Spit/109 sea level speed comparisons in 1.08 beta patch

[JtD]

The chart Kurfürst posted is not a theory, it's a calculation. Physics and maths are just as relevant as tests and pilot experience. There are methods that are standard and accepted. If you use them properly, they can be more accurate than tests and pilot experience and are imho at least as valid.

[Glider]

Originally Posted by JtD

The chart Kurfürst posted is not a theory, it's a calculation. Physics and maths are just as relevant as tests and pilot experience. There are methods that are standard and accepted. If you use them properly, they can be more accurate than tests and pilot experience and are imho at least as valid.

This is the sort of thing that raises my doubts. I am confident that the Grippen had many thosands of calculations undertaken by some of the finest minds in aviation. Using the latest computers, many hours in a simulator and then this happened. I should add that this was being flown by a test pilot.

http://www.youtube.com/watch?v=k6yVU_yYtEc

Show me any report of any 262 pilots who would go into a turning dogfight against a Mustang, Spit, La 7, whatever take your pick. The theoretical world is one thing, hard combat another.
Look at it another way, Why did the Mig 17 do so well against the F4, F105 and so on. Find any US pilot who would go into a turning combat in any of the above against an old slow Mig 17.

[bongodriver]

I love the way Kurfurst seems to think the 262 would even be in with a shot at a turning fight, at those speeds it's going to fly circles so big it's circumnavigating the globe

[ACE-OF-ACES]

Originally Posted by JtD

The chart Kurfürst posted is not a theory, it's a calculation.

True..

Originally Posted by JtD

Physics and maths are just as relevant as tests and pilot experience. There are methods that are standard and accepted. If you use them properly, they can be more accurate than tests and pilot experience and are imho at least as valid.

Agreed.. Just as relevant.. If used properly

As you (and others) know the old saying..

Garbage in Garbage out!

With regards to flight simulation..

You can think of the 6DOF flight simulation model as a black box.. With an input (plane parameters and current state) and an output (results)

The math in the black box can be good to go.. no errors.. But if you input bad values (plane parameters and current state) you will get bogus outputs (results)

With that in said..

I don't know if the 'results' of the Me262 or Spit used in the IL2Comp graph Kurfust posted have ever been validated.. As in have they ever been compared to any real world data, or checked by someone else to ensure the 'inputs' are correct.

In short, in this case the IL2Comp values are suspect until validated.. Sadly I don't know of any real world turn time data of the Me262 that can be used to validate the IL2Comp, which leaves only for someone to doulbe check the input values and 6DOF math.

[pstyle]

Hi kufurst, any chance you can link me to the records of the 109e maintaining 500kph in level flight at sealevel. Sorry if you've posted this before. Ta.

Edit; sorry I see you never stated sea level. My mistake. Unless SL means sea level, and not STRAIGHT Line?

[Osprey]

Originally Posted by Kurfürst

In fact we all do, except for you.

No actually. I have mentioned this twice and you just ignored it.

I have some good news for you though. 1946 HSFX patch 15 just fixed the Hurricane I and Spitfire I FM's to the speeds we talk about here. They are bang on the RAE tests using 12lbs. Fantastic news don't you think? ! I am interested in the link you are referring to for the 109 too because I think the 109E in HSFX may be too slow, but I want a proper flight test, not some calculation which Willie cooked his books in order to win a big fat order from his pal Hitler.

[Kurfürst]

Originally Posted by pstyle

Hi kufurst, any chance you can link me to the records of the 109e maintaining 500kph in level flight at sealevel. Sorry if you've posted this before. Ta.

Edit; sorry I see you never stated sea level. My mistake. Unless SL means sea level, and not STRAIGHT Line?

Originally Posted by Osprey

I am interested in the link you are referring to for the 109 too because I think the 109E in HSFX may be too slow, but I want a proper flight test,

Here it is. It is as proper as a flight test can get. In fact, its the most detailed performance test I have seen so far. http://kurfurst.org/Performance_test...w_109V15a.html

Of particular interest, translated from the paper.

Condition of the airframe :

The surface was painted after the serial production standard. The engine cowling was still rough, exhaust manifolds (DB-type, made at BFW) were lacking top cover. 2 Cowl- and wing-MGs were installed. Antenna wire. Undercarriage retracted, tailwheel out. For air intake, see the reports drawings.

Radiator cooler flaps were 1/4 open. Coolant temperature observed as constant 90 degrees Celsius.
Oil cooler flaps were closed. Oil temperature observed as 62/82 degrees Celsius.'

Speed was measured on the four-way flight track in Haunstetten. Altiude trials were performed near Augsburg airfield.

Measured speed for 0 m was 493 kph at 1,33ata. The engine was measured on test bench, and was found to develop 45 PS less than the guaranteed nominal output at 1,35 ata, so the flight results were corrected (see Blatt 5 for calculations) to the nominal engine ratings and German Standard day : 498 km/h at 0 m (CINA) at 1.35ata..

Originally Posted by Osprey

I have some good news for you though. 1946 HSFX patch 15 just fixed the Hurricane I and Spitfire I FM's to the speeds we talk about here. They are bang on the RAE tests using 12lbs. Fantastic news don't you think? !

It is, actually. Given that the complete lack of + 12 lbs tests, the likely farce but not unreasonable RAE "test" paper is the only source the FM modellers can use.

not some calculation which Willie cooked his books in order to win a big fat order from his pal Hitler.

You see the problem with this kind of thought is that after Willie would have won that big fat order, he would also have to deliver some 4000 aircraft and each will be tested by the German Air Ministry for specs. If they are not capable being withing plus/minus five percent of the figures Willie promised, Willie won't get a single Pfenning, which doesn't sound like a very good deal.

[JtD]

Regarding level speed performance of the 109, a question raised by I think MiG-3U puzzled me, maybe you have a good explanation, I'm at a loss for now: How come the 109E is faster than the 109F at less power, if you accept the 498 km/h for the 109E at 990ish hp from the V15 test and the 495 km/h for the 109F at 1065ish hp from the 109F Kennblatt?

[Osprey]

Originally Posted by JtD

Regarding level speed performance of the 109, a question raised by I think MiG-3U puzzled me, maybe you have a good explanation, I'm at a loss for now: How come the 109E is faster than the 109F at less power, if you accept the 498 km/h for the 109E at 990ish hp from the V15 test and the 495 km/h for the 109F at 1065ish hp from the 109F Kennblatt?

I could be wrong but I think he was being sarcastic in order to question Kurfursts 498kmph figures. Glider confused me too since he dissected MiG3U's post as if it were in support of Kurfurst, when it wasn't.

[Bounder!]

Originally Posted by JtD

Regarding level speed performance of the 109, a question raised by I think MiG-3U puzzled me, maybe you have a good explanation, I'm at a loss for now: How come the 109E is faster than the 109F at less power, if you accept the 498 km/h for the 109E at 990ish hp from the V15 test and the 495 km/h for the 109F at 1065ish hp from the 109F Kennblatt?

Just a stab, Kurfürst is probably the man for this question but looking up the weight of the 109e and 109f and it appears the later is heavier when loaded which might help account for the lack of speed increase over the emil?