On 19 May 2015, an Airbus A320 crew attempted to taxi into a nose-in parking position at Lisbon despite the fact that the APIS, although switched on, was clearly malfunctioning whilst not displaying an unequivocal ‘STOP. The aircraft continued 6 metres past the applicable apron ground marking by which time it had hit the airbridge. The marshaller in attendance to oversee the arrival did not signal the aircraft or manually select the APIS ‘STOP instruction. The APIS had failed to detect the dark-liveried aircraft and the non-display of a steady ‘STOP indication was independently attributed to a pre-existing system fault.