Kari, La-7 did not have two stage compressor (supercharger). I think you mixing two speed and two stage superchargers. I guess too many Squadron/Signals! They usually make awful mistakes on this.

According to Jukka Raunio´s Lagg-3 article in Ilmailu 11/1990, it had NACA 23016 at root and 23009 at tip.

Yes, that aileron stalling is really that flicking out of the turn. That Yak-3 Pilot´s Notes really indicate bad stall, harsh and without warning.

Your endurance figures are also begging additional explanations. For example, you write that the 109 had the same endurance (45-60 min) as the La-7. Well, true only if flying at the 30 minute rating (the maximum available in Finnish G-2s and probably G-6s as well). If flown at Dauersparleistung, over 90 minutes and if flown for max endurance, probably around 3 hours or more. Here La-7´s air cooled engine screws it for it has some 30% greater sfc at max continuous power than the DB 605.

Huomenta!


"Kari, La-7 did not have two stage compressor (supercharger). I think you mixing two speed and two stage superchargers. I guess too many Squadron/Signals! They usually make awful mistakes on this."

By two "stages" I meant two speeds. Thanks for the correction and sloppy terminology from my side. No Squadron/Signals was ever consulted. I don't even have the La-5/7 one.

My impression of the Finnish squadron log books, mission reports etc. is that one hour was more or less the maximum combat mission endurance time for Bf 109.


Cheers,
Kari

But consider Brewster Buffalo, it had excellent stall characteristics though it had NACA 23018 at root and 23009 at tip!

Hello Kari ja Jukka
I agree with Kari in that that usual flight times stated in combat reports of Finnish Bf 109G pilots were 45 - 60mins but during these flights there has been always some combat action because it seems that the Finnish Bf 109 pilots didn't file combat reports if they were not claiming something or if their Bf wasn't damaged. That's different to the practice in Le.Lv. 32 where the Curtiss H75A pilots seems to have filed reports from every contacts with the enemy.
That does not of course invalide Jukka's claim that without need to use the combat and climb power (max. 1310hp) the endurance of Bf 109G-2/-6 was longer.

Ps Kari, haven't seen You lately in Sota-arkisto so Thanks for drawing my attention to the photos for which Ed West had posted the URLs (Thanks a lot also to Ed) on the Ju 88Cs that operatted from Tallinn in early 44. I had wondered why Togo was so unsuccesful in it's fighter direction job, at least that was/is my impression after browsing through a book on the ship, when it operated in Gulf of Finland. That at least some of the Ju 88Cs were without radar explains a lot.

Juha

Päivää!

Jukka wrote:
"But consider Brewster Buffalo, it had excellent stall characteristics though it had NACA 23018 at root and 23009 at tip!"

Lavochkins had more tapered wing planform (lower tip chord / root chord -ratio) than Brewster and so more prone to drop their wing tips. I do not know if Brewster and Lavochkins had geometric twist (washout). Washout would tame the stall.

You (Jukka) surely remember the Brewster-type wing for VL Pyry (the type had elliptical wing). The new wing cured the wing drop problem, but new wings were more expensive than modifying the elliptical wings with leading edge slots.

For wing design see also this:
http://www.desktopaero.com/appliedae...ingparams.html

(Don't know if it is the best or even good one, but was the first suitable one I found with quick search on Internet).


tv.
Kari

i think russian datas are quite correct, since there is some confirmation by germans.

lipfert stated yak-3 were more dangerous than mustang (means probably only eastern front heights).

barkhorn stated yak-9u as best fighter for low altitudes. he also fought 3/4 hour against lagg-3.

rall stated his 109g(6?) wasn't able to catch la-5 and yak-9.

grislaski is quoted, that his 109 can't outturn yak-1.

general schwabedissen stated, yak-3 and la-7 were superior to 109g and 190a. schwabedissen also stated that normandie-njemen at fighterbombermissions nearly operated without losses.

at milchs meetings was stated that newer i-16 were still a danger in 9/42, la-5 has same performances than 109f4 or maybe 109g2 (1942)

i 've talked to an 190f8 pilot flew at eastern front and had at least 3 kills. he is member of the "gemeinschaft der jagdflieger". as i asked him about the truth about eastern front he meant: read pokryshkin and you know how it was.

Kari
When the wing is about to stall, any movement of ailerons may interrupt the flow and cause a stall there. In effect lift is lost and the wing drops. From the pilot's point of view it looks like reversal od aileron controls and hence is very dangerous.
To prevent this and make the aircraft safer, the wing is designed to stall at the mainplane first. This may be achieved either by a different less stall-prone profile on the wingtip or by the geometrical twist - changing the angle of atack on the wingtip, comparing to the root. Of course, penalties are paid for those sollutions.
I have a NIIVVS or CAGI test for La-7, I will dig it up and check the data there. Certainly there were performance data but I think also some discussion concerning loss of performance in series aircraft.
Another interesting thing is report filled by Hans-Werner Lerche after testing of captured La-5FN. It is not very favourable having some 40 km/h lower speeds comparing to series aircraft data. I have seen an explanation it was due to lack of automatics which caused proper settings rather hard. Of course a question arise - was it possible to achieve high performance figures in combat conditions?

Jg-51 chronicle states la-5fn 50km/h faster than 190a.

NII VVS really claimed perfomance loss for several reasons. First was due bad production quality and second due overclaiming by producer. But this meant La-7 only flew "only" 612km/h at SL instead of 640km/h claimed by producer.

Jens

Yes, I know this quote but it is not clear for me. Further research is necessary.

I am very curious how he could distinguish Yak-9U variant in the air. I do not think that the Germans were even awared of this rather rare aircraft.
His long dog-fight, although linked to Alelykhin, seems not to find any confirmation. Is there any proof that it ever occured? 45 minutes in a dog-fight should use all the fuel capacity in both aircraft!

I find it surprising, it was underlined by a Polish Yak1/9 pilot Edward Chromy, that they were slower but more manouverable than their German enemies.

I cannot exclude it but otherwise I find it quite stupid to turn with Yak when it is possible to make a safe zoom attack.
Otherwise, it is interesting to note here, that opinions of RAF pilots concerning clipped wings variant differed significantly, although the aircraft almost matched Fw 190 in roll rate (I have a graph).

I am not sure what qualifications General Schwabediessen had but generally Soviet fighters were not flown in ground attack missions because not capable of carrying bombload. This capacity was gradually introduced in 1944 but not used generally due to short range and need of every drop of fuel available in tanks. Of course Soviet fighters did straffe various targets, eg. played anti-flak role during Il-2 attacks.

In Poland, PZL P.11c were still dangerous if a German pilot did not know how to fight them. Generally, it looks for me more like excuses for poor performances of own airmen rather than a reliable opinion. Have you ever seen any mention that German Stuka pilots were so poorly trained, they were unable to keep in formation in 1944? This comes from accounts of Hungarian Stuka airmen fighting in SE Poland.

You mean the book and not KTB?

Just found a report 44-280 of tests of La-7 No 452101-39. It is a little bit long, so I need to re-read it first.[/quote]

Sorry, but i find your arguments a litlle bit biased, since you not only doubt russians figures (what is reasonable from other experiences), but german statements. I can't remember to read anywhere, that russians data claims were over. Pls show me that sources.

Rall made clear in his book, that his statement is for those, who think russians weren't able to build well planes. If you keep in mind that most dofights at eastern front were mostly under 4000m and you take both sides official numbers in aspect, you 'll see he is right. maybe 10-15kph didn't play that great role and also maybe nominal perfomance was more important.

Barkhorn statement is also founded by Walter Wolfrun: "The best Fighters in combat I met were P-51 Mustang and Yak-9U. Both of these types obviously exceeded all Bf109 variants in perfomance, including th "K"."
Barkhorn knew russians planes very good and was commander of a fightersquadron at eastern front. Yak-9U was introduced in 10/44 at northern front.

Schwabedissen wrote studies about eastern airwar for USAF. The americans had no doubt about this, due their own experiences in Korea. The fighterbombermissions were flown by NN in 1944/45 like Schwabedissen stated.

some La-7 test of the -39 is here: http://www.btinternet.com/~fulltilt/...l#No.452101-39
the other number isn't really comparable to other la-7 numbers.

Factory data of La-7 seemed to be reached with polished skin and so on, which i think was more or less normal for german tests.