NTSB Identification: LAX86FVA14.
The docket is stored on NTSB microfiche number 33448.
Accident occurred Thursday, September 18, 1986 in LEMOORE, CA
Aircraft: HILLER UH-12E, registration: N688SB
Injuries: 1 Minor.

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 PLT REPTD THAT WHILE RETURNING TO THE LOADING AREA AFTER SPRAYING A FIELD, HE HEARD A LOUD POP EMANATING FROM THE ENGINE COMPARTMENT. SHORTLY THEREAFTER HE OBSERVED A FIRE IN THE ENGINE COMPARTMENT AND LOST FORWARD AND AFT CONTROL OF THE HELICOPTER. THE PLT IMMEDIATELY EXECUTED AN AUTOROTATION. THE HELICOPTER ROLLED OVER ONTO ITS SIDE ON TOUCH DOWN. THE POST-ACCIDENT INVESTIGATION ENGINE EXAMINATION DISCLOSED THAT THE NUMBER 3 CONNECTING ROD BOLTS FAILED. FURTHER EXAMINATION REVEALED THAT THE REMAINING CON ROD BOLTS TORQUE VALUES WERE ABT 50% LESS THAN THE REQUIRED VALUES.

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

ENGINE ASSEMBLY,CONNECTING ROD..FAILURE,TOTAL

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

MAINTENANCE,OVERHAUL..IMPROPER..OTHER MAINTENANCE PERSONNEL


Index for Sep1986 | Index of months