P-47 Aileron question

JDK · **Posted:** Mon Mar 19, 2012 5:08 pm

As a result of the recent P-47 thread, I've been asked: "what was the difference between 'blunt' ailerons and the former ones?"

I don't know, so over the the WIXminds...

JDK · **Posted:** Mon Mar 19, 2012 11:00 pm

As someone asked me, the previous thread was: viewtopic.php?f=3&t=44924

As to the ailerons, any offers?

51fixer · **Posted:** Tue Mar 20, 2012 6:30 am

I don't recall the aileron difference but remember a difference in flap design and operation.
Later versions did away with a couple small doors and linkages IIRC.
As the flap moved the doors would open for clearance. The doors were linked by rods and bellcranks.
Eliminating them reduced construction time, simplified maint and allowed small weight gain.

bdk · **Joined:** Sun May 02, 2004 1:16 am **Posts:** 11330

James, are you suggested that different versions had a differing aileron leading edge radius? As I recall, the Frise type aileron design was common to the P-35, P-43 and the P-47, not to mention the Corsair and many others of the era. The Seversky/Republic ones had a sharp leading edges while the Corsair's were very blunt.

http://en.wikipedia.org/wiki/Frise_aile ... e_Ailerons

greatgonzo · **Posted:** Tue Mar 20, 2012 1:09 pm

The monographs state P-47 ailerons were changed for 'blunt' type starting with D-30 IIRC. I have been unable to find the difference so far but judging from pictures it wasn't anything drastic.

JDK, thanks for giving a try on my query

.

JDK · **Posted:** Tue Mar 20, 2012 5:29 pm

Thanks folks. bdk, I'm not suggesting anything - just passing a question over! However I've now had a chance to look some stuff up. From the first edition of our P-47 Bubbletop book (my emphasis):

"Steel Frise-type ailerons were statically balanced: the port one was fitted with a trim tab, and the starboard one with a spring tab. Metal NACA slotted flaps were hydraulically actuated. Starting with the D-30 batch, additional small split flaps were fitted on the forward auxiliary spar between the main wheel well and the gun compartment, to facilitate dive recovery."

Taking Rich's comment, greatgonzo's original question and the statement above, my best guess is that either there was a modification to the Frise aileron design at the D-30 batch as part of a programme to address dive issues at high subsonic speeds (note the Frise aileron has a potential for flutter - see bdk's reference above) or is a misinterpretation / mistranslation of the modifications / addition of the flaps as 'ailerons' at this development point. But that's a (pair of) guesses.

Of course if this was a Spitfire or Mustang thread, we'd be on page 5 of highly informed debate by now... :roll:

Thanks again to the guys above, but can we find more? Any further P-47 experts out there?

Regards
[EDIT: Correct spelling of 'Frise' rather than Friese amended.]

N77657 · **Joined:** Fri Apr 13, 2007 6:50 am **Posts:** 68

I claim to be an expert on nothing, but I do have the Republic P-47 drawings and there is a difference in ailerons depending on the variant. If I remember correctly, the early P-47s did not have the 'blunt' nose. Starthing with the D-23 variant sounds right, but I would have to go back to the drawings to make sure. If you not satisfied with the answers you have received so far, let me know and I'll do some digging.

I've never heard of a 'dive flap' ahead of the main flap. What variant did this start with?

Bill K

greatgonzo · **Posted:** Tue Mar 20, 2012 6:25 pm

D-30 tried on D-28 first being converted to new standard.. I think I'd rather will browse through my P-47 books to produce specific quote and source.

JDK · **Posted:** Tue Mar 20, 2012 6:35 pm

Thanks Bill. The dive flap sounds like the P-38 type, and is an item I was not aware of either. If you've got the drawing, you can be our expert :lol:

- would appreciate a bit more digging if you don't mind.

Clifford Bossie · **Posted:** Tue Mar 20, 2012 9:51 pm

N77657 wrote:

I claim to be an expert on nothing, but I do have the Republic P-47 drawings and there is a difference in ailerons depending on the variant. If I remember correctly, the early P-47s did not have the 'blunt' nose. Starthing with the D-23 variant sounds right, but I would have to go back to the drawings to make sure. If you not satisfied with the answers you have received so far, let me know and I'll do some digging.

I've never heard of a 'dive flap' ahead of the main flap. What variant did this start with?

Bill K

The "Dive Recovery" flaps showed up on the P-47D-30-RE and were placed behind the wheel-wells and ahead of the flaps. In this photo one is seen running top to bottom and the front hinge (to the left) looks like a piano hinge:

bdk · **Joined:** Sun May 02, 2004 1:16 am **Posts:** 11330

JDK wrote:

Thanks folks. bdk, I'm not suggesting anything - just passing a question over! However I've now had a chance to look some stuff up. From the first edition of our P-47 Bubbletop book (my emphasis):

"Steel Friese-type ailerons were statically balanced: the port one was fitted with a trim tab, and the starboard one with a spring tab.

My point was that I wasn't quite sure of your specific question, which appears to not be your question at all...???

I wonder why there is a discrepancy in the name of the designer?

I also was not aware that the P-47 had ailerons made of steel.

If the D-30 had the more blunted ailerons, was this the case for only the bubble-tops then? What about the G?

greatgonzo · **Posted:** Wed Mar 21, 2012 1:14 pm

Actually all P-47 monographs state one of D-30 changes was an introduction of blunt ailerons (MMP book included).

Steel ailerons are news to me too.

Curtiss never went further with their P-47 then a D-10 version so there wouldn't be much chance for new ailerons there.

JDK · **Posted:** Thu Mar 22, 2012 6:32 pm

Time for a *bump*!

bdk wrote:

My point was that I wasn't quite sure of your specific question, which appears to not be your question at all...???

Indeed, I'm not sure of the confusion, honestly. My original post seems clear enough - I was asked a question by someone else, I didn't know the answer, so I relayed it to a post here on WIX for the brains trust to maybe chime in. To be 100% clear, I've no propitiatory interest in the question (or topic) I was just trying to help.

bdk wrote:

I wonder why there is a discrepancy in the name of the designer?

Leslie Frise?
http://aircraftdesigners.blogspot.com.a ... frise.html
No I just misspelled it previously. Corrected.

Quote:

I also was not aware that the P-47 had ailerons made of steel.

Thinking about it, I agree, it sounds a bit suspicious to me - alu alloy would be normal. AFAIK (and I didn't edit that book) that section of information is usually taken from the official manual.

Anyone with a P-47 source covering ailerons further?

bdk wrote:

If the D-30 had the more blunted ailerons, was this the case for only the bubble-tops then? What about the G?

Just to avoid a degree of extra confusion, our book I referred to covers only bubbletops; it's not (and I'm not) making any statements over the whole of the P-47 development and changes or models outside the bubbletop set. Outside that I don't know.

Regards,

greatgonzo · **Posted:** Fri Mar 23, 2012 5:46 am

The E&M for P-47D states clearly the ailerons were alluminum alloy. Looks like the author used the word steel instead of metal.
Hinges were alluminum alloy too by the way, but forged.

N77657 · **Joined:** Fri Apr 13, 2007 6:50 am **Posts:** 68

Well, I finally had some time to go through my P-47 drawings and found that the blunt nose ailerons were introduced on the P47D-30 and up, including the N model. The other style, prior to the -30, were used on the B through -28 and the G model. If I knew how to post a picture, I would post the drawings of the two aileron noses ribs. I'll see if I can find a way to do this.

Adding to the confusion to the 'steel' aileron ribs, I have found nothing that says they were made of any type of steel. All my drawings say aluminum. However, the very early B models, those with fabric covered rudders and elevators may have used stainless steel for the ribs. I have the drawings that show this, but I have no other evidence that those elevator and rudder ribs were made this way. I believe there were a few B models with fabric covered rudders and elevators, but were quickly changed over to aluminum skinned versions: certainly after the first 30 B models produced.

Bill K

Warbird Information Exchange

P-47 Aileron question

Who is online