Two men died when their light aircraft crashed into a lake during a "disorientating manoeuvre" while carrying out an aerobatic training exercise, an inquest heard today.
Instructor Simon Hulme, 33, and his 43-year-old student Spencer Bennett were killed when their light plane crashed at Langford, Essex, on April 28 last year.
It was unclear which pilot was in control of the two-seater Yak 52 when it plummeted towards the ground in an inverted spin.
The pair, who were on the third day of the three-day course, both had controls, with the arrangement being that the student would fly the plane under the instructor's supervision with the instructor taking over if felt necessary.
It was unlikely the spin was intentional and although such a manoeuvre could be recovered from, it was not thought that either pilot had received any training in it or done so before, Tim Atkinson, senior investigator at the Air Accidents Investigation Branch (AAIB) told the inquest.
During the course the instructors would demonstrate new formations and skills ahead of the students trying them out themselves, with the instructors inside the plane with them and able to take control if felt necessary.
Mr Bennett and Mr Hulme were both dead when their bodies were pulled from the aircraft and a post-mortem examination found they died of head and chest injuries.
The force of the crash was "outside the range of human tolerance", Mr Atkinson added.
There were no technical problems found with the Russian-built plane that could have caused the crash, he told the inquest
The coroner recorded a verdict of accidental death on both pilots.