Whilst appearing to be strong, canopy transparencies are easily damaged. Once broken, canopies are difficult and expensive to repair or replace. There are a few basic precautions that can help us avoid canopy mishaps, particularly as we experience stronger winds during the autumn and winter:
– Canopies should not be left open and unattended unless some method of preventing the canopy from closing is designed in, eg a lift up instrument panel. Great care is needed in strong winds, where even a canopy held by a gas strut can be slammed closed or can be stressed and therefore damaged in the direction of opening.
– Seek help to support canopies while getting in & out of gliders.
– When seated in the aircraft, canopies should be either open and unlocked (and supported in strong winds), or closed and locked.
– When opening and closing a canopy, be very careful about applying a load to the direct vision opening in the canopy bubble or to the direct vision panel rails.
– Reaching through a direct vision opening from the outside to pull the cable release will apply stresses to the transparency which will eventually result in cracks. Opening the canopy or using the back-release are much better alternatives.
– If a canopy will not close, do not force it. Stop, open the canopy and check.
– Greasy hand marks on a canopy will become opaque under direct sunlight. Cleaning the canopy before flight will improve vision including by reducing the effect of canopy misting.
– Take care when cleaning canopies. Using the wrong cleaning materials can damage the transparency.