WWII aircraft armament machine guns and cannon

[RC20]

@Pumpkin:

RC20,
Could use of WEP time have been limited to supercharger or boost temperature?

Possibly high exhaust valve temps, high inlet air temps surpassing the knock resistance given by the water injection?

Could you even hear detonation from inside the cockpit under such stressful full power conditions?

Apparently the connecting rods were Not the weak link being very robust.

If you just eroded the piston crowns necessitating replacement that's one thing, a hole in the piston would have been very bad. Better have kept your mechanic well lubricated

Complex subject and I am no expert. EGT is used on aircraft for the lean function though when I was flying, you pulled back until a power drop off and then 1 inch forward past where it picked up again.

You did not want to spike the EGT. The complex and or FI engines, phew, many added EGT so they could protect their engines (costly things)

So its a dance between power needed with the prop speed and throttle and mixture all interacting.

Per Military historian, the FW-190 had an all in one control. Not separate levers. You could not maximize it in the air. But you also did not have to deal with EGT or Boost pressures in combat. I expect with interior lines you were not flying the long range missions the US and UK did (and Japan, phew, 700+ one way in a Zero)

So what I can tell you is Allison was far more rigorously tested than the Merlin. Maybe it was excess. They ran the 150 hours, tore it down, inspected everything and then adjusted parts build. Time consuming.

As I understand it, Merlin ran on the ragged edge of detonation and over. Never read a report of a pilot saying they hear it.

At least my use of lean, engine just fell off on power and you were very gentle on pulling that lever back. Once landed we killed the engine with full lean but it was idling.

Con rods from the Allison were used on the Merlin in air races.

Agreed on piston burn through.

And the time limit for WEP was a safe one but if you needed 30 minutes you would use it.

Keep in mind, in the UK you had the resources to do it per mfg (though I am willing to bet that was ignored during the Battle)

In the desert or the Pacific on the long end of a supply chain? Tough decisions and you may have just lived with being on that edge of failure.

Because I never flew constant speed aircraft, I never got into details per questions being asked. Just the general aspects.

[davidsog]

the FW-190 had an all in one control. Not separate levers. You could not maximize it in the air.

It was actually much more precise in most things than a human pilot trying to move separate levers watching gauges.

If you read the NACA evaluation, it was spot on. The only portion of flight it was not was if you pulled the lever to idle and descended. The system did not read density ratio as good in a descent because of the speeds of diving. The KG went to more a mechanic recipe system like the Bf-109. The only effect was the supercharger gear changeover was not always smooth because the gear had a wide range of RPM the Kommandogerat could select to enact the change based on the density ratio of the atmosphere. So it was very efficient in level flight or a climb when the aneroid wafers were functioning.

In a power idle descent, the supercharger gear change over could occur at high rpm or low rpm. Sort of the like a manual transmission changing gears early or late in a power idle descent. Of course if you were not at gear change altitude, it made no difference at all.

Merlin ran on the ragged edge of detonation and over.

When an airplane engine experiences detonation, there is no doubt in your mind what is going on.

https://youtu.be/Z1eOp_4godQ?si=JLqMucCPq57WICOx

[Pumpkin]

Maybe I should have said, pre ignition, as being the start of things going bad. Pre ignition if prolonged and intense enough can damage an engine along with its spark plugs. A detonation event can destroy an engine in very short order.

[RC20]

Guilty, I use the terms as interchangeable and as pointed out, that is not correct.

The terms “pre-ignition” and “engine detonation” are often thrown around interchangeably to describe the phenomenon that causes engine knock.

That is me.

I have heard pinging in engines. Don't know if that was detonation or per-ignition. Its a distinct noise. Climbing hills in my 4 banger jeep and 6 banger Ford. Jeep was the worst and never sorted out the issue.

As a side note, if you had the lever for leaning then you shoved it to auto rich while in the fight.

I suspect its a behind the scenes reason the P-38 was not desired in Europe (Kenny was delighted to get them). Bong and group had been flying theirs for some time, a new pilot out of flight school, it would not be the aircraft you would want to give them. Bongs group sure could fly them.

[RC20]

It was actually much more precise in most things than a human pilot trying to move separate levers watching gauges.

I won't argue that. It had to be set up right and wonder how common it was for both mfg of the control and field setting that it was right. That is a complex bit of equipment. I also figured for long range flight aka out in the Pacific, manual set would be better.

If memory serves me right, it was a known method but had got dropped in training in order to simplify things. Quick look and higher manifold pressure and lower RPM. see note:

FW-190 ops as noted, most of the time it would not be a consideration. Low on fuel just drop out of the fight and land as an airbase (well until the US/UK/French forces got so close the airbases were regular attack.


note: There is a mix of throttle and propeller pitch and they will act out in a total. So raise manifold pressure (prop) but throttle back if I have it right.

For me the more common one was your rear tail surfaces do not control rate of decent! Ok, yea, push the yoke forward and you will start down.

Speed will pick up and you will come to some degree of down and level.

The way it was taught throttle controls rate of decent, set pitch with the elevator. But yes they acted in combination with each other.

That was why you had trim. You changed that dynamic balance and then you adjusted for controls to be light and responsive.

[RC20]

Some of the US tests could throw things off. Our gasoline was top notch. German and Japan tended to somewhat lower due to their oil situation (lack) as well a just getting any refined and into the field.

So you really need to know what octane was used commonly as well as what US higher would throw results higher when in combat it was not true for the other side.

[RC20]

I did a bit of review and I believe I have the throttle and propeller pitch a bit crossed up.

Somewhat the reverse of what I put down. Again its theoretical to me as I never flew one of those higher tech (or performance spectrum) airplanes with CS.

[Pumpkin]

One thing,
If your antiknock additive runs out or stops for some reason you will be in deep $$$$ if at WOT.

Some cars today use exhaust gas recirculation for knock suppression.

If it happens to fail you will start having pre ignition problems.

[RC20]

Not familiar with EGR for that purpose though more than a few EGR aspects over the years.

Following is a U Tuber that uses a game system to convey aspects of Air Combat. I have a hard time when he is flying an enemy aircraft and is delighted when he shoots down Allied aircraft. Frankly I think he is just into the game and an us vs them. I played Panzer Blitz lo many years ago (board game, hexagonal spaces) and my friend took the Germans. He liked playing the Germans (Panthers as the game comments noted alwyas worked!) and I took the Soviets or US/UK. Just did not like playing the Germans. You can see there is no throttle back on an attack. Now the guy is very good and IL2 seems to give you better accuracy that real world.

https://www.youtube.com/watch?v=prQYthfBHBk

Latter we played US forces and Air Power was stunning in the reversal in that German forces stood no chance unless the Air Forces were grounded via a roll of the dice to determine that.

As a strange side note we picked up a Revolutionary War game which was the whole East Coast. Upshot was when the UK came after my Americans, I retreated. So it was a funny hop hop hop to attack New York, then a hop hop hop back up the Hudson getting away from the Brits. Ok, logic there, don't fight unless you have a chance to win! Turns out that was basically the Revolutionary War fight. Retreat until the Brits are weak, run em back to New York and rinse wash repeat. It also used the ebb and flow of sickness (subtract from both sides) as well as who got what logistics bump at what time in the war.

[davidsog]

That is a complex bit of equipment.

Yes it was a very complex piece of equipment especially for its time.
Bendix holds the patent and helped us restore our Kommandogerat. Although they rebuilt it, they gave it back completed with the disclaimer that they had no idea how to set it up. The Smithsonian got NASA involved and they helped to get information needed to set the thing up on the BMW801 engine to work.



From the Luftwaffe Kommandogerat manual showing the functions of the unit:



It was a hydraulic-electrical FADEC. Full Authority Digital Engine Computer is used on many jets today. A jet without one requires a pilot to look at gauges, "split" the thrust levers, and adjust them to the power settings needed. All the while, you are accelerating down the runway eating up your runway length and controlling the rest of the jet keeping where it needs to be for a safe take off. A FADEC has a dented position that does all of that adjusting in one simple move of the thrust lever. One click and one glance at the gauges is all that is required to get the perfect power setting required.

Without a FADEC, every power change is the exact same dance. With a FADEC, it is a simple click into the correct dentented position with a confirmation of a glance at the gauges.



It represents a huge reduction in pilot workload. Once more, because there is no requirement to fiddle and adjust the propeller rpm lever, manifold pressure lever, supercharger gear selection, or mixture control it takes much less time to make a correct, optimal, power change.

This allows a fighter pilot to keep his eyes on the enemy and concentrate on the fight instead of setting power he needs to win the fight.

It was not capable of doing things like Lindbergh's recipe for increasing the P38's range which is "Lean of Peak" Operations. You are correct.

The FW-190's system used an propeller rpm changeover point to switch from Rich to Lean mixture circuits. This allowed the pilot to achieve his best range cruise conditions but the system did not use "Lean of Peak" logic. It just used normal operations which is peak EGT or simply the point the engine returns to smooth operation after leaning to a stumble. The system did not stumble the engine, it just used the aneroid wafers altitude density measurements to set the best range mixture circuit along with all the other engine/propeller settings required.

That being said, even today, Lean of Peak operations are controversial among pilots. It very much requires a specific engine set up, no carboration, Fuel injection, individual cylinder EGT and CHT gauges, etc. Even with the right set up, the argument against it is increased maintenance and with the wrong set up you will have major maintenance issues. That is why some in the USAAF were not jumping on board with great enthusiasm at Lindbergh's recommendations.

Following is a U Tuber

My little brother sends me this guys stuff all the time. He's entertaining for sure.

[davidsog]

I played Panzer Blitz

I played that game a few times when I was younger. It was a good game.

I think most people choosing a side in any of these historical games has nothing to do with political nonsense or ideology. In fact, I think going down that path ranks right up there with having "fact checkers" to tell everyone what the facts are....

In the slight chance there is some idiot choosing things based on some ideology the nuttiness factor makes it self correcting for everyone around them.

[davidsog]

Maybe I should have said, pre ignition, as being the start of things going bad. Pre ignition if prolonged and intense enough can damage an engine along with its spark plugs. A detonation event can destroy an engine in very short order.

No worry, Lot of people get them confused.

One thing,
If your antiknock additive runs out or stops for some reason you will be in deep $$$$ if at WOT.

Some cars today use exhaust gas recirculation for knock suppression.

If it happens to fail you will start having pre ignition problems.

Absolutely. If you are using knock suppression system, running out of the knock suppression additive can have severe consequences.

This is why the Water Injection system of the P-47M was pulled in the ETO. They kept eating engines up and losing aircraft.

You can see with the German experience testing C3 Injection, the absolute increase in knock limited performance of the hydrogenated fuel.

1941 C3 fuel (~100/130 octane) was not the same as 1943 C3 fuel (~100/145 Octane) in terms of knock limited performance. That is why the test aircraft could fly at such high boost ratings without damage to the engine.

[RC20]

It was not capable of doing things like Lindbergh's recipe for increasing the P38's range which is "Lean of Peak" Operations. You are correct.

Side note on that, my understanding was it was known by the engineers and top engine people. Lindbergh just brought it back to attention as a method that had fallen off the radar. Unless you are doing long range missions (Lindbergh and his route proving) well not the top of the list.

I think the FW-190 system was a fantastic idea. No disagreement. The question for me has been building it (slave labor more and more ) and the time involved expense involved, was the return worth it?

Like an 88 mm SPG or TD (whichever term you want to use) . The Kwk 41 L/70 was as big as you could piratically use. An 88 or 128 might have more range but your optics and MOA (mils for the military back then?) and sans a rare lucky shot, you are spotting shot fall and adjusting. Again that trade off if you have a closer range fight and should be paying attention to that as that is what can kill you. Larger gun, heavier systems, separate charges to handle (with the 128) and what is the return? With the right round a US 76mm could punch through (most if not all). Ergo, the Sherman was not as cool as a Panther but it was good enough to do all the missions on the far end of a logistic train.

The Germans with the Panther and Tigers traded off early, mid problems with somewhat to more effective when it worked. So lots of breakdowns and losses when you could not afford it (dire consequences). I would like to see what it would have looked like if they went max Mk IV production (it had a very good gun as well being a bit shorter than the the L/70.

The US and UK could bring jets into WWII if a priority (US did send 4 P-80 to Italy)
but like the 76mm Sherman, deemed not needed. Granted (pun) the Sherman 76 needed the HVAP shell to be effective so you got a bit better gun but lose HE (call that another mystery)

Don't get me wrong, the best thing that happened was German mistakes

[RC20]

Elephant in the Room: Going Off Topic for the Last Time:

I don't view war games modern simulation or the board games with a detached view.

So yea, I liked playing what I think are the good guys.

And I don't care about the other view point. We have to deal with it. Who did what to whom going back to the days of caves and clubs, everyone has issues.

Get in the path of the Golden Hoard (sp?)

And the explanations are never simplest in reality though propaganda drives them.
You could say we created modern Japan with the forced opening (Perry?). And it does have some truth to it.

All that matters not if they attack us, then we have to deal with what is in front of us.

So yea, I take it personally. Sometimes (Hirohito) you suck it up for what was felt to be the greater good. I don't know and we don't know what the outcome of that would have been if they executed him.

[44 AMP]

A Horde is a mass of people or other living things. A Hoard is a collection of things, usually things of value.

[RC20]

Oh my. Well my mom had to teach us at one field station (no school). I made her nuts with using alternate spellings. Of course my brother had a semi photographic memory and he always got it right and made me look worse.

But as I told my mom, I would rather get 50% right than all of them wrong!

I do sit corrected though.

[davidsog]

The question for me has been building it (slave labor more and more ) and the time involved expense involved, was the return worth it?

Not sure what you are looking for here. History is what it is. Turning away from it, the good, bad, and the ugly is not the answer. It leads to its repetition at a faster rate.

Nor is burying it in an attitude of superiority for all we do. Not only does artificial visions of superiority cheapen the sacrifice/efforts of those who overcame to win, there is no guarantee of the moral side winning in any conflict. Only an honest accounting of ourselves, our weakness as human beings, and our strength, ingenuity, courage to overcome it.

Factually BMW used slave labor and is held to account post war:

https://www.jewishvirtuallibrary.org...-the-holocaust

Focke Wulf, GmbH did not use slave labor but contracted subcomponents like engines and batteries etc most certainly did use it.

In fact, Focke Wulf GmbH was the only German Aircraft manufacturer not to use it.
Did you know Ford used slave labor? All the German subsidiaries of Ford used slave labor after 1939.

https://en.wikipedia.org/wiki/List_o..._the_Holocaust

https://www.jewishvirtuallibrary.org...uring-nazi-era

Popular Pharmaceutical Company Bayer Bought Concentration Camp Victims in WWII

Everyone has heard of Bayer, the pharmaceutical company that runs aspirin commercials on television. Not everyone knows, however, of Bayer’s dark past.

The successor of pharmaceutical conglomerate IG Farben, the company was a huge donor to Hitler’s electoral campaign and supporter of the Nazis.

IG Farben worked closely with the Nazi party to take over manufacturing plants when the Germans invaded other European countries. IG Farben also held stock in and was represented on the board of the company which produced the gas used in the Holocaust gas chambers.

Auschwitz was much more than a concentration camp. It was also the setting for IG Auschwitz, a 100 percent subsidiary of IG Farben. It was the largest complex in the world manufacturing gasoline and rubber.

It was also where IG Farben tested its products.

After the war was over, the Nuremberg War trials sentenced 24 IG Farben board members and executives with mass murder and slavery, among other crimes.

https://www.warhistoryonline.com/war...tims-wwii.html

[RC20]

On a side note, I was looking at some Helicopter specs and saw the Robinson 66 Turbine engine had a limit of 5 minutes full power.

First time I had see that though it may well exist in others as well.

While listed as an RR300 engine its actually a variation of the Allison 250 Turbine. Kind of ironic I thought.

[RC20]

Not sure what you are looking for here.

Position stated and not looking for anything. End of subject as far as I am concerned.

[44 AMP]

End of subject, end of thread, and long past due.