Interceptor vs Escort.

[Soren]

Bf 109K-4 vs P-51D Mustang


Bf 109K-4 Statistics:

Engine: Daimler Benz DB-605D with MW-50 boost.
Power: 2,000 HP.
Max. Speed: 727 km/h. (452 mph.)
Max. Climb: 1,470 m/min (4,823 ft/min.)
Empty Weight: 2,673 kg. (5,298 lbs.)
Loaded Weight *Clean*: 3,148 kg. (6,940 lbs.)
Max. Weight: 3,373 kg. (7,438 lbs.)
Wing-Span: 9.97 m. (32.7 ft.)
Wing-Area: 16.4 sq.m. (176.6 sq.ft.)
Armament: 2x 13mm HMG's (MG 131) & 1x 30mm cannon (MK 10.

Bf 109K-4 Aerodynamic statistics:

Wing-loading *Loaded*: 191.9 kg/sq.m. (39.2 lbs/sq.ft.)
Wing Aspect-Ratio: 6.06 .
Airfoil: NACA 2R1 14.2 - 2R1 11.35.
Airfoil Thickness Ratio: Root= 14.2% Tip= 11.35%.
Wing CL-max *Freeflow*: 1.48 . (No slats or flaps deployed)

Lift-loading *Loaded*: 129.69 kg/sq.m. (26.5 lbs/sq.ft.)
Power-loading *Loaded*: 1.57 kg/hp. (3.47 lbs/hp.)

Bf 109K-4 Additional features:

-Automatic-Slats & Flettner-Tabs.
-Inclined seat position for better G-load resistance & Friese ailerons.


P-51D Mustang Statistics:

Engine: Packard Merlin V-1650-7.
Power: 1,720 HP.
Max.Speed: 703 km/h (437mph).
Max. Climb: 1,060 m/min. (3,478 ft/min)
Empty Weight: 3,175 kg. (7,000 lbs.)
Loaded Weight *Clean*: 4,286 kg. (9,449 lbs.)
Max. Weight: 5,487 kg. (12,096 lbs.)
Wing-Span: 11.3 m. (37.07 ft.)
Wing-Area: 21.83 sq.m. (233 sq.ft.)
Armament: 6x .50 cal HMG's (M2).

P-51D Mustang Aerodynamic statistics:

Wing-Loading *Loaded*: 196.33 kg/sq.m. (40.5 lbs/sq.ft.)
Wing Aspect-Ratio: 5.81 .
Airfoil: "Laminar" NAA/NACA 45-100 - NAA/NACA 45-100.
Airfoil Thickness Ratio: Root= 14.8 or 15% Tip= 12%.
Wing CL-max *Freeflow*: 1.28 . (No flaps deployed)

Lift-loading *Loaded*: 153.38 kg/sq.m. (31.6 lbs/sq.ft.)
Power-loading *Loaded*: 2.49 kg/hp. ( 5.49 lbs/hp.)

P-51D Mustang Additional features:

-Laminar wing & Tear-shaped canopy.
-Gyro-Gunsight.

----------------------------------------------------------------
Aerodynamic Facts:

Airfoil Thickness Ratio - Higher is better.
Wing CL-max - Higher is better.
Wing Aspect Ratio - Higher is better.

Lift-loading - Lower is better.
Power-loading - Lower is better.

Automatic leading edge slats info:
Slats extend up the range of AoA where the airflow stays attached to the wing. Without slats a wing would stall at a certain AoA, the airflow turning turbulent at the same moment with a sudden enormous increase in drag. With slats the airflow stays non-turbulent for some extra amount of AoA, and there will not be any "stepped" increase in drag when the slats deploy, only at the point where even the slats cannot prevent the wing entering a stall. The automatic-slats work at all speeds, and significantly increase the stall angle and CL-max of the airfoil.
Illustration: http://history.nasa.gov/SP-367/fig63.jpg

Laminar wing info:
Laminar flow wings lowered the drag, but this came at the cost of lower lift, especially under high G loads. A Laminar flow wing will stall earlier and more violently than a conventional wing.
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Wing Cl-max were obtained from:

Bf-109: from full scale Windtunnel test in Charlais Meudan.
P-51: from Naca Report 829, Page 26 in the PDF of the Naca Report server.

[DerAdlerIstGelandet]

Damn very good comparison, and this I believe proves that the P-51D was not as good as most would like to think it is. Not that she was not a great fighter because she was but that she wasn't as good as made out to be.

[lesofprimus]

Superiority in numbers.......

[DerAdlerIstGelandet]

Exactly. I have come to conclusion after more and more research since joining the site that the best US fighter in the ETO was the P-47. I used to really think it was the P-51D. I still think though that the P-51D made the biggest impact for the allies. Its long range allowed it to escort the bombers deep into Germany. Without the bomber losses may have been much higher.

[wmaxt]

Thats a good start and the stats show the Bf-109K should have an edge but it also doesn't show anything overwelming.

Can we dig into it further? Does anyone have roll rates, acceleration, turn rates etc.? Strictly using these numbers doesn't tell the whole story.

P-51 acceleration is 2.2mph/sec between 10k & 15k at METO power
P-51 Roll Rate 90deg/sec @ 300mph

I have read several test results that the P-51 was fully controlable to 606mph, airframe max. While all direct control aircraft are going to be affected to some extent, by speed, the P-51s controlability has always been rated above average even by people outside the "I love Mustangs" club.

Remember guy's, I've never been a big advocate of the P-51 but were all here to learn the truth and the historys of these fine aircraft and their pilots. My contention, as accepted in this thread is that the P-51 was compettitive, the question is, how compettitive? Lets compare them 1:1 and without bias and get a honest answer.

wmaxt

[wmaxt]

Originally Posted by DerAdlerIstGelandet

Exactly. I have come to conclusion after more and more research since joining the site that the best US fighter in the ETO was the P-47. I used to really think it was the P-51D. I still think though that the P-51D made the biggest impact for the allies. Its long range allowed it to escort the bombers deep into Germany. Without the bomber losses may have been much higher.

I agree to a point though I feel the P-47 w/paddle prop was as good as the P-51 until the M model which never really had a chance to prove itself. The P-47 made a significant impact that never has been recognized. And the P-51 blanket for the deeper raids was a major impact. Escort, whether P-38, P-47 or P-51 dropped the loss rate from fighters more than 50% and allowed the daylite raids to continue.

The P-38 was the best in the ETO and at the time it was used widely, I think criticle. Without the P-38 the arial offensive in Europe would have been stopped or delayed 6 months or more until the P-51/P-47D were available in the quantity required. It's been argued that the P-47/P-51 crushed the Germans but it was after the P-38s (P-51s went from 0 to dominant in this period) held the line.

wmaxt

[DerAdlerIstGelandet]

I agree its a great idea. In all of my searches though I have never seen anythign that actually states the 109's roll rate for any version.

[wmaxt]

Originally Posted by DerAdlerIstGelandet

I agree its a great idea. In all of my searches though I have never seen anythign that actually states the 109's roll rate for any version.

I just want to know, right now everybody is saying "Mines better" with no real answer. I think there close enough it's not really an issue and that seems to rile everybody up.

wmaxt

[poprune]

Aerodynamicists have proved that a bee can't fly: the power to weight ratio is all wrong and they've got damn-all in the way of aspect ratio and C of L.

Bees do fly, but do they fly better than flies fly? If they do, at what speed, height, power, weight and load configuration do they fly better or worse? And who polished what or didn't beat out those dents where someone dropped a spanner? (Sorry, fly)

In short: on the day, in the conditions and given the circumstances... who knows?


(Sorry, Soren; I'm being rude and disrespectful, for which apologies)

[DerAdlerIstGelandet]

I thought it was quite funny.

[Soren]

Aerodynamicists have proved that a bee can't fly: the power to weight ratio is all wrong and they've got damn-all in the way of aspect ratio and C of L.

No aerodynamists havent proven it wrong at all

What they have proved is that the "bumblebee" (not the "Bee") can't 'Glide', but it 'can' fly because of its static wings moving rapidly up and down creating much more lift than a similar sized fixed wing would be capable of.

So the "Its proven the bumblebee can't fly" myth, is infact just a myth.

[plan_D]

It's the many muscles and strange movement of the wing that allow it to fly. It's amazing really, I saw it on this programme where they filmed one close up and slowed it right down...

Amazing piece of natural engineering!

[lesofprimus]

Ouch.......

[poprune]

I know I was trying, in my own small way, to make a point of quite another colour...

[DerAdlerIstGelandet]

Another kick in the nuts.