JAMAICA, NY, USA
N31031
Lockheed L-1011-100
During arrival, the flight (flt) received vectors for ILS runway (rwy) 4R approach (apch). Before reaching final apch fix, visibility went below minimums for rwy 4R, & flt was offered ILS rwy 4L apch, which was still above minimums. Captain accepted, & 1st officer (F/O), who was flying the aircraft (acft), transitioned to 4L. On final apch, acft passed thru 500' AGL at 151 KCAS with throttles near idle. It continued decelerating to reference landing speed. During computer-driven, auto-land flare, acft nose rotated up, & acft's tail struck rwy. The operator's (oper's) procedures required mandatory go-around unless apch was stabilized at 500'. The crew reported all checklists had been completed; however, apch charts for rwy 4L were not reviewed, required call outs were not remembered as given by all crewmembers, & altimeter bugs remained set for runway 4R. DFDR data revealed the wing leading edge slats had not extended with the flaps. A green light on the pilot's instrument panel & 14 green lights & a gauge on the flt engineer's (F/E's) panel were not used to verify slat extension. Oper's expanded landing checklist did not require F/E to use gauge to verify slat extension. Oper's manuals did not list possibility of a "slat lock," which would not activate any warning lights or aural warnings. Maintenance records revealed slats had locked 12 times in preceding 2 yrs. Inspection methods provided by Lockheed & adopted by the oper, did not adequately specify how to check slat drive system for slack.
HISTORY OF FLIGHT On August 25, 1996, at 0710 eastern daylight time, a Lockheed L-1011-100, N31031, operated by Trans World Airlines (TWA), as flight 778 (TWA778), was substantially damaged when the tail struck the runway, while landing at John F. Kennedy International Airport, Jamaica, New York (JFK). The 3 flight crewmembers, 9 flight attendants, and 250 passengers were not injured. Instrument meteorological conditions prevailed at the time of the accident. The flight departed Las Vegas, Nevada (LAS), at 0310, and was operated on an Instrument Flight Rules (IFR) flight plan under 14 CFR Part 121. The flight crew was on the last flight of a 3 day trip. The trip sequence originated on the evening of August 23, 1996, where the crew flew the accident airplane from JFK to LAS, as TWA flight 777 (TWA777). According to interviews, the flight crew then went into a 24 hour crew rest period, during which the crewmembers had no contact with each other. While the crew was in rest, N31031 was flown to JFK, and returned to LAS by other flight crews. The accident flight, TWA778, started with the crew pickup at the hotel, at 0030, on August 25. They meet the inbound flight crew of N31031, as they passed through the terminal, and were informed that the airplane was "OK." TWA778, which was scheduled to depart the gate, at 0200, departed, at 0254. The first officer was the flying pilot and performed the takeoff. The airplane became airborne, at 0310, and was hand flown to altitude. The flight crew described the departure and en route phases of the flight as being routine and uneventful until they began their descent. Entering the New York area, flight 778 was cleared to descend to FL 190. At 0658:09, the captain made initial contact with the New York TRACON, ROBER position, and reported that they were descending to FL190. They also reported they had Airport Terminal Information Service (ATIS) VICTOR [visibility 1/4 mile fog, 200 scattered, wind calm, temperature 19, dew point 19, landing ILS 4R]. The controller replied, "...Fly heading one three zero vectors to i l s four right be advised tower visibility now reported to be zero." This was acknowledged by the captain who inquired about the Runway Visual Range (RVR). The ROBER controller replied, "...runway four right r v r is three thousand five hundred the mid point is one thousand six hundred roll out one thousand four hundred." At 0659:28, the ROBER controller transmitted to TWA778, and a preceding flight, "...kennedy special weather at one zero five eight zulu [0658 local] wind three six zero at six visibility less than one quarter mile with fog there is a broken layer at two hundred and altimeter three zero zero nine for uh be advised the remarks are surface visibility is one quarter and surface visibility south is one and one half." The transmission was acknowledged by the captain. At 0706:39, the ROBER controller transmitted, "t w a seven seventy eight heavy the r v r is rapidly going down on four right what is your minimum for four right" The pilot replied, "...twelve hundred r v r," and the ROBER controller then transmitted, "that's exactly what it's indicating now t w a seven seventy eight heavy turn right heading zero two zero your eight miles from ebbe maintain one thousand five hundred till established on localizer cleared I l s four right approach." This was acknowledged by the captain. A 0707:34, the ROBER controller asked, "t w a seven seventy eight heavy the four right r v r is down to a thousand would you like to try slipping over to the left." With no reply, the controller then asked, "t w a seven seventy eight heavy would you like to try slipping over to four left its uh r v r for the right is down to thousand uh for the left is more than six." At this time the captain replied, "o k we'll take four left." At 0707:52, the ROBER controller directed TWA778, "o k the left side I l s frequency is one one zero niner and zero two zero t w a seven seventy eight." At 0708:17, the ROBER controller asked, "t w a seven seventy eight heavy are you able to pick up the left side all right," at which point the captain replied, "yeah we're coming left now." At 0708:26, the ROBER controller transmitted, "t w a seven seventy eight heavy your at two and a half from tildi your cleared I l s four left approach contact kennedy tower one one niner point one." The flight engineer reported that she computed the Vref speed to be 131 knots and verified the setting on the captain's and first officer's air speed indicators. They had initially briefed for a category I approach to runway 4R. When the weather deteriorated, they then briefed for a category II approach to runway 4R. When approach control offered them runway 4L, it was accepted by the captain. While on the approach to runway 4L, attempts to engage the auto-throttles were unsuccessful, and the captain told the first officer to fly the approach using manual throttles. The captain reported that when the first officer requested the ILS 4L approach plate, he replied, "just fly the approach it is near VFR." The first officer also stated that the ILS 4L approach plate was never taken out for the approach and the altimeter bugs remained set for runway 4R. According to TWA manuals, the correct altimeter bug setting for a Category II approach to runway 4R would be 112 feet, and for a Category I approach to 4L would be 212 feet. At 0708:53, the captain contacted the JFK control tower and stated that they were on the localizer for runway 4 left. At 0708:59, the JFK local controller replied, "t w a seven seventy eight kennedy number one wind calm runway four left cleared to land r v r more than six thousand rollout one thousand six hundred." The first officer stated that at 50 feet above the ground (AGL), the autopilot began to flare the airplane, and he retarded the throttles. He said that it, "looked a little high." About that time, the stick shaker activated, followed by the airplane touching down firmly. The flight engineer reported that while monitoring the annunciator lights, she heard the stick shaker activate. She observed the speed to be Vref minus 10 knots. The captain stated that at 50 feet AGL, the first officer called "FLARE." At that point the nose was pitching up, and the first officer retarded the throttles. About 1second later the stick shaker sounded and the captain recalled checking the airspeed at 120 knots, and that the altitude was about 30 feet AGL. The captain pushed the throttles forward and the airplane touched down hard. The captain then took control of the airplane, closed the throttles, initiated reverse thrust, and made a normal rollout. A witness reported that he was at the approach end of runway 4L at the time of occurrence, at taxiway KILO, about 100 yards from the touchdown point. He stated that the airplane hit on the tail first and then the tires. The touchdown point was shorter than normal, and he heard a bang at touchdown. He said the visibility was about 1/4 mile with a light wind from the north at less than 5 knots. After the landing roll, the airplane was taxied to the TWA gate complex, where the engines were shut down, and the flight was towed to the gate, which was a normal procedure. After the passengers deplaned through the jetway, maintenance personnel informed the captain that there was damage to the tail of the airplane. The captain performed an external examination of the airplane, returned to the cockpit, and after a short discussion, the flight crew departed the airplane. The JFK weather observation, at 0658, recorded the visibility as less than 1/4 mile, a 200 foot broken ceiling, and the touchdown RVR greater than 6,000 feet. The accident occurred during the hours of daylight at 40 degrees, 37 minutes, 19 seconds North Latitude, and 73 degrees, 47 minutes, 8 seconds West Longitude. PERSONNEL INFORMATION Captain The Captain, age 58, was hired by TWA on August 19, 1966. He held an airline transport pilot (ATP) certificate with a rating for airplane multi-engine land and instrument airplane. He was type rated in the Boeing 727 and Lockheed L-1011. He also held a commercial pilot certificate for airplane single engine land, and a turbo-jet flight engineer's rating. The captain's most recent first-class medical certificate was issued on July 8, 1996, and contained the limitation, "Holder shall possess corrective glasses for near vision." The captain was on reserve status and volunteered for the trip sequence. According to interviews, he had a total time of 18,643 hours, of which 4,855 hours were as Pilot-In-Command (PIC). He had accumulated 351 hours as PIC, and 917 hours as Second-In-Command (SIC), in the L-1011, and had no L-1011 flight engineer experience. His initial captain line checkout in the L-1011 was completed on June 21, 1994. He was displaced by seniority and requalified as captain in the Boeing 727 on February 2, 1995. He requalified as captain in the L-1011 on June 27, 1996, and had flown the L-1011 for 105 hours during the preceding 90 days. The captain's last checks in the L-1011 were a proficiency check on June 30, 1996, and a line check on July 14, 1996. First Officer The first officer, age 54, was hired by TWA on January 9, 1970. He held an ATP certificate with a rating for airplane multi-engine land and instrument airplane. He was type rated in the Falcon 20, and Lear Jet Model 23/24/25. He also held a commercial pilot certificate for airplane single engine land, and a turbo-jet flight engineer's rating. The first officer's most recent first class medical certificate was issued on July 8, 1996, and contained the limitation, "Shall carry corrective lenses when operating airplane." The first officer was furloughed twice by TWA, the first time April 3, 1970, to April 26, 1977, and the second time from January 5, 1980, to March 7, 1985. He was initially qualified as a first officer with TWA on May 30, 1996, in the L-1011. He had accumulated 210 hours as first officer, and 3,155 hours as flight engineer in the L-1011. He completed his line operating experience on the L-1011 on June 6, 1996. The first officer's last checks in the L-1011 were a proficiency check on May 30, 1996, and a line check on June 14, 1996. Flight Engineer The flight engineer, age 28, was hired by TWA on March 4, 1994. She held an ATP certificate with ratings for airplane multi-engine land, and instrument airplane, and was type rated in the Beech 1900. She also held a turbo-jet flight engineer rating. She reported a total time of 3,900 hours, with 516 hours as flight engineer, including 379 hours as a L-1011 flight engineer. The flight engineer's initial qualification was in the L-1011. She was displaced to the Boeing 727 as a flight engineer, in March of 1995. She then became a simulator instructor in the L-1011, while holding a bid status as a Boeing 727 flight engineer. She returned to line operations in the L-1011 as a flight engineer during June/July 1996. The flight engineer's last checks in the L-1011 were a proficiency check on February 12, 1996, and a line check on August 7, 1996. AIRCRAFT INFORMATION The airplane, N31031, was a 1975 Lockheed L-1011-385-1-15 (L-1011-100), and was operated by Trans World Airlines Inc. It was powered by three Rolls-Royce RB-211-22 engines, and maintained under TWA's maintenance procedures. At the time of the accident, the airplane's estimated landing weight was 313,900 pounds. The Center of Gravity (CG) was estimated to be about 25.5 % Mean Aerodynamic Chord (MAC). The forward and aft CG limits at the estimated landing weight were, 12.8 % and 34.0 % MAC. According to the Lockheed Aircraft Company, the computed stall speed at the estimated landing weight, with the leading edge slats retracted and the trailing edge flaps set at 33 degrees, was 120 KIAS. AERODROME INFORMATION Runway 4L and 4R each had complete and separate ILS approaches. The two runways were separated by about 3,000 feet. Both approaches had glide slope intercept altitudes of 1,500 feet. The following decision heights and minimum visibility's were published for each approach. Approach Decision Height Minimum Visibility ILS 4L Category I 212 feet RVR 4,000 or 3/4 mile ILS 4R Category I 212 feet RVR 1,800 ILS 4R Category II 112 feet RVR 1,200 FLIGHT RECORDERS The airplane was equipped with a Sunstrand Data Control model 573A (S/N 3764) Digital Flight Data Recorder (DFDR). The unit was removed from the airplane and forwarded for readout at the National Transportation Safety Board's (NTSB) Vehicle Performance Division (RE-60), Washington, DC. According to the Vehicle Performance Division report of the DFDR, the trailing edge flaps had extended; however, there was no indication that the leading edge slats extended. The DFDR data revealed a series of rolls occurred during the approach, with the auto-pilot engaged. The rolls had peak oscillations of 26 degrees left and right. When correlated with the radar data and ATC transcripts, the rolls began prior to the outer marker, and continued with lessening degrees until the altitude readout indicated below 500 feet. The rolls corresponded to flight control movements and magnetic heading changes. Airplane touchdown was recorded at subframe reference number (SNR) 247 with a peak "G" of 2.11 Gs. At that time the airspeed was 117.5 knots CAS, and the left and right Angle of Attacks were recorded as 17.5 and 16.07 degrees respectively. The DFDR data revealed that during the preceding flight, TWA777 to LAS, the slats had extended. WRECKAGE AND IMPACT INFORMATION The Port Authority of New York and New Jersey reported that, at 0915, on August 25, 1996, they found a red and white paint transfer on runway 4L, about 1,000 feet from the approach end. Following passenger embarkation, and baggage unloading, the airplane was towed from the gate to the maintenance hangar. The cockpit was not secured. The airplane was inspected in accordance with TWA's "Hard Landing or Off the Runway or Off the Taxi Strip Structural Check." This was conducted on August 25, 1996. The inspection included cycling the flaps. According to a written statement from the mechanic who cycled the flaps; "...the leading edge devices did not lower and no indication [on] the F.E. panel was noted." When it was determined there was substantial damage, the FAA and NTSB were notified. According to the FAA and TWA, examination of the airplane revealed that the aft pressure bulkhead was cracked. Fuselage skin in the vicinity of the tail skid was scrapped. The number two engine thrust reverser shroud was scrapped. The right hand side APU mount was broken. In addition, several bulkheads in the immediate vicinity of the fuselage impact point were bent and/or cracked. The FAA forwarded certified copies of the original hard landing inspection, and non-routine maintenance work records for N31031. A review of page 36, item 125, of the non-routine maintenance work records contained the following notation, "Prior to attempting to move flaps R/H leading edge brake was found tripped & was reset to facilitate flap movement." This was entered by a TWA mechanic with the identification LST28022. In a signed statement, LST28022 stated, "...was present during an NTSB and FAA investigation of said aircraft. On an attempt to perform an operation check of the flap system, the leading edge flaps failed to deploy. Upon investigation the leading edge brake assembly were found tripped. At this time I made non routine remarks on M139 sheets to this effect reference items # 125 and # 126 on page 36." Another mechanic who observed this also submitted a written statement. MEDICAL AND PATHOLOGICAL INFORMATION Toxicological testing of the flight crew was accomplished in accordance with the TWA procedures. Testing on the first officer and flight engineer was negative for alcohol or drugs. The captain provided a specimen for testing; however, due to an equipment failure, results were not obtained. TESTS AND RESEARCH Slat Operation Acc
failure of the flight crew to complete the published checklist and to adequately cross-check the actions of each other, which resulted in their failure to detect that the leading edge slats had not extended and led to the aircraft's tail contacting the runway during the computer-driven, auto-land flare for landing. Factors related to the accident were: the manufacturer's inadequate inspection procedures for the slat drive system; and the operator's inadequate checklist, which did not include having the flight engineer monitor the double needle slat gauge.
Source: NTSB Aviation Accident Database
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