What happened
On 11 April 2014, an Ikarus C42 FB100, registration G-DASS, was performing a private flight from Leicester Airport. Shortly after departing the airfield, the pilot discovered that the throttle was stuck at the full power setting and could not be reduced.
To manage the situation, the pilot climbed to an altitude of 2,400 ft agl over the airfield. After several failed attempts to adjust the power, the pilot made the decision to shut down the engine and execute a glide approach. During this descent, the aircraft encountered an area of sinking air, which resulted in a heavy landing in a field of crops approximately 100 m short of the runway. The impact caused damage to the nosewheel, the left main landing gear, and the propeller. There were no injuries to the pilot.
The investigation
The AAIB investigation focused on the mechanical failure of the throttle control. Examination of the aircraft revealed that the throttle linkage had become caught on a hole located in the side panel of the centre console. Specifically, a witness mark indicated interference between a clevis pin and the panel hole, and the throttle arm was found to be bent.
Investigators found that this specific issue had been previously identified by the Ikarus distributor. A Service Bulletin (SB 28) had been issued in 2010 to address a similar incident where a student pilot was unable to close the throttle. The bulletin recommended an inspection and a modification to replace a fixed spacer with a longer version to ensure the linkage had sufficient clearance from the console panel. The modification had not been performed on G-DASS.