Piper PA 28R-201 N3509M accident near Steamboat Springs, Colorado

Probable cause

The pilot’s inability to maintain a climb while attempting to cross over a mountain pass in high-density altitude conditions that degraded the airplane’s climb performance. Contributing to the accident was the pilot’s decision to attempt the flight in mountainous terrain and to enter the pass in such a way that an escape maneuver was not possible.

NTSB analysis

The flight instructor and private pilot-rated student were flying a five-leg, cross-country flight to conclude a mountain flying training course. The final leg of the flight was intended to cross over the mountains near a popular mountain pass, which was frequented by local pilots because of the landmarks and highway below. When the flight was overdue, a search was conducted. The wreckage was located in a mountain pass about 2 miles south of the mountain pass that the pilots had intended to cross during the final leg. A postaccident examination of the airframe and engine revealed no evidence of mechanical malfunctions or failures that would have precluded normal operation.

The density altitude around the time of the accident was calculated to be about 11,200 ft, which would have degraded the airplane's performance. According to the Pilot's Operating Handbook, at a density altitude of 11,200 ft with the landing gear and flaps retracted, the airplane would have had an expected climb rate of between 175 and 200 ft per minute (fpm). Documents about mountain flying found onboard the airplane stated that flight in mountains should not be attempted unless a climb rate of at least 200 ft per nautical mile (300 fpm) is available. Therefore, it is likely that the airplane could not attain a sufficient climb rate to clear mountainous terrain and that the pilot did not enter the pass at an appropriate entrance angle, which reduced the possibility of a successful escape maneuver.

Text from the NTSB. Open the NTSB docket for CEN14FA414 for the full record.