Soviet Fun

[jonboede]

This was supposed to just be a video record of a walk around with a mechanic to point at a few things, but Taylor edited up into a nice video for practice and I think it came out well to show some of the commonality, some of the differences, and some of the difficulty working with ex-Soviet aircraft (and mechanics).

http://blog.cwam.org/2009/12/mig-23-walk-around.html

Kazik is speaking Polish, Ben's translating and I'm the dummy with all the questions.

[cozmo]

I don't like to watch videos on the computer, but that was just cool.

Didn't quite get what the covered switches in the wheel well actually do though.

[MX304]

That was very cool! One of these days I have to out and see your museum. Do you have any idea of when you might attempt a flight?

[CAPFlyer]

Cozmo -

The switches are used to preserve and de-preserve (conserve/de-conserve as thy say) the engine. The Russians designed into the MiG-23 a system of switches which automated this process. One switch activates the preservation process and the other activates the de-preservation system.

I do not know for sure how this works (but would really like to find out), but if it's similar to the Mi-24 Conservation system, then it probably pumps all of the fuel out of the lines and then circulates a certain amount of oil through the system and then while being motored injects it into the engine to create a thin film of protective oil on the inside of the engine.

[viking73]

Jon, neat video thanks for the link. So Kazik was just visiting the museum and you decided to pick his brain about the MIG-23? He sure seemed to know what he was talking about.

I need to make it up there for a visit on Saturday soon as I'm only about 45 minutes south of you...

-Derek

[Airplanejunkie]

Cozmo -

The switches are used to preserve and de-preserve (conserve/de-conserve as thy say) the engine. The Russians designed into the MiG-23 a system of switches which automated this process. One switch activates the preservation process and the other activates the de-preservation system.

I do not know for sure how this works (but would really like to find out), but if it's similar to the Mi-24 Conservation system, then it probably pumps all of the fuel out of the lines and then circulates a certain amount of oil through the system and then while being motored injects it into the engine to create a thin film of protective oil on the inside of the engine.

I'll display my ignorance here:

What would be the problem with leaving fuel in the system over the long term? I would think jet fuel would be pretty stable and a pretty good preservative in it's own right. Does the problem lie with the kero itself, additives or something else altogether (Russian wintertime temps come to mind?)

Steve

[bdk]

The fuel controls in jet engines are very sensitive to corrosion and having the seals dry out. With many jets you need to run (or at least motor) the engines every 30 days. This also keeps all the roller bearings wet with oil.

[CAPFlyer]

The fuel controls in jet engines are very sensitive to corrosion and having the seals dry out. With many jets you need to run (or at least motor) the engines every 30 days. This also keeps all the roller bearings wet with oil.

On the Mi-24, the "storage" protocol says that the engines need to be run every 30 days. I'd have to pull the books, but the manual is pretty detailed for how to preserve and de-preserve the aircraft and the specific procedure for running the engine and components (there is both a "ground" and a "hover" procedure specified).

Steve, as was said above, jet fuel can cause corrosion. In addition, all fuel has at least some water in it. As such, if you leave it in for a long time, the water will settle out and cause corrosion. Typically, you fill all tanks with light oil and then drain them to put a protective coat of oil on them. This is what I believe the automated system on the MiG does, but in the tried-and-true fashion of the Soviet system - with as little intervention as possible.

It goes back to something that Jon told me when I met him - the Soviets designed everything to be maintained by a farmer. If a farmer couldn't maintainer it, then it was simply setup in such a way that when it was time to work on it, it was removed from the aircraft and sent back to the factory or overhaul facility to be worked on. Thus all the "automation" like what you see with the start sequences on these aircraft. When all you have to do is "flip switch", you can have conscripted maintenance crews keep the aircraft in working order instead of the highly trained (and thus highly dangerous from a possible defection or spy point-of-view) crews that we're used to in "the West".

[Airplanejunkie]

Interesting and thanks. I wasn't aware of the storage considerations for turbine engines, but it makes sense. I guess it's a good thing I just run turbines vs fixing them.

Also interesting the comments on the design philosophy. I have some familiarity with the Yak 52 and know that it was designed to be fielded and essentially not maintained much beyond adding gas, oil and maybe occasionally air. Fairly short overhaul intervals, but little interim maintainence required and when it wore out, the whole shootin match went back for overhaul. Also cursedly small fuel tanks to prevent unwanted excursions from the Motherland.

Again,thanks for the info and best for the new year!