Spit/109 sea level speed comparisons in 1.08 beta patch

[swift]

The results of a calculation (what you call maths) is only as good as its data. Also there are equations and equations. Some are highly approxamtive and only thump rules for quick estimates, others may be closer to reality but also very complicated and requiring a lot of divers input data.

I would agree to use mathematical relationships to deduce aircraft behaviour if we had enough reliable data or data at all for input into the equation and some reliable data to verify the results.

My guess is the data we would need to calculate it is not available. I mean what would be great if we had all the aerodynamic coefficients as a function of Mach number and angle of attack and the corresponding reference area for each plane.

"Equations" deducing turn performance from the wing loading, sorry, this is far from anything near accurate. I would not like to have the fm built on this kind of thump rules. Then I'd rather prefer anecdotical evidence.

[camber]

I had a sad 109 experience yesterday. Flying in overcast it is easy to get confused between the top and bottom of the aircraft, leading to the following:

Originally Posted by 5./JG27.Farber

Test 4 4500metres 1.3Ata 2400U/pm IAS 400 TAS 518 or 322 mph
Test 5 5000metres 1.23Ata 2400U/pm IAS 390 TAS 518 or 322 mph
Test 6 4900metres 1.15Ata 2200U/pm IAS 370 TAS 489 or 304 mph

http://youtu.be/O4jHSMyYdkg <---- Video of tests.

Now we need to dig out the real life tests and compare.engine in the usual way
.

Seeing as you are doing some altitude 109 tests I did the same on patch 1.08. It seems not to have changed the last two patches though.

At 5000m 1.23ata 2400rpm I get IAS 400kmh which seems consistent with your Test 5 above.

The 109 does not change max speed between 2100 and 2400rpm which simplifies things.

Messerschmitt "guaranteed" top speed: (backed up by the flight test record)

570kmh TAS @ 5000m, 2400rpm, 1.3 ata (5 min limit).

CloD 109E4 (manual prop pitch) top speeds:

425kmh IAS = 561kmh TAS @5000m, 2400rpm, 1.32 ata

Full throttle boost has dropped below 1.35ata at 5000m. However the 109 1 minute takeoff boost is still working and oddly enough will still increment boost at 5000m (to 1.42ata).

440kmh IAS = 581kmh TAS @5000m, 2400rpm, 1.42ata.

So the CloD 109E4 at 5000m is 10kmh slow at the 1.3ata combat setting (will assume boosts in the 1.3-1.35ata range can be considered effectively the same). However it has access to the takeoff boost at altitude, which enables it to be 10kmh faster than the real life version.

Cheers, camber

Offline tests, cockpit off, speeds rounded to 5kmh, 4950-5050m, oil/water rads fully open, OAT 25/1000ft rule for IAS/TAS conversion.

[Glider]

Originally Posted by TomcatViP

However, do you realize guys that there was no 100oct fuel during BoB ?

Priceless

[Kurfürst]

Originally Posted by 41Sqn_Banks

Interesting .... http://www.spitfireperformance.com/n3171-cooling.jpg

From: http://www.spitfireperformance.com/n3171.html

Excellent. It should be tested in the sim under the same conditions (though this test was done in the winter) to wheter the sim has similar cooling modelling.

A vague look though tells me that the temps are rising slowly but steadily even at 6 1/4 / 2600 rpm. Overall it just looks just suitable for climbing conditions at lower powers.

[SlipBall]

Originally Posted by Kurfürst

Excellent. It should be tested in the sim under the same conditions (though this test was done in the winter) to wheter the sim has similar cooling modelling.

A vague look though tells me that the temps are rising slowly but steadily even at 6 1/4 / 2600 rpm. Overall it just looks just suitable for climbing conditions at lower powers.

That's just it though, some seem to want a 30,000 high power climb with no cooling problems.