NTSB determines engine stall cause of 2016 plane crash

WORLAND – The National Transportation Safety Board has issued a final accident report for a December 2016 airplane crash that killed a Thermopolis man and injured his passenger, both employees with the United States Department of Agriculture.

The USDA issued a statement following the crash, identifying the pilot as Grant Ewing Belden, 34, of Thermopolis, an APHIS (Animal and Plant Health Inspection Service) wildlife specialist with the agency since 2007.

Belden, a graduate from Hot Springs County High School and the University of Wyoming with a degree in rangeland management and watershed ecology, had been a pilot since the age of 16.

Belden’s passenger was identified by the Big Horn County Sheriff’s office as Miles Hausner, 56, of Worland, also a biological science technician with the USDA APHIS, and 33-year veteran of wildlife services.

After losing contact with ground crews, the aircraft went down in a desolate and hard-to-reach area in Big Horn County. Both men were retrieved, and Hausner was flown to Billings, Mont., for medical attention, while Belden was pronounced dead at the scene of the crash.

According to the NTSB, the probable cause of the crash is listed as “pilot exceeded the airplane’s critical angle of attack while maneuvering at low altitude, which resulted in an

inadvertent aerodynamic stall and subsequent impact on terrain.”

The NTSB reports that Belden was based out of Worland, and started working for the USDA as a flight crew member (gunner) in 2007. In March 2016, he started flying for program as a pilot. He completed his initial training at the USDA flight center training center in May of 2016.

The NTSB further reports that on Dec. 7, 2016, at approximately 10:15 a.m., ground crews attempted to contact Belden and Hausner, who were on a routine animal damage management patrol. Receiving no response, the ground crew activated the agency search and rescue plan at 11 a.m. and the aircraft was located at 1:30 p.m. by aerial search and rescue teams.

A review of Federal Aviation Administration air traffic did not reveal any other traffic on radar, and although a hand-held global positioning system was reportedly on board, none was found at the crash site.

The NTSB noted that even months after the accident, Hausner could not recall the specific events leading up to the accident or the flight.

According to the USDA, the standard animal damage management flight has three phases: en route to location, surveillance and the predator mitigation pass (when the flight crew gunner fires on the animal). The surveillance aspect is usually performed at 75 to 100 feet off the ground, while the mitigation portion could anywhere from 20 to 40 feet, at an airspeed of 60 to 70 miles per hour.

As a result of the accident, the USDA grounded the flight program while under investigation, as with a similar crash in New Mexico in 2015.

As a result of a board review, the USDA implemented a full-time analyst to monitor all flights, flight data monitoring on all flights, flight reviews every six months, standardized GPS reporting, mandatory flight plans and mission profiles and the establishment of minimum observation heights and speeds.

After an inspection of the aircraft, it was determined to be in good working order with no major mechanical problems.

Toxicology results for the pilot came back negative for all tests. The cause of death was ruled as “multiple and acute blunt traumatic injuries.”