A MICROLIGHT pilot had to make an emergency landing in the Ribble Valley after the propeller fell off as they cruised at 2,500 feet, it has been revealed.

The 66-year-old pilot and his passenger walked away unhurt after their tiny aircraft made a safe emergency touch-down in a field at the Trough of Bowland in April this year.

Now an official report has blamed metal fatigue on the loss of the propeller which was recovered by a local farmer 11 days after the incident.

It happened on 6 April at around 3pm when the two seater Kolb Twinstar microlight - reg G CDFA - owned by Steven Soar of Nightingale Way, Catterall, Preston and William Arthur Douthwaite, of Hullett Drive, Hebden Bridge, was on a flight from Rufforth to Rossall Field, at Cockerham at the time.

The Air Accident Investigation Branch report just published into the incident says : "The aircraft was in the cruise when the propeller detached.

"The pilot made a successful forced landing without further damage. Examination showed that the bolts securing the crankshaft extension fitting to the crankshaft had fractured in long-term high-cycle fatigue.

"The aircraft was on a flight from Rufforth to Rossall Field, Cockerham.

"Whilst flying straight and level on track at 2,500 ft, the occupants noticed a rattling sound, but without any vibration.

"About two minutes later there was a new 'mechanical' noise, followed a few seconds later by the abrupt stoppage of the engine.

"The pilot was convinced that the engine had seized, so he did not attempt a restart and instead concentrated on finding a field for a forced landing.

"This was successful and there was no further damage to the aircraft.

"On vacating the aircraft, the pilot and passenger were surprised to find that the two-bladed wooden propeller was missing, having departed without causing airframe damage.

"The aircraft was collected from the field by fellow flying club members using a trailer and the propeller was found 11 days later by a local farmer and despatched to the AAIB for further examination."

The incident has resulted in a recommendation that a new type of bolt is used to attach propellers to this type of aircraft.