The co-pilot of a plane flying from Inverness to Jersey suffered a seizure, inadvertently causing the aircraft to make a sudden movement.
A member of the cabin crew fell to floor and the co-pilot had to be restrained while he had a second, more violent, seizure.
The aircraft's commander was able to control the plane in the incident on 5 August last year.
The aircraft was diverted to Manchester where it was landed safely.
An Air Accidents Investigation Branch (AAIB) report revealed the details of the flight which was carrying four crew and 43 passengers.
There were no prior warning signs that the co-pilot would fall ill, the report said.
His first seizure caused him inadvertently to affect some of the aircraft's controls, causing the plane to "slew".
The cabin attendant who fell over was helped back to her feet by a passenger and was able to carry on with her duties.
The flight's senior cabin crew member had grabbed a seat to stop herself from falling, before making her way to the flight deck to assist the aircraft's commander.
She restrained the co-pilot, something that proved "physically demanding" during his second seizure. A passenger also volunteered to assist if needed.
After landing at Manchester, the co-pilot was taken to hospital. He was later released.
The cabin attendant who fell to the floor suffered minor injuries. None of the passengers were injured.
In the report's conclusion, the AAIB said it had been a serious incident professionally managed by the commander and the cabin crew.