Exhibit No. 11A - Group Chairman Factual Report - TWA Flight 800 ...

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$Atago Co., Ltd. Salinity Refractometer, Model S-10 Instruction Manual$

Four discrepancies were noted regarding the fuel pumps. Two of the discrepancies were noted in theleft wing. A fuel leak was found at the outboard and inboard boost pump cable feed-through for the #2fuel tank. The electric conduits were tightened and safetied for both pumps. One discrepancy noted thatthe #3 forward boost pump in the right wing was inoperative. Anew forward boost pump was installedand it was operationally checked. The last discrepancy noted that the left wing, #2 outboard fuel jettisonpump housing had a gouge, and corrosion was noted at the mating surface. The fuel jettison pumphousing was removed and replaced.Write-ups regarding the passenger air packs were numerous, however, the work accomplishedconsisted of “routine” duct leak checks that were accomplished in accordance with the maintenancemanual instructions.Inspection of the drain cavity at the canted bulkhead revealed minor surface corrosion and a pluggeddrain line at fuselage station 1,240. The corrosion was removed and the drain was unplugged.During the “D” check, the center wing fuel tank was “inspected in detail” by two TWA Inspectors.The Boeing 747 Maintenance Manual, chapters 28-11-00 and 12-09-08 were referenced to accomplish theinspection, The applicable manuals used to accomplish this task are located at the aircraft for theInspectors and mechanics to reference. TWA scheduled maintenance procedures indicate that the “D”check is the only time in which there is scheduled access to the interior of the center wing fuel tank.The routine work cards used to accomplish the detailed inspection for the center wing fuel tank were:A402 - Open Center TankA424 - Center Section Dry Bay Open-upC412 - Install Fuel Valves-Center TankC413 - Remove Fuel Valves-Center TankD450 - Inspect Wing Center TankD451 - Inspect Wing Center Tank Dry BayH402 - Close Center TankH424 - Close Center Fuselage and Tank(Exhibit E - Center Wing Tank Routine Work Cards)Work cards C412 and C413, identify the work performed for the engine cross feed check valves; thecenter tank scavenge check valve; the center tank scavenge pump inlet/removal check valve and the centertank jettison pump discharge check valves.The valves are removed from the aircraft and sent to the TWA maintenance shop for shop check andrepair as required. The fuel cross feed check valves and the center tank scavenge check valve were sent tothe shop and tested. During the test, the valves operationally checked within limitations and no partswere replaced.The work cards reference, in parenthesis, the number of o-rings to be used and their part numbers.The word “ordered” is hand written next to the reference.(Exhibit F - Check Valve Work Cards)The center tank jettison pump inlet/removal check valves and the center tank jettison pump dischargecheck valves are expendable valves and are not rotable parts. If the valve checks out as operational, it isthen put back into service. If the valve does not pass the test, it is discarded. TWA does not maintainshop records for expendable parts.11
Work Cards D450 andD451 direct the Inspector to “Detail Inspect All Items In Center Tank," and“Detail Inspect All Items In Center Tank Dry Bay.” The TWA General Policies and Procedures Manualdefines “Detailed Inspection” as:“The area inspection concept constitutes a very detailed inspection of the designated area,including but not limited to structures, tubing, cables, wiring, and any units exposed or visiblethrough routine open up. Normal assistance to visual inspection will be used as required andmay consist of mirrors, magnifying glasses, dye penetrant checks or specialized non-destructivetest equipment where applicable.”During the “D” Check, there were no non-routine work cards generated for the center wing fuel tank,and there were no structural discrepancies reported for level 2 or 3 corrosion.The last unscheduled maintenance performed to the center wing fuel tank, after the “D” Check, werefor fuel pump removals and installations. The right side jettison pump was installed on May 15, 1995; theleft side jettison pump was installed on March 27, 1996, and the scavenge pump was installed on April22, 1996. Removal and installation of the center wing fuel tank fuel pumps does not require access to theinterior of the center wing fuel tank.INSPECTOR INFORMATIONCurrently, TWA employs 226 Inspectors system wide. Inspection personnel are staffed at Kansas City,MO (47 Airframe and 92 Engine Overhaul); St. Louis, MO, (40); Los Angeles, CA (23); New York, NY(21); and San Francisco, CA (3).The Inspectors are used to inspect mechanical integrity and/or work performed on all TWA aircraft,engines, and components to assure the required standards are met, Full-time inspectors must be properlytrained, qualified and authorized to perform inspections on TWA aircraft. The inspectors must possesvalid Airframe and Powerplant certificates, pass a visual acuity test, and have a minimum of 15 monthswith the company as a Mechanic. TWA promotes its inspectors from the Union (IAM) ranks of aircraftmechanics.Two inspectors performed the “detailed inspection” on the center wing fuel tank at the last “D” Check.Both inspectors signed-off on work cards D450 and D451 on October 6, 1992.Personnel records provided by TWA indicate that both inspectors had been employed with TWA sincethe mid 1960’s. One inspector retired from TWA on November 1, 1992, the other inspector retired onMay 1, 1997. Both inspectors have held Airframe and PowerPlant certifictes since 1970. One inspectorheld inspection authority since April 1977, and the other held inspection authority since November 1985.Training records indicate that both inspectors attended and passed the required courses as specified inthe General Policies and Procedures Manual.NON-ROUTINE MAINTENANCE PERFORMED AT “C” CHECKSA review of the non-routine work cards from the “C” checks after the last “D” check identifiedmaintenance work performed in the area of the center wing section. During the “C” checks, there are noscheduled internal center wing tank inspections. Access to the center wing tank, other than at the “D”check, would be performed “as needed” and identified as non-routine.12
Page 1: DOCKET NO. SA-516EXHIBIT NO. 11ANAT
Page 6: TWA’s baseline structural inspect
Page 9 and 10: ENGINE #4Serial Number 662463Date I
Page 11: TWA records indicate that when the
Page 15 and 16: According to the Minimum Equipment
Page 17 and 18: 16. Jettison Pump - Serial number 7
Page 19: Aircraft Maintenance Log dated July
Page 24 and 25: Aircraft Maintenance Log dated Febr
Page 26 and 27: 25FUEL QUANTITY TANK UNITSThere are
Page 28 and 29: 27●July 7, 1996- The number 3 eng
Page 30 and 31: DEFERRED MAINTENANCE WRITE-UPS ON T
Page 33 and 34: TWA utilizes a computer process tha
Page 35 and 36: All of the center wing fuel tank ro
Page 39: 38At the end of the NASIP inspectio

Exhibit No. 11A - Group Chairman Factual Report - TWA Flight 800 ...

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