Thoughts on the Current Flight Model

[Kweassa]

Wow. As I said, you Luftwhiners just love to have your cake and eat it as well. You say of the Me-109, "There are plenty of rides that are just as fast as a 109K, and plenty more maneuverable too. Perking, IMHO, is to keep large quantities of uber-planes from unbalancing the arenas." And yet you would want a 66" P-38 perked, although the same statement would apply. There are plenty of rides that are just as fast as a 66" P-38, and plenty more maneuverable, too.

 Right, so both should be perked.

You think that there's nothing wrong with having a 1.98 ata Me-109, yet do not want to see a 75" P-38 (or even a 66" P-38). That's called a double standard if I ever heard one. 1.98 ata was used less on the Me-109 than the 70 and 75 inch ratings on the P-38L, but you have no problem with this little-used rating being in the game but you balk at the thought of the common, officially approved 66" rating on the P-38. That's hypocrisy.

 I'd be careful before you proceed into any more typical name-calling and side branding, because there are many different opinions on just what kind of perk policy should be adhered to by all kinds of people, including both Luftwaffe fans and USAAF fans.

 So far, it is about established that every post and thread has been degenerated into somekind of typical mud slinging between the fans, and not all of them were perpatrated by the Luftwaffe fans. You have this incredibly judgemental and deterministic attitude in regards to opinions that differ from yours and seem to have no reservations in stamping the clasic "Luftwhiner" brand to everyone who would oppose. Frankly, that makes you really no different from some classic riot-acts like Kurfurst, to our eyes.

 Concerning the comparative status of the two different planes; the Me109K-4 and the P-38, in regards to boost levels and perks, there has already been discussions and posts explaining why some boost levels are left out of the game, which for some reason you seem to just not listen to. Personally I believe our K-4 is running at 1.98, but it is still controversial. Likewise, ratings over 66" in the P-38L is equally controversial and currently there is no solid evidence that warrants its use in the game (except some abominable snowman of a memoranda you claim to have seen somewhere, but still remains to be actually presented) according to HTC's (presumed) guidline in aircrafy modelling standards.

 So I suggest you take all of that into account, before making a mess of things which would make a lot of people frown.

[Benny Moore]

I have not yet found it, but I have found someone who had it.  In the meantime, here are two other people mentioning it on two different forum.  On one, there is the text of a memorandum, and on the other there is a dead link to the scanned document.  This, of course, proves nothing, except that I am not making this up.  I'll continue searching for the actual scan of the document.

http://home.epix.net/~cap14/p38wep.jpg

MW was kind enough to scan this in for us...I thought I'd post it over here too.

War Emergency Ratings were raised from 60" to 66" with the advent of higher octain fuel.

My guess is that the P-38L started to delver on June of 44 the same month this fuel became available. So the advisory circular came after the POHs were published for the 38L.

Here is the snippet MW gave us: "P-38Js were cleared for a WER limit of 66" Hg using 150 grade fuel. The entire 8th AF fighter component switched over to 150 octane in early June 1944. No modifications to the P-38's were necessary to run at the higher limits, however it was suggested that using AC433M spark plugs was advisable."

Notice they suggest an increase of 25 MPH of speed and 800 FPM in climb below 20K.

Nice work, mw.

Worr, out

A US Air Corps. memorandum from the Chief, Petroleum Section to the Chief, Supply Divison, US Army dated 11 July, 1944, Subject: Grade 150 Aviation Fuel:

The following limiting War Emergency Rating Manifold Pressures have been established by the Eighth Air Force for the different aircraft:

Aircraft------------Old W.E.R.------New W.E.R.
P-38J---------------60"-------------66"
P-47D without water-52"-------------62"
P-47D with water----57"-------------67"
P-51B---------------67"-------------72"

It is thought that the above manifold pressures may even be increased to some extent using 150 Grade fuel, and roughly speaking the increase in speed of fighter aircraft at altitudes below 20,000 ft. is approximately 25 miles per hour. The increase in the rate of climb is approximately 800 ft. per minute. In addition, manifold pressures can be used at the higher ratings without danger of incipient detonation; this gives a greater factor of safety.

http://forums.ubi.com/eve/forums/a/tpc/f/63110913/m/2761038533/p/9
http://bbs.warbirdsiii.com/showthread.php?postid=35121

[mw]

Hiya Benny:

Have a look at these when you get a chance:

Flight Tests of Fighter Aircraft with 44-1 Fuel 75" MAP for P-38J

Preliminary 7-1/2 Hour War Emergency Rating Test of the Allison V-1710-91...
 "The Allison V-1710-91, No. A-047669, satisfactorily completed a 7-1/2 hour preliminary War Emergency Approval Test at a rating of 2000 b.h.p. at 3000 r.p.m. and 75 inches manifold pressure as conducted."

Preliminary Flight Tests of Fighter Aircraft Using PPF 44-1 Fuel at Increased War Emergency Ratings.
   "Based on these preliminary flight tests, it is concluded that satisfactory operation is experienced on the P-47D airplane ar 65" M.A.P., on the P-51B airplane at 75" M.A.P., and on the P-38J airplane at 70: hg. M.A.P., except in the case of the P-47D airplane in extended climbs with water injection."

Flight Tests on the Lockheed P-38J Airplane, AAF No. 43-28392 Using 44-1 Fuel

P-38J Airspeed Comparison Grade 104/150 Fuel

Techical Instructions. CTI-1659.  Modification of Fighter Aircraft for use of Grade 150 Fuel

Project P.P.F.  Final Release approving 70" MAP for the P-38

150 Grade Aviation Fuel 66" MAP established by the 8th AF as new WER rating for the P-38J

I probably missed some.  Check also:
WWII Aircraft Performance
P-38 Performance
100/150 Grade Fuel


Of course its quite clear that the USAAF and the 8th cleared the P-38 for MAP greater than 60".  I figure the 479th is probably the best bet to find documentation of operational use of boost in excess of 60" for the P-38J.  I've put that on my to-do list  

Mike

[Benny Moore]

Thank you very, very much!  I've been trying to get my hands on those again for years now.  How do you find this stuff, do you live in the National Archives?

[Widewing]

Originally posted by mw

Of course its quite clear that the USAAF and the 8th cleared the P-38 for MAP greater than 60".  I figure the 479th is probably the best bet to find documentation of operational use of boost in excess of 60" for the P-38J.  I've put that on my to-do list  

Mike

Mike, I want to thank you and Neil Sterling for putting up one of the most valuable aviation history websites on the web. I have posted many links to the documents you have put up and will continue to do so.

So many people will benefit from your hard work, from aviation sim fans, to historians and aviation buffs.

We, as a community, owe you guys a debt of gratitude.

My regards,

Widewing

[Charge]

Is there any information of how widely the 66" or 75" boost was taken into use in active squadrons as there were modifiations which needed to be done first?

-C+

[Benny Moore]

The modifications involved simply changing a governor.  Allison representitives went throughout the squadrons in Europe showing them how to do this.

[Charge]

Boost governor? Doesn't sound like a biggie...

BTW what is the WEP kit for P-47 that the inreased boost and 150g fuel made unnecessary?

-C+

[DblTrubl]

Wow. Great stuff MW. Bring on the 70" P-38!! One thing that caught my eye from the P-38 performance link regarding the relative turning ability of the 38F and G:

"The P-38G turns much better than the P-38F (will close 180 degrees in 360 degree circle) due to maneuver flaps."

Something to consider for those that think the 38's "magic" fowler flaps work too well in the game.

[mw]

Hiya Widewing:

Thanks so much for the kind words.  Neil and I are proud of the work we've done and very pleased that folks such as yourself find the material on the site to be interesting and of value.

Benny Moore & DblTrubl; no problem.  I'm glad we could help out.  

Mike

[Knegel]

Hi,

in a US fighter comparison from October 1944 they use the 2600HP as WEP for the P47D, 2410HP WEP for the F4U-4, but only 1600HP WEP for the P38J, while the P51B is listed only with military power(1510HP).


This indicate that the higher rating for the P38 wasnt normal, but for the P47, though the performence of the P47 is what we have now in AH.

Btw, our P38L already reach 345mph @ sea level, thats already 10mph more than the test display with 60", so our P38L already seems to use 65".


Greetings,

Knegel

[Benny Moore]

Which document is that?  I'll check it out.

[Widewing]

Originally posted by Knegel
Hi,

in a US fighter comparison from October 1944 they use the 2600HP as WEP for the P47D, 2410HP WEP for the F4U-4, but only 1600HP WEP for the P38J, while the P51B is listed only with military power(1510HP).


This indicate that the higher rating for the P38 wasnt normal, but for the P47, though the performence of the P47 is what we have now in AH.

Btw, our P38L already reach 345mph @ sea level, thats already 10mph more than the test display with 60", so our P38L already seems to use 65".


Greetings,

Knegel

The P-51D (not B) tested at the 1944 Fighter Conference is rated at 1,595 hp @ 67 in/hg.

The P-38J was not tested, but the P-38L was tested. 1,600 hp @ 60 in/hg.

I don't see any test data in the Conference report, only personal observations.

You need to look at this document. Here the speed at sea level for the P-38J is defined as 345 mph @ 60 in/hg, and the engines were making less than full rated power.



Our P-38J conforms dead-on to the above chart.

My regards,

Widewing

[Benny Moore]

That makes sense, Widewing.  Knegel, I would like to see where you came up with that.  Moreover, there's another problem with what you say.  One of the documents gives a speed increase of approximately 25 M.P.H. below 20,000 feet when going from 60" to 66".  That does not match up with your 10 M.P.H. gain when going from 60" to 65".

I'll do some more looking through various sources.  Really, though, I think that Widewing is right (as usual).

[EagleDNY]

Originally posted by Kev367th
Theres plenty of graphs, the often cited intention to swap K-4 units to 1.98ata (end Mar 1945), but nothing ever showing even one was used operationally at 1.98ata.

Equivalent would be the intention to boost some Spits to 30lbs,
Intention -  yup,
Was it tested (there are graphs) - yup
Ever used operationally - no.

I don't know about that - the link from the kurfurst site (below) has the translated german documents showing that 1.98ata was used in operational units before the end of the war.

See:
Kurfust Site

Admittedly, it looks like these would have been extremely limited in number as it looks like they needed C3 fuel with the MW50 system to get to the 1.98 ata level and not have the motors explode.  I doubt there were more than a few units that actually set their 109Ks to 1.98ata and flew combat sorties in them, probably because of the serious shortage of the higher octane C3 fuel if for no other reason.

I didn't used to think that the B4 vs C3 fuel difference was that great an issue until I read the JG26 history.  In it, a 190D9 pilot tells about running out of fuel during operation bodenplatte: he put down at a 109 field (III/JG6) - which only had B4 fuel, and he was stuck there until they sent him over a drum of C3.  I'd have thought you could have dropped 55 gallons of 87 octane in the tank for a short, low alt hop back to your home field, but I guess that wasn't the case.  

Are there luftwaffe docs that specifically state the "hpt schmidt went up in a 109k4 cleared for 1.98ata" - not that I've seen, but the translated docs on the site above sure convinced me that 1.98 was cleared and in operational use before the end of the war.  Given the shortage of C3 fuel, and that the 190D9 units needed all the C3 they could get, I can see why there were only a few 109 units running on it.  

The few units still using the 109 in '45 were slated for conversion to jets, so the 109K4 1.98ata would've been the last model to see action.  I'd like to AH go to the 1.98 on the K4, if for no other reason than it gives the game the "final version" of the 109.  

EagleDNY
$.02

Edit: the Kurfurst site's operator seems to have a personal beef with Mike Williams, which I have no basis to comment on.  The sites translated documents are the only things I was interested in.