Originally Posted by
Mechta
On gliders, a part of the daily inspection is positive control checks in which all the flying surfaces and airbrakes are operated from the cockpit with someone holding the control surface to reist the movement. The regular assembly/disassembly of gliders that live in trailers must be part of the reason for this, but I wonder how common it is in power flying?
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A positive control check won't protect against something rattling around in the glider jamming the controls. It should find if you have mis-rigged the glider.
There was a glider lost earlier this year (pilot OK) because the pilot stopped part-way through rigging for rain and forgot to connect the elevator. He can't have done positives afterwards and launched with the glider in that state. Luckily he was able to bail out and parachute to safety. Most gliders are made to be relatively easy to bail out of - canopies are large for visibility and designed to be easy to eject.
All club gliders should get a positive control check as part of the normal DI, some those of us keeping our private gliders rigged in a hangar only do the check after the glider is rigged.