Air Safety Institute Safety Spotlight
I think I can
Combine high density altitude with a heavily loaded airplane and you have a recipe for disaster. A private pilot flying a Piper Cherokee learned this after taking off from Eagle, Colorado, on the morning of August 1, 2002. The pilot and one passenger were seriously injured, and two other passengers were killed.
Eagle Regional Airport is 6,535 feet above mean sea level. The density altitude on this day was calculated to be 7,885 feet msl. According to the pilot, the airplane weighed 2,270 pounds at takeoff, 130 pounds below the maximum allowable gross weight.
After an estimated 5,000-foot ground roll, the Cherokee departed Eagle and turned right toward rising terrain. After climbing for more than 10 minutes, the pilot noticed that his climb rate was only 100 to 200 feet per minute. When the right-seat passenger mentioned the slow climb rate, the pilot responded, "It would not be a problem because they would just continue toward the higher terrain and find some updrafts."
The Cherokee struck terrain at an elevation of 10,050 feet. Density altitude at the accident site was calculated to be 12,226 feet. The climb performance charts from the Piper Cherokee pilot's operating handbook indicate that the maximum climb rate at gross weight would be between 210 and 250 fpm at 12,000 feet density altitude.
According to FAA records, the pilot had accumulated 260 hours of total time, 50 of which were in the accident make and model. The pilot's mountain flying experience was not available.
The NTSB determined that the pilot failed to perform remedial action and maintain clearance from the rising terrain. Contributing factors were the pilot's poor planning/decision making, the rising terrain, and the high density altitude.
This accident illustrates how a chain of events can lead to a grave outcome. Clearly, taking off fully loaded while at a high density altitude will result in poor climb performance. Opportunities existed for this pilot to change course, return to the airport, or not depart at all -- any of which may have prevented this accident.
Flying in areas of rising terrain and high density altitude can prove challenging, and it requires additional training for all pilots unfamiliar with the mountain flying environment. For more information, see these resources:
- The Terrain Avoidance Plan shows how to use published altitudes on both IFR and VFR aeronautical charts to establish an individual minimum safe altitude for VFR flight in such conditions. It's available at the AOPA Online Safety Center.
- AOPA's A Pilot's Guide to Mountain Flying.
Kristen Hummel manages the GA accident database for the AOPA Air Safety Foundation. She holds a commercial pilot certificate with multiengine and instrument ratings.
By Kristen Hummel