NTSB Identification: LAX96FA177.
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Accident occurred Tuesday, April 23, 1996 in SAN DIEGO, CA
Probable Cause Approval Date: 02/02/1998
Aircraft: Hughes 269C, registration: N9579F
Injuries: 1 Fatal,1 Serious.

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 helicopter was observed flying at low altitude and low airspeed. Witnesses heard the engine sputter before the helicopter lost control and landed hard in a residential area. Examination of the engine revealed evidence of two exhaust valves had stuck open due to contamination by products of combustion. The engine manufacturer publishes maintenance procedures to prevent such an occurrence that could result in a partial loss of power. The helicopter operator elected not to perform the recommended procedure. The pilot's shoulder harness failed, whereas the passenger's did not. The failure occurred in a worn area where the harness bends over the seat back. Both shoulder harnesses were not marked with the required data. The cloth data tags were missing. The history or manufacturer of the shoulder harnesses was not determined. The helicopter had an annual inspection about 6 months before the accident. Since the annual, a 100-hour and a 50-hour inspection had been accomplished. The inspections failed to detect the discrepancies with the shoulder harnesses. Toxicological testing revealed the presence in the blood of desalkylflurazepam, an active metabolite of flurazepam (Dalmane), commonly used to treat insomnia, and the presence in the urine of pseudoephedrine, phenylpropanolamine, ephrdrine, and salicylate, substances commonly found in over-the-counter cold medications.

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

the decision of the pilot to fly at low altitude and low airspeed within a hazardous performance area published in the pilot operating handbook. Factors in the accident were tailwinds, lack of operator preventative maintenance impairing engine power, airworthiness of the restraint systems, and the pilot's use of prescription drugs that can impair human performance.

Full narrative available

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