NEW ROADS, LA, USA
N349SB
Saab-Scania AB (Saab) 340B
WHILE DESCENDING FOR LANDING AT BATON ROUGE, THE CAPTAIN ACTIVELY MOVED THE POWER LEVERS FROM THE FLIGHT IDLE GATE INTO THE BETA RANGE FOR UNDETERMINED REASONS. THE PROPELLERS AND ENGINES EXPERIENCED EXTREME OVERSPEED, NECESSITATING A POWER-OFF EMERGENCY LANDING AT NIGHT AND THE AIRPLANE RAN OFF THE END OF A 5,000-FT RUNWAY. ALTHOUGH THE DESIGN AND CERTIFICATION OF THE POWER LEVERS MET EXISTING REQUIREMENTS, THOSE REQUIREMENTS WERE INADEQUATE BECAUSE THEY PERMITTED A DESIGN THAT DID NOT PREVENT MOVEMENT INTO THE BETA RANGE IN FLIGHT. THE AIRFRAME & ENGINE INDUSTRY, THE FAA, AND THE CERTIFICATION AUTHORITIES FROM OTHER COUNTRIES WERE SLOW IN REACTING TO SEVERAL PREVIOUS IN-FLIGHT BETA OCCURRENCES THAT LED TO SERIOUS INCIDENTS AND ACCIDENTS.
On February 1, 1994, at 2140 central standard time, a Saab 340B, N3495B, operated by Simmons Airlines as American Eagle flight 3641, sustained substantial damage during a forced landing at the False River Air Park in New Roads, Louisiana. The flight had been requested to descend by air traffic control from FL210, into Baton Rouge, Louisiana. The flightcrew stated after the accident that the captain was at the controls during the descent, and while passing through about 10,000 feet MSL, with the engine power levers in the flight idle position, a "loud roar" was heard followed by a loss of power on both engines. Passengers and the flight attendant stated that following the "roar," they observed "flames" or "sparks" coming from the rear of each engine. The captain continued the descent and attempted several inflight emergency airstarts, however, they were unsuccessful. The first officer observed the lights of an airport and directed the captain to the runway where he executed a dual-engine out approach. The airplane touched down on runway 18 and continued off the end of the runway, accross the grass and a ditch, and came to rest upright on all three landing gear in a sugar cane field. The passengers were evacuated via the airstair door. SEE BLUE COVER REPORT AAR-94/06
THE CAPTAIN'S MOVEMENT OF THE POWER LEVERS BELOW FLIGHT IDLE IN FLIGHT, THE INADEQUATE CERTIFICATION REQUIREMENTS AND CONSEQUENT DESIGN OF THE AIRPLANE'S POWER LEVERS THAT PERMITTED THEM TO BE MOVED BELOW THE FLIGHT IDLE POSITION INTO THE BETA RANGE, EITHER INTENTIONALLY OR INADVERTENTLY, WHILE IN FLIGHT, AND THE INADEQUATE ACTION TAKEN TO REQUIRE A POSITIVE MEANS TO PREVENT BETA OPERATION ON AIRPLANES FOR WHICH SUCH OPERATION IS PROHIBITED. (NTSB REPORT AAR=94/06)
Source: NTSB Aviation Accident Database
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