TEXARKANA, AR, USA
N254AE
Saab-Scania AB (Saab) SF-34OB
THE CONFIGURATION WARNING LIGHT ILLUMINATED DURING TAKEOFF AT APPROXIMATELY 95 KNOTS. THE CAPTAIN INITIATED THE ABORT BY MOVING THE POWER LEVERS TO FLIGHT IDLE AND APPLYING MAXIMUM BRAKING. THE CAPTAIN STATED THAT INITIALLY THE DECELERATION APPEARED NORMAL AND THE BRAKES BECAME INCREASINGLY INEFFECTIVE AND APPEARED TO FADE. SIGNS OF HEAVY BRAKING WERE FOUND ON THE RUNAWAY FOR 3,400 FEET. THE CAPTAIN ALSO STATED THAT HE EXPERIENCED SOME DIFFICULTY IN GETTING THE POWER LEVERS BACK BEYOND THE FLIGHT IDLE GATE. THE AIRPLANE ROLLED 205 FEET PAST THE RUNWAY THRESHOLD INTO A GRASS OVERRUN. SIMULATOR DEMONSTRATIONS WERE CONDUCTED TO EVALUATE THE REJECTED TAKEOFF PERFORMANCE. DEMONSTRATIONS CONCLUDED THAT IF THE PILOT INADVERTENTLY LIFTS UP ON THE BETA RANGE LOCK OUT TRIGGERS WHENEVER THE POWER LEVERS ARE IN THE FULL FORWARD POSITION, THE POWER LEVERS WILL JAM INTO TEETH WHICH WILL PREVENT THE PILOT FROM RETARDING THE POWER LEVERS. THIS SCENARIO RESULTED IN AN OVERRUN IN THE SIMULATOR. ILLUMINATION OF THE CONFIGURATION LIGHT WAS DUE TO INSUFFICIENT REBOUND ON THE RIGHT CONDITION LEVER.
On May 12, 1994, at 1756 central daylight time, a Saab SF-340B, N254AE, operating as American Eagle flight 5384, sustained minor damage during an aborted takeoff at the Texarkana Regional Airport, near Texarkana, Arkansas. None of the 25 passengers, nor the three crewmembers were injured. Visual meteorological conditions prevailed for the scheduled 14 CFR Part 121 flight from Texarkana, Arkansas, to the Dallas/Fort Worth Airport, Texas. According to the flight crew, the warning horn sounded and the "configuration warning light" illuminated on the annunciator panel during a full power takeoff roll from runway 22. At approximately 95 knots, the first officer called out "configuration light, Abort" and the captain, who was flying the airplane, immediately initiated the abort by moving the power levers back and applying full braking. The captain reported that initially the deceleration appeared normal, but quickly the brakes became increasingly ineffective and appeared to fade. Both flight crew members were not certain whether the props were in reverse and the captain further stated that he experienced some difficulty in getting the power levers back beyond the flight idle gate. The airplane rolled 205 feet past the runway threshold into the grass overrun. Signs of heavy braking action were observed on the runway for 3,400 feet of the 6,601 foot runway. The runway conditions were reported as clear and dry. All four brake assemblies sustained evidence of fire. The airplane was equipped with a Loral/Fairchild F800 Digital Flight Data Recorder (DFDR). Data for this flight was not available during the takeoff roll. A review of the data for several like airplanes revealed that this loss of data normally occurs just after the initiation of the takeoff roll (around 40-50 knots) and continues until the airplane reaches 120-130 knots). The operator's avionics facility suspects that tape jitter may be the result of under rated shock mounts on the DFDR mounting rack. Flight simulator demonstrations were conducted at the American Eagle Training Center on June 23, 1994. The primary purpose of the demonstrations were to evaluate the movement of the power levers (PL) relative to the position of the beta range lock-out triggers (BLT). Additionally, the rejected takeoff (RTO) performance of the aircraft was evaluated in two configurations, with power levers in the flight idle and ground idle positions. Several simulated RTO's were performed after the aircraft was allowed to accelerate to 100 knots. Three different RTO scenarios were demonstrated: The approved RTO procedure where the PL's were retarded to the ground idle position. An RTO with the PL's being retarded to the flight idle, and an RTO with the PL's retarded as far back as possible while pulling up on the BLT's. The resultant runway remaining for the first two scenarios were 2,600 feet and 2,200 feet respectively; however, when the power lever triggers were held up by the pilot, the aircraft rolled past the departure end of the runway. The simulator demonstrations concluded that if a pilot inadvertently lifts up on the BLT's whenever the power levers are in the full forward position and attempts to reduce the power by pulling back on the power levers, the power levers will jam into teeth which will prevent the power levers from going any further back. The RTO procedures in the company operating manual calls for the power levers to be retarded to flight idle, then pulled up on the power lever latches to release the flight idle stop and retard the power levers to ground idle. The activation of the configuration light during the takeoff roll was the result of insufficient rebound on the right condition lever while the lever was in the full forward position.
THE PILOT'S INABILITY TO RETARD THE POWER LEVERS DURING A REJECTED TAKEOFF DUE TO HIS FAILURE TO PERFORM THE EMERGENCY PROCEDURES IN ACCORDANCE WITH THE AIRCRAFT OPERATING MANUAL. A FACTOR WAS THE ILLUMINATION OF THE CONFIGURATION LIGHT AS RESULT OF INSUFFICIENT REBOUND ON THE RIGHT CONDITION LEVER WHILE PLACED IN THE FULL FORWARD POSITION.
Source: NTSB Aviation Accident Database
Aviation Accidents App
In-Depth Access to Aviation Accident Reports
