Incident Overview
On 27 October 2017 at 1820 UTC, a Saab 2000 aircraft, registration G-LGNS, experienced smoke in the cabin while taxiing onto the stand at Sumburgh Airport after an uneventful landing. The aircraft was operating a commercial passenger flight with 4 crew and 18 passengers. No injuries were reported, and no damage occurred.
History of the Flight
The commander reported that just as the aircraft taxied onto the stand, Cabin Crew 1 at the rear made an emergency call about smoke at the rear of the cabin. With winds exceeding 40 kt, the commander continued onto the stand and parked into wind. A second emergency call from Cabin Crew 2 reported smoke in the centre of the cabin. Both cabin crew members noted the smoke became visible after landing when cabin lights were switched on. The flight crew shut down the engines, and the commander opened the flight deck door to assess. Passengers were disembarked through the forward main door in about 30 seconds. The co-pilot contacted airport fire services, who arrived promptly. On fire crew advice, the rear door was opened to vent smoke and aircraft batteries disconnected. Fire crew found no hot spots in the cabin.
Aircraft Air System Description
The aircraft has two air conditioning packs supplied by compressed air from engines or the APU. The cross-bleed valve normally remains closed except for engine start. The APU, typically used only on the ground, supplies air to the right pack. The commander noted the smoke report coincided with APU start after landing.
Operator's Engineering Investigation
Operator engineers operated both packs on the ground and detected a strong oil smell from the right pack. Blue acrid smoke appeared in the cockpit, and the right heat exchanger was very dirty. The cause of the smoke was oil contamination of the air bleed from the APU. The APU and right heat exchanger were replaced, with no further smoke reports.