Pilot Debrief

CESSNA 172M near Ogden, UT — 2017-12-29

Final reportWPR18FA063
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Date
2017-12-29
Location
Ogden, UT, USA
Aircraft
CESSNA 172M
Registration
N4395R
Category
Airplane
Highest injury
Fatal
Fatalities
2
Phase of flight
Initial climb

Probable cause

The pilot's failure to maintain clearance from the water while flying over a lake with glassy surface conditions. Contributing to the accident was the pilot's use of three impairing medications.

Contributing factors

Contributing to the accident was the pilot's use of three impairing medications.

NTSB narrative

The commercial pilot and private pilot-rated passenger departed on a local flight in day visual meteorological conditions and climbed to a peak altitude about 2,370 ft above ground level. The airplane then entered a gradual, wings-level descent during which it began to fly over a large lake. The airplane impacted the water and subsequently sank. The airplane was mostly intact and exhibited no evidence of mechanical failures or anomalies that would have precluded normal operation. Given the condition of the airplane, flight track, altitude data, and the proximity to land, it is likely that the pilot intentionally descended the airplane to low altitude over the lake. It is also likely that the lake exhibited a glassy surface due to low wind conditions about the time of the accident, which would have reduced depth perception and made it difficult for the pilot to judge the airplane's height above the water. Additionally, toxicology of the pilot revealed the presence of three different impairing medications. It is likely that he was experiencing combined adverse effects of these three central nervous system depressants, which contributed to his failure to maintain clearance from the water while performing low-altitude flight.

Analysis

Primary failure mode
Human factors
First missed decision gate
Pilot could have chosen to avoid flying over the lake in glassy water conditions.

NTSB coding

Evidence available

  • ADS-B / radar
  • 15 docket documents
View NTSB final reportView NTSB docket

Docket documents15

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