ASK 13 rapid de-rotation after ballooned landing injures instructor

An instructor was seriously injured when an ASK 13 de-rotated sharply after a ballooned landing at Lasham; the glider was undamaged and the pilot-in-command unhurt. On an instructor revalidation flight, the pilot-in-command role-played as a student and ballooned the touchdown; the instructor took control, but the glider settled tailwheel-first and pitched down rapidly onto its main wheel. The probable cause was the rapid de-rotation following the balloon; a faster airbrake closure would have moderated the pitch-down.

1. Approach to land at Lasham: On an instructor revalidation flight, the ASK 13 was on final at Lasham; the PIC role-played as a student, with the instructor under revalidation in the other seat, listed as Passenger.
2. Instructor revalidation context: AAIB observes that instructor revalidation flights carry a slight increased risk of mishap when an unexpected or unusual inject is made, particularly during crucial phases.
3. Roleplay misalignment: The PIC's self-assessment: the pre-flight brief should have made clearer that, with the PIC role-playing a student, the instructor should not assume a high standard of flying.
4. Ballooned landing: As the aircraft was about to land, the PIC (acting as a student) performed a ballooned touchdown — a sudden unwanted gain in height as the glider neared the ground.
5. Instructor takes control: The instructor immediately took control of the glider to recover the landing.
6. Tailwheel-first, rapid de-rotation: The glider landed tailwheel-first and de-rotated rapidly. PIC's self-assessment: faster intervention to close (and keep closed) the airbrakes would have prevented the rapid de-rotation.
7. Serious injury to instructor: The instructor (listed as Passenger in the AAIB record) sustained a serious injury during the landing. The PIC was uninjured and the glider was undamaged.