The UK’s Aircraft Accident Investigation Branch (AAIB) cited a Gulfstream G550 crew for conducting an unstabilized approach before striking a localizer antenna and touching down on runway undershoot pavement 109 feet short of the Runway 22 threshold at London Stansted Airport on Dec. 10, 2013 at 3:25 a.m., according to its final report. One of the aircraft’s landing gear doors was damaged slightly in the incident. At the time, an RVR of approximately of 1,000 feet was reported for Runway 22, below Category 1 landing minimums.
This was in violation of the company’s operating manual: “Approaches to airports where the weather is reported below published landing minimums are not authorized.” During the approach, the captain alternately reengaged and disengaged the autopilot and autothrottles. While accurately tracking the localizer, the captain flew first above and later below the glideslope during the final approach.
While the captain was hand flying the approach, the AAIB determined that he selected “go-around” mode, which inhibited low-altitude warnings that could have prevented the incident. The crew said they did not notice any unusual noises during the approach and became aware of the damage only afterwards during a post-flight inspection.