The airline transport pilot was conducting a cross-country personal flight. Radar data indicated that the Cirrus SR22 took off from the departure airport and then climbed to an altitude of 21,000 feet mean sea level before leveling off and maintaining that altitude for about an hour.
The pilot then contacted an air route traffic control center and requested and received several descent clearances over the course of about 45 minutes.
The pilot’s communications over the next 10 minutes were consistent with impairment. During this time, he reported that he was having some difficulties but did not state the nature of the problem.
Near the end of the communications, the air traffic controller advised the pilot to descend, and the pilot replied, “hang on a second.” This was the last communication received from him.
The airplane subsequently traveled into restricted airspace near Washington, D.C., and was intercepted by two military aircraft. The intercept pilots confirmed that the Cirrus pilot was unconscious, and attempts to contact him were unsuccessful.
The airplane continued on its course off the coast of Virginia and then descended into the ocean. After impact, the airplane sank, and it was not recovered. The pilot’s body was also not recovered, so an autopsy and toxicology testing were not conducted.
A review of the pilot’s medical history revealed no evidence that he had any medical conditions or used any medications that would have impaired his ability to control the airplane. However, it is possible that he suffered impairment, as evidenced by his communications with air traffic controllers, and subsequent incapacitation from a stroke, cardiovascular event, hypoxic event, carbon monoxide exposure, or neurologic decompression sickness.
The NTSB determined the probable cause as the pilot’s impairment and subsequent incapacitation for reasons that could not be determined because the pilot and airplane were not recovered.
NTSB Identification: ERA14LA415
This August 2014 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.