Amateur-built PULSAR N91BV accident near West Jordan, Utah

Probable cause

The pilot’s failure to maintain sufficient airspeed and airplane control while initiating a turn during the initial climb after takeoff in a high density altitude environment, above the airplane’s maximum allowable gross weight, and with an overly rich fuel-air mixture due to improper carburetor maintenance.

NTSB analysis

On the morning of the accident, the pilot and the new owner arrived at the airport to pick up the airplane. The previous owner saw that their total weight was greater than he had been told during an earlier inquiry and advised the flight instructor and the new owner that their total weight might put the airplane near its maximum allowable gross weight. He also advised them not to add any more fuel than was already onboard, and then handed them the weight and balance sheet for the airplane. Subsequently, witnesses saw the airplane take off and ascend at an extremely low rate of climb. When another pilot waiting to take off asked whether they were having any technical difficulties, the accident pilot responded that there was nothing wrong but that it was just a “weak airplane.” About 1/2 mile after passing the departure end of the runway, the pilot initiated a right turn but failed to maintain sufficient airspeed, resulting in the airplane stalling and descending into the terrain. The postaccident investigation determined that the airplane was being operated above its maximum allowable gross weight and that it was being operated in a density altitude that was 2,120 feet higher than the field elevation. An engine teardown examination determined that both of its carburetors had jet needles installed that produced a richer-than-normal fuel-air mixture. This was due to an incorrect reassembly after an overhaul of the carburetors. The weight of the airplane, the high density altitude, and the overly rich fuel-air mixture most likely combined to significantly reduce the performance of the airplane.

Text from the NTSB. Open the NTSB docket for WPR12FA001 for the full record.