CESSNA U206 near Maunaloa, HI — 2017-12-10

Probable cause

The pilot's decision to continue visual flight into an area of instrument meteorological conditions while conducting an instrument approach, which resulted in a loss of visual reference and subsequent controlled flight into terrain.

NTSB narrative

The instrument-rated private pilot was conducting a personal flight under visual flight rules (VFR) from one island to the airplane's home base on another island with one passenger onboard. The airport's automated weather observation system reported marginal VFR (MVFR) conditions throughout the morning of the accident, and an AIRMET Sierra was valid for the area of the accident site for mountain obscuration, widespread MVFR ceilings, and scattered rain showers. However, there was no evidence to suggest that the pilot had obtained a weather briefing from an official, access-controlled source before departing on the flight. While en route and receiving VFR flight following services from air traffic control, the pilot requested an instrument (VOR-A) approach to the destination airport. The pilot also reported having the most recent ATIS weather information Juliet, issued at 1055. The ATIS reported 4 miles of visibility with light rain and mist, along with a ceiling of 1,400 ft broken with a broken cloud layer at 3,300 ft. The controller provided the pilot with vectors to initiate the approach and advised him to maintain VFR, which the pilot acknowledged. Two minutes later, the controller issued a frequency change to the destination airport control tower. About 4 minutes after that, the tower controller advised the pilot that the airplane was south of the final approach course. The pilot indicated that he was correcting and was "right at the edge of VFR," but that he had "pretty good visibility." There were no further communications from the accident airplane and radar contact was lost shortly thereafter. The airplane impacted remote mountainous terrain about 1,285 ft msl and about 3.35 miles southwest of the runway threshold at the destination airport; the airplane was destroyed by a postimpact fire. Postaccident examination of the airframe and engine revealed no evidence of preimpact mechanical anomalies that would have precluded normal operation. A photo taken by first responders about 1.5 hours after the accident showed a low cloud layer at the accident site. Damage to 20-ft-tall trees indicated that the airplane impacted them and then struck a second set of trees that were about 15 ft tall. Multiple tree branches with propeller cut marks were found along the wreckage path. The wreckage was located on the western side of a ridge with dirt and low growth vegetation that crested about 100 ft above the surrounding area, with about a 50° incline. It is likely that, during the approach, the pilot continued visual fight into an area of instrument meteorological conditions consisting of clouds and showers, which resulted in a loss of visual reference and subsequent controlled flight into terrain. The pilot's logbook was not available for review, and neither his recency of experience nor instrument experience could be determined. The flight instructor who conducted his most recent flight review, about 8 months before the accident, did not endorse the pilot for instrument flight. Autopsy of the pilot identified severe heart disease, which placed the pilot at risk of sudden acute symptoms such as chest pain, palpitations, shortness of breath, or fainting. Flight track information and the pilot's communication with air traffic control indicate that he was actively maneuvering the airplane, likely to avoid clouds and attempt to remain in visual conditions, until it impacted terrain. Thus, it is unlikely that symptoms from the heart disease contributed to the accident.

Analysis

Primary failure mode

Controlled flight into terrain

First missed decision gate

Pilot could have aborted the approach when advised of IFR conditions.

NTSB coding

• Controlled flight into terr/obj (CFIT) · Approach-circling (IFR)
• Decision Making / Judgment

Evidence available

• ATC audio
• ADS-B / radar
• Photos
• 16 docket documents

Docket documents16

• Additional FAA ATC Transcriptatc
• FAA ATC Packageatc
• Molokai Airport (MKK) Informationform
• Statement of Party Representatives to NTSB Investigationinterview
• FAA Aviation Safety Inspector - Record of Conversationother
• Maui County Police Department Detective - Record of Conversationother
• N3187U Cessna 182 Pilot - Record of Conversationother
• NTSB Safety Recommendations A-13-25 to A-13-27other
• NTSB Weather Studyother
• Smithsonian Institution’s Feather Identification Laboratory Resultsother
• ATC Flight Track Imagesphotos
• Accident Photographsphotos
• Google Earth Radar Dataradar
• Radar Dataradar
• NTSB Medical Factual Reportreport
• Toxicological Reportreport

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