Lavochkin La-9 question

[Hoggardhigh]

Hello,

According to this page about the Lavochkin La-9:

"The aircraft was constantly being improved. Only in 1948, 197 changes were introduced into its design, which improved the quality of the machine."

Does anybody know the meaning of this assertion, or if it is true?

BTW, I'd also like to know if the published specifications for the La-9 (such as those at Wikipedia) refer to early- or late-production examples.

Thanks

 

[FLYBOYJ]

When a combat aircraft is being produced, there are usually many modifications that may be incorporated to improve performance even though the basic design is frozen for production. To be honest 197 changes don't sound too unreasonable, I've been on programs where "changes" or "mods" numbered in the thousands.

 

[Hoggardhigh]

And as for the published La-9 specs?

 

[FLYBOYJ]

And as for the published La-9 specs?

I'm sure those changes have little effect. They might be things like better radios, instruments, nav aids, better seats, structural improvements, etc.

 

[Hoggardhigh]

I'm sure those changes have little effect. They might be things like better radios, instruments, nav aids, better seats, structural improvements, etc.

What do you mean by, "structural improvements"?

 

[FLYBOYJ]

What do you mean by, "structural improvements"?

This could be anything from strengthening the airframe in certain places to make access easier for maintenance.

 

[Hoggardhigh]

Anyone know of any other published sources with more information on the subject?

 

[nuuumannn]

According to Gunston in Russian Aircraft, the programme was gradually run down from 1947 owing to the end of the war and development of jets, stating that "Some early batches retained armament of three or four ShVAK and many had one of left side NR-23 re3moved leaving three (often retaining blister fairing for missing gun). Total production possibly 1000 including La-9UTI dual trainer with one NR-23 first flown from Jan '47, NII test June and built in small numbers from Aug '48."

The entry lists the changes made to the basic design from La-126, which was based on the La-7 with a laminar flow wing, including improved ailerons, improved engine installation, exhaust arrangement, supercharger duct inlet shifting etc... These things obviously not taking place in 1948 though, beginning four years earlier. It seems odd that so many changes were made in 1948, unless they are referring to the UTI variant, because the La-11 entered service the same year, so why would there be a need to make so many changes to the La-9, unless the writer means changes made to the La-9 to make the La-11?

As for specs listed in Wiki, whether they are early or late production wouldn't really differ much, other than the UTI figures? The wiki reference for "Further Reading" suggests Yefim Gordon's Lavochkin's Piston Engined Fighters, which is where I'm sure you'll find what you are looking for. Gunston's figures don't differ much from those in wiki, the only difference being in UTI performance listed separately.

 

[Wurger]

I'm sure those changes have little effect. They might be things like better radios, instruments, nav aids, better seats, structural improvements, etc.

What do you mean by, "structural improvements"?

This could be anything from strengthening the airframe in certain places to make access easier for maintenance.

That's exactly what they did... For instance beginning the 7th series the dividing of the elevator into two parts was given up. With the 8th series the exhaust pipes were made shorter in order to improve the thermal parameters of the engine work. For already made kites the changing was introduced in the squadrons by cutting th epipes with a hacksaw. Also with the 14th series the attachment of wing skin was strenghten by changing the rivet spacing. A part of planes got the second oxygen bottle with the valve allowing refilling without taking out of the bottles from a plane. Up to the La-9 serial 48211458, all planes were equipped with the Lend-Lease USA Fairchild F-52 photogun. Because of stock out these were replaced with the Russian S-13. The changing was done in squadron workshops. With the 20th series the La-9s got a new, more reliable system of releasing of the cockpit hood while flying with high speed. There was more of such changings covering the gunsights for instance. It seems that all these changings didn't affect the basic performance of the La-9 significantly because these were more results of service than the attempts to increase the plane performance.

The info can be found in books ...

La-9 - Wydawnictwo Militaria no.311
Fighter La-9 - Aviakolekcya no.9/2008
Fighter La-9 / La-11 - Armada no.11
La-7/La-9/La-11 the last piston fighter of the USSR, Nikolay Yakubovich, Eksmo

 

[Hoggardhigh]

Hi all,

I am a bit confused about the listed weights for the Lavochkin La-9: 7551 lb (Loaded) and 8104 lb (Maximum).

In particular, I am curious as to if the former weight includes full fuel, armament, etc.

Anyone have an explanation for this?

Thanks

 

[FLYBOYJ]

Hi all,

I am a bit confused about the listed weights for the Lavochkin La-9: 7551 lb (Loaded) and 8104 lb (Maximum).

In particular, I am curious as to if the former weight includes full fuel, armament, etc.

Anyone have an explanation for this?

Thanks

I believe the first is the "normal T/O weight" and includes full fuel and armament.

 

[Hoggardhigh]

I believe the first is the "normal T/O weight" and includes full fuel and armament.

Does anyone know if that applies to ALL Lavochkin fighters, from the La-5F/FN thru the La-11?

 

[FLYBOYJ]

Does anyone know if that applies to ALL Lavochkin fighters, from the La-5F/FN thru the La-11?

When shown like your post, I would say yes

 

[Hoggardhigh]

When shown like your post, I would say yes

And as for the maximum weight for these aircraft? What do you suppose that refers to?

 

[FLYBOYJ]

And as for the maximum weight for these aircraft? What do you suppose that refers to?

The 8104 lbs. is probably the maximum take off weight to include bombs or drop tanks

 

[Hoggardhigh]

And what about the empty weight?

 

[FLYBOYJ]

And what about the empty weight?

Lavochkin La-9 - Wikipedia

en.wikipedia.org