What happened
The FAA’s narrative, in sentence case. The FAA writes it in capitals and removes private details.
Declared an emergency due to engine failure. Unable to make airport, crashed in a field. (.4)atlantic southeast airline flight 529 was climbing through 18,000', when a blade from the left propeller separated. This resulted in distortion of the left engine nacelle, excessive drag, loss of wing lift, & reduced directional control. The degraded performance resulted in a forced landing. While landing, the airplane passed through trees, impacted the ground, & was further damaged by postimpact fire. An exam of the left propeller revealed the blade had failed due to a fatigue crack that originated from multiple corrosion pits in the taper bore surface of the blade spar. The crack had propagated toward the outside of the blade & around both sides of the taper bore. Due to 2 previous blade failures (separations), a borescope inspection procedure had been developed by hamilton standard to inspect returned blades (that had rejectable ultrasonic indications) for evidence of cracks, pits & corrosion. The accident blade was one of 490 rejected blades that had been sent to hamilton standard for further evaluation & possible repair. Main tenance technicians, who inspected the blade, lacked proper ndi familiarization training & specific equipment to identify the corrosion that resulted in fatigue. (See NTSB/AAR-96/06 for additional information).
As the FAA filed it
DECLARED AN EMERGENCY DUE TO ENGINE FAILURE. UNABLE TO MAKE AIRPORT, CRASHED IN A FIELD. (.4)ATLANTIC SOUTHEAST AIRLINE FLIGHT 529 WAS CLIMBING THROUGH 18,000', WHEN A BLADE FROM THE LEFT PROPELLER SEPARATED. THIS RESULTED IN DISTORTION OF THE LEFT ENGINE NACELLE, EXCESSIVE DRAG, LOSS OF WING LIFT, & REDUCED DIRECTIONAL CONTROL. THE DEGRADED PERFORMANCE RESULTED IN A FORCED LANDING. WHILE LANDING, THE AIRPLANE PASSED THROUGH TREES, IMPACTED THE GROUND, & WAS FURTHER DAMAGED BY POSTIMPACT FIRE. AN EXAM OF THE LEFT PROPELLER REVEALED THE BLADE HAD FAILED DUE TO A FATIGUE CRACK THAT ORIGINATED FROM MULTIPLE CORROSION PITS IN THE TAPER BORE SURFACE OF THE BLADE SPAR. THE CRACK HAD PROPAGATED TOWARD THE OUTSIDE OF THE BLADE & AROUND BOTH SIDES OF THE TAPER BORE. DUE TO 2 PREVIOUS BLADE FAILURES (SEPARATIONS), A BORESCOPE INSPECTION PROCEDURE HAD BEEN DEVELOPED BY HAMILTON STANDARD TO INSPECT RETURNED BLADES (THAT HAD REJECTABLE ULTRASONIC INDICATIONS) FOR EVIDENCE OF CRACKS, PITS & CORROSION. THE ACCIDENT BLADE WAS ONE OF 490 REJECTED BLADES THAT HAD BEEN SENT TO HAMILTON STANDARD FOR FURTHER EVALUATION & POSSIBLE REPAIR. MAIN TENANCE TECHNICIANS, WHO INSPECTED THE BLADE, LACKED PROPER NDI FAMILIARIZATION TRAINING & SPECIFIC EQUIPMENT TO IDENTIFY THE CORROSION THAT RESULTED IN FATIGUE. (SEE NTSB/AAR-96/06 FOR ADDITIONAL INFORMATION).
NTSB investigation
The NTSB’s investigation of this event, with its probable cause and findings. Matched to this report by N-number and date.