European regulators are proposing to mandate a modification to the Pilatus PC-24 in order to prevent a fuel leak and consequent possible fire.
In a consultation document, the European Union Aviation Safety Agency (EASA) says that the move – which has already been addressed by Pilatus via a safety bulletin in April – covers aircraft with serial numbers of 150 and below.
Cirium's Fleets Analyzer indicates that around 50 airframes are affected.
EASA says that the issue was discovered during routine maintenance on the twinjet when a motive-flow fuel pipe was observed to move "to the end stop within the coupling" when pressure was applied to the fuel system.
Although the pipe returned to its original position once the pressure was released, EASA says that the movement could damage O-ring seals.
"This condition, if not corrected, could lead to a fuel leak and consequently a fuel contamination of the rear fuselage, which, in combination with an ignition source in this area, could possibly result in a fuel fire or fuel vapour explosion and consequent loss of the aeroplane," says EASA.
EASA's proposed airworthiness directive requires operators to replace the affected parts within three months. Consultation runs until 29 August.