Interestingly, Germans didn't bother to make such a diagram for Bf-109E-3! I
have the manual for Bf-109E-3 (Yugoslav export version) and it reads only
four figures for turning circle:
Smallest circle radiuses:
(with flaps up)
At altitude 0 m-170 meters (0ft-557ft)
At altitude 6,000m-320meters (19,700ft-1,050ft)
(with flaps down)
At altitude 0m-125 meters (0ft-410ft)
At altitude 6,000m-320 meters (19,700ft-1,050ft)
As you can see, no performance gain using flaps at 6,000m.
Note-no speeds indicated, however it seems that all performance are measured
at max takeoff weight of 2,540kg i.e. 5,600lb (same weight in the manual and
of the tested aircraft). However, it seems (per graph) that BaE somehow
"added" some HP-per my manual, nominal HP of "export" Bf-109E-3 was 1,100HP
at 3,700m/12,100ft at 2,400rpm (5min)at 1.30atm/19.1PSI/38.9In/Hg, and the
max HP was 1,175HP, 0ft at takeoff 2,500rpm (1min) is unattainable at
12,000ft. Since my manual states 87octane fuel, maybe RaE used 100 octane
fuel? The difference is not trivial-exactly 100HP!
Now, I didn't do "stretching" to the altitudes listed in the British chart,
but they seem reasonable. Well done, RaE!
OTOH, it seems that Germans were not conducting such scrutinized tests-at
least not with Soviet aircraft. I have been reading an article of comparison
between captured Lavotchkin La-5FN and in-service Fw-190A-8 and Bf-109G-6.
This was done poorly, to say at least. Firstly, they have tested an early,
initial shortly produced FN model (manufactured in September 43, captured
and tested in September 44) that was war-weary and probably hastily repaired
(Germans reported that the engine was producing a lot of black smoke, which
was not the characteristics of fuel-injected M-82FN engine). Then they
overloaded it with ammo. Then they filled it with 87octane instead 100octane
gasoline (La-5FN demanded 100-octane gasoline, but the Germans had
previously
captured La-5F that used 87-octane so filled it accordingly). Result: around
12% of the speed/climb/altitude decrease (and worse at 1,000m). The biggest
resulting mistake was underestimation of WEP that La-5FN could produce up to
6,500 ft and use it up to 10,000ft, making it faster than both
Bf-109G-6/MW-50 and Fw-190A-8 with WEP to up to 12,000 ft. Finally, it seems
that they never compared tested La-5F/FN data, because they would find that
something was wery wrong!
Russians did the similar mistake; in 1941, they tested captured Bf-109F-1
that had a problem with compressor and got "false", reduced characteristics
above 3,000m for DB601N engine.
Nele
NULLA ROSA SINE SPINA
Guy Alcala wrote in message
.. .
Geoffrey Sinclair wrote:
The Enlightenment wrote in message
...
snip
http://dspace.dial.pipex.com/jazzitoria/aspit-2.htm
MANOEUVRABILITY
SPITFIRE TURNING DIAMETER = 1,760 feet. BF 109 TURNING
DIAMETER = 1,500 ft.
Speed, altitude, weights being used? Oh sorry that is right it is
on the web and the preferred answer therefore it is right. We will
just ignore the turning circle diagrams in the books previously
mentioned, since they give figures of less than half the above,
which means if the above figures are correct we are talking high
speed, where the Bf109 had more aileron problems than the Spitfire,
making them even less believable.
snip
While thoroughly enjoying the spanking you have so professionally
administered, I'll just clarify one minor point: the turning
_diameters_ quoted above appear to be very close to twice the turn _radii_
@ 12,000 ft. quoted in the Spit I/Me-109E-3 test, and most
other sources. The odd thing is that, if I'm reading the Spit I chart here
http://www.fourthfightergroup.com/ea...pit109turn.gif
correctly, by seeing where the straight climb line crosses the stall
boundary, the turn radii should be about 692-693 feet rather than
the 696 given in the report. Using this method on the Me-109E-3chart gives
the quoted turn radius of 885 feet. Maybe the 696' was a
typo in the original report. In any case, a few feet either way isn't
significant -- the Spit I has a far better turn radius than the
109E.
Guy