What happened
On April 17, 2005, an EADS Socata MS 880 B Rallye, registration F-BVLE, was conducting a training flight at Toussus-le-Noble aerodrome. Immediately after the aircraft rotated during takeoff from runway 25R, smoke began to fill the cockpit. The instructor took control of the aircraft and performed an emergency landing on the remaining available portion of the runway. Emergency services (SSLIA) met the aircraft and escorted it to the parking area. During the taxi to the parking stand, the smoke dissipated.
The investigation
Upon inspection of the engine cowling, investigators discovered that the oil filler cap had not been properly secured. This allowed oil to leak onto the exhaust system. The investigation focused on the pre-flight inspection procedures and the specific mechanics of the oil filler cap. The cap in question requires being inserted into the filler neck and then turned one-quarter turn to lock it in place.
Investigators found that the student pilot, who had only 13 hours of total flight time, had previously operated aircraft with both this type of locking cap and different caps that utilized a screw-thread mechanism. The student pilot stated that they did not tighten the cap because they believed it was a screw-type cap. Furthermore, the student had been instructed by previous instructors that screw-type caps should only be lightly tightened to allow for easy manipulation.
Findings
- The primary cause of the smoke was the improper securing of the oil filler cap, which allowed oil to escape onto the exhaust.
- The student pilot experienced confusion between two different types of cap closure mechanisms.
- The student pilot possessed insufficient knowledge regarding the specific equipment characteristics of the F-BVLE.
- The instructor had permitted the student to perform the pre-flight inspection independently, relying on the student's proficiency.