Pacific Western Airlines flight 314, a Boeing 737-200, crashed following a collision with a snow removal vehicle at Cranbrook Airport, BC, Canada, killing 42 occupants; 7 survived the accident. Pacific Western flight 314 was a scheduled service from Edmonton, AB (YEG) to Castlegar Airport, BC (YCG) with stops at Calgary, AB (YYC) and Cranbrook (YXC). The flight departed Calgary at 12:32 in the afternoon. The Boeing 737-200 climbed to FL200 which was reached at 12:38. Calgary ATC then reported to the Cranbrook Aeradio station that flight 314 was underway with an ETA of 13:05. At Cranbrook it was snowing with visibility reported as 3/4 of a mile. A radio equipped snow removal vehicle was sweeping the runway at the time. The Aeradio operator at Cranbrook alerted the driver of the vehicle about the incoming aircraft and gave him the ETA of 13:05; they both expected the flight would report by the “Skookum Beacon” on a straight-in approach to runway 16, thus giving the vehicle operator about seven minutes to get off the runway. At 12:46, while descending out of FL180, flight 314 contacted Cranbrook Aeradio. One minute later the crew were advised that snow removal was in progress. No further transmissions were received from the flight by Aeradio. The aircraft passed the Skookum beacon inbound on a straight-in instrument approach, and flew the ILS for runway 16 to touchdown. The aircraft touched down at 12:55 some 800 feet from the threshold and reverse thrust was selected. Suddenly the crew noticed a snow plough on the runway. A go-around was initiated immediately. However one of the thrust-reversers didn’t fully re-stow because hydraulic power was automatically cut off at lift-off. The aircraft became airborne prior to the 2000 foot mark, and flew down the runway at a height of 50 to 70 feet, flying over the snow plough. The left engine thrust reverser doors then deployed and the crew rapidly selected the flaps up from 40deg to 15deg. The airplane climbed to 300-400 feet, banked steeply to the left, lost height and side-slipped into the ground to the left of the runway. The aircraft broke up and caught fire. CONCLUSIONS (FINDINGS): 1. The estimated time of arrival of the aircraft at Cranbrook, calculated by Calgary ATC, and used by Aeradio for advisory purposes was considerably in error and resulted in a traffic conftict between the arriving aircraft and a vehicle working on the runway. 2. The flight crew did not report by the Skookum beacon on final approach, as was the normal practice at Cranbrook, thereby allowing the incorrect ETA to remain undetected. 3. Regulatory provisions concerning mandatory pilot position reporting during instrument approaches were inadequate. 4. The interfaces between the organizations providing Air Traffic Services, Telecommunications (Aeradio) and Airports Services were not well enough developed to provide a reliable fail-safe flight information service. 5. The pilots lost control of the aircraft consequent upon the left engine thrust reverser deploying in flight when the aircraft was at low speed, and in a high drag configuration. 6. The FAA design standards under which the Boeing 737 was constructed did not adequatety provide for the possibility of an aborted landing after touchdown and thrust reverser initiation. 7. The lack of a suitable national system of incident reporting, investigation, and follow-up corrective action allowed operational problems to remain uncorrected. 8. Rescue efforts at the accident scene were hampered due to lack of a fire fighting vehicle capable of negotiating deep snow and shortage of trained rescue personnel.