Gust Locks
 

Or Lack of.....
T'other night at Manch, we observed Airbus "type" a/c rudders "swinging" in the breeze. Is there an SOP to fit a lock? Either physical, [chock] or hydraulic [lock], or do the beggahs swing free?
watp,iktch

Many turboprops such as Dornier 328, Dash 8 etc, have Gust Locks for that very reason. I suppose they are more prone to it than larger aircraft.

BAe 146

Doesn't the ATR have a gustlock? But its gust lock is for the throttle, which I don't quite understand.

You shouldn't need a gust lock if the aircraft has irreversible hydraulic controls as the PFCUs will hold the control surface in position. With manual controls a gust lock will be needed to stop the surfaces slamming about in a strong wind and getting damaged. I don't know the ATR but the "gust lock on the throttle" sounds like the system on the BAe748. This has a gust lock lever in the cockpit which locks the controls. With the gust lock engaged you can't move one (or it might be both) throttle levers forward of the half way mark. This is to stop you inadvertently getting airborne with the gust lock engaged.

Yep, but this was an Airbus319. Aircrew said that hydraulics "died" so controls' "free"
watp,iktch

With Airbus 320 family when shut down, the ailerons droop and rudder swings free. Never seen a lock on one, never had a problem with one being wind damaged...