NYC96FA174

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.