OTHER JACKSCREW PROBLEMS 5 Items (First Two Are The Same Item)
ITEM 1 DATA Source; ASRS Database
AVIATION SAFETY REPORTING SYSTEM REPORT (search “jackscrew”)
Report Number: 404988
Local Date (Yr/Mon): 1998/06
Local Date (Week Day): WEDNESDAY (10th editor)
Local Quarter Time: 0601:1200 HOURS
Facility ID Nr Aircraft: CLT
Facility Nr Aircraft: CHARLOTTE/DOUGLAS INTL
Facility Distance (nm): 150
Direction from Reference Facility: WEST
Altitude MSL - HI (ft): 33000
Report Type: SINGLE REPORT
Weather Conditions: MIXED VISUAL/INSTRUMENT METEOROLOGICAL CONDITIONS
Light Condition: DAYLIGHT
Ceiling (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/UNABLE
Incident Type: EMERGENCY
Event Recurrence: DISCRETE EVENT OR OCCURENCE, DISCRETE
EVENT OR OCCURENCE
Primary 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 using vert 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 and with 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. BNA had 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 a ctlability 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 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, but would 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 maint flc 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: B737-300
Type of Operation 1: AIR CARRIER
Phase of Flight 1: CRUISE, EMERGENCY, DIVERSION TO
ALTERNATE
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SAME REPORT FROM FAA’S 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: TN
Event Type: INCIDENT - AIR CARRIER
Phase of Flight: FCD/PREC LDG FROM CRUISE
Aircraft Make/Model: BOEING B-737-322
Operator 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: PASSENGERS
Type of Operation: AIR CARRIER/COMMERCIAL
Registration Number: 352UA
Total Aboard: 96
Fatalities: 0
Injuries: 0
ITEM 3 Data Source: NTSB AVIATION ACCIDENT/INCIDENT DATABASE
Report Number: CHI01SA034
Local Date: 10/19/2000
Local Time: 13:00 CST
State: IL
City: CHICAGO
Event Type: INCIDENT
Report Status: PRELIM
Category of Operation: SCHEDULED, PART 121
Aircraft 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 Part 121, was reported to have sustained minor damage to the lower mechanical stop of the horizontal stabilizer jackscrew. The damage was discovered by American Airlines maintenance 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 of rig. "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 the airplane'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 package reflected 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 Board concluded 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: 489AA
Air Carrier Operating Certificates: FLAG CARRIER/DOMESTIC (121)
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ITEM 4 FAA INCIDENT DATA SYSTEM REPORT
Data Source: FAA INCIDENT DATA SYSTEM
Report Number: 19981006040189C
Local Date: 10/06/1998
Local Time: 17:10
City: PHILADELPHIA
State: PA
Event Type: INCIDENT - AIR CARRIER
Aircraft Damage: NONE
Phase of Flight: CLIMB TO CRUISE
Aircraft Make/Model: BOEING B-727-214
Airframe Hours: 43704
Operator Code: C8GA
Operator: CAPITAL CARGO INTERNATIONAL AIRLI - C8GA
Narrative
(-5) On October 6, 1998, at approximately 17:10 local, crew reported that the horizontal stabilizer 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 emergency while 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 checked munerous 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, dated October 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 reported discrepancies. 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.
Primary Flight Type: SCHEDULED AIR CARRIER
Secondary Flight Type: CARGO
Type of Operation: AIR CARRIER/COMMERCIAL
Registration Number: 227JL
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ITEM 5 FAA INCIDENT DATA SYSTEM REPORT
Data Source: FAA INCIDENT DATA SYSTEM
Report Number: 19961107040449C
Local Date: 11/07/1996
Local Time: 16:24
City: DAYTON
State: OH
Airport Name: WRIGHT-PATTERSON AFB
Airport Id: FFO
Event Type: INCIDENT - AIR CARRIER
Phase of Flight: FINAL APPROACH
Aircraft Make/Model: DOUG MD-11-XXX
Airframe Hours: 550
Operator Code: DALA
Operator: DELTA AIR LINES INC - DALA
Narrative: pilot reported, when slats extended on descent, were unable to change stabilizer trim, electrically or manually. Under investigation by NTSB at the present time. Horizontal stabilizer trim gearbox drive pin sheared.
Primary Flight Type: SCHEDULED AIR CARRIER
Registration Number: 814DE
Total Aboard: 2
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THIS NTSB MONTHLY REPORT DATABASE ADDED THE FOLLOWING;
Source;
Scheduled 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 console mounted 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 drive gearbox. 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 and acceptance 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.
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 the stabilizer 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 the same 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 assembly could 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 “first convenient 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 established limits 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 metal particles in the lubricant on the jackscrew. The operator decided to remove the jackscrew assy for repair/overhaul. (X).” (SDR # 2000080400209).
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Reuters; Tuesday December 12, 9:14 pm Eastern Time
FAA sees no redesign from Alaska Airlines crash
Source;
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.
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 aircraft that include the DC-9, MD-90 and Boeing 717.
End