Wind probably caused difficulties for a helicopter piloted by the former world rally champion Colin McRae that crashed killing all four people on board, an inquiry heard.
A civil engineer, Donald Cook, said the aircraft appeared to be flying lower than normal but the engine had seemed fine. He told the inquiry into the September 2007 crash: "It was quite a windy day. I thought, the guy's probably having difficulty flying in that condition."
The crash killed McRae, 39, his five-year-old son Johnny, the boy's six-year-old school friend Ben Porcelli and a family friend, Graeme Duncan, 37.
The aircraft came down near McRae's home in Lanark as he flew home from a trip to see a friend.
Cook, 54, told Lanark sheriff court he was out walking his dog when he spotted the aircraft flying low. "It was at maybe three or four hundred feet, quite a bit lower than helicopters would normally fly at."
Several witnesses spoke of an unusual noise from the helicopter.
Robert Muncie, 54, said it had been making a "clunking" noise like the sound of bricks in a cement mixer. And Anne Cooper, 57, said it was making a noise like coins in a washing machine.
The inquiry will resume on 24 January.
