Glider
Captain
Thanks for this
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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).
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-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)..?
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).
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?
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
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!
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.
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.
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
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.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.
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.
They were locked down because of maintenance constraints and the aircraft performed well with or without them.
The last of the preflights are then completed before you sit down in the cockpit; this entails checking the inner slat movement-that the flaps are moving with them and that both sides move equally. The outer slats are aerodynamically actuated and are totally independent of the inner slats and of each other. The inner slats are also aerodynamically actuated but are linked so that they operate together. These inner slats also operate the flaps; when the slats deploy, the flaps are automatically extended.
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
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.
QUOTE]
Dave - I know that the 4th FG and 355th FG received their first P-51D-5's just after D-Day.. I am pretty sure none of the 8th FC received a 51D before May. IIRC they arrived in Britain in May but didn't reach operations until late May or June
Of course I have been wrong before.
I'll check with Ted Damick to see what his records have for the first D-5 to arrive in ETO depots?
I doubt it would do nothing but raise the stall and landing speed by a few knots - there have been many aircraft where because of modifications or problems in the field high lift devices were removed or disabled or limitations placed on flap settings.
there have been many aircraft where because of modifications or problems in the field high lift devices were removed or disabled or limitations placed on flap settings.
No Soren, I think what was shown here is the British had a firm understanding of leading edge slats and how they worked. If this British test pilot backed off a maneuver as alleged in this report, it wasn't out of fear of the system or the aircraft.By now its been solidly proven that the British test pilot did not push past slat deployment. He simply wasn't used to them and got concerned when they deployed therefore backing off the maneuver (Hence his comment). This was normal for green 109 pilots as explained by several LW aces. Furthermore this fully explains the results of the British comparative tests and why they are questioned by modern 109 pilots as-well.
So you're landing at 76 rather than 65 mph....The slats also do way more than just lower the stall speed by a few knots, 10 knots wouldn't be unusual.
By now its been solidly proven that the British test pilot did not push past slat deployment.
Any docmented examples? These are very much a part of the design. An engineer sets the design parameters to achieve specific design goals. Removing LE devices and TE devices will make certain performance goals unattainable. Things like safe controlled landings for example.
As you know, coefficients of lift, drag, and angle of attack are connected in a fixed and finite relationship.
All the best,
Crumpp