jackscrew problems

8/3/2019 Jackscrew Problems

1/7

OTHER JACKSCREW PROBLEMS 5 Items (First Two Are The Same Item)

ITEM 1 DATA Source; ASRS DatabaseAVIATION SAFETY REPORTING SYSTEM REPORT (search jackscrew)

Report Number: 404988

Local Date (Yr/Mon): 1998/06Local Date (Week Day): WEDNESDAY (10th editor)

Local Quarter Time: 0601:1200 HOURS

Facility ID Nr Aircraft: CLTFacility Nr Aircraft: CHARLOTTE/DOUGLAS INTL

Facility Distance (nm): 150

Direction from Reference Facility: WEST

Altitude MSL - HI (ft): 33000Report Type: SINGLE REPORT

Weather Conditions: MIXED VISUAL/INSTRUMENT

METEOROLOGICAL CONDITIONS

Light Condition: DAYLIGHTCeiling (ft): 9000

Event Anomaly Desc: ACFT EQUIPMENT PROBLEM/CRITICAL,OTHER

Anomaly Consequence: FAA INVESTIGATORY FOLLOW-UP

Anomaly Detected by: COCKPIT/FLC

Anomaly Resolution: NOT RESOLVED/UNABLEIncident Type: EMERGENCY

Event Recurrence: DISCRETE EVENT OR OCCURENCE, DISCRETE

EVENT OR OCCURENCEPrimary Problem Area: AIRCRAFT AND THEIR SUBSYSTEMS

Narrative

Acft was level at fl330, .74 mach on autoplt using vnav and lnav. At approx xa00z, capt returned

to cockpit after using lavatory facilities. FO was experiencing difficulty holding alt. Tried usingvert spd ctl but was ineffective. Capt assumed ctl of acft and tried to level off acft using vert spd

-- still ineffective. Autoplt disengaged and acft flown manually to alt, however, when electr AC

trim was used, nothing happened. Circuit breakers were chked in. Manual stabilizer trim was

tried next but trim wheel was jammed (could not trim nose down). Sys maint was contacted andwith their guidance proceeded to troubleshoot sys. Nothing seemed to work. 'nose up' trim

worked but once new pos was reached could not trim 'nose down.' declared an emer and diverted

to preplanned alternate field (BNA). All other suitable arpts were experiencing hvy wx. BNAhad the best wx and the longest rwy. proceeded to BNA while still talking to maint and Chicago

dispatch to consider all options. Cabin crew notified of sit and were instructed to 'prep' the cabin

for emer lndg and possible evac. Upon dscnt into BNA, acft was leveled at 6000 ft to do actlability chk. Once flaps were extended to 10 degs down and lndg gear positioned down, lost all

stabilizer trim (both nose up and nose down). Elevator ctl was adequate to conduct apch.

'jammed stabilizer apch' emer procs were followed. a 15 deg flap lndg was utilized. Extended

straight-in apch was used. Lndg was uneventful. Crash crew chked for hot brakes after exiting


2/7

rwy. No injuries or damage to the acft occurred. All crew members conducted themselves in a

highly professional manner. Callback conversation with rptr revealed the following info: rptr

capt confirmed acft type as B737-300. He had not received feedback from his company yet, butwould get it. When talking with his company maint they mentioned something about a gear box

and jackscrew probably causing the prob. As soon as they landed they were questioned by the

FAA regarding the trim prob.

Report synopsis: B737-300 acft in cruise had difficulty with stabilizer trim. Even electric

trim would not ctl it nor manual. Flc could not trim nose down. After coord with company maintflc declared emer and diverted. Lndg was uneventful and, though the stabilizer was completely

jammed, flc had no difficulty ctling the acft for apch and lndg.

Aircraft make/model 1: B737-300Type of Operation 1: AIR CARRIER

Phase of Flight 1: CRUISE, EMERGENCY, DIVERSION TO

ALTERNATE

----

SAME REPORT FROM FAAS INCIDENT DATA BUT NOT THE DETAIL ABOVE

ITEM 2 FAA INCIDENT DATA SYSTEM REPORT

Data Source: FAA INCIDENT DATA SYSTEM

Report Number: 19980610024089C

Local Date: 06/10/1998

City: NASHVILLE

State: TNEvent Type: INCIDENT - AIR CARRIER

Phase of Flight: FCD/PREC LDG FROM CRUISE

Aircraft Make/Model: BOEING B-737-322Operator Code: UALA

Operator: UNITED AIR LINES INC - UALA

Narrative

DIVERTED TO BNA DUE TO INOPERATIVE HORIZONTAL STABILIZER

TRIM SYSTEM.

Detail

Primary Flight Type: SCHEDULED AIR CARRIER

Secondary Flight Type: PASSENGERSType of Operation: AIR CARRIER/COMMERCIAL

Registration Number: 352UA

Total Aboard: 96Fatalities: 0

Injuries: 0


3/7

ITEM 3 Data Source: NTSB AVIATION ACCIDENT/INCIDENT DATABASE

Report Number: CHI01SA034


Local Time: 13:00 CST

State: IL

City: CHICAGOEvent Type: INCIDENT

Report Status: PRELIM

Category of Operation: SCHEDULED, PART 121Aircraft Type: AIRPLANE

Aircraft Damage: MINOR

Aircraft Make/Model: DOUG DC-9-82

Operator Name: AMERICAN AIRLINES, INC.Operator Code: AALA

Narrative

On October 19, 2000, at 1300 central standard time, a McDonnell Douglas MD-82,

N489AA, owned and operated by American Airlines, Incorporated, under 14 CFR Part121, was reported to have sustained minor damage to the lower mechanical stop of the

horizontal stabilizer jackscrew. The damage was discovered by American Airlinesmaintenance personnel at O'Hare International Airport, Chicago, Illinois, during a "B"

check, while performing work card 3901, "Flight Controls-Horizontal Stabilizer-Actuator

Assembly check."

An on-scene investigation revealed that the elevator variable load feel unit was out ofrig. "This prevented the stabilizer down control mechanism from functioning properly

and resulted in the acme nut making contact with the lower mechanical stop."

Examination of the elevator variable load feel cable was within tolerance. A review of theairplane's maintenance records showed that work card 3901 had been previously

accomplished on August 31, 2000, during a "B" check at La Guardia Airport, Flushing,

New York. A heavy "C" check was accomplished in June, 2000. Neither work packagereflected any documented maintenance that might have affected the rig function of the

stabilizer jackscrew mechanism or the variable load feel unit.

A company Board of Inquiry was held at the La Guardia Airport. The Boardconcluded that the heavy "C" maintenance crew released the airplane with confidence

that it was in an airworthy condition. The Board determined that the mechanic who

accomplished the 3901 card at the "B" check did not fully understand the intent of the

work card in that it required a second individual to properly monitor the jackscrew travel."The mechanic did not note any damage while performing this check. The Board was

unable to determine the origin of the mis-rigging of the variable feel load unit.

Probable Cause (????????????)

Registration Number: 489AAAir Carrier Operating Certificates: FLAG CARRIER/DOMESTIC (121)

---


4/7


Data Source: FAA INCIDENT DATA SYSTEM Report Number: 19981006040189C


Local Time: 17:10City: PHILADELPHIA

State: PA

Event Type: INCIDENT - AIR CARRIERAircraft Damage: NONE

Phase of Flight: CLIMB TO CRUISE

Aircraft Make/Model: BOEING B-727-214

Airframe Hours: 43704Operator Code: C8GA

Operator: CAPITAL CARGO INTERNATIONAL AIRLI - C8GA

Narrative

(-5) On October 6, 1998, at approximately 17:10 local, crew reported that the horizontalstabilizer jammed at 5.0 degrees nose up at flight level 180 and remained jammed down to 700

feet AGL. The crew dumped approximately 20,000 pounds of fuel and declared an emergencywhile returning to the point of departure at KPHL. The aircraft landed rwy 9R at approximately

17:37 local without further incident and taxied to the cargo ramp. The ARRF responded as a

precaution. Initial correction action was to clean and lubricate the stabilizer trim jack screw and

gear box, which was found to be dry of lubricant. The stabilizer trim system was ops checkedmunerous times on the ground and tested ok. Work was conducted by carrier's contractor at

KPL, Emery World Wide Airlines. The aircraft was released for a test flight on October 7, 1998,

to evaluate the previous corrective action under flight conditions. This flight was unsuccessful.The test flight crew again reported the stabilizer jamming at 1,3,5 and 6 degrees, remaining at 6

degrees until after landing. Subsequent corrective action was to remove and replace the

stabilizer jack screw IAW B-727 MM 27-40-41 and ops check ok. (log page 4860, datedOctober 10, 1998). This corrective action was conducted by AOG. Services, a contract

maintenance provider based out of JFK airport, N.Y., utilizing A & P mechanics working under

their certificates. The aircraft was test flown on October 11, 1998 with no reporteddiscrepancies. All aspects of this investigation were coordinated with the CHDO/PMI. ^privacy

data omitted . Filed component information: jackscrew, PN: 65-19482-16, S/N: G-10457.

Time since new/overhaul: 7662.6 hours/3997 cycles. Installed on aircraft: January 3, 1989 by

Pan American Airways. AEA-FSDO-17 considers this investigation closed.


Secondary Flight Type: CARGOType of Operation: AIR CARRIER/COMMERCIAL

Registration Number: 227JL

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5/7


Data Source: FAA INCIDENT DATA SYSTEM

Report Number: 19961107040449C


Local Time: 16:24

City: DAYTONState: OH

Airport Name: WRIGHT-PATTERSON AFB

Airport Id: FFOEvent Type: INCIDENT - AIR CARRIER

Phase of Flight: FINAL APPROACH

Aircraft Make/Model: DOUG MD-11-XXX

Airframe Hours: 550Operator Code: DALA

Operator: DELTA AIR LINES INC - DALA

Narrative: pilot reported, when slats extended on descent, were unable to changestabilizer trim, electrically or manually. Under investigation by NTSB at the present

time. Horizontal stabilizer trim gearbox drive pin sheared.


Registration Number: 814DE

Total Aboard: 2---

THIS NTSB MONTHLY REPORT DATABASE ADDED THE FOLLOWING;

Source; http://www.ntsb.gov/aviation/IAD/97A018.htmScheduled 14 CFR 121 operation of DELTA AIR LINES, INC. Incident occurred NOV-07-96 at

DAYTON, OH. Aircraft: McDonnell Douglas MD-11, registration: N814DE.

Injuries: 209 Uninjured. (The discrepancy in the number aboard is not explained - editor)

While en route the flight crew experienced a failure of the pitch trim control system. The crew

was unable to change the pitch trim by the yoke mounted trim switches or the center consolemounted horizontal stabilizer control handles. The crew stated that when the slats were extended

on descent, they were unable to change stabilizer trim. Subsequent examination of the horizontal

stabilizer pitch trim system found that there was no lubrication on the screw actuator assemblies

and that the fuse pin had sheared in the output drive unit of the horizontal stabilizer drivegearbox. The sheared fuse pin locked the horizontal stabilizer in its last set position, as designed.

A review of Assembly Orders at Douglas Aircraft (DAC) found that DAC production personnel

and DAC Inspection personnel stamped the assembly orders indicating completion andacceptance of the lubrication. However, the investigation revealed that no lubrication had been

applied to the screw actuator nuts.

Probable Cause;Failure of the output drive unit shear pin due to lack of lubrication to the screw actuator

assemblies. Contributing to the cause was the aircraft manufacturer's production and inspection

personnel failing to lubricate the screw assemblies after initial installation and again after

washing.


6/7

A History of Significant Wear In MD 80 and MD-11 Aircraft.

Dec 14. As the Alaska Flight 261 NTSB Hearing unfolds the FAA has made a statement that thestabilizer problem seen at Flight 261 has not been seen at other carriers. (See Reuters story

below for one press account).

Contrary to that, there are seven priors filed with the FAA including five referenced in a July

31, 1997 Douglas Service Bulletin and two others this year alone in two Service Difficulty

Reports (SDRs) filed on March 31,2000 and on June 6, 2000. The FAA has also claimed thesame jackscrew is used on the MD-11.

From that July 1997 filing with the FAA, that Douglas Service Bulletin said;

Five operators reported instances of the horizontal stabilizer actuator nut assembly

prematurely wearing out. The premature wear of actuator nut assembly and resultant

excessive free play on the jackscrew assembly are caused by a jackscrew surface finish

which is out of design specification tolerance. Excessive wear of the actuator nut assemblycould result in a jammed actuator nut assembly and subsequent loss of horizontal stabilizer

function. Recommended compliance date for a initial inspection for free play was firstconvenient maintenance period, but not to exceed 400 cycles (landings) from the issue

date. ( Douglas service Bulletin MD-11-27-067).

An FAA AD (AD-98-16-9) followed nine months later in 1998.

In spite of that 1998 AD the two Service Difficulty Reports this year reported the following;

Occurrence Date, 03/31/2000. During inspection of the horizontal stabilizer jackscrew assy,

metal shavings were found within the grease on and around the jackscrew. Further, the

ACME screw and nut wear check showed the end play was beyond limits. The establishedlimits are .030 - .040 inch IAW MM-27-40-1 and .050 was obtained. Non-routine work card

4000277-0055 has been written documenting these discrepancies. Removed, replaced, and

ops checked horizontal stabilizer assy IAW MM 27-40-1. (X). (SDR 2000050900161).

Occurrence Date, 06/14/2000. The operator is of the opinion that the jackscrew assy has

never been removed. However, documentation is unavailable at this time to verify the status

of this jackscrew assy. A visual inspection of the horizontal jackscrew assy revealed metalparticles in the lubricant on the jackscrew. The operator decided to remove the jackscrew

assy for repair/overhaul. (X). (SDR # 2000080400209).

---

Reuters; Tuesday December 12, 9:14 pm Eastern Time

FAA sees no redesign from Alaska Airlines crash

Source; http://biz.yahoo.com/rf/001212/n12266621.html

WASHINGTON, Dec 12 (Reuters) - The Federal Aviation Administration said on Tuesday it saw no need to order a

redesign of a tail mechanism at the center of inquiries into the January crash of an Alaska Airlines plane that killed

88 people.


7/7

A top FAA official, speaking ahead of hearings into the crash that start Wednesday, said the carrier had

experienced problems with the jackscrew device that moves the MD-80's horizontal stabilizer that were not

seen at other airlines.

``At this point we don't see design changes as a result of this accident,'' FAA associate administrator Tom

McSweeny told reporters, citing the generous safety margin of strength built into the parts.

``There was some fairly significant wear occurring there,'' McSweeny said of Alaska Airlines experience with

the jackscrew mechanism.

Everyone on Alaska Airlines Flight 261 was killed Jan. 31 when its pilots lost a battle to control the plane after

radioing that they were having trouble controlling the stabilizer mounted on the top of the MD-80's tail.

The National Transportation Safety Board has said its hearing will examine issues including Alaska's maintenance

practices, the design of the jackscrew, and FAA's oversight of both the airline and the aircraft design.

The 2-foot (60 cm) jackscrew is normally powered by electric motors and threaded vertically through another part, a

gimbal nut, to move the stabilizer which maintains level flight and is also used for gradual climbing or descent.

The jackscrew was retrieved from the seabed off Point Mugu, north of Los Angeles, with threads from the gimbal

nut wrapped around it. Investigators, in safety board reports, have questioned whether the jackscrew had been

lubricated properly.

McSweeny said the MD-80 jackscrew mechanism had conformed to FAA design rules in 1977 and would still meet

today's certification requirements. He said other systems with two jackscrews are used on the larger MD-11 and

DC-10 aircraft but they were not necessarily more dependable.

He said Alaska Airlines had been in the process of trying to standardize its lubricants and incompatible greases may

have been mixed on the jackscrews.

Traveling from Puerto Vallarta, Mexico, to San Francisco, the pilots of Flight 261 had requested an emergency

landing in Los Angeles and were trying to stabilize the plane over the Pacific Ocean when the crash occurred.

Investigators know from the plane's flight data and cockpit voice recorder that Flight 261's stabilizer went into a full

nose-down position about 12 minutes before the crash.

The crew regained control after a steep dive by using the elevator panel on the trailing edge of the stabilizer. But

they lost control of the jet for good shortly after extending, for a second time, the wing slats and flaps they would

need for landing.

Alaska Airlines is the nation's 10th largest carrier and a subsidiary of Seattle-based Alaska Air Group (NYSE:ALK-

news).

Boeing Co. (NYSE:BA-news) in 1997 bought McDonnell Douglas which designed the MD-80 and related aircraftthat include the DC-9, MD-90 and Boeing 717.

End story------------ [email protected]
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