P-47 flaps

[DaHand]

http://rwebs.net/avhistory/opsman/pursuit/section6.htm
In this copy of the P-47 flight manual, it says never lower flaps above 197 mph.
All of our 47's can lower a notch well above 300mph. Who is correct?

I would bet hitech knows more than the web home for Pat and Randy Wilson. 

[Charge]

"Generally what flaps will do is allow you to reach higher AoA and hence higher lift for the price of extra drag"

I'd say no. Me bets you can actually pull less AoA because what the flaps do they increase the camber of the wing, but that happens in relation to fuselage, so in fact for the same speed -as you deploy flaps- you'd need to push nose down to maintain same altitude.

Only slats enable you to pull more AoA than would be normally possible for that particular wing profile.

-C+

[Stoney]

I'd say no. Me bets you can actually pull less AoA..

That's correct.  Flaps decrease the stall AoA of the flapped area, but increase the Clmax of the flapped area.  So, at the same AoA you get more lift from the flapped area.

[Stoney]

I would bet hitech knows more than the web home for Pat and Randy Wilson. 

Its actually a very good web resource on the P-47.

[RTHolmes]

I would bet hitech knows more than the USAAF, who commissioned, tested and flew jugs in combat. 

fixed. still want to bet?

[SmokinLoon]

http://rwebs.net/avhistory/opsman/pursuit/section6.htm
In this copy of the P-47 flight manual, it says never lower flaps above 197 mph.
All of our 47's can lower a notch well above 300mph. Who is correct?

My wife's grandfather, the late Ted Davis, was a naval aviator instructor during WWII.  He was stationed in TX.  Before he passed away I had many wonderful conversations with him regarding the F4F/FM2, F4Ux, F6F, and some other aircraft.  One of the things he mentioned was the menouvers they were not supposed to attempt or teach, but did anyway.  The manuals, the company reps, and the Sr. instructors were all dead set against doing things the manurfacturer said not to do.  When out and away from the tower, the actual instructors pushed those aircraft to the limit and did things they were never supposed to do.

I think that would include deploying flaps at certain "forbidden" speeds.   

[FLS]

The difference is that landing uses full or near full flaps for drag as well as slow speed lift. I've read recommendations for 50% flaps at high alts for P-47s in order to improve handling. It's likely that they were going faster than 195 MPH at 30-40k altitude.

I can't find where I read this so I may be confusing it with another aircraft. I found a reference for a P-47B that if you dropped flaps above 190 MPH they would only deploy a few degrees until your speed reduced. No mention of this in the POH for the later models so I can't say if that changed.

[2bighorn]

"Generally what flaps will do is allow you to reach higher AoA and hence higher lift for the price of extra drag"

I'd say no. Me bets you can actually pull less AoA because what the flaps do they increase the camber of the wing, but that happens in relation to fuselage, so in fact for the same speed -as you deploy flaps- you'd need to push nose down to maintain same altitude.

Increase in camber increases lift coefficient (in most cases). Basically, at given speed you get more lift, hence you can increase max AoA with flaps.

[Stoney]

Basically, at given speed you get more lift, hence you can increase max AoA with flaps.

Typically, your stall AoA decreases.  Or, to be more precise, the effective AoA of the wing increase because the chord line slope increases when flaps are deployed (the trailing edge of the wing is lowered, hence the chord line is "steeper").  So, no, you don't increase your max AoA.  You do increase your Clmax though, hence more lifties.  Slats can increase max AoA, but not flaps.  Slats give the chord line a more shallow slope, which lowers the effective AoA. 

This link illustrates better what I'm trying to relate here...

http://www.nordian.net/pdf/easa_principles_of_flight_demo.pdf

[STEELE]

I can't find where I read this so I may be confusing it with another aircraft. I found a reference for a P-47B that if you dropped flaps above 190 MPH they would only deploy a few degrees until your speed reduced. No mention of this in the POH for the later models so I can't say if that changed.

Crump (banned  ) posted pages and pages of material on the fw 190's , including but not limited to, the fact that flaps could and were deployed as combat flaps at speeds in excess of 300mph. If your search this forum for said info, U will find it has been erased or get a "404" message (page not found)   
So all of our AH 47's get to deploy flaps well above 300mph despite what the manuals say, but the 190's/109's H E double hockeysticks NO!   Now what??

[FLS]

We don't have the P-47B. If you have an actual reference for a FW190 deploying flaps at 300 mph please post it.

[save]

Yes, and the 109 could get flaps out up to 700 km/h
we have had that flight curve in this forum before.

The P-47 flaps are fully variable like the 109.  Looking at various POH's for the P-47D's they state:

(Image removed from quote.)

(Image removed from quote.)

From this we can infer that the stated restriction is most likely the lower bound limit for full flap extension for landing and not limits for partial flap extensions.

[Stoney]

Crump (banned  ) posted pages and pages of material on the fw 190's , including but not limited to, the fact that flaps could and were deployed as combat flaps at speeds in excess of 300mph. If your search this forum for said info, U will find it has been erased or get a "404" message (page not found)   
So all of our AH 47's get to deploy flaps well above 300mph despite what the manuals say, but the 190's/109's H E double hockeysticks NO!   Now what??

Like i said Steele, HTC obviously wants the Luftwaffe rides to underperform...   

p.s.  The conspiracy talk just strengthens your overall argument.

[dtango]

Pyro's statement on 109 flaps...

It was my intent to increase the number of flap notches in the 109 to the maximum of 5 that the system supports since it had a completely variable system.  

On the issue of speeds, I had assumed I was mistaken since so many people were stating that to be the case.  However, I checked the German 109E manual, the Finnish G-2 manual, and the German 109K manual just to be sure and they all stated the same thing.  Don't operate them at speeds greater than 250 km/hr, don't have them full down at speeds greater than 250 km/hr.  Now in this version, I've stretched this out to the limit of credibility IMO unless I want to throw out the standards we've used for everything else and just crank up the numbers on everything.  But I've already explained that we're not going to do that.

What about the P-47 flaps?  It appears there isn't consistency like the 109 manuals regarding the flap limits.

P-47B/C/D/G manual (TO No. 01-65BC-1) - 195 mph limit
P-47D manual (AAF No. 50-5) - no mention of flap limits
P-47D-25 to D-35 manual (AN 01-65BC-1A) - don't extend flaps / have them full down above 190 mph
P-47N manual (AAF 51-127-4) - no mention of flap limits

[dtango]

Like i said Steele, HTC obviously wants the Luftwaffe rides to underperform...  

p.s.  The conspiracy talk just strengthens your overall argument.

STEELE = Crumpp???