Diving speed.

[flanker72]

Hello.
I have a request, I am looking for news on the diving speed fighter aircraft of the interwar period and the Second World War. These include the following aircraft:

Nieuport-Delage NiD-52/62/622/629;
Loire Lo-43/45/46;
Dewoitine D-500/501/510;
Dewoitine D-37/372/376;
Caudron CR-714C1;
Arsenal VG-33C1;
Bloch MB-150/151/152/155/157;
Bloch MB-700;
Potez 230;
Morane Saulnier MS-405/406/410/435/450;
Wibault 70C1;
IAR-80/81;
IAR-16;
SET-XV;
PWS-10;
PZL P-7a;
Ikarus IK-2/IK-3;
Heinkel He-51;
Arado AR-64/65/67/68;
Heinkel He-112;
Messerschmitt Bf-109B/C/D/E/T/F/G/K;
Focke-Wulf FW-187;
Focke - Wulf 190A/D;
Focke - Wulf Ta-152C/H;
Dornier Do-335A;
Messerschmitt Bf-110B/C/D/E/F/G;
Avia B-534/634;
Praga E-44;
Letov S-102;
Avia B-135;
Fiat CR-1/20/32/42;
Fiat G-50/55/56/57/59;
Macchi Mc-200/202/205;
Reggiane Re-2000/2001/2002/2005;
Fokker D-XXI/XXIII/G-1;
Koolhoven FK-58/58A
Gloster Gladiator;
Gloster Gaunlet;
Hawker Hurricane MKI/II/IV;
Hawker Typhoon/Tempest/SeaFury;
Hawker Fury ( biplane );
Spitfire MK I/II/V/VI/VII/VIII/IX/XII/XIV/XVI;
Seafire MK I/III/XV;
Fairey Fulmar/Firelfy;
Bristol Bulldog;
Bristol Beaufighter MKVIF;
DeHavilland Mosquito ( oll types );
DeHavilland Hornet/SeaHornet;
Grumman FF/F2F/F3F/F4F/F6F/F7F/F8F;
Boeing P-12/F4B;
Boeing P-26/281;
Seversky P-35/35A/43;
Republic P-47 ( oll types );
North American P-64;
Vought P-66;
Curtiss Hawk 75/P-36;
Curtiss P-40 ( oll types );
Lockheed P-38 ( oll types );
Northrop P-61;
Nort American P-51 ( oll types );
Bell P-39 ( oll types );
Brewster F2A;
Curtiss Hawk III/IV;
Bellanca 28-90/28-110;
Polikarpov I-5/I-15/I-153/I-16 ( oll types )/I-17;
Mikojan-Gurevich Mig-3/9;
Jakovlev Jak-1/-3/-7/-9/ ( oll types );
Lavochkin La-5/7/9/11;
LavochkinGudkovGorbunov LaGG-3;
Nakajima A2N/A4N;
Mitsubishi A5M/A6M/A7M;
Kawasaki KI-10/KI-27/KI-43/KI-44/KI-45/KI-46/KI-61/KI-100;
Kawanishi N1K1/N1K1-J/N1K2-J;
Mitsubishi J2M;
Kyushu J7W1;
Boomerang CA-12/CA-13/CA-14/CA-15

I would be grateful for any help.

 

[GregP]

Damn! That's a LOT of work. Have you tried finding it yourself?

 

[Juha]

Gladiator 300 mph IAS
Fokker D. XXI 303 mph IAS
MS 406 325 mph IAS
Fiat G.50 365 mph IAS
Brewster B-239 385 mph IAS
Curtiss 75A Hawk 445 mph IAS

these are from one graph I don't have time just now to check the info from manuals etc

Juha

 

[FLYBOYJ]

Are those numbers Vne or Vd?

 

[flanker72]

I tried, but in many cases met with large differences, for example, Bf-109B, some sources indicate diving speed 850 km / h, another 800 km / h up to 750 km / h. Therefore, so long is my list, I would like to compare the obtained data with what I managed to fix. Maybe someone from the forum members have access to better sources than I do.

 

[flanker72]

Gladiator only 300 mph, a little low for my taste compared to the fighters Avia B-534 which reached 361 mph, and yet these were the aircraft of a similar system, the two biplanes with fixed landing gear, engines with similar power.

 

[GregP]

That's a much better post than your first one. I'll look and see what I have.

 

[FLYBOYJ]

When you go through your sources check for published diving speed, if it's not listed more than likely never exceed speed could be considered.

 

[GregP]

I have some POH's in pdf form and they usually have the information ... but I don't have bearly as many POH's for WWII fighters is the list above.

 

[tomo pauk]

The dive limits are stated for quite a few of ww2 aircraft in this thread:

http://www.ww2aircraft.net/forum/aviation/dive-limits-40365.html

 

[FLYBOYJ]

Forgot about that thread, great info there.

 

[GregP]

I looked in some of my Pilot's Operating Handbooks and found the folowing:

I have a 1940 flying manual for the Messerschmitt 110 produced by the RAF, It does not give a variant … just calls it a "Messerschmitt 110." It lists the aircraft limitations, but does not specify whether the speeds are VD or VNE. From the way it is worded, I assume VNE. It lists the maximum permissible indicated speed as 650 kph (406 mph); max IAS with flaps and undercarriage down is 250 kph (155 mph); and best approach speed as determined by RAE pilots is listed as 160 kph (100 mph).

AAF Manual 51-121-5 for the North American P-51 Series D and K lists Max permissible speeds as 505 mph IAS. I take that to be Vne since this is a flying manual, not a design manual.

I have a flight manual supplement for the North American X-15 dated February 1962. It has a rather interesting airspeed limitation chart. Altitudes are pressure altitudes. It goers linearly from about Mach 0.7 at sea level to Mach 1.5 at about 18,000 feet, then jumps over the next thousand feet to about Mach 1.5, then jumps almost linearly to about Mach 2.2 ay 37,000 feet, up to Mach 3 at 39,000 feet, and then goes to Mach 3.5 at 40,000 feet. There is a high permissible Mach if properly configured that can take Mach 3.5 up to about 49,000 feet. Since we KNOW it went way faster than these numbers, I surmise they did so at higher altitudes than 40,000 feet. Mach number is true Mach number. The record is 4,519 mph (7,274 kph) set by Pete Knight on 3 Oct 1967, but his altitude is not given with the speed record. I seem recall it was over 60,000 feet. If you use 761 mph as Mach 1, then Pete went Mach 5.94. I believe q max was something like 2,200 pounds, and I expected a q max for these speeds.

For the Supermarine Spitfire IX and XIV, I have max IAS as 450 mph between sea level and 20,000 feet, 430 mph to 25,000 feet, 390 mph to 30,000 feet, 340 mph to 35,000 feet, 310 mpg above 35,000 feet. Altitudes are pressure altitudes.

For the de Havilland Sea Hornet F.20 I have the following in IAS knots and pressure altitude. Sea level to 10,000 feet – 350 kts, 340 kts to 20,000 feet, 260 kts above 20,000 feet.

For the de Havilland Mosquito FB.6 I show the following in knots IAS when clean (any other configuration is slower). 370 kts to 10,000 feet, 350 kts to 15,000 feet, 320 kts to 20,000 feet, 295 kts to 25,000 feet, 260 kts to 30,000 feet, and 235 kts to 35,000 feet. No indication whether the altitudes are pressure altitude or indicated altitude. Since most of the rest are pressure altitudes, I'd assume that unless I could confirm it otherwise.

For the Hawker Sea Fury 10 and 11 I have the following in knots and pressure altitudes when the aircraft is clean (slower if carrying stores). 425 kts below 10,000 feet, 385 kts to 15,000 feet, 355 kts to 20,000 feet, 320 kts to 25,000 feet, 285 kts to 30,000 feet, 255 kts to 35,000 feet.

For the Grumman F6F Hellcat I have 415 knots IAS for the F6F-3 and 430 knots IAS for the F6F-5, all altitudes. Grumman tended to make things very strong rather than design just for the requirements.

For the Northrop P-61 Black Widow I show an unusual airspeed indicator and limitation, It has a moving redline and will be at either 430 mph IAS or Mach 0.7, whichever is less, regardless of altitude. Better hope the ASI works when you commence diving, huh?

I have a flight manual for a P-4N that shows the max diving speed to be 485 mph IAS regardless of altitude. Seems like it was fairly stout, too. I know our P-40N is built like a tank.

For the Bell P-39Q Airacobra I show a max permitted dive speed of 523 mph IAS but a max recommended dive speed of 475 mph IAS, regardless of altitude. The manual strongly recommends starting your pullout from a dive at 10,000 feet to avoid overstressing the aircraft. That sort takes the starch out of a diving attack from 3,000 feet, doesn't it?

Never heard of a Wildcat, Hellcat, P-39, P-40, or P-61 that was thought to have been a weak airframe. They may had had some issues along the way, but not enough strength wasn't one of them.

 

[flanker72]

It is amazing how much you can learn online August. Very thank you all for the information about most of what you sent me here I had no idea I had not access to such sources. Thanks again for the info. I just hope that the subject does not get tired quickly and I get a little more information. I care about most aircraft data lesser known, less popular.

 

[Just Schmidt]

In Mikesh, Robert C:Zero Fighter ,Janes Publishing Company Limited 1981, it is stated that teh zeros' allowed diving speed rose to 410 mph pr hour With the model 52, A6M5. That was again improved to 460 mph in the model 52a, A6M5a. I can't find information to what the limitation on the earlier models were.

 

[FLYBOYJ]

In Mikesh, Robert C:Zero Fighter ,Janes Publishing Company Limited 1981, it is stated that teh zeros' allowed diving speed rose to 410 mph pr hour With the model 52, A6M5. That was again improved to 460 mph in the model 52a, A6M5a. I can't find information to what the limitation on the earlier models were.

The official numbers will be in the flight manual (Summary of Provisional Handling Instructions, Feb. 1944). Although Janes is a pretty reputable source, it's still second hand information and they have published wrong or incomplete information.

Here's a link for the A6M3

http://www.ww2aircraft.net/forum/other-mechanical-systems-tech-/a6m3-operations-manual-6098.html

 

[Kryten]

One question with diving speed, would it be the indicated airspeed that is the relevant limiting factor?

 

[FLYBOYJ]

One question with diving speed, would it be the indicated airspeed that is the relevant limiting factor?

On most aircraft, yes.

 

[Hop]

One question with diving speed, would it be the indicated airspeed that is the relevant limiting factor?

And Mach. The Mach speed was usually the limiting factor at higher altitude.

For example, from the P-47N manual, max IAS dive speeds in mph:

Sea level - 564
10,000ft - 482
20,000ft - 400
30,000ft - 318

For the Spitfire IX:

SL - 20,000ft - 450
20 - 25,000ft - 430
25 - 30,000ft - 390
30 - 35,000ft - 340

 

[Juha]

Are those numbers Vne or Vd?

Hello as I wrote the info was from a graph, did some checking from Lentäjän näkökulma II, the Fokker D.XXI speed was max achievable, Brewster B-239 speed was Vne and the Hawk 75 speed was in fact TAS without altitude info or info was it Vne or something else.