WASHINGTON (AP) _ Low fuel, a hard-to-reach handle to switch gas tanks and modificiations to his homemade airplane may have figured in the crash that killed singer John Denver last year, federal investigators said Monday.
The National Transportation Safety Board, wrapping up the fact-finding phase of its investigation into the crash last Oct. 12, also confirmed that Denver lacked an aviation medical certificate _ a requirement for a valid pilot’s license _ at the time of the crash.
The Federal Aviation Administration had disqualified Denver for the certificate in March 1997, after learning that he had violated a previous FAA order to abstain from drinking. Denver had received the warning in 1995 after being arrested for drunken driving. An autopsy showed no signs of alcohol or drugs at the time of the plane crash off the California coast.
While drawing no conclusions, the report suggests factors that may have contributed to crash that killed the 53-year-old singer-songwriter, famous for such hits as ``Rocky Mountain High″ and ``Sunshine On My Shoulders.″
First, Denver’s plane almost certainly was low on fuel when he took off from the Monterey Peninsula Airport in the late afternoon to practice takeoffs and landings. Denver bought the plane only two weeks earlier from another pilot.
In the interim, the plane was taken on a test flight, flown to Monterey and then flown on the day of the crash. Investigators said that activity would have used 12 to 17 gallons of gas, but the last known quantity on board was 15 gallons before the test flight. There was no record of Denver refueling the plane.
Although investigators determined the engine was still running at the time of the crash, witnesses reported hearing a ``pop″ or ``backfire,″ along with reduced engine noise, just before the plane plunged into the sea about 150 yards off shore.
If one of the two fuel tanks had gone dry and the engine had started to sputter, there were indications that Denver would have had trouble switching to the other tank.
The plans for his homemade Long E-Z say that the fuel selector handle _ which switches the fuel flow between the left and right tanks _ should be located between the pilot’s legs. But the plane’s builder, aircraft maker Adrian Davis Jr., said he put it behind the pilot’s left shoulder because he did not want fuel in the cockpit.
On the day of the crash, Denver and a maintenance technician talked about the inaccessibility of the handle. ``They tried a pair of Vice Grip pliers on the handle to extend the reach of the handle, but this did not work,″ the report said.
Under those circumstances, the pilot would have had to remove his shoulder harness, turn around and switch the handle.
``Two pilots shared experiences of having inadvertently run a fuel tank dry with near catastrophic consequences because of the selector and (fuel) gauge locations,″ the report said.
According to the report, Denver’s plane had another modification besides the fuel selector location: a 150-horsepower engine. That was bigger than the design specifications of a 110- to 115-horsepower engine and consumed more gas than the standard engine.
The plane’s designer said he had heard of some builders installing up to 200-horsepower engines with no problems.
The report also said there was no evidence of a bird strike, as some had speculated.
The safety board will use the report in determining the probable cause of the crash.