The pilot and co-pilot of a Glasgow-bound flight carrying 116 passengers had to turn back to London's Heathrow Airport after they became dizzy and light-headed.

The two women quickly embarked on established procedures for dealing with "]incapacitation in the cockpit of the Airbus schedule flight when taken ill, shortly after take-off. Details of the scare involving the 3.42pm flight to Scotland on December 20 last year have emerged for the first time in a report by the Air Accidents Investigation Branch (AAIB).

It described in its investigation into the incident how "during the climb out of Heathrow both pilots had experienced symptoms of dizziness and light-headedness".

The pilots donned their oxygen masks and returned to Heathrow where the aircraft landed without further incident. "No fault was found with the aircraft and no-one else on the aircraft experienced adverse symptoms," added the report.

On returning to Heathrow, the airport's fire and rescue services examined the cockpit but could find no evidence of smoke or fumes. The two affected crew did not require medical attention.

The pilots, who have not been named, were examined by paramedics but neither was displaying any abnormal symptoms by that time. The AAIB report says: "Whilst the company operations manual requires any crew member who becomes incapacitated in flight to consult a company doctor as soon as possible after landing, the crew were still able to operate the aircraft as effective crew members."

According to the report, the captain said her light-headedness had begun when she had looked down to the console to change a radio frequency.

The report concluded: "The symptoms experienced by the commander may have been as a result of the after effects of a cold, combined with the coincidental head and aircraft movement. The temporary symptoms experienced by the co-pilot may have been effect of the potentially evolving situation of an incapacitation at an early stage in the flight leading to possible mild hyperventilation."

She only felt light-headed for 25 seconds and had said the symptoms had been unique in her 12-year career with the operator. Both resumed their flying duties without any recurrence of the symptoms.

l The AAIB report into the crash of a 70-year-old Tiger Moth biplane in Moray last August says the pilot thought it had stalled. He suffered minor injuries.