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Wings West Airlines Saab-Scania AB (Saab) 340B incident

13 May 1997 · San Luis Obispo, CA, United States

Saab-Scania AB (Saab) 340B · Incident: partial loss of engine power (non-mechanical) during initial climb

From San Luis County Regional Airport (SBP) to Los Angeles International Airport (LAX)

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Event

NTSB case
LAX97IA180
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
Incident
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
0 · all aircraft and ground
Ground fatalities
0
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
Airline
WeatherVisual meteorological conditions (VMC): good enough to fly by looking outside. Instrument conditions (IMC): cloud or low visibility, flying by instruments. Glossary
Visual Meteorological Cond

Saab-Scania AB (Saab) 340B

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
N313AE
Onboard fatalities
Unknown
Route
From San Luis County Regional Airport (SBP)To Los Angeles International Airport (LAX), Los Angeles, CA
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 121: Air Carrier
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
Initial climb
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
Partial loss of engine power (non-mechanical)
DamageDestroyed: beyond practical repair. Substantial: damage that affects the structure, performance or handling and normally needs major repair. Minor: less than that. Glossary
None

Cause areas

  • Compressor assembly › Contamination

Approximate · Coordinates as recorded by the NTSB; no uncertainty radius is established.

NTSB narrative

The flight crew reported that all pretakeoff checks were normal and that prior to setting takeoff power the Constant Thrust on Takeoff (CTOT) computer was set to 100-percent engine torque for takeoff. The ensuing takeoff was normal through liftoff and gear retraction; however, during initial climb the left engine experienced compressor stalling and lost power. As the crewmembers were executing the engine failure checklist, the right engine first increased power in Automatic Power Reserve (APR) and then began to similarly stall and lose power. After about 20 seconds the engines recovered sufficient power to enable the flight crew to remain airborne and return for landing on the departure runway. Review of the digital flight data recorder (DFDR) output and internal examination of each engine revealed that the engines had compressor stalled due to accumulated dirt and contaminants on the compressors. A review of the right engine DFDR data revealed that, while the left engine was stalling, the flight crew had retarded the right engine power lever past the 64-degree power lever angle position which tripped off the CTOT system. The resulting transient in fuel flow, in company with an atmospheric temperature inversion, reduced the stall margin of the right engine.

Probable cause

Compressor stalls of both engines due to in-service compressor contamination. Factors in the compressor stall of the right engine were an atmospheric temperature inversion and a transient fuel flow condition produced when the constant thrust on takeoff (CTOT) system was disabled by the pilot's inadvertent movement of the right engine power lever during execution of the emergency procedure.

Verbatim NTSB analysis and probable cause from the NTSB dataset

Sources

NTSB record LAX97IA180
Event ID
20001208X07944
Case number
LAX97IA180
Dataset
historical-pre2008
Source SHA-256
89e2df6d848e7ab3b42e7d7c7a03ff403303057a26ca04c95b3ea67201c3ce74
Source notes (4)
  • 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, damage. 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: fc48162fd655d397a27b596a7607a7b3292671f212d1284d8fdca52fa7b90402; retrieved 2026-09-18T17:33:58.759Z.