Accident Zenair STOL CH701 971-BS, Sunday 7 October 2012

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Date:	Sunday 7 October 2012
Time:
Type:	Zenair STOL CH701
Owner/operator:
Registration:	971-BS
MSN:	01
Fatalities:	Fatalities: 1 / Occupants: 2
Other fatalities:	0
Aircraft damage:	Destroyed
Category:	Accident
Location:	Ilet du Gosier - Guadeloupe
Phase:	Take off
Nature:	Training
Departure airport:	Hydro Base Ilet du Gosier
Destination airport:	Hydro Base Ilet du Gosier
Investigating agency:	BEA
Confidence Rating:	Accident investigation report completed and information captured

Narrative:
The student and the instructor took off from the water aerodrome at Le Gosier to carry out an instructional flight. Shortly after take-off at around 200 ft, the student indicated that the instructor was taking over the controls, reduced the power and announced that there was a problem and that they were returning. The float-equipped ultralight banked to the right, the instructor is unable to control the bank. The aircraft hit the surface of the sea in a right turn with a steep bank attitude. The aircraft sank to a depth of 3 m around 300 m from the shore.

It is likely that during the take-off, the right rear shroud ripped due to the forces exerted on the wing (lift) as well as the repeated impacts of the floats on the sea surface. The failure of the shroud resulted in:
- a change in the right wing pitch, reducing lift and causing the microlight to turn to the right;
- a release of tension in the aileron control cables, making warp control ineffective

The accident is due to the pilot's underestimation of the effect of corrosion on the shroud's resistance, which led to the loss of control.

Accident investigation: