The National Transportation Safety Board’s preliminary report on the November 10 crash of a Mitsubishi MU-2B on approach to Runway 18L at Tulsa, Okla., quotes a witness as saying that the turboprop’s left propeller did not appear to be turning moments before the crash. The accident killed Perry Inhofe, the only person aboard the aircraft.

The MU-2 was cleared to land just after passing the outer marker inbound–5.6 miles from the end of the runway–when a Tulsa tower controller noticed the aircraft beginning a left turn. The controller queried the pilot, who told ATC the left engine was shut down.

ATC declared an emergency, but no further communication from the aircraft was received.

After several more turns, the MU-2 crashed in wooded terrain five miles north of the airport. The aircraft’s left propeller was found in the feathered condition, indicating Inhofe had time to pull the aircraft’s condition lever to cutoff, feathering the prop and shutting off the fuel to the engine.

Reported weather at the time of the accident was scattered mid-range clouds, good visibility and light wind.

Perry Inhofe is the son of U.S. Senator James Inhofe (R-Okla.), who is also a pilot and aviation advocate.

The accident is the first for an MU-2 since the crash of an MU-2B in Elyria, Ohio in January 2010.

The FAA published a Special FAR (SFAR) on the MU-2 in 2008 after numerous accident investigations pointed to inadequate pilot training. Inhofe, an orthopedic surgeon, had completed the SFAR’s required pilot training before the accident.