Page:CAB Aircraft Accident Report, American Airlines Flight 320.pdf/6

 The last altimeter setting for La Guardia given to the crew of Flight 320 by company radio about one hour prior to the crash were 29.85 and plus 90, whereas at the time of the crash the altimeter setting was 29.75.

Other aircraft approaching La Guardia shortly before and after the accident did not report icing difficulties. The rapid influx of warm air aloft was causing a of increasing proportions.

Investigation revealed that all required airport, boundary, and runway lights at La Guardia were on.

Subsequent to the accident and in accordance with standard procedures, the FAA conducted an immediate ground check of all navigation facilities serving La Guardia. The following day these facilities were also flight checked and found to be functioning normally. The crew of NEA DC-3, which preceded Flight 320 on the backcourse ILS, reported that all facilities were operating normally.

More than 90 percent of the primary structural components of the aircraft and the majority of the systems components (hydraulic, pneumatic, air-conditioning, electrical, etc.) were recovered.

The lower surface of N 6101A showed a general distribution of water impact damage which was somewhat more severe on the right than on the left side. Water impact broke all three landing gears rearward and tore off the landing gear doors and wing flaps. The landing gear shock strut pistons, with their wheel assemblies attached, broke away, floated, and were recovered separately. The lower forward fuselage belly was completely destroyed by the water impact and very little of it was recovered.

The fuselage shell above the floorline was broken into four general sections; the cockpit, the forward passenger cabin, the center passenger cabin, and the aft passenger cabin with the tail cone and vertical tail surface still attached. The left and right sides of the forward and center cabin areas were torn apart either by the impact or during recovery. The entire cabin floor was broken up into small pieces except in the extreme aft end where it was torn partially loose and buckled upward in the center. All seats were broken out of their structural attachments except in the extreme aft end of the cabin. The horizontal tail surfaces on both sides of the aircraft were broken off upward just outboard of the fuselage. The elevators remained attached to the stabilizers.

The wings were broken into four main sections. These were the two outer panels with the ailerons and outboard nacelles attached, and the two inboard nacelles with their integral wing structure and broken main landing gears. The leading edge of the right wing outboard of number 4 engine received severe water impact damage and the wing tip was torn completely off. In contrast, the left wing outer panel only had a small area of water impact damage near the aft edge of the lower surface of the wing tip.

The wing structure between the nacelles on each side and inboard through the fuselage was completely shattered and was recovered in small pieces.