NTSB Identification: LAX86MA309.
The docket is stored on NTSB microfiche number 33949.
Accident occurred Friday, July 18, 1986 in MORGAN CITY, LA
Probable Cause Approval Date: 02/12/1988
Aircraft: AEROSPATIALE AS-355F-1, registration: N57967
Injuries: 1 Uninjured.

NTSB investigators traveled in support of this investigation and used data obtained from various sources to prepare this aircraft accident report.

THE PLT FLEW TO A NEARBY ARPT TO PRACTICE TAKEOFFS & LNDGS. HE RPRTD THAT AFTER 3 LNDGS 'OUT OF A HOVER,' HE RETURNED TO THE DEPARTURE HELIPORT & LNDD AGAIN FROM A HOVER. DRG TOUCHDOWN, THE HELICOPTER BGN TO ROCK FM SIDE TO SIDE & ENTEREDGROUND RESONANCE. THE PLT RPRTD HE LOWERED THE COLLECTIVE PITCH TO THE BOTTOM STOP, BUT STATED THE SIDEWARD BOUNCING FM SKID TO SKID WORSENED. HE REACHED FOR THE OVERHEAD THROTTLES, BUT WAS BEING FLAILED ABOUT THE COCKPIT & COULD NOT HOLD ONTO THEM. SUBSEQUENTLY, THE HELICOPTER WAS EXTENSIVELY DAMAGED. WITNESSES VERIFIED THE SIDE TO SIDE BOUNCING & RPRTD HEARING A LOUD METALLIC SOUND BEFORE THE HELICOPTER TOUCHED DOWN. A POST-CRASH EXAM REVEALED THE L FRONT, L REAR & RGT REAR SUPPORT TUBES (GEARBOX BARS) WERE BUCKLED IN A 'D' SHAPE & FRACTURED AT MIDSPAN. METALLURGICAL EXAM OF THE FRACTUREAREAS DISCLOSED EVIDENCE OF HIGH STRESS, LOW AMPLITUDE FATIGUE. NO HISTORY OF HARD LNDGS OR MAINTAINANCE/MANUFACTURING DISCREPANCIES WERE FND CONCERNING THE GEARBOX BARS; L FRONT BAR HAD 1522 HRS OF SVC, REAR BARS HAD 3396 HRS OF SVC.

The National Transportation Safety Board determines the probable cause(s) of this accident to be:

REASON FOR OCCURRENCE UNDETERMINED




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