N93AAAero Commander 500-B · 1964

On March 1, 2013, about 1545 mountain standard time, an Aero Commander 500B, N93AA, lost power on both engines shortly after takeoff, and the pilot made a gear-up forced landing on a golf course fairway near Broomfield, Colorado. The airline transport pilot and one passenger received minor injuries. The airplane was substantially damaged. The airplane was registered to and operated by American East Airways Corporation under the provisions of 14 Code of Federal Regulations Part 91 as a test flight. Visual meteorological conditions prevailed for the local flight, which operated without a flight plan. The flight originated from Rocky Mountain Metropolitan Airport (KBJC), Broomfield, about 1540.

The pilot said that during the airplane preflight, the fuel gauge indicated 65 gallons, but the design of the fuel system precluded a visual inspection of the fuel level. The pilot said he took off on what was to be a test flight after the installation of the left engine. Shortly after reducing to climb power, the left engine began to surge and lose power. The pilot made an immediate left turn back towards the airport and contacted the control tower to advise he was making a single-engine straight-in landing approach. When he lowered the landing gear, the right engine began to surge and lose power. The pilot declared an emergency. Realizing he had insufficient engine power and altitude to return to KBJC, he retracted the landing gear and made a no-flap gear-up landing on the Omni Interlocken Golf Course.

The pilot, age 69, held an airline transport pilot certificate with a multiengine land rating, and commercial privileges in airplanes single-engine land/sea and glider ratings. He was type rated in the Boeing 737 and a Dornier Alpha Jet. He also held a flight instructor certificate with airplane single/multiengine and instrument ratings, and a ground instructor certificate with an advanced rating. His first class airman medical certificate, dated December 3, 2012, contained restrictions for corrective lenses to be worn for distant vision, and possess glasses for near and intermediate vision.

The pilot estimated he had logged more than 15,000 total flight time, of which more than 414 hours were accrued in the Aero Commander.

N93AA, serial number 500B-1296-111, was manufactured by the Aero Commander Corporation in 1964. It was powered by two Lycoming IO-540-E1B5 fuel-injected engines, rated at 290 horsepower each.

According to the aircraft's maintenance records, an annual inspection was done on February 13, 2013, at a total airframe time of 10,020.6 hours. The Hobbs meter read 586.7 hours. At that time, the left engine was replaced by an overhauled engine (serial number L-8807-48). The engine had accrued 5,391.0 total hours before overhaul. The right engine, serial number L-11118-48, had been overhauled on April 18, 2012. Total hours prior to overhaul were not given, but it had accrued 167.6 hours since overhaul.

Both propellers were Hartzell models HC-A3VK-2B. The left propeller (serial number BJ74) and the right propeller (serial number BJ252) had accrued 167.6 hours since overhaul. Total hours on the propellers were not given.

Weather recorded by the KBJC AWOS (Automated Weather Observation Station) at 1549 was as follows:

Wind, calm; visibility, 40 statute miles; sky condition, 9,000 feet scattered clouds, ceiling 22,000 feet, broken clouds; temperature, 7 degrees Celsius (C.); dew point, -8 degrees C.; altimeter, 30.24 inches of mercury.

N93AA, serial number 500B-1296-111, was manufactured by the Aero Commander Corporation in 1964. It was powered by two Lycoming IO-540-E1B5 fuel-injected engines, rated at 290 horsepower each.

According to the aircraft's maintenance records, an annual inspection was done on February 13, 2013, at a total airframe time of 10,020.6 hours. The Hobbs meter read 586.7 hours. At that time, the left engine was replaced by an overhauled engine (serial number L-8807-48). The engine had accrued 5,391.0 total hours before overhaul. The right engine, serial number L-11118-48, had been overhauled on April 18, 2012. Total hours prior to overhaul were not given, but it had accrued 167.6 hours since overhaul.

Both propellers were Hartzell models HC-A3VK-2B. The left propeller (serial number BJ74) and the right propeller (serial number BJ252) had accrued 167.6 hours since overhaul. Total hours on the propellers were not given.

The fuselage structure, forward of wing attach point, was bent upwards and there was vertical deformation throughout the length of the fuselage, particularly the lower portion. The outer 3 feet of the left wing was crushed back to the spar, and the left propeller blades were bent.

The pilot said that when he preflighted the airplane, the fuel gauge indicated 65 gallons. Due to the design of the fuel system, it is not possible to visually check the fuel level unless all tanks are completely full. An FAA inspector applied battery power to the airplane post accident and the fuel gauges displayed 65 gallons of fuel. According to the salvage company that recovered the airplane, approximately ½-gallon of 100LL aviation gasoline was drained from the fuel system.

The following are excerpts from Section V of the Aero Commander 500B Maintenance Manual:

"Fuel is contained in five rubberized fuel bladders, two of which are located in each wing, inboard of the nacelles, and one in the center wing section above the baggage compartment. The five cells have a total capacity of 150-159 U.S. gallons and are interconnected by two-inch diameter tubes to ensure adequate fuel flow from the wing cells to the center cell. All cells are filled through the fuel fill port located on top of the right wing above the forward fuel cell.

"The fuel quantity indicating system is comprised of an indicating gage, mounted on the instrument panel… with a dial to indicate the quantity of fuel in the fuel cells. The fuel quantity gage dial is marked from E (empty) to 135 U.S. gallons. Fuel cell capacity above 135 gallons is not indicated."