What happened
On 13 July 2018, a Dornier Alpha Jet FB, registration OE-FAS, was performing a flight display at Farnborough Airport in Hampshire. During the routine, the aircraft utilized two oil-fuelled smoke generators mounted on the wing pylons to produce smoke. As the aircraft transitioned onto its final approach for landing, the pilot deactivated the smoke generation system. The pilot used cockpit-mounted mirrors to confirm that the smoke production had ceased.
While the aircraft was on approach, spectators noted flames emerging from both smoke generators. The pilot did not become aware of the fire until the aircraft was in its landing roll. In an attempt to manage the situation, the pilot used circuit breakers to isolate the smoke generation system. Although the flames were briefly extinguished, they reappeared, prompting the pilot to declare a MAYLEAY. The fire eventually extinguished itself before the arrival of the airfield rescue services.
The investigation
Following the incident, the operator's engineers conducted a technical examination of the smoke generation equipment. The investigation focused on the behavior of the fuel-fed system during the shutdown sequence. The inspection of the generators revealed no mechanical or technical defects, and the system has since been returned to normal service without further issues.
Findings
- The incident was caused by residual heat in the smoke generator nozzles igniting a small amount of pooled fuel.
- This fuel accumulation occurred because the generators were switched off at the moment they had depleted their fuel supply.
- There were no injuries to the crew and no damage was sustained by the aircraft.