Any good explanation about "new" spit diving ability

[Crumpp]

Lednicer, D., "A CFD Evaluation of Three Prominent World War II
Fighter Aircraft," Aeronautical Journal of the Royal Aeronautical
Society, June/July 1995.


Anybody have a copy of this article?  Found a couple of broken links to it.


Also does anybody have a credible source on the Merlin powered spits mach numbers?

The Spit you are refering too Karnak, I am pretty sure was a post war Griffen powered model.  Besides, breaking the plane automatically disqualifies the mach number.  The point is to safely recover the A/C.

Crumpp

[straffo]

None of those will tell you the Spit should be something of a great diver - it`s a large drag machine of medium-light weight, with relatively low wingloading

think of wave drag.

[Crumpp]

Here is what the RAF tactical trials between a Spitfire Mk IX (+16 boost) and a FW-190A4/U8 say about dive performance:


In a dive from 23,000 feet the FW-190 could leave the Spitfire without difficulty and their was no gainsaying that in so far as manuverability was concerned, the german fighter was the markly superior of the two in all but the tight turn.  The Spitfire could not follow in aileron turns and reversals at high speed.  From high speed cruise, a pull up into a climb gave the FW-190 an initial advantage owing to it's superior accelleration and the superiority of the german fighter was even more noticable when both Aircraft were pulled up into a zoom climb from a dive.

Crumpp

[MiloMorai]

Originally posted by Crumpp



Also does anybody have a credible source on the Merlin powered spits mach numbers?

The Spit you are refering too Karnak, I am pretty sure was a post war Griffen powered model.  Besides, breaking the plane automatically disqualifies the mach number.  The point is to safely recover the A/C.

Crumpp

Those Spits are Mk XIs (PR version of the Mk IX) and the test were done beginning in Jan '44. See "Spitfire, the History"


True if both a/c were at co-speed but the 'bouncing' a/c would be at a greater speed. So much for any accelleration differences.

[Crumpp]

Milo,

I don't think any high speed trials were ever conducted on the FW-190A except by the RAF enemy test flight.  There it was dove to mach .80 and still was very controllable, exhibited no adverse effects and was easily recovered.  Since the purpose of the test was to test the FW-190 against the Spitfire AND the 190 demonstrated it's superiority in a dive under all flight conditions, No further test were conducted to explore the dive limits of the 190.  Mach .80 is in all likelyhood NOT the mach number limit of the FW-190.

Crumpp

[Crumpp]

True if both a/c were at co-speed but the 'bouncing' a/c would be at a greater speed. So much for any accelleration differences.

It is not only a dive accelleration difference, Milo.  It is total dive superiority over a Merlin powered spit  no matter where you measure the dive.

Crumpp

[GODO]

Crumpp, some time ago were posted the results of a Fw190 dive tests piloted by K. Tank. At mach 0.8 there were not even vibrations. Dont remember initial and final altitudes.

[Crumpp]

It is just a matter of whether or not the Spit's head start is enough to overcome the initial acceleration deficit and as F4UDOA's "Most over rated flight characteristics" thread pointed out, the differences are not very significant when starting from the same speed.

Was is most revealing about that test is how BIG a difference they made in combat.  Just read the mock combat test conclusions.  The Zeke was totally outclassed by all the USAAF fighters and could only fly defensive circles.

Crumpp

[MiloMorai]

Originally posted by Crumpp
It is not only a dive accelleration difference, Milo.  It is total dive superiority over a Merlin powered spit  no matter where you measure the dive.

Crumpp

Tank's dive test in an D-9:

7km - ~600kph
6km - 700kph

No speeds given for lower altitudes.

For the A-8, a simular speed of 700kph was reached at 6km.

(from Tank's bio book)

Spit XI was restricted to 690kph @ 7km and 724kph @ 6, and ASIs are inaccurate (said by some members here), what was the true speed of the Fws in Tank's test? Were comb pitots fitted to his a/c? The Spit is easily faster than the Fw. (Issy says a/c could be pushed past their restriction speeds)

Now would you like to explain how with, say a 50mph speed advantage (not unrealistic) on a 'bounce', the Fw could 'get away' from a Spit IX

The comparison by the Brits of an A-3 and Spit XII (simular power to the IX) had the Spit accellerating faster than the A-3. Later models of the A, being heavier, would be even slower.

ps Should add that I give my bro a hard time about his 'love' of the Spit.  Tank's a/c are my favorites, so don't put the fws on a pedistal like Issy does for his 109.

[Urchin]

Originally posted by Crumpp
Here is what the RAF tactical trials between a Spitfire Mk IX (+16 boost) and a FW-190A4/U8 say about dive performance:


In a dive from 23,000 feet the FW-190 could leave the Spitfire without difficulty and their was no gainsaying that in so far as manuverability was concerned, the german fighter was the markly superior of the two in all but the tight turn.  The Spitfire could not follow in aileron turns and reversals at high speed.  From high speed cruise, a pull up into a climb gave the FW-190 an initial advantage owing to it's superior accelleration and the superiority of the german fighter was even more noticable when both Aircraft were pulled up into a zoom climb from a dive.

Crumpp

Which is modelled perfectly in AH2, I tested it.  

The 190A5 was faster in the dive than both the Spit V and Spit IX, and zoomed higher than both when zooming at the end of a dive and from level flight.  

I firmly believe that the "descrepancy" between what you read in the real life tests, and what you see in testing side by side in game is the result of net lag.  There are several good documents about it linked from the BBS, I'm lazy so I'm not going to go digging through to find them.

[Telstar]

FWIW

I have reference to a Spitfire Mk PR.XI, (EN409) reaching speeds of Mach 0.92 (620MPH)
The pilot, Alan Martindale was later killed in another aircraft, due to prop failure.

Another Spitfire (PL827) carried on the testing reaching Mach 0.85 regulary.

[Crumpp]

Tank's dive test in an D-9:

7km - ~600kph
6km - 700kph

No speeds given for lower altitudes.

For the A-8, a simular speed of 700kph was reached at 6km.

(from Tank's bio book)

I have a copy of the 190A7 bis A9 pilots handbook.  Tommorrow I have a meeting with a friend who checking my translations.  I will check to see if it has the dive restrictions listed.

You can read about the 190A-3's performance vs Spit Mk IX here.

Please find a tactical trial of the FW-190 vs Spit IX were the Spit out dives the 190.  There is not one out there.  Even the RAF admits the 190 could dive better than the spit.

http://www.odyssey.dircon.co.uk/Spitfire9v190.htm


The FW 190 outdove BOTH the Spitfire and the 109.  Additionally it maintained great manuverability while doing it.

The 190 did have some nasty "habits" that I would like to see modeled when Pyro redoes the Flight Model.  The Stick forces were well harmonized and needed about 6-8 pounds of input up to around 400mph.  At that speed they suddenly heavied up to about 40 lbs.  The elevator was extremely sensitive according to Brown and Beauvais.  You very easily induce an aggravated stall at ANY speed.  When trimmed for level flight at cruise speed and dove, the 190 developed a marked nose down trim that "must have been scary" when the A/C was fought at low altitudes.

In fact the elevator was so touchy that many transitioning "concrete stick" 109 pilots had trouble.  One pilot Beauvais talks about could not loop the 190 at any speed.  Everytime he tried the plane would nose straight up and fall off to the side with all of his speed gone.  Beauvais took his 190 up and flew a loop just 50 kph above stall speed.  They 109 pilot was using too much control input which would instantly kill the 190's speed.  Combining the nose down trim, control force's change, and touchy elevator would have made the 190 challenging to fight in effectively IMO.  Easy to fly but hard to fight.

The weight increase between the 190A3 and the 190A8 fighter version was NOT that substantial AND the power increase was 200 H.P. The FW 190A8 had a better power to wieght ratio than the FW-190A3.  The FW's development paralleled the Spit Mk IX's development.  There is a reason the RAF did not tell it's merlin powered spit pilots to "mix it up" with 190A's.  There is also a good reason the LW made more FW-190A8's than any other version.  A detailed weight chart for all versions of the 190A7 bis A9 is included in the pilots manual.  This is also covered in another thread.

I don't put FW's on a pedestal either Milo.  I go by the facts.  It is easy to see that the FW series in AH is not able to fight in the manner it historically could against the Spitfire.  That has been covered in other threads ad nauseum.

Crumpp

[Angus]

Corresponds  with the legend:
"A   rather inexperienced pilot starting with the 190 soon becomes very dangerous, while old 109 hands don't like it"

[MiloMorai]

Thanks for the sermon Crumpp.

wing loading

A-3 - 212.84kg/m^2

A-6 -  224.43kg/m^2

A-8/R2 - 237.70kg/m^2 (/R2 only 50kg heavier than A-8)


weight/power

A-3 - 3.12kg/kw

A-6 -  3.23kg/kw

A-8/R2 - 3.42kg/kw

from Tank's bio

Now what is this about a better ratio for the A-8 over the A-3? An ~500kg TO increase is NOT substantial?

"There is also a good reason the LW made more FW-190A8's than any other version."

Yes the A-8 was in production longer than any other model. Besides all German a/c production output increased during its production.

"Even the RAF admits the 190 could dive better than the spit."

When they started the dive at the same speed. Yes the Fw was more manueverable in the dive. Tactical trials and combat are 2 different 'kettles of fish'. "Providing the Spitfire IX has the initiative, it undoubtedly stands a good chance of shooting down the FW 190." Are you only reading what you want to see? According to you, this statement should not be in the link.

[Crumpp]

Actually if you study the 190A series and Merlin Spitfire development the planes were very well matched with the exception of the Spit V which was clearly outmatched. The 190A series retained it's advantages in zoom climb, Level speed, acceleration and maneuverability throughout it's life cycle. The Merlin powered spits were able to close the performance gap and at some altitudes eliminate them BUT each A/C only retained commanding performance gaps over the other in one area each. The 190 always retained the option to dive away to lower altitudes where it's advantages where even greater.

You have to remember, if you compare the 190A3 to the 190A8, the 190A8 is in fact the better fighter. I will post the weights when I get my 190 pilots manuals back so you can confirm this. Both the Merlin and the BMW-801D2 were continuously upgraded in performance. The 190A8 increased in weight over the 190A3. It also increased in power to weight and the 190A8 had a significantly better P/W ratio with 1.65ata at 2700 U/min than the 190A-3 at 1.42ata at 2700 U/min.

Even that weight increase though has become greatly exaggerated over the postwar years. Most of the references I have seen are up to 900 KG OFF on the loaded weight of a fighter version of the 190A8 and put it in the neighborhood of 4800-4900Kg. A fully loaded 190A3 is weighed in at 3850Kg. A fully loaded fighter version of the 190A8 is 4100kg. Most of this is in the outer wing MG151's and ammo. The Armour on the fighter version of the 190A8 is the exact same as the 190A4. In fact they carry the same part number. Only difference between it and the 190A3 is the pilots head armour was thicken from 9mm to 12 mm and widened a few inches.

Crumpp