Spit/109 sea level speed comparisons in 1.08 beta patch

[IvanK]

Ok then its straight line running not sustained turn performance. So wrt your comment :

"If the Bf-109E3 maintains his trim speed of 400 kph, he is tough customer for a Spitfire to deal with." I respectfully disagree. Obviously I prefer to accept the RAE's views rather than yours.

WRT the sustained turn performance based on RAE computation at 12000ft, 400Kmh/248mph (TAS). The Spitfire can sustain 2.95G giving an approximate sustained turn rate of around 14.0 deg sec. The 109 on the other hand can sustain only 2.3G giving an approximate turn rate of 10.5deg sec.

So according to the RAE The Spit at 12,000ft/400Kmh TAS has 0.65G sustained G advantage over the 109 and 3.5 deg sec sustained turn rate advantage. Thats a nose position advantage of just on 119degrees in a single 360 degree turn. Sustained turn radius wise the Spitfire is around 526ft smaller to boot. So based on RAE calculations the 109 is not so "tough a customer at 400Kmh" in any turn fight.

A 109 Pilot in this engagement is just going to watch the Spitfire translate aft in his canopy until he ends up nose in lead with guns firing. Best option for the 109 (imo) is as soon as he sees the aft translation back through his 3/9 line to ease off on the G (maybe holding the bank on for deception) extend (using his superior 1G Ps) then transition into a climb, get the separation he needs and come back into the fight at a later point..... and that sort of thing is exactly what the good On line 109 drivers do.

Ties in with the Historical record and what we see On line every day.

[MiG-3U]

Well IvanK, had RAE chosen the lowest available speed and max lift coefficient values for the Spitfire and the highest available speed and max lift coefficient values for the 109, at the altitude which is most favorable for the 109, their results would have agreed with Crumpp's

Ironic mode off: Why waste time with obviously deeply biased stuff? Just google with keywords: Crumpp Spitfire calculation. You will get thousands of hits from the several sim forums over the past few years, I think he has produced enough text and calculations for several books.

[JtD]

I just recalled I still have my near three year old turn performance estimate spreadsheet. I attached it, so anyone interested can produce charts to their likings. I've added some 109 E and Spitfire I data, feel free to use your own data sets. If you have any questions, just ask.

[Kurfürst]

Originally Posted by JtD

I just recalled I still have my near three year old turn performance estimate spreadsheet. I attached it, so anyone interested can produce charts to their likings. I've added some 109 E and Spitfire I data, feel free to use your own data sets. If you have any questions, just ask.

Thanks, this is very usuful.

I fooled around with the specs a bit, with best/worst case data in bost cases, but interestingly the tables keep showing that the 109E is evening things out in turn and then having an advantage at and above around 400 km/h.

Math is just too impartial I guess.

[JtD]

The only way to change that would be using 100 octane performance for the Spitfire I, giving it a level speed similar to the 109. Or go to high altitude, were Spitfire and 109 are always fairly close in terms of speed. Other than that, 30ish extra km/h is quite a bit.

[Kurfürst]

Originally Posted by JtD

The only way to change that would be using 100 octane performance for the Spitfire I, giving it a level speed similar to the 109. Or go to high altitude, were Spitfire and 109 are always fairly close in terms of speed. Other than that, 30ish extra km/h is quite a bit.

Agreed! 100 octane is giving a Spit roughly equal speed at low level, even greater speed at low-medium altitudes, which governs most of the high speed turning stuff. Apart from that, without 100 octane the Spit is a bit of trouble against the 109E at higher speeds, since the latter is faster at low altitudes, and in the end its speed that govers most of the high speed turning stuff (since parasitic drag is much more dominant there). Its simply how the turning formulae works, something that some of spit fanatics simply do not want to accept.

Higher altitudes would be interesting btw. The Spit has a more power there (save for the 109E/N) and the two aircraft about the same speed. The Spit has less wingloading, the 109 has higher AR - thus the main factors governing turning are going both ways.. my guess would be a slight Spit advantage there though (save again for the 109E/N).

Bottomline, it doesn't matter how good the plane can turn, if the pilot can't fly it right through the edge. 1-2 seconds can be generally made up by good piloting skills, both ways.

[Crumpp]

Kurfurst says

but interestingly the tables keep showing that the 109E is evening things out in turn and then having an advantage at and above around 400 km/h.

When you calculate out the performance, it is easy to see why Mtt defaulted the trim to 400kph.

That is a very good speed to dogfight the airplane.

[NZtyphoon]

Originally Posted by MiG-3U

Well IvanK, had RAE chosen the lowest available speed and max lift coefficient values for the Spitfire and the highest available speed and max lift coefficient values for the 109, at the altitude which is most favorable for the 109, their results would have agreed with Crumpp's

Ironic mode off: Why waste time with obviously deeply biased stuff? Just google with keywords: Crumpp Spitfire calculation. You will get thousands of hits from the several sim forums over the past few years, I think he has produced enough text and calculations for several books.

So noted: screeds of data all showing the terrible inferiority of the Spitfire, and all stemming from one or two reports.