ASN logo
Accident description
Last updated: 20 October 2017
Status:Final
Date:Monday 4 December 1978
Time:19:45 MST
Type:Silhouette image of generic DHC6 model; specific model in this crash may look slightly different
de Havilland Canada DHC-6 Twin Otter 300
Operator:Rocky Mountain Airways
Registration: N25RM
C/n / msn: 387
First flight: 1973
Total airframe hrs:15145
Engines: 2 Pratt & Whitney Canada PT6A-27
Crew:Fatalities: 1 / Occupants: 2
Passengers:Fatalities: 1 / Occupants: 20
Total:Fatalities: 2 / Occupants: 22
Airplane damage: Damaged beyond repair
Location:15 km (9.4 mls) ENE of Steamboat Springs, CO (   United States of America)
Phase: En route (ENR)
Nature:Domestic Scheduled Passenger
Departure airport:Steamboat Springs Airport, CO (SBS/KSBS), United States of America
Destination airport:Denver-Stapleton International Airport, CO (DEN/KDEN), United States of America
Flightnumber: 217
Narrative:
The aircraft took off from Steamboat Springs at 18:55 but was forced to return after encountering severe icing conditions. The Twin Otter struck a mountain at 10530 feet.

Probable Cause:

PROBABLE CAUSE: "Severe icing and strong downdrafts associated with a mountain wave which combined to exceed the aircraft's capability to maintain flight. Contributing to the accident was the captain's decision to fly into probable icing conditions that exceeded the conditions authorised by company directive." 

Accident investigation:
cover
Investigating agency: NTSB
Status: Investigation completed
Duration: 150 days (5 months)
Accident number: NTSB/AAR-79-06
Download report: Final report

Sources:
» NTSB Safety Recommendations A-79-70
» NTSB-AAR-79-6


Follow-up / safety actions

NTSB issued 4 Safety Recommendations

Show all AD's and Safety Recommendations

Photos

Add your photo of this accident or aircraft

Map
This map shows the airport of departure and the intended destination of the flight. The line between the airports does not display the exact flight path.
Distance from Steamboat Springs Airport, CO to Denver-Stapleton International Airport, CO as the crow flies is 186 km (116 miles).

This information is not presented as the Flight Safety Foundation or the Aviation Safety Network’s opinion as to the cause of the accident. It is preliminary and is based on the facts as they are known at this time.
languages: languages

Share