Warbirds with folding wings question

Jack Cook · **Posted:** Wed Jul 30, 2008 3:34 pm

Here I was going say 4 but then I was only 11 when Bill Compton was flying his F6F-3. My puny effort probably didn't enter into the equation :shock:

gilt · **Posted:** Wed Jul 30, 2008 3:35 pm

bipe215 wrote:

Chris Brame wrote:

Bearcat - wingtips that snapped off when the plane exceeded its recommended dive speed.

Here pony pony...

I thought it was a 'G' value that determined the snapping off of the outer panels. In other words, if the pilot saw he had to get into a serious dogfight, he could pull x number of G's, lose the wing panels and then pull all the G he could handle. I'm not sure, have to reread Corky's book.

Steve G

The orginal design had a weak point that was supposed to allow 3' of each wing to break away to unload the wings if the G limit was reached. There were problems with the design/function so it was redesigned with different rivets/structure, when that did not solve the problems it was redesigned (again) with a G switch and explosive bolts at the break away joints, when problems continued the break away design was eliminated.

The Bearcat was designed to be a lightweight fighter for "converted carriers" (CVE or Jeep carriers) the USN would not allow Grumman to adhere completely to their orginal lightweight design but it was over 2000 lbs lighter than the F6F with essentially the same size/engine so they needed a way to protect the lighter structure from overload failure, this feature was not designed to allow the pilot to selectively reduce wingspan for combat as has been theorized.

Tom-

davidbray · **Posted:** Wed Jul 30, 2008 4:17 pm

for the Bearcat, if you did lose the wingtips, how did this affect roll stability? did the tips breaking take the ailerons with them? (i haven't had the chance to study a Bearcat up close)

retroaviation · **Posted:** Wed Jul 30, 2008 4:25 pm

I can't find it now, but surely in cyberspace somewhere, there is a picture of a prototype Bearcat with the pilot standing next to it with only one of the wingtips gone. Clearly, he made it back okay, but the program was essentially stopped after that incident.

Gary

famvburg · **Joined:** Fri Oct 07, 2005 9:41 am **Posts:** 540

The new Naval Fighters series book on the F8F by Ginter & Meyer, mentioned in my Fornoff Bearcat Q recently has some pics of the 1-tipped F8F. Regarding the aileron, where it would separate left about half the aileron. It has a pic of it where during testing to blow both tips, only one tip went. The caption says its flight characteristics were hardly effected. Considerng how far off the book is about Fornoff's Bearcats, take that for what it's worth.

retroaviation wrote:

I can't find it now, but surely in cyberspace somewhere, there is a picture of a prototype Bearcat with the pilot standing next to it with only one of the wingtips gone. Clearly, he made it back okay, but the program was essentially stopped after that incident.

Gary

famvburg · **Joined:** Fri Oct 07, 2005 9:41 am **Posts:** 540

What does the Helldiver use?

MKD1966 wrote:

I know the Corsair, Skyraider, Sea Fury and TBM have hydralic wing folds and the Wildcat is a manual fold system, but what about the Hellcat, Tigercat and Bearcat... Just curious as I never seen one of these fold wings at a airshow...

retroaviation · **Posted:** Wed Jul 30, 2008 4:56 pm

The Helldiver is hydraulic.

PeterA · **Posted:** Wed Jul 30, 2008 4:58 pm

Chris Brame wrote:

Bearcat - wingtips that snapped off when the plane exceeded its recommended dive speed.

Here pony pony...

I think the Seafury had a similar system. :wink:

PeterA

warbird1 · **Joined:** Fri Sep 21, 2007 6:25 pm **Posts:** 2760

PeterA wrote:

Chris Brame wrote:

Bearcat - wingtips that snapped off when the plane exceeded its recommended dive speed.

Here pony pony...

I think the Seafury had a similar system. :wink:

PeterA

Peter that's not a factory mod. That is a highly secret picture of the new clipped wing Sea Fury that will be debuting at the Reno Air Races this year! With half of the wing clipped, it's expected to exceed 600 mph! Unfortunately the landing speed is about 200 knots.

bipe215 · **Posted:** Wed Jul 30, 2008 8:34 pm

davidbray wrote:

for the Bearcat, if you did lose the wingtips, how did this affect roll stability? did the tips breaking take the ailerons with them? (i haven't had the chance to study a Bearcat up close)

Corky Meyer had to demonstrate take offs and landings with only one tip gone. They were shooting for the standard 13G airframe but couldn't do it and meet the weight requirements. So they designed it so a 7.5 G pull would lose the tips, then you had a 13G airplane to play with.
There were some quality control issues with the special rivet joint. This combined with the rigors of carrier ops caused some tips to depart at high speed with some fatalities. Grumman then resorted to using explosive prima chord to blow the tips off. They finally perfected this method at the end of the war. Later though, a set of tips blew off while the aircraft sat on the carrier, killing a sailor. They dropped the program and G-limited the airplane after that.
This info from Corky Meyers Flight Journal>

Steve G

JDK · **Posted:** Wed Jul 30, 2008 8:52 pm

Ask as question...

Great answers guys, much more than I could've come up with...

Cheers

51fixer · **Posted:** Wed Jul 30, 2008 9:15 pm

skymstr02 wrote:

warbird1 wrote:

How many people are required to fold the wings on the Bearcat and Hellcat? Can it be done with one person?

On the F6F, two or three guys on the wing, and a guy in the cockpit working the hydraulic pump and the wing lock selector valve. They're really not that heavy, but have a lot of mass.

The lock pin in the F6F is hyd but the folding movement is manual with a lock pin that holds the wing in the folded position. It takes a few hands to push the wing either direction. I just remember that I was too short to push on the wing tip once it got close to being locked in the extended position.
Rich

Hal B · **Posted:** Wed Jul 30, 2008 9:54 pm

warbird1 wrote:

Regarding the manual wing folding aspect of the Bearcat and Hellcat, how exactly is that done? Is it just a matter of unlocking something and then just pushing on the wing, or are ropes or cables involved or what? How heavy are those wings to push around? How many people are required to fold the wings on the Bearcat and Hellcat? Can it be done with one person?

One person can easily fold the wings on a Bearcat. Basically just release the latch, insert a bar in the hole on the lower surface of the outer wing panel (see the picture in Kenlyco's post) then pull up and out on the bar until the wing folds. You just have to hold back on the bar a little as the wing tip goes past vertical.

gilt · **Posted:** Thu Jul 31, 2008 8:23 am

For the full and definitive story...................

http://findarticles.com/p/articles/mi_q ... tBody;col1

jschillereff · **Posted:** Thu Jul 31, 2008 4:45 pm

Here’s a video clip I uploaded that shows the Tigercat unfolding the wings and a little racing from Reno last year. http://www.vimeo.com/1419498
P.S. if you go to the bottom of the page you can down load the videos and they will probably play better on your player rather than the flash one on the site.

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Warbirds with folding wings question

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