An aircraft suffered a loss of power before crashing in Florida, killing its pilot.

CCTV footage shows the Aeromarine Merlin Lite motorglider manoeuvring in midfield, turning right and left, before striking the ground nose-down.

The tragic incident occurred on April 2 last year at South Lakeland Airport (X49) in Mulberry, where the pilot sustained fatal injuries.

Authorities released an investigation this month that confirmed the motorglider was being operated as a Title 14 Code of Federal Regulations Part 91 personal flight.

An incident report from the Aviation Safety Network stated: 'The kit manufacturer manager reported that the accident flight was the pilot/builder's second flight in the motorglider, the first of which was two days before the accident.

'A witness at the airport reported seeing the pilot taxi for takeoff and that the engine sounded 'a bit rough' but due to the nature of the small two-stroke engine, he was not concerned. The witness reported that the motorglider took off and, when it reached about 100ft to 150ft above ground level, the engine sputtered then went silent.'

A post-accident examination of the motorglider revealed no mechanical failures or issues with the airframe or flight controls that would have prevented normal operation prior to impact.

The report continued: ' Examination of the engine revealed that the original airbox had been replaced with an unrestricted cone-type air filter. The main carburetor jet had also been replaced with a smaller jet, which would have resulted in the engine running slightly lean (the builder had reported that he thought the engine had been running too rich).

'Additionally, a hole was noted in the center of the engine's single piston. A metallurgical examination of the piston revealed light gray deposits covering portions of the crown surface around the hole.

'The piston crown had features consistent with pre-ignition damage. This damage was likely the result of an excessively lean mixture due to the unrestricted air intake and smaller main jet. The hole in the piston would have resulted in a total loss of engine power.'

The National Transportation Safety Board (NTSB) released its final report on June 4, identifying the probable cause as the pilot/builder's unauthorised engine modifications.

Officials added that contributing to the accident was the pilot's failure to maintain sufficient airspeed and his exceedance of the aircraft's critical angle of attack after the power loss, leading to an aerodynamic stall and spin at an altitude too low for recovery.