AAIB investigation to Dornier Alpha Jet FB, OE-FAS
On final approach flames emitted from the wing-mounted smoke generators, Farnborough Airport, Hampshire, 13 July 2018.
Summary:
The aircraft had been conducting a display routine making use of smoke produced by two oil-fuelled smoke generators, mounted on the wing pylons. The pilot had switched off the smoke generators as the aircraft turned onto the final approach to land and he observed the smoke stop using the cockpit-mounted mirrors. During the approach, spectators observed flames coming from both smoke generators. The pilot became aware of the flames during the landing roll and isolated the smoke generation system using the circuit breakers. After briefly extinguishing the flames reappeared, so the pilot declared a MAYDAY. The flames self extinguished before AFRS reached the aircraft. An examination by the operator’s engineers did not find any defect with the generators and all subsequent operation of the system has been normal.
The event is thought to have been caused by the smoke generators being switched off as they ran out of fuel, which caused a small quantity of fuel to pool in the smoke generator nozzle which then ignited due to the residual heat present in the nozzle.
Download report: