Lessons Learned: Trainee Pilot Moves Fuel Control to Wrong Position
Trainee pilot of Robinson R22 Beta, G-KKRN inadvertently moved fuel control to wrong position.
At approximately 800 ft agl while approaching White Waltham, the trainee pilot of a Robinson R22 Beta, G-KKRN inadvertently moved the fuel mixture control to the lean position instead of selecting the carburetor heating (carb heat) on. The selection of lean caused the engine to stop. The incident occurred on February 3, 2025, near Wokingham, Berkshire.
After immediately taking control, the instructor established the helicopter in autorotation but did not have sufficient time and height available to initiate an engine restart. While the helicopter experienced a partial rollover on landing, neither pilot was injured in the accident. The risk of misidentification of the mixture control when selecting carburetor heating in the Robinson R22 Beta (R22) was first formally documented by the manufacturer in January 1981. The instructor was aware of the misselection risk and had briefed his student on the correct operation of the controls before the accident flight.
This accident is a reminder that, while risks can be identified and mitigated, the limitations of human performance mean lapses leading to risks maturing cannot be completely eradicated.
The accident occurred on an R22 conversion course for a pilot who was already qualified on the Guimbal Cabri G2 (G2) helicopter type. On the morning of February 3, 2025, the trainee satisfactorily completed a general handling/familiarization flight in G-KKRN. The syllabus for the second flight included simulated emergency handling, engine out training, and practice autorotations.
Before flight, the instructor briefed the trainee on all aspects of the exercises to be undertaken, including the risk of carburetor icing and the appropriate use of carburetor heating. On both flights, the trainee occupied the right seat and carried out the full start sequence, including checking the correct operation of the carburetor heating system.
The flight progressed as planned until the aircraft was being positioned to rejoin the circuit at White Waltham. Shortly after passing visual reporting point Sierra (M4 Junction 10), the instructor asked the trainee to descend to circuit joining height. He initially began descending without selecting carburetor heating on so the instructor asked him to level off and reminded him of the need to select carburetor heating before entering a descent. The trainee was then instructed to continue the approach and descend.
At this point, the trainee reached down and pulled what he thought was the carb heat control but was actually the mixture control. Realizing his mistake, he called that he had “pulled the fuel” at which point the engine rpm was dropping rapidly. The instructor immediately took control and entered autorotation from approximately 800 ft agl.
Once autorotation had been established, the instructor asked the trainee to push the mixture control back down to the fully rich position, the intent being to try an engine restart if time allowed. Having established the autorotation as his immediate priority, the instructor then focused on field selection. With the M4 motorway to his right, and trees and powerlines to his left, the only viable option was the ploughed field ahead. At this stage there was not enough height left to consider a restart, therefore the instructor concentrated on executing an engine-off landing at the slowest possible forward airspeed.
As the skids touched down, they dug into the soil and the helicopter tipped forward onto its nose before “gently” rolling to the right. During the period immediately after ground contact, the main rotors struck the rear empennage, which detached from the helicopter and was thrown forward of the wreckage.
Neither pilot was injured in the accident, and both were able to self-evacuate through the left door.
Content/image source/credit: AAIB (Air Accidents Investigation Branch), “AAIB investigation to Robinson R22 Beta, G-KKRN,” published September 11, 2025.
