Statuts:	Enquête Officielle
Date:	29 NOV 2003
Heure:	08:01
Type/Sous-type:	Swearingen SA227-AT Merlin IVC
Compagnie:	Ameriflight
Immatriculation:	N439AF
Numéro de série:	AT-439B
Année de Fabrication:	1981
Heures de vol:	15126
Moteurs:	2 Garrett TPE331-11U-611G
Equipage:	victimes: 1 / à bord: 1
Passagers:	victimes: 0 / à bord: 0
Total:	victimes: 1 / à bord: 1
Dégats de l'appareil:	Détruit
Conséquences:	Written off (damaged beyond repair)
Lieu de l'accident:	5,5 km (3.4 milles) E of Spokane-Felts Field, WA (SFF) (Etats-Unis d'Amérique)
Phase de vol:	En approche (APR)
Nature:	Cargo
Aéroport de départ:	Seattle-Boeing Field International Airport, WA (BFI/KBFI), Etats-Unis d'Amérique
Aéroport de destination:	Spokane-Felts Field, WA (SFF/KSFF), Etats-Unis d'Amérique
Numéro de vol:	1966

Détails:
The Merlin cargo plane was transporting 127 packages from Seattle to Spokane. The aircraft was dispatched with the primary (NAV 1) ILS receiver having been deferred (out of service) due to unreliable performance the evening before the accident, thus leaving the aircraft with the secondary (NAV 2) ILS receiver for ILS use. Approaching Spokane, the pilot was cleared for an ILS/DME runway 21R approach. Weather at the destination airport was poor with a 400 foot overcast. The pilot was given a low altitude alert by the tower and acknowledged, reporting that he was descending through 2,800 feet. At that point the aircraft was well below the ILS glideslope and about 13 seconds from impacting the trees. The pilot was given a low altitude alert by the tower and acknowledged, reporting that he was descending through 2,800 feet, which was confirmed on the mode C radar readout. At that point the aircraft was well below the ILS glideslope and about 13 seconds from impacting the trees.

PROBABLE CAUSE: "The pilot-in-command's failure to maintain proper glidepath alignment during an ILS approach in poor weather resulting in collision with trees and terrain. Contributing factors were the unreliable status of the primary (NAV 1) ILS receiver (leaving the pilot with only the secondary (NAV 2) ILS receiver), the low ceilings and trees."

Sources:
» NTSB