Abbott GLASAIR LEGEND C-GUTT

Summary

On 24 March 2005 at about 18:15 local time, a Abbott GLASAIR LEGEND registered C-GUTT, operated by Martin Abbott, was involved in an accident near Cascade, Montana, United States. One person was on board and nobody was injured. The aircraft was substantially damaged. The NTSB has published a probable cause for this accident; it is quoted in full below.

Date

24 March 2005 at 18:15

Classification

Accident

Location

Cascade, Montana, United States

Coordinates

47.3097, -111.5161

Aircraft

Abbott GLASAIR LEGEND

Registration

C-GUTT

Category

Airplane

Engines

1

Operator

Martin Abbott

Operating rule

Part 91: General Aviation

Purpose of flight

Personal

Phase of flight

Not recorded

Route

Springbank → Great Falls

Aircraft damage

Substantial

Weather

IMC

Light

Day

NTSB number

SEA05LA066

Nobody was injured.

The accumulation of wet snow on the engine inlet assembly protection screen during a rapid increase in outside air temperature, while on an instrument approach for landing. Factors include falling snow, a sudden and significant increase in outside air temperature, and rough, snow covered terrain in the area where the pilot found it necessary to attempt a forced landing.

Quoted verbatim from the NTSB record. This site does not paraphrase or interpret it.

Read the full NTSB narrative

The aircraft was descending in light snow, at idle power, on an ILS approach when it passed through an area where the outside air temperature increased from eight degrees Fahrenheit to thirty-two degrees Fahrenheit in a time span of about 20 seconds. Soon thereafter the aircraft's engine suddenly stopped producing power. Because he was unable to get the engine restarted, he descended straight ahead, and eventually lowered the landing gear for an attempted off-field power-off landing. Although he was able to make an uneventful touchdown in a rough open snow-covered field, as the aircraft began to roll, its wheels sunk into the snow, and all three gear legs collapsed. When the gear collapsed the airframe contacted the terrain and sustained substantial damage. After the accident, recorded data was downloaded from the aircraft's electronic engine fuel control system, and it was determined that at the time of the power loss, fuel pressure to the engine was within normal parameters, but N1 rpm and ITT (inter-turbine-temperature) were dropping. An inspection of the engine did not reveal an evidence of any anomaly or malfunction, but it was discovered that just upstream from the compressor, and just downstream from the NACA-form engine air inlet ducts, was a protective screen with one-eight inch diameter openings in its surface. The loss of power during the sudden OAT increase was consistent with the previously dry snow becoming wet and heavy during the rapid temperature increase, and then accumulating on the aforementioned protective screen, starving the engine of inlet air.

Quoted verbatim from the NTSB record.