Statuts:	Enquête Officielle
Date:	30 MAI 1979
Heure:	20:55 EDT
Type/Sous-type:	de Havilland Canada DHC-6 Twin Otter 200
Compagnie:	Downeast Airlines
Immatriculation:	N68DE
Numéro de série:	229
Année de Fabrication:	1969
Heures de vol:	21050
Moteurs:	2 Pratt & Whitney Canada PT6A-20
Equipage:	victimes: 2 / à bord: 2
Passagers:	victimes: 15 / à bord: 16
Total:	victimes: 17 / à bord: 18
Dégats de l'appareil:	Perte Totale
Conséquences:	Written off (damaged beyond repair)
Lieu de l'accident:	Rockland, ME (Etats-Unis d'Amérique)
Phase de vol:	En approche (APR)
Nature:	Transport de Passagers Nat.
Aéroport de départ:	Boston-Logan International Airport, MA (BOS/KBOS), Etats-Unis d'Amérique
Aéroport de destination:	Rockland-Knox County Regional Airport, ME (RKD), Etats-Unis d'Amérique
Numéro de vol:	46

Détails:
Flight 46 departed Boston with a 65-minute delay due to adverse weather encountered on an earlier flight leg that day. Around 20:30 the crew requested weather information for Rockland and 3 alternate airports. Weather at Rockland was indefinite ceiling, 300 feet, sky obscured, visibility 3/4 mile in fog; wind light and variable - conditions deteriorating. Navy Brunswick Approach Control then cleared the flight to descend to 3000 feet at captain's discretion. At 20:42 the flight was cleared to cruise at 3000 feet for a Richmond runway 03 approach. Last radio transmission was when the crew reported inbound from the Sprucehead NDB. The Twin Otter struck trees 80 feet above the ground with its left wing and continued striking trees before coming to rest 1,2 miles SSW of the runway 03 threshold, 340 feet from initial impact. The aircraft fuselage came to rest on its left side with the forward 16 feet-section of the fuselage crushed.

PROBABLE CAUSE: "The failure of the flight crew to arrest the aircraft's descent at the minimum descent altitude for the non-precision approach, without the runway environment in sight, for unknown reasons.
Although the Safety Board was unable to determine conclusively the reason(s) for the flight crew's deviation from standard instrument procedures, it is believed that inordinate management pressures, the first officer's marginal instrument proficiency, the captain's inadequate supervision of the flight, inadequate crew training and procedures, and the captain's chronic fatigue were all factors in the accident."

Sources:
» ICAO Circular 173-AN/109 (1-30)
» NTSB Safety Recommendations A-80-42/43
» NTSB-AAR-80-5