Spitfire XIV vs Bf-109 K-4 vs La-7 vs Yak-3

[Vincenzo]

Ty Corsning
this is the graph http://www.ww2aircraft.net/forum/fl...performance-data-vvs-fighter-types-29604.html
Tomo can you translate the graph note? i think that graph data are the same of George under Ла-7 эталон ном and Ла-7 эталон ф so i don't think they cam from test

 

[Juha]

Bf 109F recovering and leveling out from near vertical dive at 520 mph within 4000 feet in appx. 4 seconds...

It wasn't a standard Bf 109F but a Bf 109F with G-wings, and with enlarged vertical stabilizer that was later incorporated in the late 109Gs and K-4s. The elevator trim tab is enlarged in surface area by 100% compared to the standard version. The horizontal stabilizer trim is limited in its upwards range of motion to +1°15 by a stop unit. Also the control movement was limited to 50% of the reference movement of the ailerons.

But I agree that 109K-4 was still a capable fighter, with excellent roc and speed. It was also small, so more difficult to see.

Juha

 

[CORSNING]

tomo, WHAT! I'm an old fart. That's waaaaaaaay to much monkey business for me.

Vincenso, yep that's the graph all right.

Juha, I agree. The rest of you listen to him. Sounds like he knows what he's talking about.

 

[Tante Ju]

It wasn't a standard Bf 109F but a Bf 109F with G-wings, and with enlarged vertical stabilizer that was later incorporated in the late 109Gs and K-4s. The elevator trim tab is enlarged in surface area by 100% compared to the standard version. The horizontal stabilizer trim is limited in its upwards range of motion to +1°15 by a stop unit. Also the control movement was limited to 50% of the reference movement of the ailerons.

But I agree that 109K-4 was still a capable fighter, with excellent roc and speed. It was also small, so more difficult to see.

Juha

Yes I read report but I do not think it effects anything as far as manouvre in pitch concerned.

 

[Juha]

As the report say (translation) "The first flights were pre-tests to the high-speed flights. They were done with a throttle position equivalent to a boost of 1.0 at sea level. The first tests demonstrated that at speeds over Va=650 km/h the plane lost stability (at median centre of gravity). Movements, starting at the vertical stabilizer; appeared around the yaw and longitudinal axes. Nine test flights were performed with the usual smaller tail with a horn mass balance. (Flight report Nr. 879/270). To reduce the instability around the yaw axis the stabilizer of Me109 W.Nr. 14026 was attached to W.Nr. 9228 (the vertical stabilizer destined for the 109 G production model)."

So normal 109F couldn't dive anywhere near 520mph (837km/h) and probably the elevator trim tab was enlarged in surface area by 100% compared to the standard version for some reason. And as we know wings of 109G were stronger than those of 109F.

 

[Tante Ju]

But we are taling 109K which had all of these improvements (quite probably as a result of these trials) and also had different gearing for the elevator for lighter stick forces. Probably for these reasons it was cleared for dives up to 850 km/h (or 100 km/h greater than F/G).

Also importance of Va (IAS) and Vw (TAS). We are talking about 830 kph TAS (which depending on altitude may be quite a bit less than 650 kph IAS).

 

[CORSNING]

Just letting you all know that I edited my post #398. I put the actual numbers in from the graph from the TEST FLIGHT DATA section. I do not know where the original numbers came from that I posted. Sorry guys, Jeff.

 

[Milosh]

Yes one must take altitude into consideration.

This is for the Bf109G-6 (diving speed limits)

The maximum permissible indicated airspeeds in the different heights are not being observed and are widely exceeded. On the basis of evidence which is now available the speed limitations ordered by teleprint message GL/6 No. 2428/41 of 10.6.41 are cancelled and replaced by the following data:

Up to 3 km (9,842 ft.) 750 km/h. (466 m.p.h.)
At 5 km (16,404 ft) 700 km/h. (435 m.p.h.)
At 7 km (22,965 ft) 575 km/h. (357 m.p.h.)
At 9 km (29,527 ft) 450 km/h. (280 m.p.h.)
At 11 km (36,089 ft) 400 km/h. (248 m.p.h.)

These limitations are valid for the time being for all building series including the Me 109 G. A corresponding notice is to be placed upon all air-speed indicators in aircraft.

 

[drgondog]

Yes one must take altitude into consideration.

This is for the Bf109G-6 (diving speed limits)

The maximum permissible indicated airspeeds in the different heights are not being observed and are widely exceeded. On the basis of evidence which is now available the speed limitations ordered by teleprint message GL/6 No. 2428/41 of 10.6.41 are cancelled and replaced by the following data:

Up to 3 km (9,842 ft.) 750 km/h. (466 m.p.h.)
At 5 km (16,404 ft) 700 km/h. (435 m.p.h.)
At 7 km (22,965 ft) 575 km/h. (357 m.p.h.)
At 9 km (29,527 ft) 450 km/h. (280 m.p.h.)
At 11 km (36,089 ft) 400 km/h. (248 m.p.h.)

These limitations are valid for the time being for all building series including the Me 109 G. A corresponding notice is to be placed upon all air-speed indicators in aircraft.

What was the documented Vmax in Mach number for the "do not exceed' dynamic pressure loading. I know the max dive documented for the P-51D was .85/.86 terminal dive - and annotated as 'written off' due to various components which had clearly reached Ultimate stress.

What was the highest Mach number documented for the 190G/K, versus the Placard dive limit warning to pilots?

 

[Juha]

But we are taling 109K which had all of these improvements (quite probably as a result of these trials) and also had different gearing for the elevator for lighter stick forces. Probably for these reasons it was cleared for dives up to 850 km/h (or 100 km/h greater than F/G).

Also importance of Va (IAS) and Vw (TAS). We are talking about 830 kph TAS (which depending on altitude may be quite a bit less than 650 kph IAS).

You are right on vertical vertical stabilizer and wings (wings of K-4 were stronger than those of early Gs) but Va max reached in the tests was 737km/h and I doubt that the control movement of the ailerons was similarly restricted in K-4s. Probably the horizontal stabilizer trim wasn't limited in its upwards range of motion to +1°15 by a stop unit in K-4s. Not sure on the elevator trim tab surface area.

 

[Juha]

What was the documented Vmax in Mach number for the "do not exceed' dynamic pressure loading. I know the max dive documented for the P-51D was .85/.86 terminal dive - and annotated as 'written off' due to various components which had clearly reached Ultimate stress.

What was the highest Mach number documented for the 190G/K, versus the Placard dive limit warning to pilots?

In that German test max Mach number reached was .805, the highest reached in 109 I'm aware of was during Curtiss tests with a captured 109G-10, .82.

Juha

 

[parsifal]

dumb question....how would an aircraft like the 109, with notoriously stiff controls at high speed and such limited interior space for the pilot to pull on the stick, be able to be pulled out a dive going Mach 0.82? Is that even possible?

 

[Milosh]

Using the stab trim wheel, which several pilots have noted they did.

 

[Juha]

Or simply pulling as hard one could, the narrowness of the cockpit didn't hinder straight pull but one needed muscles.

 

[tomo pauk]

The interior was narrow, but not short IIRC. So no obstacles to pull the stick.

 

[spicmart]

With both having similar dimensions what design features made the La-7 a better dogfighter in the higher speed realm than the Me109K-4?

 

[parsifal]

I dont understand why, but i think it goes to the details of the design. The CGs, the wing design, the engine characteristics, the wing loading, the design and area of the control surfaces, would all be factors in the manouvre characteristics of each type. However in reality there wasnt much difference between types of a given genre

 

[alejandro_]

A few days ago I finished reading the war diary of Helmut Lipfert, which I really enjoyed. In one of the chapters you can fin a combat aganst a Yak-3 (I guess it could also have been a Yak-9U). It took place over the Gran bridgehead (Hungary) in January 1945. He was probably flying a Bf 109 G-10/14

At about the same time I made acquaintance of the new Yak. This latest Russian fighter was somewhat superior to us in speed and maneouvrability, it's armament was equal to ours, and only in the dive did our machines prove to be superior. Our new meeting with the new Yak almost ended badly: Prokoph and I were inside friendly territory and suspecting nothing untoward. It was my custom in the air never to fly straight and level. Not only did I continually change direction, but altitude as well. As a result many wingmen didn't like flying with me. But thanks to this constant remaining in motion it was impossible for the enemy to sneak up unnoticed. Prokoph was the best wingman of all for this type of flying.*

So it was that I noticed a lone Yak approaching from behind. We were low on fuel and therefore didn't want to get involved in combat. The Russian appeared to have other ideas. Although we were flying at maximum speed he drew even nearer and finally forced us to start turning. We escaped the first attack only by breaking away suddenly. The Ivan pulled up and away and then came down again behind Prokoph. At first I flew around the circle and tried to get *on the enemy's tail, but that was out of the question. By no we were turning at full throttle near ground level. The Russian took his time and repeatedly pulled up out of the turn., dropped down again, allowed for deflection and fired.

When he began to fire I issued corrections to Prokoph. who listened to my words and inmediately did as instructed. mMy wingman was hit several times, but he followed my instructions precisely and so avoided being shot down. This was too much for me. "Keep turning" , I called to Prokoph, and tightly as possible! I'm going to climb above the Russian and come down from above to help you.

Prokoph's aircraft was hit several more times in the tail. If I hadn't been so furious, I would have had to admire the Russian for the way he repeatedly sheared upward, dropped down into the circle from above and only fired when he had allowed adequate deflection. Prokoph didn't whine and cry for help, rather he turned for his life. Then I was in a position to come down from above. "Straighten out, Prokoph!".

The Russian machine straightened out almost simultaneously and I fired a fraction of a second before the enemy pilot. My full burst hit him just as he opened fire, causing him to break away and turn around. I had hit him well, but he had nevertheless scored several more hits on Prokoph. I now moved in behind the Russian, who swung gently back and forth in front of me so all I could do was spray bullets instead of aiming precisely. In spite oh his black smoe trail he pulled away and steadily increased the range between us. I might still have been able to catch him, but our fuel was must gone. I had no choice but to turn away.

There was no deniying that I was impressed with this Russian type. The new Yak appeared to me a far more dangerous adversary than the Mustang.

Prokoph, whom I had inmediately sent home, had already landed when I returned. "Now then, Herr Hauptmann", he greeted me, "we'ill want to get our own back for that!"

Our chance was not long in coming. There now seemed to be nothing but these new Yaks -which we designated the Yak-3- over the Gran bridgehead. It was well that we had met them before. Most of our comrades didn't want to believe our reports and had to learn the hard way. We had a running series of bail-outs.

Pag 158-159

 

[jim]

A few days ago I finished reading the war diary of Helmut Lipfert, which I really enjoyed. In one of the chapters you can fin a combat aganst a Yak-3 (I guess it could also have been a Yak-9U). It took place over the Gran bridgehead (Hungary) in January 1945. He was probably flying a Bf 109 G-10/14

At about the same time I made acquaintance of the new Yak. This latest Russian fighter was somewhat superior to us in speed and maneouvrability, it's armament was equal to ours, and only in the dive did our machines prove to be superior. Our new meeting with the new Yak almost ended badly: Prokoph and I were inside friendly territory and suspecting nothing untoward. It was my custom in the air never to fly straight and level. Not only did I continually change direction, but altitude as well. As a result many wingmen didn't like flying with me. But thanks to this constant remaining in motion it was impossible for the enemy to sneak up unnoticed. Prokoph was the best wingman of all for this type of flying.*

So it was that I noticed a lone Yak approaching from behind. We were low on fuel and therefore didn't want to get involved in combat. The Russian appeared to have other ideas. Although we were flying at maximum speed he drew even nearer and finally forced us to start turning. We escaped the first attack only by breaking away suddenly. The Ivan pulled up and away and then came down again behind Prokoph. At first I flew around the circle and tried to get *on the enemy's tail, but that was out of the question. By no we were turning at full throttle near ground level. The Russian took his time and repeatedly pulled up out of the turn., dropped down again, allowed for deflection and fired.

When he began to fire I issued corrections to Prokoph. who listened to my words and inmediately did as instructed. mMy wingman was hit several times, but he followed my instructions precisely and so avoided being shot down. This was too much for me. "Keep turning" , I called to Prokoph, and tightly as possible! I'm going to climb above the Russian and come down from above to help you.

Prokoph's aircraft was hit several more times in the tail. If I hadn't been so furious, I would have had to admire the Russian for the way he repeatedly sheared upward, dropped down into the circle from above and only fired when he had allowed adequate deflection. Prokoph didn't whine and cry for help, rather he turned for his life. Then I was in a position to come down from above. "Straighten out, Prokoph!".

The Russian machine straightened out almost simultaneously and I fired a fraction of a second before the enemy pilot. My full burst hit him just as he opened fire, causing him to break away and turn around. I had hit him well, but he had nevertheless scored several more hits on Prokoph. I now moved in behind the Russian, who swung gently back and forth in front of me so all I could do was spray bullets instead of aiming precisely. In spite oh his black smoe trail he pulled away and steadily increased the range between us. I might still have been able to catch him, but our fuel was must gone. I had no choice but to turn away.

There was no deniying that I was impressed with this Russian type. The new Yak appeared to me a far more dangerous adversary than the Mustang.

Prokoph, whom I had inmediately sent home, had already landed when I returned. "Now then, Herr Hauptmann", he greeted me, "we'ill want to get our own back for that!"

Our chance was not long in coming. There now seemed to be nothing but these new Yaks -which we designated the Yak-3- over the Gran bridgehead. It was well that we had met them before. Most of our comrades didn't want to believe our reports and had to learn the hard way. We had a running series of bail-outs.

Pag 158-159

Mr Alejandro
I believe you have noticed that Lipfert flew WITHOUT MW50. He makes absolutely no mention in the entire book for Mw50.

 

[spicmart]

Me 109 G-10/14? Those were as fast as or faster than the most common Yak-3 with Klimov 105 as engine which made about 660 km/h.
The G-10 reached 685 km/h iirc.