Author Topic: Vermillion, need some La7 info.  (Read 307 times)

Offline fscott

  • Banned
  • Copper Member
  • **
  • Posts: 127
Vermillion, need some La7 info.
« on: March 07, 2001, 06:54:00 PM »
Do you know why some texts report maximum La7 speed at 423 mph, while the official Gordon & Khasonov reports it at 408 for the 2 cannon version, and 410 mph for 3 cannon version?  Who or where do they come up with the 423 mph?  I would assume that G&K would be the more correct version, yet many books quote 423 mph.

OBTW, the 3-cannon format will be an available option for the La7.

fscott

Offline juzz

  • Copper Member
  • **
  • Posts: 193
      • http://nope.haha.com
Vermillion, need some La7 info.
« Reply #1 on: March 07, 2001, 09:56:00 PM »
La-7 site with performance data on a few different airframes.

Link to chart provided by Oleg Maddox, with this description:
Quote
Here is right speed curves for SERIAL PRODUCTION La-5, La-5FN and La-7. Units taken in troops after they had some intensive operation there. (Tests made for each 6-10 planes and then calculated middle parameters for summer and winter time. So it is middle parameters - not the best)

Offline Vermillion

  • Platinum Member
  • ******
  • Posts: 4012
Vermillion, need some La7 info.
« Reply #2 on: March 08, 2001, 07:24:00 AM »
Fscott, do you have the Gordon & Khazanov book?

If you do, look at the performance tables in the back of the book. You will notice that almost every aircraft has two sets of data for it, which they term "prototype" and "production".  

"Production" flight testing, as its termed in this book, was actually done for quality control purposes, on random production line aircraft.  So that they could find problems in their production lines, and fix them.  Lately I have been told a more precise translation of of the original russian term that they call "production" would be called "control".

So what happens is that you have two sets/type of data for Russian aircraft in comparison to the typical one set for Allied aircraft. Remember its important to know how and why a set of data is collected to understand the data itself.

Pyro has been using the lower set of data for Aces High, called the "production" data.  Thats why I and others say we will see the 408mph number, which is the "production" data set, instead of the "prototype" data set number of 423mph.

I'm hoping to soon recieve some original russian documents that talk about how the two different data sets were compiled (the methodologies), so that I can compare them to the Allied methodologies, to see which is actually the correct data set too use.

Its an old arguement among us VVS fans. Prototype or so called Production data.

OH and if your looking in the Gordon & Khazanov book for the La7 prototype, its listed as the La5FN** 1944 Standard, which was later named La7.

------------------
Vermillion
**MOL**, Men of Leisure

Offline fscott

  • Banned
  • Copper Member
  • **
  • Posts: 127
Vermillion, need some La7 info.
« Reply #3 on: March 08, 2001, 10:23:00 AM »
Ah..makes sense.  But tell me why the La7 Prototype has such lousy numbers at 408 mph? The Production is listed as 410mph.

Also, you mean La5** Standard, not La5n.  It has a top speed of 422.5 mph, BUT it's sea level speed is only 370 mph!  I think I would rather have the 380 mph versions.  So are you sure this is the same aircraft? Why is it's sea level speed so dismal comapred to the prototype and production La7?

fscott

Offline Vermillion

  • Platinum Member
  • ******
  • Posts: 4012
Vermillion, need some La7 info.
« Reply #4 on: March 08, 2001, 12:42:00 PM »
Isn't the 408 and 410 numbers the difference between a 1944 two gun La7, and the 3 gun 1945 La7, and not a proto versus production difference?  Differences in performance that small are hard to pin down, and can be attributed to about anything from instrument error, to test conditions, or to pilot difference. Really about anything.

Without having the book in front of me here at work, yes I'm pretty sure the La5** is actually the prototype for the La7, it talks about it the text section of the La7.

Now why the prototype did only 370 at sea level, and the production planes were hitting 380, is not something I have looked at before. So really, I have no clue.

------------------
Vermillion
**MOL**, Men of Leisure