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Purpose of Cable Restraints on Bearcat Outboard Gear Doors?

Posted: Wed May 20, 2009 8:35 pm
by octane130
Does anyone know the purpose of the restraining cables between the outboard main gear doors and and the struts on the Grumman Bearcat? Are these maybe to keep control of the doors (i.e. keep them from deforming or departing the aircraft) if you exceed max gear-down speed, which I understand is quite easy to do?

Image

Posted: Wed May 20, 2009 9:30 pm
by retroaviation
Good question and good guesses, but what that cable does is it actually pulls the lower portion of the gear leg back into the upper portion when the gear is retracted. In other words, the gear struts extend so far (because they're built to land on carriers) that if they weren't pulled back "in," the tires would meet in the middle when the gear is retracted. Does any of that make sense?

Howard Pardue's -1 Bearcat has a spring loaded mechanism that looks more like a shimmy dampner that you'd find on a Spam can or something.

Also, the Corsair and the Helldiver have a very similar setup, using cables to "compress" the gear upon retraction, so it will fit in the wells. NEVER let a line guy convince you to air up the struts on your Corsair, Bearcat, or Helldiver, by sight, as this will potentially put enough pressure on the strut that it can break the cable, causing the gear to "miss" the wheel well and make your sheet metal guy pretty mad. ;-)

Gary

Posted: Wed May 20, 2009 9:45 pm
by octane130
retroaviation wrote:Good question and good guesses, but what that cable does is it actually pulls the lower portion of the gear leg back into the upper portion when the gear is retracted. In other words, the gear struts extend so far (because they're built to land on carriers) that if they weren't pulled back "in," the tires would meet in the middle when the gear is retracted. Does any of that make sense?

RETROAVIATION: Your explanation absolutely makes sense; I'm a technical guy, but I would have never guessed that explanation myself though :lol:. Question answered. Keep up the good work with your Fifi posts and all the others. Believe me, your posts are just fascinating and well appreciated. :lol:

Posted: Wed May 20, 2009 10:02 pm
by airnutz
Ditto! Thanks for 'splainin Retro! :D

Posted: Thu May 21, 2009 8:43 am
by retroaviation
Glad to help. :-)

Gary

Posted: Thu May 21, 2009 1:29 pm
by Matt Gunsch
That is something that is not limited to Warbirds, the Bellanca Viking uses a cable to compress the strut to fit it into the wheel well. that is one plane you check the pressure in the struts when you are done servicing it.