Page:CAB Accident Report, Allegheny Airlines Flight 604.pdf/5

- 5 - The right engine was basically intact externally but the front and rear accessory cases ware burned away. The front row master rod failed and all link rods were separated. The cylinder barrel skirts were bent in the direction of engine rota- tion. The master rod piston pin was intact and the piston pin bushing was in place around the pin. The rear row master rod and all link rods were intact. The Nos. 1 and 2 propeller blade shim plates indicated an impact blade angle of 95 degrees, which is the feathered angle for this propeller. The No. 3 blade left no impression on the shim plate.

The left and right fuel shutoff valves were open. The firewall shutoff valves were destroyed by fire.

1.13 Fire

Fire was observed in the vicinity of the right engine while the aircraft was in flight. A flash fire occurred on the right side of the aircraft during the skid along the ground, and an intense ground fire gutted-the aircraft several minutes after impact.

1.14 Survival Aspects

This was a survivable accident, there were no fatalities. The cabin attendant rushed to the cockpit when she observed smoke coming from the right engine. The captain advised her that they were returning to the airport. She returned to the cabin, advised the passengers to fasten their seat belts, that they were returning to the airport, and then sat down next to a female passenger in need of comfort. She stated that she barely had time to fasten her seat belt when the aircraft crashed. She was thrown forward at impact and landed on a passenger in seat 9D (3 right window seat). The passenger in seat 1D reported his seat broke loose at impact.

Most passengers exited through the large opening at the forward end of the cabin. Eighteen went out the right side where some difficulty was encountered in the underbrush and limbs which had piled up ahead of the aircraft. Ten people went out of the left side of the split fuselage. Evacuees on the right side were apprpox- imately four feet above the ground and those on the left side had to jump or slide down the fuselage about ten feet. The forward left overwing window exit was opened by a female passenger, and utilized by a total of nine passengers.

The captain was assisted from the aircraft by the first officer and hostess. She also re-entered-the burning aircraft to make certain that all passengers had escaped.

1.15 Tests and Research

The Convair engineering test pilot who flew the majority of the certification flights for the Convair 340 testified regarding the performance characteristics of the aircraft. He pointed out that the failure of the right engine is less critical then the left engine, and that in any case the aircraft should be trimmed with the dead engine higher than the operating engine. This would necessitate less rudder