Pilot Debrief

PIPER PA32R - 301 near Townsend, MT — 2015-03-26

Final reportWPR15FA135
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Date
2015-03-26
Location
Townsend, MT, USA
Aircraft
PIPER PA32R - 301
Registration
C-GAUS
Category
Airplane
Highest injury
Fatal
Fatalities
1
Phase of flight
Descent

Probable cause

The pilot's decision to depart on and to continue a visual flight rules flight over mountainous terrain into instrument meteorological conditions, which resulted in controlled flight into terrain. Contributing to the accident was the pilot's lack of recent instrument flight experience, which exacerbated his difficulty in maintaining control of the airplane while encountering downdrafts and mountain obscuration conditions.

Contributing factors

Contributing to the accident was the pilot's lack of recent instrument flight experience, which exacerbated his difficulty in maintaining control of the airplane while encountering downdrafts and mountain obscuration conditions.

NTSB narrative

The instrument-rated private pilot received an official weather briefing before beginning the visual flight rules (VFR) cross-county flight over mountainous terrain. The briefing included information about turbulence, icing, and mountain obscuration along the proposed route of flight, and the briefer stated that VFR flight was not recommended in areas of higher terrain with mountain obscuration. However, the pilot elected to depart on the flight. The passenger reported that during the flight, the weather started closing in, and they were soon in the clouds. The pilot was receiving VFR flight following service, and reported to the controller that he was turning around; soon after communication was lost. Review of radar data revealed that, over the last 4 minutes of the flight, the airplane made multiple turns while ascending to 10,125 ft msl over mountainous terrain with peaks reaching 9,400 ft in height; it then headed southbound and descended to an altitude of 9,300 ft msl before dropping off radar. The accident site was located in heavily wooded and snow-covered terrain at an elevation of 8,350 ft. Damage to the airplane and to the trees at the accident site was consistent with controlled flight into terrain with the engine operating at a high power setting. Examination of the pilot's logbook indicated that an instrument check ride was accomplished in December 2008, about 6 years 3 months before the accident and that the pilot had not logged any flight experience between December 2008 and October 2014, about 6 months before the accident. According to the logbook, the pilot was not current to act as pilot-in-command under instrument flight rules and likely was not proficient in instrument flight. A weather model simulation revealed that the airplane likely encountered rapid horizontal wind speed changes along with downdrafts during the last 4 minutes of the flight. These downdrafts, which were likely encountered while the airplane was in clouds, would have increased the pilot's difficulty of maintaining level flight. If the pilot had been instrument current, he would likely have been better prepared to cope with the weather conditions encountered, including the mountain obscuration and the downdrafts.

Analysis

Primary failure mode
Controlled flight into terrain
First missed decision gate
Pilot could have chosen to avoid flying into clouds and mountainous terrain.

NTSB coding

Evidence available

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

Docket documents16