AAIB Special Bulletin S1/2015 - Saab AB Saab 2000, G-LGNO
Loss of control in flight, near Sumburgh Airport, 15 December 2014.
The flight crew decided to discontinue their approach to Runway 27 at Sumburgh Airport because of weather ahead. As it established on a southerly heading the aircraft was struck by lightning. The commander made nose-up pitch inputs but perceived that the aircraft did not respond as expected. After reaching 4,000 ft amsl, the aircraft pitched nose-down to a minimum of 19° and the applicable maximum operating speed (Vmo) was exceeded by 80 KIAS with a peak descent rate of 9,500 ft/min. The aircraft started to climb after reaching a minimum height of 1,100 ft amsl. Recorded data showed that the autopilot had remained engaged, and the pilots’ nose-up pitch inputs were countered by the autopilot pitch trim function, which made a prolonged nose-down pitch trim input in an attempt to maintain its altitude-tracking function.