UK investigators are examining a Gulfstream G550 which damaged the instrument landing system at London Stansted airport during an early morning arrival, forcing a downgrade of the site's low-visibility capability.

While the Air Accidents Investigation Branch confirms it is probing the incident, it has not given details of the jet involved. However, a source familiar with the situation indicates that the aircraft is a Saudi-registered airframe (HZ-A6) and that it touched down some 25m (82ft) short of the runway threshold while landing at about 03:30 on 10 December.

The long-range, large cabin business jet struck an antenna and suffered undercarriage door damage as well as scratches to the hull.

Stansted’s operator has not given any detail about the event beyond confirming a G550 was involved and that the aircraft “landed safely”. It states simply that the incident “resulted in some damage to our ILS”.

Poor weather at Stansted combined with the ILS damage forced the subsequent diversion of several flights.

UK air traffic control service NATS, which is responsible for the ILS, has restored the system to its full capability.