A passenger plane carrying 47 people was forced to make an emergency landing at Inverness Airport yesterday after a vapour rose from the floor minutes after take-off.
Passengers on the 2.40pm flight to Manchester feared it was smoke at the time.
But a spokesman for operator Loganair confirmed that the fault was determined by engineers to be excess water vapour from the air-conditioning system.
Passengers were due to be transferred on to another plane yesterday evening to make their journey south.
Subsequent flights were delayed as a result of the issue which resulted in a full-scale emergency call out and the plane having to be towed off the runway.
One passenger – who wished to remain anonymous – on board the affected Embraer 145 aircraft said the plane was only in the air for about 10 minutes but it “felt like six hours”.
The man, who flies twice a week between Inverness and Manchester, added: “Smoke (as it appeared) was coming through the floor about five minutes into the flight.
“The cabin crew were rushing round and the next thing we were coming back in to land. The smoke appeared again as we were landing.
“It was not a very nice experience, let’s put it that way, but the staff were superb in handling it.
“I think the pilot did well in not saying anything, as that would have created a panic.
“There were a few women panicking a bit, but not very much.”
Yesterday at the Dalcross airport, the BMI Embraer 145 aircraft was being towed off the runway and escorted by two airport based fire engines.
A fire service spokesman said that six appliances – three from Inverness, two from Nairn and one from Forres – were initially called to the scene.
Once the plane had been towed back to its stand, engineers could be seen inspecting the aircraft’s landing gear.
The Loganair spokesman said: “Shortly after take-off the cabin crew notified the captain of an irregular vapour coming from the air vents of the Embraer 145.
“The captain immediately returned to Inverness, landing safely – met by emergency services as is standard procedure in this type of scenario.
“The aircraft was inspected by engineers and the fault was determined to be excess water vapour from the air-conditioning system.
“Loganair would like to apologise to its customers for the delay in their journeys which this issue has caused.”
A spokesman for Highlands and Islands Airports Limited said: “Emergency procedures were implemented in response to a request from the pilot and the plane landed safely and everyone disembarked.”