What happened
On 10 September 2017, a Gulfstream G5XB operated by Avcon Jet AG was conducting an approach to runway 25 at Paris-Le Bourget airport. While following a LOC A approach, which features a 26° offset from the runway centerline, the crew incorrectly identified a disused former runway located between runways 27 and 25 as the active runway 25.
Upon realizing the error at a height of approximately 250 ft, the pilot flying attempted a right turn to intercept the correct centerline. This maneuver occurred at a very low altitude, causing the aircraft to overshoot the centerline. As the aircraft banked, the angle-of-attack protection activated and the stick shaker was triggered. The pilot then initiated a go-around; however, because the engines required several seconds to reach full thrust, the aircraft continued to descend. At a height of approximately 20 ft, the left wing of the M-SAWO struck runway lighting, resulting in broken light components and damage to the aircraft's leading edge and lower wing surface. The crew successfully completed a second approach and landed normally.
The investigation
The BEA examined flight data recorder (FDR) information, cockpit voice recordings, radar data, and pilot statements. The investigation focused on the sequence of events leading to the unstable approach and the specific environmental factors at Le BourSBorget. Investigators also reviewed the crew's altimeter settings, noting that the crew had incorrectly set the altimeter to 1014 hPa when the actual QNH was 1004 hPa, resulting in a displayed altitude approximately 280 ft higher than the true altitude.
Findings
Several factors contributed to the incident:
- Erroneous runway identification: The crew mistook the disused runway for runway 25, likely due to the light-colored concrete section at the start of runway 25 being visually similar to the disused runway surface.
- Late maneuver execution: The decision to attempt a centerline interception was made at too low an altitude, leading to an unstable approach and high angle of attack.
- Altimeter error: The incorrect QNH setting created a representation bias, potentially delaying the crew's realization of their actual altitude and flight path deviation.
- Delayed go-around: The decision to abort the approach was made too late, and the delay in engine thrust spool-up prevented the aircraft from climbing sufficiently to clear the runway lights.
- Visual confusion: Existing markings and lighting on the disused runway were not sufficient to allow the crew to clearly differentiate it from the active runway 25.