Corsair vs. BF 109G,K or FW 190's

[drgondog]

Kurfurst - this is the Order Of Battle reference

Flugzeugbestand und Bewegungsmeldungen, Jagdverbände

Regards,

Bill

[drgondog]

Kurfurst - this is the Order Of Battle reference

Flugzeugbestand und Bewegungsmeldungen, Jagdverbände

Here is the NA test data on the rate of climb and climb rate. So, it appears Gruenhagen's reference to 3.4 minutes to 20,000 feet was not in error.

I did not realize the initial climb rate at SL was 6400 ft min and still doing 5700 fpm at 17500 and 470mph at 35,000 feet

http://www.wwiiaircraftperformance.o...-51g-chart.jpg

Regards,

Bill

Soren - you can complain about Mike's collection of test reports not conforming to your notions of the Fw 190D-9 or other LW a/c... but you should emulate Kurfurst and at least produce similar bona fide test data form LW to refute what you believe to be 'predjudice'??

[Crumpp]

If you are flying in a tight turn on the edge of the stall then one wing is going more slowly than the other. As a result the slats will not open evenly, one will open before the other causing the aircraft to 'stagger' or 'lurch' to one side for a second.

There is nothing bad aerodynamically about properly designed LE devices. They are mainstay of modern wing design.

Handley Page automatic slats deploy at a specific coefficient of lift. The wing deploys them "as needed". Handley Page automatic slats represent both a camber change and energize the boundry layer.

The pilots reaction to this is much more important to flight performance than the slat itself. My aircraft has them and yes, they took some getting used too. Once I conditioned my reactions though, the low speed performance with them deployed is fantastic. The effect is very noticable.

Yes the plane will lurch if the pilot does not react properly with appropriate inputs. That is not to say the slats are at fault. The pilot is at fault for not having the experience to use them. The slats definately will improve low speed performance. That is why most modern fighters have LE devices.

All the best,

Crumpp

[Glider]

Originally Posted by Crumpp

There is nothing bad aerodynamically about properly designed LE devices. They are mainstay of modern wing design.

Handley Page automatic slats deploy at a specific coefficient of lift. The wing deploys them "as needed". Handley Page automatic slats represent both a camber change and energize the boundry layer.

The pilots reaction to this is much more important to flight performance than the slat itself. My aircraft has them and yes, they took some getting used too. Once I conditioned my reactions though, the low speed performance with them deployed is fantastic. The effect is very noticable.

Yes the plane will lurch if the pilot does not react properly with appropriate inputs. That is not to say the slats are at fault. The pilot is at fault for not having the experience to use them. The slats definately will improve low speed performance. That is why most modern fighters have LE devices.

All the best,

Crumpp

I am not saying that there are any problems with the design of the slats, they are doing exactly what they are designed to do.
What I would like to ask when the plane deploys one slat due to being in a tight high banked turn does it lose speed in that period before the second slat deploys?
I think you can see where I am coming from, if you are in a tight turning battle with an enemy close behind then any loss of momentum, no matter how slight could explain the comments in the reports.

[Crumpp]

I think you can see where I am coming from, if you are in a tight turning battle with an enemy close behind then any loss of momentum, no matter how slight could explain the comments in the reports.

I agree with you. If a pilot was not used to the rapid stick movements and loud bang of the slats deploying he would certainly loose some monentum.

What I would like to ask when the plane deploys one slat due to being in a tight high banked turn does it lose speed in that period before the second slat deploys?

Yes, it does lose some speed. Velocity as you know is the key component of turn performance.

More importantly, the usable angle of attack is increased further tightening the turn.

This is why experienced 109 pilots felt that the real maneuvering did not begin until the slats deployed.

All the best,

Crumpp

[Glider]

Thanks for this

[davparlr]

Originally Posted by Kurfürst

The point being the P-51D does not seem having '23 – 27 mph advantage' over any of these aircraft.

At least, the 354mph achieved by the P-51D/67" vs. the 352mph achieved by the G-14 is not ~25 mph difference in my book, more like 2 mph (though the 109 achieves it with slightly more power available, so on even footing, the Mustang is probably a bit better, say 360-365).

I got the info from this site which looks authentic including the identification of the aircraft number. In addition, two other sources I have and trust agree to the data shown in this flight test. The P-51D shows 375 mph at SL using about 1630 hp. I think my comments are good.

http://www.wwiiaircraftperformance.o...5342-level.jpg

How come, the P-51D was introduced what, June-July 1944, the 109K in October the same year. 'Much later' - like what, four months...?

The P-51D was introduced into the 8th AF in March ’44. The Bf-109K was introduced in November, ’44. Six months in WWII during this time was a generation of aircraft development. In the summer and fall of 1944, a whole family of aircraft with much greater performance over the mainstay of WWII aircraft, was introduced on both sides. These include Fw-190D-9, Bf-109K, F4U-4, P-47M/N, P-51F (later H), Ta-152H, and others.

The P-51H, with it`s performance apprx. on the level of the 109K, appeared in when, something like August 1945 on operation, some 10 months after the 109K (I am not sure about the 51H ever seeing combat in WW2)..?

The XP-51F, the predecessor of the H, flew in Feb. 44. Unlike Germany, who was desperate to stop the hordes of P-51s, P-47s, B-17s, B-24s, and Brit planes, with advanced aircraft, the US, whose aircraft performance was adequate and the quantity was overwhelming, did not expedite new models. Had the need arose, there is no doubt that a P-51H or the similar P-51F could have been available in the fall of ’44.

Still, the 355 mph or so achieved by the P-51D in normal condition at 67" does not seem to me higher than 370 mph achieved by the 109K at 1.8ata (alternate comparison can be made at similiar power at 81"/1.98ata, at comparable power ie. 379/377mph. Again not much of a difference).

My multiple sources show that the P-51D was capable of 375 mph at SL at about 1640 hp. The Bf-109K had 1800 horses available and could not achieve that (and my source for that is not Mike Williams site).

PS : You might want to add the 1.98ata climb rates into your climb rate comparison to keep the playing field even, also I can`t understand why the F4U4 climb figures you are showing are so much higher than every other Navy document shows.

Ie.

SL
Your F4U-4 4800 vs 4400 reported for F-4U4 at 12450 lbs, at 70", inOctober 1944 specs.

10k
Your F4U-4 4800 vs ~4300 reported for F-4U4 at 12450 lbs, at 70", in October 1944 specs. (revised and superseed to 4000 fpm in April 1945)

20k
Your F4U-4 3800 vs 2980 reported for F-4U4 at 12450 lbs, at 70", in October 1944 specs.
(revised and superseed to 3270 fpm in April 1945)

30k
Your F4U-4 2000 vs ~1400 reported for F-4U4 at 12450 lbs, at 70", in October 1944 specs

Your data is very significantly higher than the official US performance data reported in October 1944. Why?

I don’t know. While the data I referenced looks authentic and professional and states that it is flight test data (no tail numbers however), I have researched a lot and have not come up with support data for those values. Since I do not like depending on sole source data, especially when other data is available, I must withdraw my comments referencing F4U-4 climb rates.

[davparlr]

Originally Posted by AL Schlageter

24 April 1944

Flight Tests on the North American
P-51B-5-NA Airplane, AAF No. 43-6883

Maximum speed at sea level (67" Hg. manifold pressure & 3000 RPM) - 371.0 MPH

15 June 1945

Flight Tests on the North American
P-51D Airplane, AAF No. 44-15342

Maximum speed at sea level

War Emergency power (3000 RPM and 67") 375 MPH
Military power (3000 RPM and 61") 364 MPH
Normal Rated power (2700 RPM and 46") 323 MPH

Flight test of the P-51B in May ’44 with 150 gas shows a airspeed at SL of 374 mph. The number I gave before of 386 mph was on manufacturer estimates and is not as reliable as flight test.

http://www.wwiiaircraftperformance.o...p51b-level.jpg

[davparlr]

Originally Posted by Soren

What a surprise, Mike William's site again - thought you guy knew better by now not to use his site as reference for German a/c performance.

The FW-190 Dora-9 has a climb rate of 4,400 ft/min, the Bf-109K-4 over 5,000 ft/min ! Even with the thin experimental DünblattSchraube the Bf-109 K-4 boasted a 4,800 ft/min climb rate!

As you know, I always insist on having the best data in my data base. All the numbers I showed on the Fw-190D-9 and airspeed for the Bf-109K were based on data you provided. Unfortunately, I do not have any data from you on climb for the Bf-109K, so the only data I could use was from Mike Williams site and this particular data (but not most at Mike’s site) may be a bit suspect. I would be glad to update my data base to better data if you could give it to me.

PS: Have you got time to climb figures for the F4U-4 as-well ?? I'd like to see wether the F4U-4 is able even to beat the Dora-9 to 10km.

Unfortunately, I do not have this data. I will try to find some.

And about your assumption on the RAF test-pilots, well thats all it is, an assumption.

Kurfürst and I have both provided more than enough evidence as proof that the British test-pilot flying the 109 didn't push it beyond the deployment of the slats.

Let me sum it up here:

1.) The British test-pilot makes the comment: "The 109 being embarrased by the opening of its slots", this alone being a clear enough sign that he wasn't pushing past slat deployment.

2.) During the British comparative testing the test-pilot didn't even accomplish to turn the 109 as tightly as the FW-190 or P-51, eventhough the Bf-109 clearly & always out-turned the FW-190 & P-51 in German & Soviet comparative testing.

3.) Several German experten make it clear that green 109 pilots didn't push past slat deployment, the slight notch and loud bang sometimes heard convincing the green pilots that they were right at the limit.

4.) The 109E had frequent problems with slat failure, being enough reason for even a German experten to choose not to push the 109 to the limit in turns because of their past experience with the Emil. The British test-pilots (if not having experienced troubles with the slats on the Emil and therefore being concerned when testing later versions) had themselves heard nothing but bad news about the slats, seeing that a few Westlands crashed because of slat failure and that this had led o hem being locked shut in flight, given more than enough reason for British pilots to be vary about the slats.

You haven't changed my mind. It is just inconsistent with the nature of flight test pilots. And my impression of British pilots is that they are a daring lot.

[Crumpp]

http://www.wwiiaircraftperformance.o...p51b-level.jpg

According to this graph, the data is recorded at an isobaric altitude in May 44. It is the pressure altitude and is not corrected for density. At higher altitudes our TAS increases as we factor in the SMOE.

May is a high density alitude month generally speaking and the chart clearly states it is not corrected to STO.

This means our airplanes level speed performance in this graph will be faster than it will be under STO.

All the best,

Crumpp

[Crumpp]

These graphs represent performance of an aircraft using the manufacturer's data on the type in a standard atmosphere. All data was compiled and calculated under the NACA Standard Atmosphere of 1922 using KEAS so altitude conversion is not necessary. Altitude effects will shift the curve, changing the specific velocity in KTAS performance occurs but will not effect the shape or general conclusions.

Compressibility effects were applied adopting a standard of 200KTS and 10,000feet. Position error corrections were taken from the manufacturers supplied data along with IAS data.

Here is the maximum sustainable load factor for an FW-190A8 in clean configuration, overloaded fighter variant:




Here is the P51D in clean configuration, overloaded fighter variant:




At TO Weight, the FW-190A8 holds a slight advantage in Nzmax sustainable in the medium and low velocity realms. At higher velocity where the P51D becomes the faster aircraft, the P51D holds a slight advantage in Nzmax sustainable. Neither aircraft has an advantage that would be noticeable in the air. Pilot skill would make the difference.

What is clear is that these aircraft in like configuration are very much equals in sustained turning performance.

I have other configurations and aircraft types calculated too.

All the Best,

Crumpp

[davparlr]

Originally Posted by Crumpp

According to this graph, the data is recorded at an isobaric altitude in May 44. It is the pressure altitude and is not corrected for density. At higher altitudes our TAS increases as we factor in the SMOE.

May is a high density alitude month generally speaking and the chart clearly states it is not corrected to STO.

This means our airplanes level speed performance in this graph will be faster than it will be under STO.

All the best,

Crumpp

Several believable flight test show the P-51B was capable of SL speeds of over 370 mph to up 388 mph. Actually, I have to withdraw my previous comment about the 386 mph being a manufacturers speed when these show actual test results.

http://www.wwiiaircraftperformance.o...level-blue.jpg

[FLYBOYJ]

Originally Posted by Soren

The British test-pilots (if not having experienced troubles with the slats on the Emil and therefore being concerned when testing later versions) had themselves heard nothing but bad news about the slats, seeing that a few Westlands crashed because of slat failure and that this had led o hem being locked shut in flight, given more than enough reason for British pilots to be vary about the slats.

Again Soren, you're assuming or imagining things - I challenge you to show any evidence that any Brit who flew Lysanders to be "vary" of the LE slats. They were locked down because of maintenance constraints and the aircraft performed well with or without them.

Off topic but for you Lysander fans...


YouTube - Westland Lysander in Action

Here's one being flown today - watch the clip, on take off and landing you could see the slats deploy. If these items were such a hazard, its amazing 60 years later they are being used on the last flying examples.

YouTube - Westland Lysander

[Glider]

Which reminded me, I should have thought of it earlier.

[Crumpp]

Several believable flight test show the P-51B was capable of SL speeds of over 370 mph to up 388 mph. Actually, I have to withdraw my previous comment about the 386 mph being a manufacturers speed when these show actual test results.

Certainly the performance is believable. All aircraft performance is a percentage range over a mean average. The manufacturer only reports the average and not the optimistic or pessimistic examples.

Without more information on this particular flight test it is simply impossible to make any conclusions.

However we can certainly conclude that North American was privy to all of the data on their own design when they reported the performance averages and percentage range to the USAAF.

They were locked down because of maintenance constraints and the aircraft performed well with or without them.

Do you have proof that the slats where locked down? I find this very unusual as it would alter the handling and performance of the aircraft considerably. It would alter the design drastically.

All the best,

Crumpp