Swift Museum Foundation GC-1A N80823

The airplane departed with an adequate supply of fuel in the main fuel tank but an unknown amount of fuel in the tip tanks. After the airplane took off, the mechanic who performed the last condition inspection and who was near the departure end of the runway noted an unusual sound; he said the sound was abnormal and expected the pilot to return, but he did not. The airplane’s GPS indicated that the flight proceeded south to the southern Long Island coastline then turned to the west, paralleling the coastline while climbing to a maximum altitude of 2,602 feet. The flight continued on the westerly heading along the southern coast of Long Island and descended to 2,383 feet and then turned north; the VHF transceiver was set to the Farmingdale automatic terminal information service. The flight continued on the northerly heading and descended to 1,812 feet, then turned to an easterly heading, followed by a southeasterly heading toward the southern coast of Long Island. The flight then turned back to an easterly heading with a steadily decreasing altitude and a steady groundspeed of about 86 knots. When just west of Moriches Inlet, the GPS altitude was noted to be 60 feet, and the groundspeed was 85 knots. Several witnesses located near the crash site heard a sputtering engine. One witness stated that the airplane was running flawlessly, but he thought it was going to land because it was flying “way too slow.” Another witness who was located about 1,000 to 1,500 feet west of the Moriches Inlet reported seeing a flock of birds take flight followed by the airplane pitching up and then pitching down into the inlet. Postaccident inspection of the airframe, flight controls, engine, and engine systems revealed no evidence of preimpact failure or malfunction. Although minimal damage was noted on the propeller, no evidence of a bird strike was noted on any component of the airplane. The flaps and landing gear were extended, consistent with a precautionary landing. During the postaccident examination, the left side of the engine exhaust, where it enters the muffler, was circumferentially fractured at a weld, and cracks were noted in a weld-repaired area of the left side exhaust system components; the fracture and cracks can be attributed to overload as a result of impact. There was no evidence of exhaust gas escaping the repaired area. Further, no carbon monoxide was detected in specimens of the pilot or passenger taken during the postmortem examinations. Although a crack to the left side exhaust system had been detected 9 days earlier and repaired at a non-aviation facility, it did not play a role in the accident. The fuel selector was found positioned to the tip tanks, both of which were breached during the impact sequence; therefore, no determination could be made as to the quantity of fuel in the tanks at the time of the accident. Although the remaining quantity of fuel in the main fuel tank was not quantified during the postaccident investigation, the airplane had only been operated for 40 minutes since the main fuel tank was filled; the main fuel tank can hold over 2 hours of fuel. No obstructions of the fuel supply from the main or tip tanks were noted, and the engine-driven fuel pump tested satisfactorily. Although about 6 ounces of water was drained from the main fuel tank, the water was consistent with ocean water; no other contaminants from the tank were noted. Water contamination was also noted from a sample of fuel and water drained from an open fuel supply line for the right tip tank; however, the right tip tank was breached and the water was likely from the ocean. No fuel or contamination was noted in the carburetor bowl. Although a valve on the left side of the firewall was inoperative, which allowed heated air to enter the cockpit by the pilot’s side, no determination could be made as to how or if that factored into the accident sequence. Further, that condition had been known by the pilot since September. Based on the flight track and groundspeed recorded by the GPS and the fact that the landing gear and flaps were extended, it is likely that the pilot was performing a precautionary landing. However, the reason for the attempted precautionary landing could not be determined from the available evidence. Based on the witness statement of birds in the area, it is likely that during the precautionary landing, the pilot reacted to the birds by pitching the airplane up, stalled the airplane, and was unable to recover because of the low altitude.

Quoted verbatim from the NTSB record.