History of the Flight
On 3 October 2019, a Cessna 152 (registration G-BMXA) departed Perth on a training flight with a planned route to Edinburgh and return. Approximately 15 minutes after takeoff, thick white smoke began entering the cabin through the heating vents. The instructor, who held a Private Pilot’s Licence with 388 total flying hours (59 on type), took control from the student and initiated checklist drills for an engine fire. He retarded the fuel mixture lever to idle cut-off and accelerated to VNE, but quickly noted no signs of flames, only smoke. He readvanced the mixture to fully rich to keep the engine running and broadcast a MAYDAY call to Perth Radio, apprising them of the situation and his intention to make a precautionary forced landing.
The instructor instructed the student to liaise with air traffic control. The student entered squawk code 7700 on the transponder and provided position updates. Selecting a suitable field, the instructor positioned the aircraft for landing. At approximately 400 ft agl, confident of reaching the field and its suitability, he selected full flap and shut down the engine. The aircraft landed in a field of recently planted crops. The two occupants vacated the aircraft and moved upwind, taking the fire extinguisher. Neither crewmember was injured, and the aircraft suffered no damage.
Aircraft Examination
After landing, the crew observed oil streaking down the left side of the aircraft and dripping from beneath the engine cowling. Subsequent examination revealed a crack in the engine crankcase. The crack had caused a significant oil leak, which was the source of the smoke entering the cockpit.
Analysis
The instructor recognized the absence of flames and chose to keep the engine running until assured of landing in his selected field. Given the extent of the oil leak, it is unlikely the engine would have continued running long enough to reach an airfield. The field landing was an appropriate and well-executed decision.