Accident at Alamo, California, 3 Aug 1986 (N49606)

Accident narrative

On August 3, 1986, at 1235 Pacific daylight time, a Bell 206B helicopter, registration N49606, crashed into a wooded area while circling a residence in Alamo, California. The helicopter, owned and operated by Joe Foster Excavating, Inc., was destroyed. Both the pilot and the passenger, who was the owner of the helicopter, sustained fatal injuries. Visual meteorological conditions prevailed.

### The flight

The helicopter departed Livermore Airport in Livermore, California, at 1130, operating under visual flight rules without a flight plan. At 1150, the flight landed at a ranch near Danville. The pilot remained in the right front seat while the passenger visited with friends. The passenger told the ranch owner they intended to fly over a mutual friend's residence in Alamo and continue to Discovery Bay. The helicopter departed the ranch at 1220.

Ground witnesses reported the helicopter approached the Alamo residence from the west at 50 feet above ground level. The helicopter completed two 20-degree left banking turns over the residence. As it began a third turn, the helicopter entered an abrupt 90-degree left bank, pitched downward about 45 degrees, and crashed into the trees. Witnesses stated the engine and rotor systems sounded normal and steady until the main rotor blades struck the trees with a sound like a cannon explosion. There was no post-crash fire.

The 49-year-old pilot held an airline transport pilot certificate. A resume indicated he had accrued 16,272 total flight hours as of May 1985, including 5,110 hours in helicopters.

### Medical and certification history

The investigation revealed an extensive medical history. In October 1981, a cardiologist diagnosed the pilot with an irregular arrhythmia—atrial fibrillation. Treatments, including medication and an attempted electrical cardioversion in October 1982, were unsuccessful in returning his heart to a normal rhythm. The treating physician noted the pilot continued to drink heavily and smoke against medical advice.

The pilot's Federal Aviation Administration (FAA) medical certification had been the subject of a prolonged review. In January 1984, an FAA-designated Airman Medical Examiner (AME) at a rehabilitation clinic administered a stress electrocardiogram (EKG) and recommended a special-issuance second-class medical certificate. In June 1984, an FAA medical consulting panel, which included three board-certified cardiologists, reviewed the pilot's records and recommended that certification be denied due to atrial fibrillation and coronary disease. The Federal Air Surgeon (FAS) at the time denied the request.

In October 1984, a new FAS was appointed. In January 1985, the new FAS issued the pilot a special-issuance second-class medical certificate restricted from pilot-in-command duties. In April 1986, the same AME reevaluated the pilot using a non-standard stress EKG protocol and recommended an unrestricted certificate.

On May 5, 1986, the FAA issued an unrestricted second-class medical certificate valid for 12 months, authorized by the FAS. The issuance letter admonished the pilot to cease all flying activities if he experienced any adverse change in his medical condition.

Two days later, on May 7, 1986, the pilot went to a hospital emergency room with chest pains and developed ventricular fibrillation (a myocardial infarction). He was resuscitated and hospitalized. A coronary angiogram disclosed an occlusion and narrowing of his coronary arteries. Following a stress EKG on May 30, which the pilot could not complete due to fatigue, his physician instructed him to return in three weeks. The pilot never returned.

During the investigation, the FAS testified that he had relied heavily on the AME's report, mistakenly believing the AME was a board-certified cardiologist because of the clinic's name, "The Center for Heart and Health." The FAS did not consult his medical staff regarding the recertification and rejected the medical panel's earlier recommendation.

### What the investigation found

The helicopter crashed about 309 feet south of the residence. Examination of the airframe and engine revealed no evidence of pre-impact failures or malfunctions. The flight controls displayed overload signatures caused by impact forces. The engine exhibited extensive rotational scoring and damage indicating high rotational speed and combustion at impact.

The passenger's body was found clear of the wreckage. The Safety Board noted that his seatbelt and shoulder harness displayed no evidence of impact stretching, indicating he had removed his restraints before the crash. The Board concluded this reinforced the probability that the pilot became incapacitated and the passenger either attempted to assist him or the pilot attempted to extricate himself.

Postmortem examinations attributed both deaths to multiple traumatic injuries. However, pathologists noted the pilot had severe coronary atherosclerosis, with up to 90 percent narrowing of his coronary arteries, and extensive myocardial scarring. The Armed Forces Institute of Pathology concluded the pilot was at a very high risk for developing a sudden incapacitating arrhythmia and that severe coronary artery atherosclerosis was the most likely cause of death.

Safety Board medical consultants reviewed the pilot's records and concluded he had multiple cardiac abnormalities that rendered him ineligible for any medical certificate. They found the AME's stress tests were uninterpretable and used a protocol less strenuous than the standard Bruce protocol.

The Board also noted the pilot's history of disregarding Federal Aviation Regulations, including two prior civil penalty settlements for incidents that included low flying. The Board concluded the pilot was flying dangerously low before the accident, though it noted the outcome would probably have been the same at a higher altitude.

### Probable cause

The National Transportation Safety Board determined that the probable cause of this accident was "the pilot's incapacitation resulting from a myocardial event. Contributing to the cause of the accident was the pilot's failure to comply with the provisions of both his medical and pilot certificates and the inadequate procedures used by the Federal Air Surgeon to medically recertify the pilot."