Ameriflight Flight 1996
Fairchild Swearingen SA227-AT · Accident: in flight collision with object on approach
From King County International Airport - Boeing Field (BFI) to Felts Field (SFF)
Event
- NTSB case
- SEA04FA023
- Event typeAccident: someone killed or seriously injured, or the aircraft substantially damaged (NTSB definition). Incident: an occurrence that affected or could have affected safety, short of that. Glossary
- Accident
- InvestigationHow far the investigation had got when the record was published: preliminary, ongoing, final or completed. Unknown where the source does not say. Glossary
- Completed
- API-reported fatalities
- 1 · all aircraft and ground
- Ground fatalities
- Unknown
- OperationWhat kind of flying it was, grouped by the rules it flew under: airline (US Part 121), air taxi and commuter (Part 135), general aviation (Part 91 and similar), military or government. Glossary
- Charter & commuter
- WeatherVisual meteorological conditions (VMC): good enough to fly by looking outside. Instrument conditions (IMC): cloud or low visibility, flying by instruments. Glossary
- Instrument Meteorological Cond
Fairchild Swearingen SA227-AT
- Aircraft type
- Fairchild Swearingen SA227
- Category
- Airplane
- RegistrationThe aircraft's tail number, such as N12345 or G-ABCD. Registrations are reissued, so the same one years apart can be a different aircraft. Glossary
- N439AF
- Operator
- Ameriflight
- Onboard fatalities
- Unknown
- Route
- From King County International Airport - Boeing Field (BFI), Seattle, WATo Felts Field (SFF), Spokane, WA
- Aircraft age
- Not recorded
- Flight rulesThe regulations the flight operated under: in the US, Part 91 (general aviation), Part 121 (airlines), Part 135 (air taxi and commuter) and others; for flights abroad, the NTSB's coarser commercial or non-commercial code. Glossary
- Part 135: Air Taxi & Commuter
- Phase of flightThe stage of the flight when things started to go wrong: standing, taxi, takeoff, initial climb, en route, maneuvering, approach or landing. Glossary
- Approach · IFR final approach
- First occurrenceThe single coded event the NTSB judges best describes what happened (records from 2008 on). Older records name the first occurrence in the sequence instead. Glossary
- In flight collision with object
- Also codedOther events the NTSB coded in the sequence, such as a wire strike after a loss of power. Flight Findings uses them for its kinds of event. Glossary
- Tree(s)
- DamageDestroyed: beyond practical repair. Substantial: damage that affects the structure, performance or handling and normally needs major repair. Minor: less than that. Glossary
- Destroyed
Cause areas
- Pilot in command › Proper glidepath, not maintained
Approximate · Coordinates from the NTSB case API, which marks them as estimated or does not say; no uncertainty radius is established.
NTSB narrative
The pilot, who had more than 3,340 hours of pilot-in-command time in the make/model of the accident aircraft, and was very familiar with the destination airport and its ILS approach procedure, departed on a cargo flight in the SA227 turboprop aircraft. 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. The pilot arrived in the destination terminal area and was given vectors to intercept the ILS localizer, and radar data showed the aircraft intercepting and tracking the localizer accurately throughout the approach. Mode C altitude readouts showed the aircraft approaching from below the glideslope at the required intercept altitude of 4,100 feet, passing through and above the glideslope and then initiating a relatively constant descent, the angle of which exceeded the glideslope angle of -3.5 degrees. Weather at the destination airport was 400 foot overcast and the decision height for the ILS/DME runway 21R approach was 270 feet. The aircraft passed through the tops of trees in level flight about 530 feet above the airport elevation and slightly under 3 nautical miles from the runway threshold. 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. Post crash examination of information captured from the left and right HSI units and an RMI revealed that the NAV 1 receiver was most likely set on the ILS frequency, and the NAV 2 receiver was most likely set on Spokane VORTAC, a terminal navigation facility located very slightly right of the nose of the aircraft and 14 nautical miles southwest of the destination airport.
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.
Verbatim NTSB analysis and probable cause from the NTSB dataset
Sources
NTSB record SEA04FA023
- Event ID
- 20031205X02005
- Case number
- SEA04FA023
- Dataset
- historical-pre2008
- Source SHA-256
- 89e2df6d848e7ab3b42e7d7c7a03ff403303057a26ca04c95b3ea67201c3ce74
Source notes (5)
- Unreviewed is an editorial label, not an investigation status. API-sourced is not report-checked or human-reviewed. Explicit event totals are used without summing aircraft injury tables; onboard allocation is withheld. Unknown values remain unknown. The operation category is mapped from the NTSB-reported FAR part and has not been reviewed.
- Filled from the NTSB case API where the bulk record had no value: investigation status, coordinates. Values present in the bulk record are kept.
- The date is the local date, which is the same as the UTC date the NTSB stores.
- API snapshot SHA-256: 5897c923576bf752525c57e29d94da72ca7eba7f184822efb93f5e4afa3ba3ac; retrieved 2026-09-18T13:01:25.478Z.
- The NTSB's operator name is blank for N439AF; the operator shown is the name the NTSB's other records give its FAA operator code, JIKA.