Deming, NM, USA
N21767
CESSNA 172S
The pilots were departing on a cross-country flight. A witness who saw the airplane shortly after takeoff observed the airplane turn back toward the airport, enter a steep right bank, and descend toward the ground. The airplane impacted terrain in a nose-down, right-wing-low attitude. Witnesses on a golf course next to the airport reported that airplane's engine was running at the time of impact. Neither pilot has any memory of the takeoff or the crash. Postaccident examination of the airplane revealed no evidence of a preimpact mechanical malfunction or failure of the flight control system or the engine that would have precluded normal operation. The propeller exhibited damage that was consistent with the engine producing power at impact. Calculations indicate that the airplane was at least 131 lbs over the maximum takeoff weight before the flight. The required takeoff distance and climb performance could not be determined because the airplane's weight exceeded the pilot operating handbook's performance chart parameters. However, overall airplane flight performance is reduced as the airplane's weight increases, resulting in a higher takeoff speed, longer takeoff run, reduced rate and angle of climb, and higher aerodynamic stalling speed. Additionally, the density altitude was about 7,736 ft at the time of the accident, which likely further increased the takeoff distance required for liftoff and adversely affected the engine power available and the climb rate. Given the available information, the pilots did not maintain adequate control of the airplane during the initial climb after takeoff, which resulted in the airplane exceeding its critical angle of attack and an aerodynamic stall at a low altitude.
On June 10, 2016, about 1520 mountain daylight time, a Cessna 172S airplane, N21767, was substantially damaged when it collided with terrain shortly after takeoff from Deming Municipal Airport (DMN), in Deming, New Mexico. The two pilots sustained serious injuries. The airplane was operated as a Title 14 Code of Federal Regulations Part 91 business flight. One of the pilots stated that the airplane operator had asked him to reposition the airplane from Washington to Florida. He reported that while on a previous flight leg the airplane had an electrical system failure that required an unscheduled stop at Blythe Airport (BLH), Blythe, California, to troubleshoot the issue. After landing safely at BLH, the pilot sustained a hairline fracture when he rolled his ankle on a stone as he ran toward the fixed base operator (FBO) building at the airport. The pilot sought medical attention for his fractured ankle, which required an aircast/walking boot and crutches. The pilot and the FBO owner later determined that the alternator was operating properly, and that the battery held a charge. The pilot, despite his ankle injury, then flew the airplane to Lake Havasu City Airport (HII), Lake Havasu City, Arizona, where a maintenance shop could further investigate the electrical system. The pilot reported that there were no issues with the airplane during the flight from BLH to HII. The maintenance facility at HII could not identify any issues with the airplane's electrical system and returned the airplane to service. The airplane operator decided to send a replacement pilot to complete the remaining flight legs to Florida because the initial pilot had a cast on his right leg. The two pilots reportedly agreed that the replacement pilot would complete all takeoff and landings. The replacement pilot flew the next flight leg from HII to DMN. After refueling at DMN and having lunch, the next flight leg was scheduled from DMN to Fort Stockton-Pecos County Airport (FST), Fort Stockton, Texas. The pilot with the fractured ankle was seated in the left pilot seat because he intended to fly the airplane during the cruise portion of the flight. The takeoff and landing were reportedly to be flown by the replacement pilot seated in the right pilot seat. The airport manager at DMN reported that the airplane was topped-off with 100 low-lead aviation fuel before the flight. The winds were reported to be light-and-variable when the airplane departed DMN. The assistant airport manager saw the airplane taxi and takeoff on runway 26. He did not observe anything unusual during the takeoff. A law enforcement officer, who was driving in his squad car, reported seeing the airplane heading west shortly after takeoff from the airport. He stated that the airplane was about 200 ft above the ground when it entered a steep turn to an east heading back toward the airport. The airplane subsequently entered a steep right bank and descended toward the ground. According to a Federal Aviation Administration (FAA) inspector, neither pilot has any memory of the takeoff or the crash. The FAA inspector stated that there were two witnesses on a golf course next to the airport who stated that the engine was running when the airplane descended into terrain. A lawyer representing the pilot seated in the left seat sent the National Transportation Safety Board investigator an email stating that his client remembers that the engine "stumbled and quit" as he checked the magnetos during the before takeoff engine runup; however, the engine and magnetos operated normally during a second engine runup with the fuel mixture leaned. Additionally, the pilot seated in the left seat reportedly told his mother that the "engine quit" while he was being treated at the hospital after the accident. However, the pilot's lawyer stipulated that his client does not recall telling his mother that the airplane had a loss of engine power, nor does he remember a loss of engine power during the flight. A postaccident examination was conducted by a FAA airworthiness inspector and investigators from the airframe and engine manufacturers. The initial point-of-impact was on taxiway C adjacent to runway 4. The airplane impacted the ground in a nose-low and right-wing-low attitude. There was a propeller slash mark observed in the asphalt taxiway. The wreckage debris path was oriented on east heading. The nose landing gear strut and wheel had separated from the airplane. The forward fuselage exhibited compression damage that was consistent with a nose-down impact. The right main landing gear strut was bent upward and aft, and the right wheel and tire had separated from the axle. The left wing remained attached to the airplane and appeared undamaged. The right wing was bent down at the wing root, and the right lift strut was fractured about midspan. The right aileron was in one piece and remained attached to the middle and inboard hinges. The tail was fractured at the forward edge of the vertical stabilizer. The elevator and rudder remained attached to their respective horizontal and vertical stabilizers. Flight control cable continuity was established from the ailerons and elevators to the control yokes. Partial control cable continuity was established from the rudder and elevator trim tab to the forward floor assembly under the pedestal where impact-related damage had jammed the rudder pedals and the elevator trim control chain. The wing flaps were found fully retracted. The wing fuel tanks were not ruptured; however, the airplane had come to rest upright and the fuel had drained out of a fractured fuel supply line forward of the firewall. The fuel caps remained attached to both wing fuel tanks. The fuel selector was found in the BOTH position. The firewall fuel shutoff valve was found open. The fuel strainer assembly did not contain any debris. The ignition switch was found in the BOTH position. The master battery and alternator switches were found ON. The engine had separated from the firewall and was found inverted at the accident site. The engine was recovered to a hangar where it was stored upside down until the examination. Internal engine and valve train continuity were confirmed while the engine crankshaft was rotated through a rear accessory gear. Compression and suction were noted on all four cylinders in conjunction with crankshaft rotation. The spark plugs were found installed and secured at each cylinder position with their respective spark plug lead attached. The ignition harness was found attached to both magnetos and the individual spark plug leads. The ignition harness exhibited impact-related damage and was not tested. The spark plugs were removed and exhibited features consistent with normal engine operation. The upper spark plugs were covered in engine oil, consistent with the engine being upside down after the accident. The lower spark plugs were not covered in oil and their electrodes exhibited coloration consistent with normal operation. The left magneto was found securely clamped at the mounting pad. The left magneto impulse coupling was audible when the engine crankshaft was rotated, and the magneto-to-engine timing measured 25° before top dead center (BTDC) at the No. 1 cylinder. The left magneto was removed, and its drive was intact and properly secured. The left magneto produced a spark at all four plug leads when rotated by hand. The right magneto was found securely clamped at the mounting pad. The right magneto impulse coupling was audible when the engine crankshaft was rotated, and the magneto-to-engine timing measured 26° before top dead center (BTDC) at the No. 1 cylinder. The right magneto was removed, and its drive was intact and properly secured. The right magneto produced a spark at all four plug leads when rotated by hand. A lighted borescope inspection of each cylinder did not reveal any anomalies with the cylinders, pistons, valves, or valve seats. The engine compartment fuel lines were found intact and secured at their respective fittings. The fuel injection servo remained attached to the mounting pad of the plenum. The throttle and mixture controls were found attached to their respective control arm on the fuel servo. The fuel inlet screen was properly installed and free of contamination. There were no obstructions observed to the fuel servo and the associated induction system. Fuel was found in the fuel pump and manifold valve. The fuel pump was removed, and its drive mechanism was intact. The fuel injection nozzles were free of contamination or obstruction. The exhaust system gas path did not contain any oil residue, and the exhaust tubes exhibited significant ductile bending from impact-related damage. The postaccident engine examination did not reveal any anomalies that would have precluded normal operation during the flight. The two-blade fixed-pitch propeller remained attached to the crankshaft flange, and the spinner remained attached to the propeller. Both propeller blades exhibited leading edge gouges, torsional twisting, chordwise striations across the cambered surface, and trailing edge S-shape bends. One propeller blade was missing about 6 inches of blade tip and the fracture features were consistent with impact-related damage. The airplane was equipped with aerial photography equipment. The Pilot Operating Handbook (POH) found in the airplane contained a weight-and-balance data sheet dated May 3, 2010, clearly described that the aerial photography equipment had been removed. The weight-and-balance sheet found in the airplane's POH listed an airplane empty weight of 1,718.20 lbs and a useful load of 839.80 lbs. The FAA inspector asked the operator to provide the current weight-and-balance data sheet that reflected the actual configuration of the airplane with aerial photography equipment installed. The operator provided the FAA inspector with a weight-and-balance data sheet dated September 21, 2010, which was annotated "converted aircraft back to camera operations configuration." The correct weight-and-balance data sheet listed an airplane empty weight of 1,863.33 lbs and a useful load of 694.67 lbs. Postaccident weight-and-balance calculations were made using the data sheet dated September 21, 2010, the combined weight of both pilots (460 lbs), the estimated weight of their bags (40 lbs), and a full fuel load (318 lbs). Based on the available information, the airplane's calculated ramp weight and center-of-gravity location were 2,681.3 lbs and 42.49 inches aft of the datum. The airplane's POH lists the maximum ramp weight and maximum takeoff weight as 2,558 lbs and 2,550 lbs, respectively. At maximum takeoff weight, the aft center of gravity limit is 47.3 inches. The handbook does not provide a method for interpolation of center of gravity limits for weights in excess of the maximum takeoff weight. A review of the POH's takeoff distance chart revealed that the airplane's weight at the time of the accident exceeded the chart's performance parameters. The maximum weight for which takeoff data was supplied was 2,550 lbs. As a result, takeoff performance calculations could not be determined. Similarly, the POH did not contain climb performance data for airplane weights that exceeded 2,550 lbs. With the recorded temperature and dewpoint, the calculated density altitude at the time of the accident was about 7,736 ft. According to the Pilot's Handbook of Aeronautical Knowledge (FAA-H-8083-25B), overall airplane flight performance decreases with an increase of airplane weight, which results in a higher takeoff speed, longer takeoff run, reduced rate and angle of climb, and higher aerodynamic stalling speed. According to FAA pamphlet Density Altitude (FAA-P-8740-2), operations at high-density altitudes will have decreased airplane performance. Whether due to high altitude, high temperature, or both, reduced air density adversely affects aerodynamic performance and decreases the engine's horsepower output in normally aspirated engines. A takeoff at a high-density altitude will require additional runway to achieve liftoff, and the airplane's climb performance will be adversely affected after takeoff.
The pilots’ failure to maintain adequate control of the airplane during the initial climb after takeoff, which resulted in the airplane exceeding its critical angle of attack and an aerodynamic stall at a low altitude. Contributing to the accident was the operation of the airplane above its maximum takeoff weight at a high density altitude at the time of the accident.
Source: NTSB Aviation Accident Database
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