared failed. Hamilton Sundstrand is still evaluating the failed boards in order to define the necessary corrective actions. EMBRAER is planning to release a SNL as soon as the investigation is completed.

Meanwhile, in case of events similar to the one described above, EMBRAER recommends the replacement of the affected AMS processor board (channel 1 or 2).

Cross Bleed Valve Contamination


EMBRAER received a report concerning a Cross Bleed Valve stuck in the closed position which affected engine cross start when the aircraft was on the ground. Inspection of the valve revealed an external contamination coming from a drain located above the valve as root cause. The same contamination was also found in other aircraft from the same customer.

The new design will introduce a hose to direct the fluid to the fairing drain, thus bypassing the valve and avoiding its contamination.

The solution will be introduced in the fleet by means of a Service Bulletin, expected for July, 2008.


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In case of "XBLEED FAIL" CAS messages or a "XBLEED VLV (CLOSED) [C1(C2)]/WRG FAULT" maintenance messages, please refer to applicable FIM tasks.

Acronyms

AD = Airworthiness Directive

AIPC = Aircraft Illustrated Parts Catalog

AMM = Aircraft Maintenance Manual

AMS = Air Management System

ANAC = Agência Nacional de Aviação Civil (Brazilian Civil Aviation Authority)

AOA = Angle of Attack

AOM = Airplane Operations Manual

APM = Aircraft Personality Module

CAS = Crew Alerting System

CMC = Central Maintenance Computer

CMM = Component Maintenance Manual

DLS = Data Load System

ECS = Environmental Control System

EDP = Engine Driven Pump

EIPC = Engine Illustrated Parts Catalog

ELPU = Emergency Light Power Unit

EMM = Engine Maintenance Manual

FADEC = Full Authority Digital Electronic Control

FAP = Flight Attendant Panel

FH = Flight Hour

FHDB = Fault History Database

FIM = Fault Isolation Manual

FOL = Flight Operations Letter

GMO = Ground Maintenance Override

IFSD = In-Flight Shut down

LDI = Loadable Diagnostic Information

LRU = Line Replaceable Unit

MLG = Main Landing Gear

MMEL = Master Minimum Equipment List

OB = Operational Bulletins

PACIC = Passenger Address/ Cabin Interphone Controller

PN = Part Number

SB = Service Bulletin

SN = Serial Number

SNL = Service Newsletter

SPDA = Secondary Power Distribution Assembly

TCPS = Temperature Compensated Pressure Switch

TR = Thrust Reverser

TSA = Tail Strike Avoidance

Note: All abbreviations used in EMBRAER Maintenance Manuals can be found in the Introduction to AMM Part II.

operator e-jets news rel 15

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