Canopies
If a canopy opens in flight, it can be disastrous. Uncontrolled opening on the ground will usually result in damage.
Here’s a note recently published by one of our busier gliding clubs, which states: the simple rule is, if the canopy is closed, it is locked.
The pre-flight checks also include checking that the canopy is down, locked and resists upward pressure (via a suitable part of the canopy frame).