NTSB Identification: ANC90FA134.
The docket is stored on NTSB microfiche number 43803.
Accident occurred Saturday, August 04, 1990 in 40 SE BETTLES, AK
Probable Cause Approval Date: 04/30/1992
Aircraft: HELIO COURIER H-295, registration: N6493V
Injuries: 3 Fatal.

NTSB investigators either traveled in support of this investigation or conducted a significant amount of investigative work without any travel, and used data obtained from various sources to prepare this aircraft accident report.

THE PILOT HAD INDICATED TO BETTLES FSS THAT HE HAD LOST POWER AND THAT HE HAD A FIRE ON BOARD. THE WRECKAGE WAS SUBSEQUENTLY LOCATED 40 MILES SE OF BETTLES. ON-SITE EXAMINATION SHOWES THAT THE RIGHT WING, BOTH AILERONS, LEFT FLAP, RUDDER, VERTICAL FIN AND STABILATOR HAD ALL SEPARATED FROM THE AIRPLANE IN FLIGHT. TWO OF THE THREE VERTICAL FIN/STABILATOR-TO-FUSELAGE MOUNTS HAD FAILED IN OVERLOAD; THE THIRD MOUNT WAS RELATIVELY UNDAMAGED WITH THE BOLT MISSING AND VISIBLE ELONGATION OF THE BOLT HOLE. ENGINE EXAM REVEALED EXTENSIVE FIRE DAMAGE TO THE #5 CYLINDER, THE HEAD AREA HAVING BEEN COMPLETELY CONSUMED BY FIRE. THE ROD CAP AND ONE BOLT COULD NOT BE FOUND AT THE WRECKAGE SITE. FOUR MONTHS PRIOR TO THE ACCIDENT MAJOR REPAIRS WERE MADE TO THE AIRFRAME, THE ENGINE NOSE CASE WAS REMOVED AND OVERHAULED, AND THE PROPELLER WAS OVERHAULED. AIRCRAFT AND PILOT INVOLVED IN LANDING ACCIDENT ON 6/29/88 SUBSTANTIALLY DAMAGING THE AIRCRAFT. LYCOMING SB RECOMMENDS ENGINE TEARDOWN AFTER SUDDEN STOPPAGE; NO RECORD OF COMPLIANCE.

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

THE FAILURE AND SEPARATION OF THE #5 CONNECTING ROD BOLT AND CAP WHICH RESULTED IN THE RUPTURE OF THE ENGINE HOUSING AND SUBSEQUENT ENGINE FIRE DUE TO OIL SPILLAGE, AND AN INADEQUATELY MOUNTED VERTICAL FIN/STABILATOR. A CONTRIBUTING FACTOR WAS THE INADEQUATE MAINTENANCE AND INSPECTION OF THE AIRCRAFT AFTER A PREVIOUS ACCIDENT.

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