On June 21, 2012, at 1530 mountain daylight time, a Cessna model R182 airplane, N4720R, was substantially damaged when the main landing gear collapsed while landing at Dona Ana County Airport (5T6), Santa Teresa, New Mexico. The private pilot was not injured. The airplane was registered to and operated by Marine Military Academy (Air Wing) Incorporated, under the provisions of 14 Code of Federal Regulations Part 91. Day visual meteorological conditions prevailed for personal flight, which was operated without a flight plan. The flight departed Skypark Airport (KBTF), Bountiful, Utah, about 1130 with 5T6 as the intended destination.

The pilot reported that as the flight approached 5T6 he listened to the airport's weather broadcast, which indicated the local wind was from the east at 19 knots, gusting 23 knots. He entered the traffic pattern on a left downwind for runway 10 (9,549 feet by 100 feet, asphalt) and before turning onto base he lowered the landing gear and selected flaps 10-degrees. He reported that the green landing gear position light illuminated after the landing gear had extended. While on base he selected flaps 20-degrees and through his cockpit window visually confirmed that the left main landing gear was extended. Shortly after touchdown, during the landing roll, the left main landing gear began to retract, which was followed by the right main landing gear. The airplane then veered off the left side of the runway. The airplane sustained substantial damage to the right wing and right horizontal stabilizer during the accident. The left wingtip also exhibited some scraping from contact with the runway.

During the postaccident recovery, as the airplane was lifted off the ground, the main landing gear fully extended, without electrical power supplied, into the down-and-locked position. The landing gear was checked and all three down-lock assemblies appeared to be properly engaged. The airplane was then repositioned into a hangar for additional testing.

The airplane was placed onto jack stands in order to perform several cycles of the landing gear extension/retraction system. No anomalies were observed as the landing gear was cycled four times using the airplane's electro-hydraulic system. During landing gear extension, the nose landing gear would extend first, followed by the main landing gear. The related gear down lock assemblies engaged properly when the landing gear was fully extended. There were no observed hydraulic fluid leaks. In addition to the four normal landing gear cycles, the landing gear extended from the fully retracted position into the down-and-locked position via the emergency landing gear extension system. Testing of the landing gear position indicating system confirmed that the green position light would not illuminate until all three landing gear were fully extended into a down-and-locked position. The amber position light illuminated while the landing gear was in the fully retracted position. The postaccident examination did not reveal any mechanical anomalies or failures that would have resulted in the main landing gear collapse.

At 1455, the airport's automatic weather observing station reported the following weather conditions: wind from 080 magnetic at 12 knots gusting to 17 knots, visibility 40 statute miles, temperature 38 degrees Celsius, dew point 9 degrees Celsius, altimeter 30.01 inches of mercury. No cloud data or weather type was provided.