- 3 -
During and following attempts to feather, the airspeed decreased, as did the sound of the No. 4 engine overspeed. The crew increased power on the remaining three engines and with the resultant increase in airspeed, the sound of No. 4 engine indicated its r. p. m. was rising. Because of this development an emergency was declared at approximately 1351 end clearance to descend was obtained from the Traffic Control Center at Detroit. Power was reduced on Nos. 1, 2, and 3 engines, than an emergency descent was started and was continued at nearly maximum airspeed. At some time during this phase of the descent the crew depressurized the cabin.
At approximately 1353, at an altitude of about 9,000 feet, the No. 4 propeller broke loose and all four blades separated from the hub. One of the blades struck No. 3 engine, then passed through the passenger—occupied portion of the fuselage. Descent was continued to about 3,000 feet, where power was again applied to Nos. 1, 2, and 3 engines. The r. p. m. of No. 3 engine did not go above 11,500 and the fire warning came on. Although no fire was observed, the engine fire procedure, which includes feathering of the propeller, was successfully accomplished.
Examination of the aircraft at Windsor revealed that the propeller and the front part of the No. 4 engine forward of the propeller reduction gear layshafts had broken away in flight. All of these parts were recovered in the vicinity of Flat Rock, Michigan.
