DCA94MA033

NTSB accident investigation · Saab-Scania 340B · New Roads, LA · February 2, 1994

Accident · Minor injuriesClass 1 · MajorFinal report
Date
February 1, 1994, 21:40 local (Feb 2, 1994, 03:40 UTC)
Place
New Roads, LA
Injuries
1 minor, 25 uninjured
Damage
Substantial damage
Phase of flight
Enroute
Aircraft
N349SBSaab-Scania 340B
Weather
Visual (VMC) · Night/dark
Status
Completed · report April 12, 1995
Report
Board-adopted at Board Meeting
Investigation class
Class 1
NTSB office
Major Investigations Division
Safety recommendations
Yes
Case key
10982

From the NTSB’s public API. By law, NTSB reports can’t be used as evidence in lawsuits over the accident.

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Probable cause

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)

Sequence of events

NTSB’s coding before 2008: each occurrence and phase of flight, and the causes and factors under it. The codes are defined in NTSB’s coding manual.

Loss of engine power(total) - nonmechanicalDescent - normal
All engines
Throttle/power control - improper use ofPilot in commandCause
Acft/equip,inadequate designManufacturerCause
Insufficient standards/requirements,aircraftManufacturerCause
Insufficient standards/requirements,aircraftFaa(organization)Cause
Insufficient standards/requirements,aircraftOther govt organizationCause
Forced landingEmergency descent/landing
OverrunEmergency descent/landing

Analysis

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.

Factual narrative

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

Aircraft

Registration
N349SB
Reported as
Saab-Scania 340B
Category
Airplane
Serial number
340B-349
Airframe hours
528
Engine
GE CT7-9B, turbo prop
Damage
Substantial damage
Flight
Part 121
Registered owner
Simmons Airlines
Airworthiness certificate
Standard, Transport
Last inspection
Continuous airworthiness · January 9, 1994 · 129 hours before
Departed
DFW · Dallas/Ft.Worth, TX
Destination
BTR · Baton Rouge, LA
Flight plan
IFR
Airport
LA30 · False River Air Park, runway 18, 5,000 × 75 ft, asphalt

Matched to the registry by N-number and the event date; the registry’s history has gaps, so older matches can be wrong. Compare the reported make and model.

Flight crew

As NTSB recorded them. NTSB leaves out names.

Role
Pilot
Age
52
Certificate
Airline transport
Airplane ratings
Multi-engine land
Instrument ratings
Airplane
Medical
Class 1, Valid Medical--w/ waivers/lim
Seat
Left
Flight hours
20,000 total

Weather

Conditions
Visual (VMC) · Night/dark
Wind
220° at 4 knots
Visibility
10 statute miles
Lowest ceiling
12,000 ft broken
Temperature
37 °F, dew point 27 °F
Altimeter
30.00 inHg