Incident Overview
On April 11, 2017, at approximately 08:30 UTC, a Gulfstream GIV-X (G450) twin-engine jet sustained substantial damage during a ground incident at Salzburg Airport (LOWS). The aircraft was on a private flight (FAR Part 91) under instrument flight rules. No injuries were reported.
Flight Details
The aircraft departed Salzburg at 08:12 UTC bound for Bangor International Airport, Maine, USA. Shortly after takeoff, the landing gear could not be retracted because the landing gear safety pins were still installed. The crew decided to return to Salzburg. After landing, while on the taxiway for approximately 10 minutes, the crew attempted to remove the safety pins. During this process, the nose landing gear retracted, causing the nose of the aircraft to contact the ground.
Landing Gear System
The landing gear system on the Gulfstream GIV-X (G450) includes safety pins that are inserted to prevent inadvertent retraction during ground operations. The flight crew had failed to remove these pins before departure. The aircraft manufacturer's documentation included procedures for landing gear malfunction and for attempted retraction with safety pins installed.
Investigation Findings
The official investigation determined that the probable cause of the accident was the inadvertent retraction of the nose landing gear during removal of the safety pins, after the gear could not be retracted due to the pins still being installed. The investigation also identified two contributing factors: the crew's lack of system and procedural knowledge regarding the landing gear system, and insufficient depiction of the landing gear system in the aircraft manufacturer's documentation.
Probable Cause
The probable cause of the accident was the inadvertent retraction of the nose landing gear during removal of the landing gear safety pins, after the gear could not be retracted due to the pins still being installed. Contributing factors were the crew's lack of system and procedural knowledge regarding the landing gear system and insufficient depiction of the landing gear system in the aircraft manufacturer's documentation.