Accident Overview
On June 10, 2016, at about 1520 mountain daylight time, a Cessna 172S airplane, registration N21767, was substantially damaged when it collided with terrain shortly after takeoff from Deming Municipal Airport (DMN) in Deming, New Mexico. The two pilots on board sustained serious injuries. The flight was conducted as a Title 14 Code of Federal Regulations Part 91 business flight.
Flight History
The airplane was being repositioned from Washington to Florida. During a previous flight leg, an electrical system failure had necessitated an unscheduled stop at Blythe Airport (BLH) in Blythe, California. After landing safely, one pilot sustained a hairline ankle fracture while running toward the fixed base operator building. He sought medical attention and received an aircast and crutches. The alternator and battery were found to be operating properly. The pilot then flew the airplane to Lake Havasu City Airport (HII) in Lake Havasu City, Arizona, where a maintenance shop could not identify any electrical issues and returned the airplane to service.
The airplane operator decided to send a replacement pilot for the remaining legs because the initial pilot had a cast on his right leg. The two pilots agreed that the replacement pilot would perform all takeoffs and landings. The replacement pilot flew from HII to DMN. After refueling and having lunch, the next leg was planned to Fort Stockton-Pecos County Airport (FST) in Fort Stockton, Texas. The pilot with the fractured ankle was seated in the left pilot seat, intending to fly during cruise, while the replacement pilot was in the right seat for takeoff and landing.
Witness Observations
The airport manager at DMN reported the airplane was topped off with 100 low-lead aviation fuel before departure. Winds were light and variable. The assistant airport manager watched the airplane taxi and takeoff on runway 26, observing nothing unusual. A law enforcement officer driving a squad car saw the airplane heading west shortly after takeoff at about 200 ft above ground level. The airplane then entered a steep turn to an east heading back toward the airport, followed by a steep right bank and descent toward the ground. According to a Federal Aviation Administration (FAA) inspector, neither pilot remembers the takeoff or the crash. Two witnesses on a nearby golf course stated that the engine was running when the airplane descended into terrain.
A lawyer representing the pilot in the left seat reported that his client recalled the engine stumbling and quitting during a magneto check during the before-takeoff runup, but a second runup with the fuel mixture leaned was normal. The pilot also told his mother that the engine quit while being treated at the hospital, but the lawyer stipulated that the pilot did not recall making that statement nor did he remember a loss of engine power during the flight.
Postaccident Examination
The initial point of impact was on taxiway C adjacent to runway 4. The airplane impacted in a nose-low, right-wing-low attitude, leaving a propeller slash mark on the asphalt. The wreckage debris path was oriented east. The nose landing gear strut and wheel separated. The forward fuselage had compression damage consistent with a nose-down impact. The right main landing gear strut was bent upward and aft, and the right wheel and tire separated. The left wing appeared undamaged. The right wing was bent down at the root, and the right lift strut was fractured. The tail was fractured at the forward edge of the vertical stabilizer. Control cable continuity was established for ailerons and elevators; partial continuity for rudder and elevator trim tab was found, with impact damage jamming the rudder pedals. Wing flaps were fully retracted. Fuel tanks were not ruptured, but fuel had drained from a fractured supply line. The fuel selector was in the BOTH position, fuel shutoff valve open, fuel strainer clean, ignition switch BOTH, master switches ON.
The engine had separated from the firewall and was found inverted. Internal continuity was confirmed; compression and suction were noted on all cylinders. Spark plugs exhibited normal operation features. Both magnetos produced spark and were timed correctly. A borescope inspection revealed no anomalies. Fuel system components were intact and clean. The postaccident engine examination found no anomalies that would have precluded normal operation. The two-blade fixed-pitch propeller remained attached, with blade damage indicative of impact.
Weight and Balance
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, indicating the equipment had been removed. However, the FAA inspector obtained a later data sheet dated September 21, 2010, reflecting the aircraft converted back to camera operations, with an empty weight of 1,863.33 lbs and useful load of 694.67 lbs. Postaccident calculations using this sheet, combined weights of pilots (460 lbs), bags (40 lbs), and full fuel (318 lbs), gave a ramp weight of 2,681.3 lbs and center of gravity at 42.49 inches aft of datum. The POH lists maximum ramp weight as 2,558 lbs and maximum takeoff weight as 2,550 lbs. The accident weight exceeded both limits. The POH does not provide data for weights above 2,550 lbs, so takeoff and climb performance calculations could not be determined.
Density Altitude Considerations
With the recorded temperature and dewpoint, the calculated density altitude at the time of the accident was about 7,736 ft. According to FAA handbooks, increased airplane weight results in higher takeoff speed, longer takeoff run, reduced rate and angle of climb, and higher stalling speed. Operations at high-density altitudes further degrade performance by reducing air density and engine horsepower output.