Aviation Accident Summaries

Aviation Accident Summary ANC90FA134

40 SE BETTLES, AK, USA

Aircraft #1

N6493V

HELIO COURIER H-295

Analysis

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.

Probable Cause and Findings

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.

 

Source: NTSB Aviation Accident Database

Get all the details on your iPhone or iPad with:

Aviation Accidents App

In-Depth Access to Aviation Accident Reports