History of Flight
On April 15, 2018, about 2100 central daylight time, an experimental, amateur-built David Bordiuk Challenger II Special airplane, registration N635DT, was substantially damaged after colliding with terrain near Friona, Texas. The flight instructor and student pilot, who was also the airplane's owner, were fatally injured. The flight was conducted under Title 14 Code of Federal Regulations Part 91 as an instructional flight. Night visual meteorological conditions prevailed, and no flight plan was filed. The local flight departed from Hefner Farms Airport (7TS9) in Bovina, Texas, about 2020.
According to the flight instructor's wife, the departure occurred "right at sunset" from an airstrip north of their home. About 2045, the flight instructor's sister observed the airplane flying low over her location, about 3 miles north of the airstrip, and noted that both pilots waved. When the pilots did not return, the instructor's wife attempted to contact them by cellphone and searched the airstrip and hangar area. She then notified local authorities. The airplane was found about 0100 the following morning. No witnesses to the impact were identified.
Personnel Information
The flight instructor's most recent logbook entry was dated March 31, 2018. His logbook contained no entries for the Challenger model but included 11.1 hours in a Kolb Twinstar Mark III. An April 10, 2016 entry noted a flight with the student pilot to acquire the Challenger.
Federal Aviation Administration (FAA) records indicated that the student pilot held a third-class medical certificate issued in February 2012, with restrictions for night flying and color signal control. The certificate expired on February 28, 2017. At the time of the medical application, the student reported no prior civil flight experience.
Aircraft Information
The airplane received an FAA experimental, amateur-built special airworthiness certificate in August 1996. FAA records show that its registration was cancelled in August 2012 due to a reported sale, but the necessary documentation to complete the transfer was never submitted. As a result, the airplane was unregistered at the time of the accident.
A previous owner held the airplane from 2006 until early 2016. He flew it once in spring 2007, encountering turbulent wind, and did not fly it again. Friends occasionally flew it with no reported issues. He sold the airplane to the flight instructor in early 2016 without filing any FAA paperwork.
The flight instructor's wife stated that the student pilot purchased the airplane in early 2016. The instructor performed electrical system rewiring and brake system maintenance. The first flight under the student's ownership occurred on April 5, 2017, about one year after purchase. The accident flight was the second flight since that purchase.
Available maintenance records showed the most recent logbook entries dated December 2004. A bill of sale from December 2006 was included with the records.
Meteorological Information
The flight instructor's sister described the weather as "very nice," clear, and "not windy." Sunset occurred at 2024, with civil twilight ending at 2050. The moon set at 2011 and was in a new moon phase.
Wreckage and Impact Information
The accident site was in a harvested corn field about 0.4 mile northwest of the departure airstrip. The airplane came to rest upright, facing south. An irrigation boom was located about 400 feet north-northwest of the wreckage, but no evidence of impact with the boom was found.
Postaccident examinations of the airframe and engine, conducted by the National Transportation Safety Board (NTSB) with assistance from the engine manufacturer, revealed no anomalies consistent with a preimpact failure or malfunction.
Medical and Pathological Information
Autopsies performed by South Plains Forensic Pathology in Lubbock, Texas, attributed the deaths of both pilots to blunt force injuries sustained in the accident. FAA toxicology testing of the flight instructor was negative for all tested substances. Testing of the student pilot detected dextrorphan (a metabolite of the cough suppressant dextromethorphan) and doxylamine (an over-the-counter antihistamine) in liver tissue, but not in cavity blood.