Hanksville, UT, USA
N28WF
CESSNA 177A
The pilot reported that about 1 hour into a local flight, he made a low fly-by over a remote airstrip. When he applied power to climb, the engine responded normally. However, about 15 seconds later, after he raised the flaps, the airplane’s airspeed slowed, and the airplane stopped climbing. The pilot stated that he was in a mountainous canyon and, believing that the airplane would not climb satisfactorily, he performed a forced landing in the canyon. During the forced landing, the airplane’s nosewheel dug into the soft, sandy terrain, the nose landing gear separated, and the main landing gear collapsed. The pilot reported having taken off with full tanks and stated that he should have had about 40 gallons of fuel remaining after the 1-hour flight. When the airplane was recovered, no fuel was found in the left tank and only 1/3 gallon of fuel was found in the right tank. However, the fuel system lines around the fuel selector and the fuel shut-off valve were compromised, and it is likely that any remaining fuel leaked out of the tanks during the several days that passed between the accident and recovery of the wreckage. Examination of the airplane and its engine found no evidence of any preimpact mechanical malfunctions or failures that would have prevented normal operation. At the calculated density altitude of 6,000 feet, the normally aspirated engine’s maximum output of 150 horsepower (hp) would be reduced to 120 hp. Aircraft performance can become marginal in high density altitude conditions, and both maneuvering at low altitude and operating at high density altitude require pilot vigilance to maintain adequate airspeed during climb.
On May 8, 2012, about 1045 mountain daylight time, a Cessna 177A, N28WF, was substantially damaged when it impacted terrain while maneuvering at low altitude near Hidden Splendor Airfield (U660; elevation 4,821 feet), Hanksville, Utah. The commercial pilot and his passenger received minor injuries. The airplane was being operated by AME High LLC under the provisions of 14 Code of Federal Regulations Part 91. No flight plan had been filed for the local flight, which had originated from Spanish Fork, Utah, about 1 hour before the accident. Visual meteorological conditions prevailed. About 1 hour into the flight, the pilot made a low pass over a remote airstrip descending to an altitude of about 25 feet above ground level and then applying power to climb back to cruise altitude. He said that the engine responded normally. However, approximately 15 seconds later, as the pilot raised the flaps, the airplane’s airspeed began to slow down, and the airplane stopped climbing. The pilot said he pushed the yoke in to lower the nose, but the airspeed did not increase. With the throttle all the way in and the mixture slightly leaned, the airplane began to descend. At that point the pilot found himself in a canyon and believing that the airplane would not climb, he selected an open sandy area and performed a forced landing. The nose wheel dug into the soft terrain, the nose landing gear separated, and the main landing gear collapsed. The airplane’s fuselage was bent and wrinkled, and the bottom of the forward section of the fuselage was crushed and buckled. The fuel lines around the fuel selector and the fuel shut off valve were compromised. When the pilot contacted the aircraft salvage team for recovery, he stated that one wing fuel tank was empty and the other had 12 gallons in it. After the pilot left the scene, some hikers reported placing vice grips on one of the fuel lines to stop an observed fuel leak. When the salvage team arrived at the accident site several days later, they reported finding no fuel in the left tank and 1/3 gallon in the right tank. The fuel selector was found on the right tank, but the fuel shut off valve was closed. They reported that both wings were undamaged, and the wing flaps were in the up position. They reported separating the engine from the airframe to facilitate its recovery from the bottom of the canyon. On May 23, 2012, two Federal Aviation Administration inspectors examined the recovered wreckage. Their examination of the engine revealed no evidence of any preimpact mechanical malfunctions or failures that would have prevented its normal operation. When they examined and disassembled the carburetor, no fuel was found. During disassembly of the engine driven fuel pump, evidence of fuel was observed on the diaphragms and check valves. Using a temperature of 60 degrees Fahrenheit, the density altitude at the accident site was calculated to be 6,000 feet, and at this density altitude, the normally aspirated 150-horsepower engine would have been capable of producing 120 horsepower. The pilot reported that on his departure from Spanish Fork, the airplane had full fuel tanks or 48 gallons of useable fuel on board. The manufacturer’s “Owner’s Manual” for the 1968 model airplane indicates a fuel burn rate in cruise flight of between 8 and 9 gallons per hour.
The pilot’s failure to maintain adequate airspeed while maneuvering at a low altitude in high density altitude conditions, which resulted in the airplane’s inability to climb or maintain clearance from terrain.
Source: NTSB Aviation Accident Database
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