History of Flight
On May 17, 2014, about 1020 Mountain standard time, an Aero Commander 500S, registration N40TC, impacted terrain shortly after takeoff from Sierra Vista Municipal Airport – Libby Army Airfield, Fort Huachuca, Arizona (FHU). The airline transport pilot (ATP) survived the accident but died as a result of his injuries about two weeks later. The commercial pilot was seriously injured; the airplane sustained substantial damage. The airplane was registered to and operated by Ponderosa Aviation Inc. under 14 Code of Federal Regulations Part 91 as an orientation flight. Visual meteorological conditions prevailed, and no flight plan was filed for the local area flight.
The commercial pilot reported that the purpose of the flight was to perform an orientation flight with the ATP, who was new to the area. Both pilots conducted a thorough preflight inspection and discussed the airplane's characteristics, safety guidelines, and protocols. The airplane was started and a run-up was completed. The takeoff roll began with all gauges in the green; airspeed reached 80 knots and the airplane lifted off. About 350 feet above the ground, the pilots felt a jolt and a perceived loss of power; the airplane was not responding. The commercial pilot immediately shut off the boost pumps, and the ATP initiated a slow left turn to return to land, but the airplane did not respond. The airplane descended rapidly in a nose and right wing low attitude and impacted the ground at about a 45-degree angle. After impact, the commercial pilot turned off the master switch to stop the stall warning buzzer and exited.
Witnesses reported that the airplane sounded normal until reaching about 800 feet at the departure end of the runway; they then heard a distinct popping sound followed by silence. The airplane made an approximate 45-degree left turn with no engine noise, descended at a high rate, and the wings leveled before it went out of sight. Shortly thereafter, they observed a cloud of smoke.
Personnel Information
The ATP, age 65, held an airline transport pilot certificate for airplane single-engine land/sea and multi-engine land issued February 22, 2008. He also held a flight instructor certificate for airplane single- and multi-engine land, an instrument rating issued February 24, 2013, and a second-class medical certificate issued December 10, 2013, with the limitation that he must wear corrective lenses for distant and near vision. At his most recent medical examination, he reported a total of 13,100 flight hours, with 150 in the last six months. The operator reported he had about 600 total hours in the accident airplane make and model.
The commercial pilot, age 70, held a commercial pilot certificate for airplane single- and multi-engine land and instrument airplane issued September 30, 2008, and a second-class medical certificate issued July 16, 2013, with the limitation that he must wear corrective lenses. He reported a total of 16,560 flight hours, with 4,100 in the accident airplane make and model. He further reported flying 80 hours in the make and model in the previous 90 days and 15 hours in the previous 30 days.
Aircraft Information
The five-seat, high-wing, retractable gear airplane, serial number 3091, was manufactured in 1976. It was powered by two Lycoming IO-540-E1B5, 290-horsepower engines and equipped with Hartzell Propeller model HC-C3YR-2UF controllable pitch propellers. The airplane's last maintenance was a conditional inspection on April 28, 2014, at a recorded tachometer reading of 21,659.3. The airplane was repositioned to FHU on May 5, 2014, and was not flown until the day of the accident. Upon arrival, it was filled with 22 gallons of Avgas.
Meteorological Information
At 0956, the weather at FHU was reported as wind from 320 degrees at 7 knots, visibility 10 statute miles, clear skies, temperature 28°C, dewpoint -16°C, and an altimeter setting of 30.11 inches Hg.
Wreckage and Impact Information
The airplane came to rest on airport property with the cabin twisted 90 degrees from the wing structure. The wings and engines were level. The right wing was fractured about midspan, and all three propellers were bent aft. The outboard about three feet of the left wing was bent upward; two propellers on the left engine were bent forward and one bent aft. The forward fuselage was mostly intact but came to rest on its left side; the bottom sustained crush damage. The aft fuselage was fracture separated, and the empennage came to rest upside down.
Tests and Research
A postaccident examination of the airframe and engines revealed no anomalies that would have precluded normal operations. Flight control continuity was established throughout. Continuity of the fuel system from the fuel tanks to the firewall components was also established. About 5 gallons of fuel were found in the sump tank, but there was no fuel in the system from the sump tank to the engines. The left and right shutoff valves mounted to the sump tank were in the OFF position; these valves are electrically actuated by cockpit switches. The right fuel switch in the cockpit was ON, and the left fuel switch was OFF. The sump tank shutoff valves and boost pumps were removed and functionally tested; both operated normally.
Visual examination of the left engine showed no evidence of catastrophic failure. Overhead components and accessories were in place with no impact-related damage. The oil sump was intact with no preimpact oil leakage. The oil filter was clear of debris. Spark plugs exhibited normal wear. Cylinder interiors examined via borescope showed normal wear. The crankshaft rotated manually, and cylinder compression, valve train, and accessory gear continuity were established. Magnetos produced spark on all ignition wires; after a few rotations, the left magneto stopped producing spark but later functioned normally in a bench test. All fuel lines secured to the engine had no evidence of leaking, and no fuel was found in the fuel lines or system components. Fuel nozzles and the manifold valve were clear of debris.
Visual examination of the right engine also showed no evidence of catastrophic failure. Components were in place with no impact damage. Spark plugs exhibited normal wear. Borescope examination showed normal cylinder wear. The crankshaft rotated manually, and continuity was established. Magnetos produced spark on all ignition wires. The oil sump was intact with no leakage. The oil filter was clear of debris. The oil suction screen contained a piece of metal later identified as part of the left magneto bearing retainer cage. All fuel lines secured to the engine had no evidence of leaking, and no fuel was found in the fuel lines or system components. Fuel nozzles and the manifold valve were clear of debris.