Cessna 172 N8063B accident near Limington, Maine

Probable cause

An impairing medical event of undetermined origin that led to a loss of control during takeoff.

NTSB analysis

The 58-year-old student pilot attempted a takeoff in light wind, but about 2,000 feet down the runway, he lost control of the airplane. Only one witness saw the airplane after liftoff, and noted that it was "swerving all over the place before it crashed." While airborne, the airplane veered off the left side of the runway, then impacted the ground with the right wing tip, nosed down, bounced, and came to rest upright, facing opposite the direction of takeoff. All witnesses heard the engine operating throughout the event, with one stating that it "was running smooth, normal sounding." Subsequent examination of the airplane revealed no preexisting mechanical anomalies that would have precluded normal operation.

The pilot was obese, with a history of Type 2 diabetes and high cholesterol. Although he reported some medications on his Federal Aviation Administration (FAA) medical certificate applications, he routinely failed to report others. Documentation from his most recent FAA medical examination included the use of two medications not recommended to be used together because of the risk of hypoglycemia. Postmortem toxicology testing identified only salicylate, but would have been unable to identify many of the pilot's other medications.

According to the medical examiner, the cause of death was multiple blunt impact trauma to the head and chest, indicating that the pilot was still alive when he lost control of the airplane. Diabetics who become symptomatic from hypoglycemia may not notice warning signs until their psychomotor functioning is very impaired. It is unknown what precautions the pilot may have taken that day to prevent hypoglycemia or what the pilot's eating schedule was. In addition, because postmortem glucose levels are low and do not correlate with premortem levels, even if the pilot was severely hypoglycemic at the time of the accident, there would be no specific evidence to identify it.

The pilot also had severe coronary artery disease, with 85-95% occlusion of the left anterior descending artery, that put him at increased risk of a sudden, impairing cardiac event that would have left no observable evidence at autopsy.

There were no operational or mechanical factors to explain the student pilot's loss of control at takeoff, but he did have multiple medical conditions that could have resulted in acute impairment without leaving evidence. Although the exact mechanism could not be determined, it is likely that the impairment resulted from one or more of the student pilot's medical conditions, which then caused him to lose control of the airplane.

Text from the NTSB. Open the NTSB docket for ERA13FA388 for the full record.