Accident Overview
On March 28, 2018, about 0830 eastern daylight time, an experimental Lancair IV-P, Canadian registration C-GSQQ, sustained substantial damage during a taxi incident at Sebring, Florida. The private pilot and two passengers were not injured. The airplane was operated as a Title 14 Code of Federal Regulations Part 91 personal flight.
Sequence of Events
The pilot landed uneventfully on runway 01 after completing a GPS approach. He exited the runway onto taxiway A4 and stopped. After reconfiguring the airplane and performing taxi checks, he noticed a Boeing 737 (B737) south of his position, facing south on a taxiway that paralleled the runway. The pilot thought the B737 was parked. Neither he nor the right front seat passenger recalled seeing any people on the ground around the B737. The pilot noticed that the left engine cowling was missing but could not perceive whether either engine was running. There were no barricades blocking the taxiway.
The pilot began taxiing westbound about 200 to 300 ft behind the B737 with no aileron control input applied. The left wing suddenly rose, and the right wing contacted the taxiway. The airplane cartwheeled and came to rest upright on grass at the north edge of the taxiway with the nose landing gear fork and wheel assembly separated. The pilot reported that the empennage was cracked and that both wings sustained damage at their roots, consistent with up-and-down flexing.
Ground and Communication Details
Maintenance personnel onboard the B737 reported they were in contact with personnel in two vehicles on the ground near the nose landing gear but were not monitoring the common traffic advisory frequency (CTAF). Both engines of the B737 were stabilized at 85% power. An individual in one of the vehicles had a portable radio transceiver and was monitoring the CTAF. This individual saw the accident airplane when it first turned off the runway and crossed the hold short line. He attempted to communicate with the accident pilot on the CTAF, but his transmission was stepped on by another pilot who was airborne and also attempting to warn that the B737's engines were running. He then began driving toward the accident airplane, and when it encountered the jet blast, he broadcast to the B737 cockpit to secure the engines, then went to the accident airplane to render assistance.
Airport Operations
At the time of the accident, the B737 was positioned at the "north spot," one of two pre-approved engine run locations on the airport. The executive director of the airport reported that there was an unwritten policy requiring his direct approval for maintenance engine runs for the B737. Personnel involved in the engine runs reported that airport personnel gave such approval; however, the director reported that neither he nor any airport staff gave approval for engine runs that day.