Page:CAB Accident Report, Pan American World Airways Flight 212.pdf/8

- 8 - 1. When spoi1ers are used, reverse thrust is initiated three seconds after touchdown.

2. When spoilers are not used, reverse thrust is initiated two seconds after touchdown.

3. Full reverse is achieved eight seconds after throttle movement.

The flight recorder tape on PAA 212 was removed and a readout was conducted on that portion of the tape representing approximately the five minute period bee fore touchdown. (See Attachment #1). During this tune period, the parameters showed no evidence of abnormality in their functioning. The readout shows that approximately 12 seconds prior to touchdown the aircraft was at an altitude of 400 feet above mean sea level (MSL) and at an indicated airspeed (1A8) of 178 knots; the IAS at touchdown was 160 knots. JFK Airport is 12 feet above MSL

Analysis

The aircraft, its powerplants, and systems were operating normally at the time the accident occurred.

An error in the dispatching of PAA 212 out of Dulles International Airport resulted in an actual takeoff gross weight of 208,282 pounds which was 6,282 pounds greater than that specified in the company's release from New York for the Dulles departure. Predicated on the computed dry tank weight of the aircraft (149,502 pounds) and the amount of fuel removed from the aircraft (46,986 pounds) the gross weight of N779PA at the time the accident occurred was 196,488 pounds. This was 6,488 pounds in excess of the maximum allowable gross weight for landing at JFK Airport. The 46,986 pounds of fuel removed from PAA 212 subtracted from the fuel aboard at takeoff from Dulles, 58,780 pounds, was 11,794 pounds, the amount burned off in flight. This was compatible with the 12,000 pounds estimated to be burned off.

Based on the reported surface wind of 210° at 4 knots 9 minutes prior to the accident and 230° at 6 knots 11 minutes after the accident, it is believed that FAA 212 landed at JFK Airport with an average tailwind component of 5 knots. The only wind information given the crew by FAA ATC personnel was by the local control}? approximately two minutes prior to toucndown when he reported the wind "calm." The wet runway surface afforded fair to poor braking at best as attested to by the crew of PAA 212, the captain of the DC-8 that landed ahead of PAA 212, and examination of the whitish scrub marks left by the MLG tires of N779PA. The lack of nose gear tire marks, coupled with the whitish scrub marks made by the left and right MLG tires, snows that there was some braking effect although poor For all practical purposes the tires on the right MLG were smooth as opposed to relatively new ribbed tires on the left MLG. The rear tires of tandem installa- tions produce most of the braking on wet runways. Where directional control was