The Aero AT3 is a part -21 aircraft which has a history of the canopy opening in flight. This is a common event although I have not heard of a canopy detaching from the aeroplane.
The overhead canopy pops into the fuselage by two lugs either side forward of the firewall. There are no conventional hinges. The canopy rotates forward vertically around the lugs assisted by two hydraulic closers, one either side. The canopy must be lowered with care as it twists side to side if not held centrally and therefore can be closed off centre. If this is the case then the locking pins will miss the associated slots at the rear of the opening even though the locking lever can be moved to the locked position. The canopy will not be locked when this happens. This failure to lock cannot be seen and can only be known by pushing outward at the rear pin point on each side. This takes some effort. If the pins have missed the slot the canopy can be pushed outward and this movement can be seen.
Last edited by Fl1ingfrog; 10th Mar 2021 at 11:12.