UK investigators believe a landing Loganair Embraer ERJ-145 ran over a towbar left on a London Southend airport runway because it did not have any markings to increase its visibility to inspectors.

The towbar had been inadvertently left attached to the nose-wheel of a Cessna P210N light aircraft which had departed Southend some 30min earlier.

As the Cessna took off from runway 23, the towbar fell off and landed on the runway surface.

Two aircraft – a landing Piper PA-28 and a departing Britten-Norman Islander – each used the runway in the time before the ERJ-145 conducted its approach and was cleared to land.

The UK Air Accidents Investigation Branch also states that a runway inspection was conducted in the interval between the PA-28’s arrival and the Islander’s take-off.

When the ERJ touched down – in daylight and good visibility – its captain saw an object on the right of the centreline, about 8-10m in front of the aircraft, while the jet was still travelling at 105-110kt.

“He applied slight left rudder as the object disappeared out of view,” says the inquiry. “[He] felt a small bump through the rudder pedals but was not sure if this was caused by the aircraft clipping the object or running over the centreline.”

After the crew reported the sighting to air traffic control, runway inspection personnel recovered the towbar which was located about 350m from the runway 23 threshold. It had been run over by the ERJ, the inquiry states, but the jet (G-SAJK) was undamaged.

Analysis of the event, which occurred on 7 August last year, could not determine whether the PA-28 or Islander had passed the towbar during their runway occupancy, while the runway inspection was intended to check for wildlife – so the inspection vehicle’s driver might have been focused on the sky rather than the runway surface.

But the inquiry points out that the towbar was painted in dark colours, rendering it “inconspicuous” against the runway surface. “The towbar might have been seen sooner if it had reflective or other high-visibility markings,” it adds.

Investigators also note that the Cessna pilot had been distracted en route to the airport by an alarming road traffic incident between his motorcycle and a cyclist. The inquiry suggests this incident pre-occupied the pilot’s mind during preparation for flight, and was “probably” behind his forgetting to remove the towbar. The pilot also unintentionally left his bags behind at Southend.

Stressful events can be “difficult to put out of mind”, the inquiry warns: “It may be tempting to continue with a planned operation and not realise the effect of such an event on subsequent performance.”