Ice caused flight to stall

A LOGANAIR flight from Aberdeen to Sumburgh with 28 people on board stalled mid flight due to a build up of ice, according to accident investigators.

The Loganair-operated Saab 340 was 30 minutes into a 9am flight on 3 October last year when it experienced difficulties.

The aircraft was climbing when ice started forming on its windscreen wipers and it stopped accelerating properly.

Suddenly the plane experienced a few seconds of vibration, similar to a “car driving over a cattle grid”.

The autopilot disengaged and the 51 year old pilot took control, pitching the aircraft downwards, which stopped the vibration and allowed the autopilot to re-engage after a few seconds.

The aircraft continued to Sumburgh where it landed safely, with no one injured.

The Air Accident Investigation Board report published on Wednesday said: “Once level, the aircraft did not accelerate as expected and a descent was initiated, with the autopilot engaged using vertical speed mode.

“An unusual vibration was then experienced, followed by a stall warning system activation and the autopilot disengagement.

“The aircraft was recovered in a non-standard manner, a safe airspeed was achieved and the autopilot was re-engaged. Unusual ice formation on the wings corroborated calculations by the manufacturer that the aircraft had encountered severe icing.”

As a result of the incident the aircraft’s two pilots and one cabin crew were given extra simulator training to practice stall recovery and a new training programme has been introduced.