PIA Flight 17
|
A Sikorsky S-61N, similar to the accident helicopter | |
| Accident summary | |
|---|---|
| Date | 2 February 1966 |
| Summary | Mechanical failure. |
| Site | Near Faridpur, East Pakistan |
| Passengers | 21 |
| Crew | 3 |
| Fatalities | 23 |
| Injuries (non-fatal) | 1 |
| Survivors | 1 |
| Aircraft type | Sikorsky S-61N |
| Operator | Pakistan International Airlines |
| Registration | AP-AOC |
| Flight origin | Dhaka, East Pakistan |
| Destination | Faridpur Heliport, Faridpur, East Pakistan |
Pakistan International Airlines Flight 17 was a scheduled domestic flight from Dacca to Faridpur in East Pakistan (now Bangladesh) operated by a Sikorsky S-61 twin-engined helicopter. The Pakistan International Airlines helicopter crashed near Fardipur because of collision with a vulture. With the loss of twenty passengers and all three crew. One passenger survived.[1]
Accident
The S-61, registered AP-AOC, left Dacca at 14:03 and within 15 minutes an oil leak had started from an external oilpipe line of the main gear box.[1] The flight continued and while it was at 500 feet (152 m) crossing the Padma River the sole survivor noticed that the oil leak was visible in the passenger cabin.[1] About 3.5 miles (5.6 km) from Faridpur heliport, a vulture hit one of the rotor blades on the left side of the helicopter.[1] The flight continued normally and the pilot lowered the landing gear at 300 feet (91 m).[1] Although both engines were running the helicopter experienced a loss of power to the main transmission, the pilot corrected the resulting turn to the left, the helicopter continued rolling and rocking in a steep uncontrolled descent into the ground at 14:23.[1]
Probable cause
The accident was attributed to the disengagement of the left and right spur gear teeth in the main transmission caused by the load due to the failure of the rear sleeve bearing journals. The failure was caused by an oil leak although the evidence was destroyed by fire and the source of the leak was not established.[1]