CEN14FA414

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.

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.

Electronic Devices Onboard The following electronic devices were found in the wreckage and sent to the NTSB Recorders Laboratory, Washington, DC for examination and download. A Garmin GNS 530, s/n: 78412859, which sustained major impact damage. External power was applied and the device did not respond. No data was recovered from the device. An Apple iPad Mini (1), s/n: DLXLV31PFLMP, which sustained major impact damage. The internal circuit board was removed and cleaned. The circuit board was placed in a surrogate iPad mini. Several attempts to power the surrogate unit with the accident circuit board were unsuccessful. No data was recovered from the device. An Apple iPad Mini (2), s/n: F4KLV34SFLMN, which sustained major impact damage with noticeable bending throughout the device. An interior examination revealed the circuit board containing the device's memory had sustained deformation from flexure damage. Due to the impact damage, no recovery could be attempted and no data was recovered from the device. A Go Pro Hero 3, s/n: unknown, which received minimal impact damage. The internal micro SD card containing the device's image data was located and removed. Two picture files were located and dated after the accident date and time; the pictures were determined to be from responders to the accident scene. No data pertinent to the investigation was found. Density Altitude According to an FAA safety document, FAA-P-8740-2 – AFS-8 (2008), density altitude is pressure altitude corrected for nonstandard temperature variations. A high density altitude means that air density is reduced, which has an adverse impact on aircraft performance. Altitude, temperature and humidity are factors that contribute to a high density altitude. An increase in density altitude can result in increased takeoff distance and a reduced rate of climb. Mountain Flying A Colorado Mountain Flying document was recovered from the wreckage and revealed the following information. The Do's of Mountain Flying: Consult POH for takeoff, climb and ceiling capabilities of the aircraft before flown. When calculated climb rates are less than 200 feet/NM, do not depart. A high density altitude may prevent you from reaching the altitude listed in the POH as the service ceiling. Enroute Plan to cross all passes and terrain with a minimum 1,000 foot clearance. Know these elevations and use the altimeter – DO NOT GUESS. Monitor the rate of climb when climbing across terrain; shuttle climb if necessary. Cross all passes at a 45 degree angle so a turn toward lower terrain can be accomplished with 90 to 120 degrees of turning (Escape Maneuver). Reach pass crossing altitude (1,000 feet above pass terrain) 3 miles before reaching the pass. Climb Performance According to the airplane's pilot operating handbook (POH), at a density altitude of 11,200 feet with the landing gear and flaps retracted, the pilot could have expected a climb rate of 175-200 feet per minute. Based on the mountain flying information above and the airplane groundspeed speed of 90 knots, the required rate of climb would have been 300 feet per minute. An autopsy was performed on the instructor pilot by the forensic pathology consultant of Routt County, Colorado, on August 10, 2014. The cause of death was blunt force injuries. The FAA Civil Aerospace Medical Institute completed a Final Forensic Toxicology Fatal Accident Report which revealed no significant findings. The instructor pilot sustained distinct injuries to both hands. An autopsy was performed on the pilot receiving instruction by the forensic pathology consultant of Routt County, Colorado, on August 10, 2014. The cause of death was multiple blunt force injuries and the manner of death was an accident. The FAA Civil Aerospace Medical Institute completed a Final Forensic Toxicology Fatal Accident Report which revealed no significant findings. The private pilot sustained distinct injuries to one hand. Examination of the accident site revealed that the airplane impacted trees and mountainous terrain about 12 miles southeast of SBS at an elevation of 9,100 feet above mean sea level (msl). The initial point of impact was identified by a pair of damaged tree tops on the edge of an open grassy field on the mountainside. A 120 yard path with several damaged trees was identified on a heading of 240 degrees. A large impact crater was noted 105 yards from the initial tree strike. The fuselage came to rest 15 yards southwest of the impact crater on its right side and was oriented on a heading of 350 degrees. The left and right wings separated from the fuselage and came to rest in the debris path. The outboard section of the left wing was separated near the initial tree strike. The leading edge contained two distinct leading edge circular impact impressions. The left aileron had separated near mid span. The inboard section of the left wing was found 75 yards through the debris path and exhibited signs of thermal damage; the respective landing gear remained attached to the wing and was fully extended. The outboard section of the right wing was also found near the initial tree strike and contained a large leading edge circular impact impression. The inboard section was found separated from the fuselage and near the initial tree impact area. The landing gear remained attached to the wing and was extended about 45 degrees. The top of the fuselage was fractured near the cockpit; the first responders further opened the top of the fuselage to allow access during rescue operations. The empennage remained partially attached to the rear fuselage. The stabilator was twisted and bent upward 90 degrees. The vertical stabilizer and rudder were deformed and fractured near the rear fuselage. The engine and propeller remained partially attached to and situated under the fuselage. The propeller nose cone was oriented on a heading of 180 degrees. A postaccident examination of the wreckage was completed by the NTSB investigator-in-charge and a representative from Lycoming Engines, at Beegles Aircraft Service, Greeley, Colorado on October 15, 2014. The examination revealed the following: The engine was separated from the firewall and hung from an engine hoist for the examination. The propeller was removed and the blades were labeled Blade A and Blade B for identification purposes only. Blade A was bent slightly aft with minor leading edge damage. Blade B was bent 90 degrees aft with leading edge damage, the blade tip was twisted and a portion was missing from the trailing edge. The fuel pump, vacuum pump, magnetos, valve covers and top spark plugs were removed. The spark plugs appeared normal as compared to the Champion Aviation Check-a-Plug Chart AV-27. The crankshaft was rotated by hand and suction and compression was established on all cylinders. Engine drive train continuity was established throughout. The cylinders were examined with a lighted borescope and no anomalies were noted. Engine control continuity was confirmed throughout. The left magneto was rotated by hand and produced a spark at each lead. The right magneto was rotated by hand and no spark was observed from any lead. The magneto was disassembled and no visual damage was observed. The right magneto was sent to Continental Motors' analytical department for examination and a bench test. The magneto was reassembled and the contact points were cleaned. With a slave harness attached the magneto produced a spark at each lead. The magneto wobbled slightly during the test; the discrepancy was attributed to impact damage. The oil pick up screen was found free of contamination. The fuel servo exhibited no signs of visual damage. The fuel servo brass plug was found tight and secured. The fuel inlet screen was found clear of contaminants. The fuel flow divider was found clear of contaminants and the diaphragm was intact and in good condition. The fuel injectors were found clear unobstr