Accident de Havilland Canada DHC-6 Twin Otter 200 N563MA, Tuesday 6 September 1977

Date:	Tuesday 6 September 1977
Time:	14:52
Type:	de Havilland Canada DHC-6 Twin Otter 200
Owner/operator:	Alaska Aeronautical Industries
Registration:	N563MA
MSN:	196
Year of manufacture:	1969
Total airframe hrs:	15369 hours
Engine model:	Pratt & Whitney Canada PT6A-20
Fatalities:	Fatalities: 13 / Occupants: 13
Other fatalities:	0
Aircraft damage:	Destroyed, written off
Category:	Accident
Location:	Mt Iliamna, AK - United States of America
Phase:	Take off
Nature:	Passenger - Scheduled
Departure airport:	Iliamna Airport, AK (ILI/PAIL)
Destination airport:	Anchorage International Airport, AK (ANC/PANC)
Investigating agency:	NTSB
Confidence Rating:	Accident investigation report completed and information captured

Narrative:
The Twin Otter struck the southwest side of Mount Iliamna, approx. 7000 feet MSL in IMC conditions.

PROBABLE CAUSE: "The failure of the flight crew to use proper navigational procedures for the route to be flown, especially their failure to use the available back-up means of navigation to verify the position and the progress of the flight."

Accident investigation: