Saab 340B N394AE

Summary

On 10 January 2001 at about 16:25 local time, a Saab 340B registered N394AE, operated by American Eagle Airlines, Inc., was involved in an incident near San Antonio, Texas, United States. 27 people were on board and nobody was injured. The NTSB has published a probable cause for this accident; it is quoted in full below.

Date

10 January 2001 at 16:25

Classification

Incident

Location

San Antonio, Texas, United States

Coordinates

29.5397, -98.4909

Aircraft

Saab 340B

Registration

N394AE

Category

Airplane

Engines

2

Operator

American Eagle Airlines, Inc.

Operating rule

Part 121: Air Carrier

Phase of flight

Not recorded

Route

DFW Airport → Laredo

Aircraft damage

Not recorded

Weather

IMC

Light

Day

NTSB number

FTW01IA051

Nobody was injured.

the ingestion of ice/slush into both engines, which resulted in dual engine power fluctuations.

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

Read the full NTSB narrative

The flight was in cruise, in icing conditions, when both engines experienced momentary power fluctuations (PF) as a result of ice ingestion. Evaluation of the flight data recorder information revealed that the left engine experienced four Type II (compressor stall) PF events, and the right engine experienced one Type I (partial/full quenching of the engine's combustor flame) PF event and one Type II event. The flight descended, the power fluctuations ceased, and the flight proceeded to land at its intended destination. The Saab 340 fleet has undergone extensive research, with regards to power fluctuations, since it was certified in the U.S. in 1985. In 1985, it was determined that ice accumulates on the engine inlet splitter lip, breaks off, and enters the engine resulting in a flame-out. An auto-ignition system was developed to provide a means to re-light the engine. Aircraft certification rules require that no accumulation of engine inlet ice occur that will adversely affect engine operation. In 2000, the FAA's position was that even though no re-design of the engine inlet was found that would preclude ice accumulation on the splitter lip, the risk associated with a PF event was acceptable. Furthermore, the FAA determined that the risk of a dual engine power loss due to the existence of an icing condition and failure of both engines' auto-ignition systems was acceptably low. Lastly, the FAA stated that inappropriate crew response risks associated with PFs combined with an in-flight shut down were quantitatively indeterminate, but deemed qualitatively acceptable by FAA certification pilots and human factors specialists.

Quoted verbatim from the NTSB record.