Throwing some light on rates of turn

[Ernst]

I just remembered this:

http://www.youtube.com/watch?v=TFl8X4y9-94

[IvanK]

I think this "G" is in fact a Buchon.

[Kurfürst]

Originally Posted by IvanK

I think this "G" is in fact a Buchon.

It's a bit offtopic, but I never quite understood this 'Buchon' thing. Sure the Buchon handles slightly differently (from what I gather, directional stability was worse than on the 109, which already exhibited low directional stability characteristics), but in essence it was just a German built G-series airframe, with a very similar Merlin/HS engine wrapped onto it.

[IvanK]

A Merlin installation v a DB605 installation is significantly different though.

Though I havent seen any Specfic excess power differences between the two I am sure they would be significant thus affecting sustained turn and climb performance. My Gut feeling is the DB605 variant would be the lesser performing aeroplane.

[Holtzauge]

The additional data posted by IvanK now gives the engine power as well and the turn time at 20,000 ft can as MIG-3U points out be read out of that figure to be in then order of 30 s. In fact the same report contains an even more precise figure of radius 1045 ft, bank angle 51 degrees and turn time 31.5 s in table 4 on page 4.

While we are waiting for Crummps 21 s 68 degree bank proof here are some C++ simulation results showing the relative performance between the 1.3 ata Me109E and Spitfire Mk1 at +6.25 boost:

As expected the Spitfire is somewhat better at 20,000 ft due to the lower wing loading. However, the interesting thing is however that at low level (1 km) my simulations show that while the Spitfire turn better at low speeds, the Me109E turns better than the +6.25 boost Spitfire Mk1 at TAS speeds over 290 Km/h. However, if one assumes the +12 boost then it is of course no contest, either at low or higher speeds.

[Ernst]

Originally Posted by Holtzauge

Concerning Kurfurts post I'm not going to be drawn down to that level. Replying to that in an appropriate manner requires breaking the forum rules. Toddler tantrums require strict parenting and I leave that up to whomever it may concern.

So returning to the grownup discussion:

The additional data posted by IvanK now gives the engine power as well and the turn time at 20,000 ft can as MIG-3U points out be read out of that figure to be in then order of 30 s. In fact the same report contains an even more precise figure of radius 1045 ft, bank angle 51 degrees and turn time 31.5 s in table 4 on page 4.

While we are waiting for Crummps 21 s 68 degree bank proof here are some C++ simulation results showing the relative performance between the 1.3 ata Me109E and Spitfire Mk1 at +6.25 boost:

As expected the Spitfire is somewhat better at 20,000 ft due to the lower wing loading. However, the interesting thing is however that at low level (1 km) my simulations show that while the Spitfire turn better at low speeds, the Me109E turns better than the +6.25 boost Spitfire Mk1 at TAS speeds over 290 Km/h. However, if one assumes the +12 boost then it is of course no contest, either at low or higher speeds.

Hello Holtz,

Do you consider 109 slats in your simulation?

[Holtzauge]

Yes, slats are in there implicitly but not modelled as such: I assume a power off low Mach Clmax of 1.45 and since the slats on the Me109 start to come out at around Cl=0.8 and IIRC are fully deployed at 1.2 they can be said to be modelled.

Originally Posted by Ernst

I just remembered this:

This video which claims to "proof" that the 109 was equivalent in turn to the spit is pretty much useless. The first interviewed guy never flew a spit as he admitted himself. The second guy we don't learn about his flight experiences. We therefore just learn that the 109 was a good turner (perhaps better than ingame but that's another discussion) and better turner than the P51. Now that is nothing new at all.

Fun to watch but not even anecdotical evidence on how close the Spit and the 109 were.