XP-39 II - The Groundhog Day Thread

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I was using Wagner's exact words, not my interpretation. The .30s were clearly less effective and less reliable. I guess the Russians were crazy to get rid of them and increase the performance of their planes.
 
 
I was using Wagner's exact words, not my interpretation. The .30s were clearly less effective and less reliable. I guess the Russians were crazy to get rid of them and increase the performance of their planes.

You have repeatedly said in prior posts that the 30 cals were "ineffective". That's YOUR word, not Wagner's.

Why is it so hard for you to accept that Russia wasn't PNG or Guadalcanal, and that the U.S. pilots flying in the Pacific clearly wanted the 30 cals?
 
show me a quote where any AAf pilot wanted the .30s.
 
The mixture control could be varied between the pre determined settings. How else did the pilot get a "best power" setting?

So HOW did the pilot determine which way to adjust the mixture?

Do your own research, it's all in wwiiaircraftperformance.

Actually there are aren't any test reports of a A6M2 in good operational condition that were operated correctly on wwiiaircraftperformance.
I am no expert, but I am certain that I have done considerably more research on Japanese aircraft than you have.

Same airframe. Wouldn't two P-39Ds have the same aerodynamics? Only difference between the C and D were internal.

Same airframe, different propeller part number. Different arrangement of equipment and balance may cause some very different aerodynamic consequences. This has been explained to you.

The pilot in the test caused his engine to detonate, was he highly proficient?

This pilot probably was fairly certain he could over boost that particular engine. Problem is that he guessed wrong about the actual limit before detonation. Even highly proficient pilots make mistakes and guess wrong. Being proficient and being perfect are different things.

- Ivan.
 
show me a quote where any AAf pilot wanted the .30s.

Two can play at that game. Show me a quote where any AAF pilot said they wanted the 30 cals taken out? Better yet, show me any instance where any AAF P-39 had the 30 cals removed for performance reasons.

C'mon...I want to see the evidence to contradict my points. Are you at least willing to accept that the USAAF P-39s flew with the 30 cals and that, given the simplicity of removing them, that does at least indicate that the pilots thought it was better to have the 30 cals than not to have them?
 
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What was an ineffective gun against a Japanese aircraft? In aviation history planes were continually loaded with more stuff, fuel guns ammunition armour radios mirrors radars, the cases of "stuff" being taken out are rare and for special reason, generally pilots wanted guns and armour.
 
 
By feel? Here's from an Allison user's manual:



Of course, the Allison was behind the pilot, so he may have had some difficulty with this procedure. Alternately, if you have climbed, you are likely lean. If you have descended you are likely rich. Both assume you haven't touched the mixture before changing altitude. Generally speaking, you either lean or rich to get peak exhaust gas temperature and then adjust from there. In WWII, they always ran rich of peak temperature, maybe 100° rich of peak. Today, we generally run lean of peak.

But is isn't a quick thing. Usually, setting the mixture correctly in a Cessna takes maybe 1-1.5 minutes. 1 minute of straight and level inattention in a combat zone may mean you are dead. The rule of thumb is never fly straight and level in a combat zone for more than 30 seconds.

That's why the "Auto Rich" setting was so handy in combat. You could set it there and forget it until combat was over or you had rejoined and were on the way home. "auto lean" ws a great way to cruise home, but not a good for combat when power changes were required.
 
So this will be done when?
The performance test said the P-39D developed 368mph at a mixture setting of "Best Power" and 365mph at a mixture setting of "Auto Rich". We are talking about 3mph with a slightly different mixture setting, right? When do you think it was done? At this point I would really like to know. For 3mph.
 
Yes they did, but they also wanted to be able to climb above their adversaries. If deleting the .30s meant being able to get above your opponent then I think the vast majority of pilots would prefer being above their opponent. What good are .30s when your opponent has the advantage? And you still have plenty of firepower without them.
 
Either way by feel and sound. We're talking about 3mph.

First of all, you are looking at the wrong detail. The important thing is NOT the 3 MPH difference in maximum speed because in a maneuvering fight with changing altitudes you will never see the difference in maximum speed.
The objective here is the extra 25 HP that gives that extra 3 MPH maximum speed.
The fuel mixture requirements of the engine will be constantly changing as the power (torque) demands and altitude are changing. In combat, the pilot has many other things demanding constant attention. Assessing the instantaneous fuel needs of the engine is not a smart distraction in that situation.

wwiiaircraftperformance. Not a single one? All were wrong? What about the one that showed the 335mph top speed?

Okay, show me all the reports that said the A6N2 was faster then 330mph.

If you are asking an honest question, I will give you an explanation because you obviously think there is more there than there actually is.
Only the first five entries for the Zero are for the A6M2.
There are five entries, but only two aircraft were tested.
One was a A6M2 that fell into the hands of the AVG in China. It was tested against a P-40K and a P-43.
Its Propeller was never in spec and it could not make more than about 2075 RPM, thus its performance is hardly indicative of a properly functioning A6M2.

The second aircraft tested was the crashed and rebuilt Aleutian A6M2 and I won't rehash what was wrong with that testing which I have covered before. Its testing and summaries for different audiences covers about 4 of the 5 reports.

As I have stated before, the only service that had good operational A6M2 and knew how to operate them properly (the only service that had the opportunity) never chose to test for maximum speed in a manner comparable to the Allies.


We have been here before. We got here several times over the last couple days.


The testing of the Aleutian A6M2 was meant to show the superiority of American fighters as much as possible.
I have already explained the evidence (I believe to the satisfaction of others here). Maybe it should not have been a contest, but the participating pilots were most likely informed of the intended results. I have seen government "tests" in other areas that were conducted that way.

- Ivan.
 

Lets start with do you know why you adjust mixture?
 
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