Accident Details
On October 30, 2013, at 2140 central daylight time, an Aero Commander 500-B, registration N917GT, made a gear-up landing at Lubbock Preston Smith International Airport (LBB), Lubbock, Texas. The aircraft sustained substantial damage to the lower fuselage. The commercial pilot, the sole occupant, was not injured. The airplane was registered to Central Airlines Inc. and operated by Central Air Southwest under 14 CFR Part 135 as an on-demand cargo flight on an instrument flight rules flight plan. Visual meteorological conditions prevailed. The flight departed El Paso International Airport (ELP) at 2000 mountain daylight time and was destined for LBB.
Pilot's Account
The pilot reported departing ELP from runway 8R to avoid a thunderstorm approaching from the west. He climbed eastward in a clear corridor, with lightning to the north and south, to a cruise altitude of 9,000 feet mean sea level. At Carlsbad VOR, he requested a direct routing to LBB to avoid storms along the planned Hobbs VOR route. He described moderate turbulence throughout the flight, with a ground speed of 216 knots and a 50-knot tailwind.
Approaching LBB from the southwest, surface winds were 260 degrees at 11 knots. The descent was very bumpy. He initially planned to land on runway 35L due to cells east and west of the airport but changed to runway 17R because of familiarity, then back to 35L as turbulence increased with an approaching western cell. Flying a left base for runway 35L, he encountered wind shear and turbulence. A strong southwest wind caused him to overshoot the final approach. He was high and fast, dealing with wind shear bumps. He reduced power, maneuvered back to centerline, performed a GUMPS check (gas, undercarriage, mixture, propellers), and descended to intercept the visual approach slope indicator glide path. He applied half then full flaps. During the last 100 feet, he anticipated a nice landing but then heard metal scraping the runway. The airplane slid left of centerline and stopped at intersection Juliet.
The pilot stated he did not recall seeing green landing gear position lights. He recited but did not perform the GUMPS check due to being focused on controlling the airplane through wind shear. He believed he landed gear-up and instinctively activated the gear handle during the slide. He acknowledged it was hard to believe, but he thinks he left the landing gear up.
Post-Accident Inspection
Photos from the Federal Aviation Administration showed the airplane on the runway with the left main landing gear extended and parallel to the vertical axis, the right main landing gear extended and aft, and the nose landing gear retracted. According to the operator's maintenance personnel, during normal retraction, the right main gear begins first, followed by the left main, then nose gear. During extension, the nose gear extends first, followed by right main, then left main. Significant weight on a gear could alter the sequence.
Maintenance personnel from a fixed base operator at LBB recovered the airplane and noted the landing gear selector handle was in the down position, and the left main gear was down and locked. When raised on jacks, the right main gear extended and locked. After placing weight on the empennage, the nose gear was pulled down and locked. The operator's maintenance personnel replaced one propeller and one engine and flew the airplane back to the base in Kansas City, Missouri, under a ferry permit with no landing gear system maintenance. The airplane was flown with gear extended. After arrival, the gear was retracted and reported to function normally.
Pilot Experience
At the time of hiring, the pilot held a commercial pilot certificate with about 1,177 total flight hours, including 15 hours in multiengine airplanes and 113 hours in complex airplanes. It was his first commercial air carrier pilot employment. On July 25, 2013, he passed competency/proficiency checks under Parts 135.293, 135.297, and 135.299 administered by a company check airman. At the time of the accident, he had 1,521 total hours, with 285 hours in the accident airplane make and model.