Mooney pilot’s VFR flight into IMC proves fatal

The instrument-rated private pilot and owner of the Mooney M20J regularly used the airplane to commute for work between his home airport and an airport located about 80 miles to the south.

On the day of the accident, he departed his home airport and, about five minutes after takeoff, established the airplane on a direct course towards an aeronautical navigation beacon that was located on a mountain peak about 28 nautical miles south of the airport, at an elevation of 5,793′ mean sea level (msl).

After takeoff, the airplane initially climbed to about 7,300′ msl, then descended to about 6,500′ msl, before ultimately descending to about 5,750′ msl, where it remained for the last several minutes of the flight.

The pilot was not in radio communication with any air traffic control (ATC) facility during the flight, and had not filed a flight plan, but the airplane had been tracked by ground-based ATC radar. The ATC radar track data ended near the accident site near Lake Hughes, California. The pilot died in the crash.

Both radar and the data from the pilot’s onboard GPS device showed that the airplane remained in about straight and level flight for at least eight minutes before the impact.

The wreckage was about 70′ below the mountain peak. Ground scars and airplane damage indicated that the airplane was in level flight, with significant engine power, at the time of impact.

Meteorological conditions at an airport near the accident site suggested that an overcast ceiling of about 4,750′ msl was present near the accident site. That ceiling would have obscured the peak, and would have been about 1,000′ lower than the impact point elevation.

It is likely that the pilot flew into instrument meteorological conditions (IMC), which obscured the peak from his view as he attempted to cross the mountain range.

The investigation was unable to determine whether the pilot entered IMC intentionally or unintentionally, or how long the airplane was operating in IMC before impact.

The investigation also was unable to determine why the pilot was operating on a track at an altitude that did not provide terrain clearance, even if he did intentionally enter IMC without operating under instrument flight rules.

Because the ATC radar and GPS altitudes for the flight were congruent, altimetry malfunctions and errors can be eliminated as causal factors.

The pilot’s GPS unit was capable of providing both visual and aural terrain/obstacle alerts, but the terrain and alert configuration settings of the GPS were not able to be determined.

It is possible that the pilot either ignored or deactivated those features, depriving himself of those protection capabilities. Such a deactivation could have been the result of his comfort level with flying in that region, or it could have been inadvertent.

Although the investigation could not determine what assumptions, tools, or methods the pilot used to ensure adequate terrain clearance for the accident flight, he had sufficient and accurate information available, or potentially available, to enable him to avoid terrain.

All elements of this accident are consistent with a controlled flight into terrain (CFIT) event. Although the specific underlying reasons for the CFIT event could not be determined, it is likely that the pilot’s comfort with the route, combined with his determination to complete the flight to reach work, caused him to enter IMC. That entry into IMC, coupled with an improper route and altitude combination, resulted in the collision with the peak.

Probable cause: The pilot’s controlled flight into mountainous terrain while attempting to operate under visual flight rules in instrument meteorological conditions (IMC).

NTSB Identification: WPR17FA055

This January 2017 accident report is provided by the National Transportation Safety Board. Published as an educational tool, it is intended to help pilots learn from the misfortunes of others.