What happened
On June 18, 2021, at approximately 17:30 local time, a Learjet LJ-3SS, registration LV-IYQ, was involved in a ground excursion at Laguna del Sauce International Airport (SULS) in Uruguay. The aircraft had arrived from Aeroparque Jorge Newbery in Argentina to transport a passenger.
After landing on runway 19, the tower instructed the crew to perform a 180-degree turn on the runway to proceed via runway 01 and exit via taxiway C. However, the crew mistakenly entered taxiway B. Upon realizing the error, the crew attempted to execute the required 180-degree turn within the runway safety area. During this maneuver, the nose gear and the right main gear left the paved surface and entered the adjacent natural grass area. The wheels sank into the soft ground, causing the aircraft to become immobilized.
All three occupants—the two pilots and one passenger—were uninjured. There was no fire and no damage to the aircraft, though significant mud accumulated on the landing gear.
The investigation
The CIAIA investigation examined the aircraft's maintenance records, the crew's performance, and the mechanical state of the steering system. The investigation noted that the aircraft's airworthiness certificate and maintenance were up to date.
While the crew reported that the nose wheel steering system disconnected during the turn, investigators found no physical evidence of a mechanical failure. The investigation also noted that the aircraft had been involved in a previous runway excursion in September 2020. Investigators considered the possibility that the steering system was inadvertently deactivated by the pilot via the Control Wheel Master Switch (MSW) during the maneuver, or that the system was subjected to extreme operational stress.
Findings
- The crew entered the incorrect taxiway, necessitating the 180-degree turn.
- The loss of directional control on the ground led the aircraft off the taxiway.
- There was no evidence of a mechanical failure in the steering system, though an inadvertent manual disconnection of the steering via the MSW was possible.
- The aircraft's weight and maintenance status were within legal and operational limits.