P-51D Turn Comparison With 1 Notch Flaps

[WarTooth]

Guys,

I've always wondered just how much better a P-51D is at turning when that 1st big notch of flaps is deployed (at 400 mph or less).  I have been using this with mixed results not quite knowing the comparable turn radius.  The Gonzo site is nice but lists only turn radius when flaps are set to FULL.  Some have claimed Zero like turn ability (I doubt it).  Some choose never to use it in this manner (too much speed loss etc.).

For you long time P-51D pilots, when it has deployed the first notch flaps which (non-flapped, trimmed etc.) plane can you compare it to in turnability?

Thanks,

WT

[moot]

I'd give you a link to the few threads where this was discussed in detail, including some with comparison charts, but I can't recall what some of the key words (to search for) were..  You could probably find it pretty easily though.  It's somewhere in this AC&V forum.

[WarTooth]

moot,

I did do some searching before and after your post.  I found some good posts on the P-51 but they do not seem to answer my question.

Thanks sir,

WT

[moot]

The only answer I'm sure about is the tests Kweassa made with all planes a while back, which I think were in the present flight model revision.  He tested them with no flaps, one notch, and full flaps.  I made a bar diagram for one of the data sets.. I think for no flaps.  If you dig it up I'll make a chart for the other two.
The thread was started by Kweassa, I can't remember any word in the title though. Sorry

[VansCrew1]

Guys,

I've always wondered just how much better a P-51D is at turning when that 1st big notch of flaps is deployed (at 400 mph or less).  I have been using this with mixed results not quite knowing the comparable turn radius.  The Gonzo site is nice but lists only turn radius when flaps are set to FULL.  Some have claimed Zero like turn ability (I doubt it).  Some choose never to use it in this manner (too much speed loss etc.).

For you long time P-51D pilots, when it has deployed the first notch flaps which (non-flapped, trimmed etc.) plane can you compare it to in turnability?

Thanks,

WT

At the top of the rope is when i use flaps the most. Also i use anywhere from 1 notch to full flaps to force someone to over shoot. For getting the typical plane off your six i use 3 to 4 notches while moving back and forth forcing him to overshoot and generally ill have enough speed to get a shoot on him or turn with him if i have to. Along with flaps throttle control is big as well as the "K" key(or whatever you have it set as) for trim up.

[SectorNine50]

I know I was reading somewhere on the Aces High website that said something like "if you get to more than 2 notches of flaps, your probably in over your head."  I really strongly disagree (at least in terms of in-game... I'm not going to talk about real life with a man who's actually flown a Pony... ), sure there are times where you REALLY don't want to get that slow, and putting out that many notches would be an awful idea.  The Pony turning ability is really helped quite a bit by flaps, plus you can decelerate at an incredible pace with those combat flaps that come out early.  It's funny to watch Spits spaz when they realize your slowing as quickly as them.

In terms of "zero like turn ability," I think what most are talking about is the ability to float about like the Zeke can.  A lot of the American aircraft with combat flaps have this ability, I'm sure you've heard of/seen an F4U maneuver at very slow speeds giving them the image that they are floating in air as you fly past.  However, if you put a Zeke and a F4U or Pony in a "float fight," the Zeke will win hands down.

You actually gain quite a bit of turning ability off that one notch of flaps, and even more on the notches above 10 degrees (But remember to be constantly adjusting them, you want those puppies up as much as possible so you don't bleed E unnecessarily).  A really good demonstration is to get someone to get on another Pony's six, and try to maneuver with it without using flaps at all, it will give you an idea of how much those flaps really help (even though it's not a concrete number), even at just one notch.

(I rambled a bit... But I think I at least touched on the topic... lol)

[moot]

Sector, the F4U is by far the most agile US plane in flap fights. It's the exception rather than the norm, in the US planeset. It has enough thrust to keep fighting even in full flaps. The pony is one of the worst because of how little power the engine puts out.  One notch of flap is the most efficient flap position in terms of extra lift/drag ratio in a knife fight, as well as strictly in terms of turning radius (IIRC).
The P38 has very exploitable flaps but isn't as deft as the F4U.

[Angus]

Was just about to say that.
Knew a pilot who got out of a tough turnfight with a 190 with his P51C, - with one notch of flaps.
The German bailed and lived.

[Charge]

Interesting fact Angus, as always. Why did he need flaps to get out of a "tough turnfight" with an a/c with much bigger wing loading? And why did the "Germie" finally bail? Was he devastated that the P51 got away and rather bailed than went home and faced the ridicule of his fellow pilots?

Fascinating. 

-C+

[Wmaker]

Interesting fact Angus, as always.

 

[WarTooth]

moot,

Though no one is answering the question I asked, but offering cool and appreciated advice, the Kweassa material should be adequate for me to find the answer on my own.  If no one if forthcoming that knows the answer to the question I asked I'll be sure to post my findings.

Thanks for pointing me in the right direction,

WT

[moot]

Here's that thread..
http://bbs.hitechcreations.com/smf/index.php/topic,166537.0.html

[WarTooth]

moot,

That rocks!   

Thanks sir,

WT

[Obie303]

Why can't we get Kweassa's post stickied or at least put on the Trainer's page?  Lots of good information there.

[dtango]

Wartooth:

Here's a chart posted by Badboy about a year ago.  This is a chart of the P-51D comparing sustained turn rate and radius with various flaps settings.  It was in a very long thread we had about P-51 flight modelling here:
http://bbs.hitechcreations.com/smf/index.php/topic,212801.msg2545404.html#msg2545404

P-51D Sustained Turn Comparison with Flaps



P-51D Instantaneous Turn Comparison with Flaps
Here's a cobbled up EM chart I did back in 2003 for some internal training I was doing with the 412th which has some assessment related to instantaneous turn performance.  (The Ps=0 line is for WEP power setting).  It's a much older FM so I wouldn't rely on the actual values but it demonstrates what you might expect in relativity.




One of the not so obvious axioms of air combat is that performance is relative.  Be wary when someone gives advice that has "always" or "never" in it.  For instance let me give you two examples related to this topic:

(1) P-51D Instantaneous Turn Comparison with Flaps RELATIVE to Other Aircraft




Here's the same EM chart I did in 2003 with the La-7 and F6F-5 compared relative to the P-51D.  Again older FM so the values may be different now but it illustrates the point I'm trying to make.  Dropping 1-2 notches of flaps may help the P-51D in a instantaneous turning against an La-7.  However against an F6F-5 in this case deploying flaps for the P-51D is not really useful at equalizing the relative performance difference.


(2) P-51D Instantaneous Turn Comparison with Flaps RELATIVE to Weight



From the same 2003 data here is a comparison of the P-51D's instantaneous turn performance with flaps but at various weights.  As you can see the relative difference in weights for the same aircraft can make a huge difference in turn performance with or without flaps.  For instance in a P-51 to P-51 matchup, the P-51 with 25% fuel might not want to deploy flaps against a P-51 at 75% that may be at 1 notch because the lighter Mustang has a better instantaneous turn performance vs. the heavier one while bleeding less E because of the reduced drag of not flaps deployed.

Cheers!

Tango, XO
412th FS Braunco Mustangs