OKLAHOMA CITY - The National Transportation Safety Board blames the pilot for a 2010 plane crash in which he died.

John Hugon was the only person on board the single-engine Beechcraft Bonanza A-36 when it crashed at about 9:30 on the night of November 17, 2010, near Lake Overholser.

The plane was flying from Lawton to Wiley Post Airport when it crashed.

According to the NTSB's final report on the crash, called the Probable Cause report, the board blames the crash on "the pilot's loss of control of the airplane during night instrument meteorological conditions, likely due to spatial disorientation."

That means Hugon literally could not tell which way was up.

The NTSB reports that Hugon told the air traffic controller he had problems with his landing gear indicator as he approached Wiley Post Airport.  Several witnesses reported seeing the airplane appear from the clouds and descend rapidly before impacting the ground.  Investigators found no evidence of any pre-impact mechanical problems.

The NTSB says toxicology testing found the presence of prescription medications for headaches, pain and depression, but investigators say they could not determine to what extent, if any, the pilot may have been impaired.

The NTSB noted that the weather, darkness and the pilot's diverted attention to the landing gear issue could have increased the risk of spatial disorientation.

Hugon, 55, was a prominent Fort Worth businessman.  He was president and director of Hugon Capital Management L.P. and was also a member of the board of directors of Oklahoma City-based BancFirst Corporation.

According to the NTSB, Hugon had 1,400 hours of flight time and was instrument-rated, meaning he was qualified to fly in conditions of low visibility.