GULFSTREAM AEROSPACE G-IV

Full Narrative

On August 14, 2026, about 1459 central daylight time, a Gulfstream Aerospace G-IV airplane, N406JS, was substantially damaged when it was involved in an accident near St. Louis, Missouri. The three crew members and 7 passengers were not injured. The airplane was operated as a Title 14 Code of Federal Regulations part 135 on-demand air taxi flight.
According to the crew, they received a STEER BY WIRE FAIL Crew Alerting System (CAS) message before departure from Eagle County Regional Airport (EGE), Eagle, Colorado. They completed the appropriate checklist and the message cleared. While on approach to Runway 8R at Spirit of St. Louis Airport (SUS), St. Louis Missouri, after lowering the landing gear, the crew again received a STEER BY WIRE FAIL CAS message. The crew completed the checklist; however, the message did not clear.
The airplane landed on the runway and as the nose wheel contacted the runway it began to shimmy. The nose landing gear (NLG) separated from the airplane followed by a collapse of the left main landing gear. The airplane veered left into the grass and came to rest upright. During the accident sequence, the airplane sustained damage to the lower fuselage and left wing.
According to the pilot, during the preflight inspection, the airport ground crew was unable to install the pip pin that goes into the NLG torque link that is used to engage and disengage the scissor link with the Nose Wheel Steering actuator for the NLG. The pilot was able to install the NLG pip pin which has a secondary safety pin that is normally installed into the pip pin to help ensure it remains engaged. The pilot reported that he forgot to install the secondary safety pin.
Postaccident examination of the runway and surrounding grass areas found several items of debris. The NLG pip pin, which is normally seated in the NLG torque link, was found separated from the NLG with three ball locks remaining as seen in figure 1. The NLG pip pin normally has four ball locks; the missing ball lock and the NLG upper scissor link could not be located. Examination of the NLG revealed that the safety pin was found intact in the open position and with the separated NLG still attached to its lanyard cord as seen in figure 2.

Figure 1. Nose landing gear pip pin.


Figure 2. Nose Landing Gear with open safety pin and torque link depicted.
The airplane was equipped with a cockpit voice recorder and flight data recorder, which were removed and sent to the National Transportation Safety Board Vehicle Recorders Laboratory in Washington, DC, for download. The wreckage was retained for further examination.