Narrative:
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."
Controlled Flight Into Terrain (CFIT) - Ground
| Status: | Final |
| Date: | Saturday 29 November 2003 |
| Time: | 08:01 |
| Type: |  Swearingen SA227-AT Merlin IVC |
| Operator: | Ameriflight |
| Registration: | N439AF |
| MSN: | AT-439B |
| First flight: | 1981 |
| Total airframe hrs: | 15126 |
| Engines: | 2 Garrett TPE331-11U-611G |
| Crew: | Fatalities: 1 / Occupants: 1 |
| Passengers: | Fatalities: 0 / Occupants: 0 |
| Total: | Fatalities: 1 / Occupants: 1 |
| Aircraft damage: | Destroyed |
| Aircraft fate: | Written off (damaged beyond repair) |
| Location: | 5,5 km (3.4 mls) E of Spokane-Felts Field, WA (SFF) ( United States of America)
|
| Phase: | Approach (APR) |
| Nature: | Cargo |
| Departure airport: | Seattle-Boeing Field International Airport, WA (BFI/KBFI), United States of America |
| Spokane-Felts Field, WA (SFF/KSFF), United States of America | |
| Flightnumber: | 1966 |
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:
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."
Accident investigation:
 |
|
Classification:
Controlled Flight Into Terrain (CFIT) - Ground
Sources:
» NTSBPhotos
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 Seattle-Boeing Field International Airport, WA to Spokane-Felts Field, WA as the crow flies is 371 km (232 miles).
Accident location: Exact; as reported in the official accident report.
Distance from Seattle-Boeing Field International Airport, WA to Spokane-Felts Field, WA as the crow flies is 371 km (232 miles).
Accident location: Exact; as reported in the official accident report.
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.
The Aviation Safety Network is an exclusive service provided by:
