Author Topic: Internal vs. external gust locks: any difference?  (Read 3706 times)

Offline RagDragger

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Internal vs. external gust locks: any difference?
« on: July 19, 2010, 06:58:19 PM »
Ok all, I have a technical question for the brain trust here:

I'm currently flying a 172 in a corporate flight department.  Where the aircraft is currently based, there is no hangar space available.  As a result, it sits outside with the internal gust lock in place in order to prevent damage to the control surfaces by the wind.  My boss seems to think that this is insufficient and the wind blowing over the control surfaces, even with the internal gust lock, is essentially "putting hours on the airframe."   He wants to acquire external gust locks.  I'd agree that a rudder lock would be a good idea, since the internal lock doesn't cover that on a 172.  Here are my questions:

1.  Is there any truth to the idea that the wind blowing over the internally locked control surfaces is putting wear on the airframe in any way equivalent to flight?  I have to admit I'm skeptical on this point.   

2.  Are external locks on the ailerons and elevators going to be any more effective than the internal lock? 

Any A&P's out there who can help me with this one?  Thanks in advance.   
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Offline Mike

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Re: Internal vs. external gust locks: any difference?
« Reply #1 on: July 20, 2010, 05:59:43 AM »
I can ask around but here is my first gut instinct after having worked on these things for a while:

1.) I don't think sitting in the wind counts as flying-wear-and-tear. But I do know that trucking helicopters is really hard on them versus flying them, They're just not designed for it. So airplanes could take a similar beating in the wind....
And of course the sun will probably be your bigger problem, messing up your panel, those little sun blinds some Cessnas have, and all the interior plastic (the plastic aroud the vents coming from the spar loves to get brittle and fall off)

2.) If you have just a control lock and a cross wind blows on your rudder, it will put stress on the rudder and the whole linkage all the way back to the control yoke. If you have a lock right at the control surface you wouldn't stress the linkage as much. Now, I am not sure how much wind it would take to bend something right there at the rudder but gut instinct would speak for a lock right at the rudder/aileron and whatever you think you need to put it on.


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Offline RagDragger

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Re: Internal vs. external gust locks: any difference?
« Reply #2 on: July 20, 2010, 09:21:50 PM »
That was kinda my feeling.  I dunno, I'll have to see what the bossman decides he wants to do.  Thanks!
God looks out for drunks and dumb animals.  Fortunately, I qualify on both counts.