Pacific Western Airlines Flight 314
| Pacific Western Airlines Flight 314 | |
|---|---|
 An identical Boeing 737-200 from Pacific Western Airlines |
|
| Accident summary | |
| Accident type | Loss of control when trying to go around due to asymmetrical thrust (blocked thrust reversal) |
| place |
Cranbrook / Canadian Rockies International Airport , near Cranbrook , British Columbia , Canada
|
| date | February 11, 1978 |
| Fatalities | 42 |
| Survivors | 7th |
| Injured | 7th |
| Aircraft | |
| Aircraft type |
 Boeing 737-275
|
| operator |
Pacific Western Airlines
|
| Mark |
C-FPWC
|
| Departure airport |
Edmonton Airport , Alberta , Canada
|
| 1. Stopover |
Calgary Airport , Alberta , Canada
|
| 2. Stopover |
Cranbrook / Canadian Rockies International Airport , British Columbia , Canada
|
| Destination airport |
Castlegar Airport , British Columbia , Canada
|
| Passengers | 44 |
| crew | 5 |
| Lists of aviation accidents | |
The Pacific Western Airlines Flight 314 (Flight number: PW314 ) was a scheduled domestic flight to the Canadian airline Pacific Western Airlines from airport Edmonton to Castlegar airport with stops at the Calgary airport and the Cranbrook / Canadian Rockies International Airport . On February 11, 1978, a Boeing 737-275 with the aircraft registration C-FPWC had an accident on this flight . The machine had to abort an initiated landing at Cranbrook Airport and make a missed approach because a snow clearing vehicle unexpectedly appeared on the runway. The missed approach led to a loss of control and a crash. 42 people were killed in the accident, only 7 survived.
Airplane and occupants
The aircraft involved in the accident was a Boeing 737-275, which was 7 years and 10 months old at the time of the accident. The machine was assembled in the Boeing factory at Boeing Field in Washington State and made its maiden flight on April 24, 1970, before being delivered to Pacific Western Airlines in May of the same year. The aircraft had the factory number 20142, it was the 253rd Boeing 737 from ongoing production. The machine was certified with the aircraft registration C-FPWC . The twin- engined narrow -body aircraft was equipped with two Pratt & Whitney JT8D-9A engines.
There were 44 passengers and 5 crew members on board.
the accident
Up to the approach to the Cranbrook / Canadian Rockies International Airport, the flight went without any special incidents. It was snowing at the airport at the time of the accident and visibility was 1200 meters. The machine had taken off from Calgary at 12:32 p.m., the flight was supposed to take 23 minutes, this flight duration was transmitted to Cranbrook Airport. The airport there was not monitored, there was no air traffic control that controlled the air traffic. Instead, an "Aeroradio" station only transmitted weather data and gave information.
It was snowing at the airport and a snow plow cleared the runway. The Aeroradio station informed the driver of the snowplow that the Boeing 737 would land at 13:05. It was agreed that the Boeing crew would report as soon as they fly over the "Skookum" radio beacon, which would have corresponded to a period of around seven minutes. At 12:45 p.m., the crew contacted the aeroradio in Cranbrook and received current data on the weather situation and the condition of the runway. At 12:47 p.m. the radio station in Cranbrook informed the pilots that snow clearing work was being carried out.
After the crew had received the information about the ongoing snow clearing work, they did not send any further radio messages to the aero radio in Cranbrook and had the aircraft touch down at 12:55 about 240 meters behind the runway threshold for landing. When the pilot saw the Plow located on the runway, they initially activated the thrust reverser, but decided in the next moment a go-around . The machine flew over the runway at a height of 50 to 70 feet (approx. 15-20 meters) and also flew over the snow clearing vehicle.
The pilots adjusted the buoyancy aids from 40 to 15 degrees. The thrust reversing vanes had been extended on landing, the right one retracted when going around, while the left did not retract fully. The landing gear also remained extended. Six seconds before impact, the machine was about 1.5 kilometers from the runway threshold when the left rudder was moved for a moment. The aircraft then leaned steeply to the left and then fell to the left of the runway from a height of 300 to 400 feet (90-120 meters). The machine was completely destroyed by the impact and the subsequent fire.
root cause
Tests at Boeing showed that the machine would have been controllable if one engine had been given full thrust while the other was idle. In the present one, however, one engine received full thrust while the other braked the engine on one side due to the activated thrust reverser, which led to loss of control and a crash. The thrust reverser of the left engine did not retract completely because the hydraulic system was automatically cut off when it was lifted off.
The go-around would have been successful if the thrust reverser vanes of the left engine had been retracted.
See also
Sources and web links
- Accident report in the Aviation Safety Network
- Transcription of radio traffic in the Aviation Safety Network
- Incident report in the Lessons Learned the Federal Aviation Administration
- Canadian Investigation Bureau Accident Report
Coordinates: 49 ° 36'41 " N , 115 ° 46'56.1" W.