Cessna 172S N21750 accident near Land O'Lakes, Florida

Probable cause

The pilot’s decision to continue the cross-country flight while fatigued, which resulted in him falling asleep during the initial descent for landing.

NTSB analysis

The pilot purchased the airplane and he was returning to his home base. The pilot checked in with an approach controller about 52 miles north-northwest of the destination airport; at the time, the airplane was flying under visual flight rules, and night visual meteorological conditions prevailed. The pilot initiated a gradual descent from 7,500 feet mean sea level and an air traffic controller radioed the pilot after he observed the airplane descending below 1,000 feet mean sea level. The pilot never responded to the controller’s radio calls, and the airplane impacted pastureland about 17 miles from the destination airport.

Examination of the wreckage revealed that the airplane collided with trees at a very shallow descent angle. No evidence of a pre-existing mechanical failure or anomaly was observed.

A review of the pilot’s actions during the 9 days prior to the accident revealed that he flew a 5-day international trip as a crewmember for the airline for which he flew as a captain, and then returned to Zurich 3 days before the accident. About 4 hours later, he began a trip as a passenger to Colorado.

On the day before the accident, the pilot began the first of three legs of a cross country flight, with the third leg being the accident flight. He was awake for about 18 hours at the time of the accident, with stops only being taken for food and airplane servicing.

Over the 9-day period before the accident, the pilot made three crossings of the Atlantic Ocean (each exceeding 6 time zones). These multiple and frequent time zone crossings would result in circadian disruption and would have diminished the pilot’s ability to obtain restorative sleep during this period, which, in combination with the pilot’s extended time awake on the day of the accident, would have caused the pilot to be in a fatigued state. The circumstances of the accident and his fatigue-inducing schedule in the preceding days indicate that the pilot most likely fell asleep during the initial descent for landing, and the airplane subsequently descended into the trees and terrain.

Text from the NTSB. Open the NTSB docket for ERA12FA572 for the full record.