Investigators Cannot Find Cause of Challenger's Uncommanded Flap Failure | Aviation International News

Cause of Challenger's Uncommanded Flap Failure Unknown

Charter flight landed safely after departing Farnborough Airport

Failures in the No 1 flap retract relay on a Challenger 604 — A damaged contact in the No 1 flap retract relay of a Challenger 604 meant that it failed to arrest an uncommanded flap movement. © UK AAIB

By Charles Alcock • Managing Editor

January 19, 2024

The exact cause of an uncommanded flap movement on a Bombardier Challenger 604 departing London-area Farnborough Airport has not been fully resolved by the UK’s Air Accident Investigation Branch (AAIB). A field investigation report published on Thursday provides details on some latent failures in the No. 1 flap retract relay, which it said meant it did not arrest the malfunction with the flaps.

At the start of a charter flight to Malaga in Spain on Aug. 10, 2022, the German-registered Challenger (tail number D-AAY) experienced an uncommanded flap movement above the maximum flap extension speed, during which the flaps moved to their fully extended position. The aircraft returned to Farnborough with the flap extended, but subsequent testing on the ground could not determine the reasons for the malfunction. It was established that a latent failure in the No. 1 flap retract relay had occurred on at least the previous 64 flights.

The rest of this article continues for AIN Members with the full report, analysis and background. The rest of this article continues for AIN Members with the full report, analysis and background. The rest of this article continues for AIN Members with the full report, analysis and background. The rest of this article continues for AIN Members with the full report, analysis and background. The rest of this article continues for AIN Members with the full report, analysis and background.

The rest of this article continues for AIN Members with the full report, analysis and background. The rest of this article continues for AIN Members with the full report, analysis and background. The rest of this article continues for AIN Members with the full report, analysis and background.

The rest of this article continues for AIN Members with the full report, analysis and background. The rest of this article continues for AIN Members with the full report, analysis and background. The rest of this article continues for AIN Members with the full report, analysis and background. The rest of this article continues for AIN Members with the full report, analysis and background. The rest of this article continues for AIN Members with the full report, analysis and background. The rest of this article continues for AIN Members with the full report, analysis and background.

The rest of this article continues for AIN Members with the full report, analysis and background. The rest of this article continues for AIN Members with the full report, analysis and background. The rest of this article continues for AIN Members with the full report, analysis and background. The rest of this article continues for AIN Members with the full report, analysis and background.

Challenger 600 Series

Bombardier

NTSB: Citation V in Overrun Was Snow-coated, Overweight

Rejected takeoff initiated above the decision speed

A Citation V that slid off the runway in Pagosa Springs in 2024

Libyan Officials Investigate Latitude Runway Overrun

Three crew survived crash on empty leg charter trip from Istanbul

Misrata Airport Citation crash

NBC News Helicopter Crashes in LA, Killing Three

Helicopter was covering a fatal collision between an SUV and bus when it went down

Mayor Karen Bass speaks at a press conference near the scene of the crashes on September 15

Forgotten Safety Pin Preceded Gulfstream IV Excursion

Airplane veered into grass with no injuries reported

Screenshot 2026-09-14 at 8.07.17 AM

District Court Rejects Appeal of GARA-related Lawsuit

Plaintiffs argued that police aircraft are exempt from GARA statute of repose

Helicopter accident flight path

NTSB: Pax Safely Lands King Air after Pilot Collapsed

Pilot died of cardiac arrest during the flight

Teen Driver Breaches Fence, Hits PlaneSense PC-12 at KPSM

Vehicle also struck parked ground-support tractor; there were no injuries

the pilatus PC-12 photographed on a ramp

NBAA Report Flags Powerplant, Collision Risks in Q2 Data

Six fatal accidents resulted in 22 fatalities in the quarter