Aces High Bulletin Board
General Forums => Aircraft and Vehicles => Topic started by: SgtPappy on April 17, 2012, 11:47:32 PM
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Question 1)
Was there a standard P-51B/C production block that fixed the gun jamming problem of the P-51B/C and Mustang III? Also, what did the RAF and USAAF do differently to solve the problem?
As many of us know these Mustangs had gun jamming issues. I've read one example of a field-mod where a member of the 354th FG took B-26 ammo feed motors and put them in a P-51B to stop the jamming problem (from P-51 Mustang Vs Fw 190: Europe 1943-45 By Martin Bowman).
The same book states that there were eventual field kits and final factory-stock modifications were implemented for the P-51B/C that solved the problem. It's all over the internet as well, but I can't find any more sources concerning this jamming fix.
Question 2)
Also, in my Great Book of WWII Airplanes, it is stated that some P-51B/C's had 6x .50 cals. Is this correct? I have never seen another source. The same book illustrates some P-51B/C's (by the same artist) with P-51D wings, where the P-51D-type kink in the leading edge is prominent and I don't think that's correct at all.
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some P-51B/C's had 6x .50 cals
That's just a misprint/quote. They were delivered with 4 and there was no field mod from any source I have seen where they added 2 more. Even the P-51B/C (Mustang IIIs) flying late into the war had 4 guns wether they were USAAF, RAF or RCAF. Removing a gun from a gunbay is a far cry from adding a gun where no gun bay exists to begin with.
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Question 2)
Also, in my Great Book of WWII Airplanes, it is stated that some P-51B/C's had 6x .50 cals. Is this correct? I have never seen another source. The same book illustrates some P-51B/C's (by the same artist) with P-51D wings, where the P-51D-type kink in the leading edge is prominent and I don't think that's correct at all.
This is where history becomes a pest and a problem - I've read a few times P51C's carried 6x 50s, not sure which company in the 50s and 60s read wikipedia, however this information was incorrect.
I've made posts in the wishlist in the past about "prototypes" and other things that were incorrect and was called on it, now If I can't figure out something I ask someone like AKAK what his opinion would be, or someone who would know the information.
Basically there is a lot of guessing involved, for example the Russian airforce - its nearly impossible to get decent material on Russian birds during WW2, or Japan for that matter.
Why? Japan was bombed into the stone age, factories that produced the aircraft were bombed, so where else would the golden egg be?
Most common mistakes are usually "prototypes" for example in one thread someone declared the Ki-84 flew with 4x 20mm cannons, however from what I gather it had 3 prototypes, one crashed - so a third had to be made, it wasn't put into production.
Gun packages are another, for example German Field Modification Kits - some housed up to 6x 20mms per wing - looks great on paper, but the idea wore off once you realize at this time there were hundreds of escorts - and a fighter that couldn't turn - and had to fly a straight line into bombers - was a sitting duck.
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Field mods are a very interesting thing that would be nice to be in Aces High in the future sometime.
I think they really bring out the potential in a lot of planes. But yes, it's hard finding info on a lot of planes, which is why I ended up here... after reading all this questionable information that I mentioned earlier.
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Most common mistakes are usually "prototypes" for example in one thread someone declared the Ki-84 flew with 4x 20mm cannons, however from what I gather it had 3 prototypes, one crashed - so a third had to be made, it wasn't put into production.
You're mistaking the two 20mm and two 30mm for the four 20mm armaments. Several hundred Ki-84's were produced with the four 20mm guns while only two or three prototypes were built of the two 20mm and two 30mm armament. I've even heard that due to lack of availability on the gun it was two 20mm and one 30mm.
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I may be misunderstanding this discussion and a few other comments in other threads. Is there a P-51B model that went into combat with 4x20mms? I 'think' it was something like the A-36, ground attack and basically a B model with bomb racks and 20mms?
If so, would this not make for a perked upgrade? I say perked because I know I and other PonyD drivers would wreck havoc with that gun package.
Boo
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I may be misunderstanding this discussion and a few other comments in other threads. Is there a P-51B model that went into combat with 4x20mms? I 'think' it was something like the A-36, ground attack and basically a B model with bomb racks and 20mms?
No, that was the Allison engined Mustang Mk Ia.
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You're mistaking the two 20mm and two 30mm for the four 20mm armaments. Several hundred Ki-84's were produced with the four 20mm guns while only two or three prototypes were built of the two 20mm and two 30mm armament. I've even heard that due to lack of availability on the gun it was two 20mm and one 30mm.
Interesting, I have a couple of manuals and books, I didn't see anything on the 30mm version - then again I don't even have the production numbers or prototypes, one books in Japanese and the other Polish.
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I just read in Mustang Aces of the 9th & 15th Airforces & RAF by Jerry Scutts that the RAF saw less gun jamming issues due to their low alt operations which saw less gun freezing. I wonder then how the USAAF fixed their B's and C's or if there was a factory-kit that fixed new P-51s.
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I just read in Mustang Aces of the 9th & 15th Airforces & RAF by Jerry Scutts that the RAF saw less gun jamming issues due to their low alt operations which saw less gun freezing. I wonder then how the USAAF fixed their B's and C's or if there was a factory-kit that fixed new P-51s.
I think in the end it was the transition to the 51D that fixed the issue. The guns in the B/C were installed slanted in the thinner wing of the B/C. This too contributed to the problem at higher Gs. The solution really was he installation of the guns upright as was done in the D model with had the wing redesigned to allow for this.
Up til then it was the field mods and resourceful crew chiefs that did their best to keep the guns going on the early Merlin 51s.
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I think in the end it was the transition to the 51D that fixed the issue. The guns in the B/C were installed slanted in the thinner wing of the B/C. This too contributed to the problem at higher Gs. The solution really was he installation of the guns upright as was done in the D model with had the wing redesigned to allow for this.
Up til then it was the field mods and resourceful crew chiefs that did their best to keep the guns going on the early Merlin 51s.
The primary issues for the slanted guns were a.) ammo feed motor freezing up and as you noted, G forces affecting ammo feed (more on one side than other due to the slant.
The only difference in the P51D/K wing from the B/C was the greater root chord to enable the extended angle 'strake'.
Same arfoil and dimensions from 61.5 all the way out to the tip where the guns and ammo were placed.
From Wing Station 61.5 they were the same except for adding the extra .5 space in gun and ammo bays, exhaust chutes, etc. As far as the armament, the 50's were indeed placed vertically, the inboard ammo capacity increased, improved electric gun heaters were installed. Field modifications included making changes to the buffer springs inside the M2 plus various other changes to reduce stoppages.
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Any idea why the slanted 50s? I apparently bought the wrong explanation.
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Wow, ok because most of us were under the impression that the wings were thinner. Thanks for enlightening us, Drgondog. I'd really like to see a schematic of the P-51B/C and D wing stations if you have them.
But like Guppy said, why were the guns slanted if they ought to have fit in vertically? Did any of the field-mods come in kits from North American like some sources say?
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I have no idea why they were slanted - remember the wing/bays for the P-51, and the Mustang IA, were constructed so that 4x20mm guns plus 125 rounds each were belt fed into them.
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Responding to the idea of "should we have field mods" I dont want to fight an enemy knowing that it "might" have something rare and totally different from what I would expect. If I fight a P51, I expect it to perform like a P51, just like any other aircraft. The exception is the F4U's where you could potentially expect anything (which might have something to due with perk cost)
What I mean is, I know what a 190 is generally capable of, and I know what a zero is generally capable of. Adding too many vaients makes it too difficult to be able to make the decision of how to fight it.
In AH gameplay that removes alot of the fun of the fight. Knowing what your enemy can and can not do makes for a better experience.
Fighting a F4U is inmho one of the largest upsets to this until you get in icon range, and thats fun! But add too many and it becomes a crapshoot on what tactics to use.
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Hmm I agree somewhat... but the thing is a lot of the best field mods were in place near the end of the war. The field mod we have here is really just one that allows for guns to work. In AH, however, guns don't jam so that's a big plus.
But like I said earlier, it seems that a lot of the performance-modified planes were late war aircraft. For example, by 1945, so many P-51s/47s/38s, Spitfires and Tempests were using 150 grade fuel to boost their performance. Also, your comment of "adding too many variants" sort of applies to Spitfires and 109s in that there are so many different variants, you don't know how to fight it exactly till within icon range. A lot of the time, people just prepare for the worst case scenario and then figure out what they can and cannot when they get a closer look. I like field mods in that they seem to bring out an plane's full potential and during WWII, fighting any ol' 109 didn't always mean it was just another 109.
With respect to the P-51 guns, I've seen some pictures of the gun bays and it actually looks as if the guns are slanted as to avoid staggering the guns and putting a gun barrel into the free-stream air. That is, the slanted gun allows one ammo belt to be fed almost on top of the other ammo belt. The P-51D seems to spread the guns slightly so that one of the belts can feed around the other guns and into its own gun. See the P-51B and D gun bays below:
Mustang P51B/C/III
(http://farm3.staticflickr.com/2611/3902251100_9c095ba2c0_z.jpg)
Mustang P-51D/IV
(http://upload.wikimedia.org/wikipedia/commons/d/d3/P-51_Guns.jpg)
Finally, I found a site that has more detail concerning the field-modified guns but it doesn't offer up any sources. The excerpt is:
The B model, with two canted .50s in each wing, had a fault not discovered until used in combat. The feed mechanism, designed to lift 35 pounds of ammunition, was not enough to pull the belted ammunition through the articulated ammo tracks during violent maneuvers, resulting in many stoppages. The inboard guns' ammunition trays each held 350 rounds and the outboard guns each carried belts of only 280 rounds. The fact that the four guns were mounted in a slanted position also contributed to stoppages. Booster motors with star wheels salvaged from Martin B-26 turrets did the trick of providing the extra energy to properly feed the guns. The boosters were so successful that additional quantities were requisitioned to modify all B models. from http://www.cebudanderson.com/viewfromtheline.htm (http://www.cebudanderson.com/viewfromtheline.htm)
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Also notice that the feed direction is different in B and D configurations. Is it possible that the feed direction was not switchable in early Brownings so the starboard guns in B had to be slanted to allow proper feed, but not the port side guns?
-C+
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Well, no because the guns are slanted in both wings, not just one. Another explanation I found is given in 359th Fighter Group by Jack Smith. Here is an excerpt relating to the gun jams:
Field work eased the problem, but 368th FS armourer Larry Lovell exposed a major fault with the individual weapons... He stated that the machine guns manufactured by Kelsey Hayes, under contract from Browning, were of inferior quality... they would jam after just a few rounds... crates of Kelsey Hayes replacement guns were not accepted by the 368th.
However, careful attention to the loading of ammunition by armourers paid big dividends, as was demonstrated in the group's June 1944 records which revealed that just one gun stoppage was reported among the 368th's P-51B/Cs and 3410 rounds were expended.
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I wish aces high would acknowledge the existence of field modifications and somehow integrate them into the game.
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Perhaps one day but it's a big undertaking and I think the general consensus on the BB is that people would rather not have them.
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Weren't the C's the same thing as a D except for the obvious birdcage canopy a maybe a few other details?
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Weren't the C's the same thing as a D except for the obvious birdcage canopy a maybe a few other details?
No - the P-51C was the same as the B except it was made in Dallas and delivered several months later into the ETO.
Having said that, the B/C were very close to the D as far as the BOM is concerned with the major changes of removing turtle deck, installing new more sloped windshield and bubble canopy, changing the wing root and associated inboard wing from station 61.5 to C/L, adding mounts and modifying gun bays to include an extra .50 in each wing, changing the wheel door cover as well as uplock mechanism and one or two more changes,,
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No - the P-51C was the same as the B except it was made in Dallas and delivered several months later into the ETO.
Having said that, the B/C were very close to the D as far as the BOM is concerned with the major changes of removing turtle deck, installing new more sloped windshield and bubble canopy, changing the wing root and associated inboard wing from station 61.5 to C/L, adding mounts and modifying gun bays to include an extra .50 in each wing, changing the wheel door cover as well as uplock mechanism and one or two more changes,,
So when is the redone "Angels, Bulldogs and Dragons - History of the 355FG in WWII" coming out? :)
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So when is the redone "Angels, Bulldogs and Dragons - History of the 355FG in WWII" coming out? :)
Guppy - thanks for your interest. I am delivering the 'package' to Schiffer in June.. approximately 500 pages plus another 500-800 photos and 60 high def color side elevations by Steve Deisely of the Group's (plus Scout Force) fighters flown out of Steeple Morden..
80% WWII but inclusion of 355TFW victory credits and losses from Vietnam plus some superb narratives from Billy Sparks and John Piowaty from Weasel and Strike Force POV in F-105F and D. The 355th TFW in Vietnam and the 355FW (A-10) in Middle East/Afghanistan will be detailed in Our Might Always - Volume II.
Same Diary format but brings in the rest of the 8th AF notable days as well as deep dives into major air battles crystallizing the LW order of battle as well as US.
Last I will include the tabulation of all the 8th AF Fighter Groups (as well as the 354th because they were so important) breakdown of air and ground victories by a/c flown and scores by type shot down - as well as the breakdown of ETO victory credits (per USAF 85) by fighter type by period that I have shared here.
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Consider one sold already. Very much looking forward to it :aok
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Save one for me :aok
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Thanks to both of you. The book will have a chapter on 8th AF FC operations along with the data I have shared here on ETO victory credit totals as a supplement to discuss the multiple phases of 8th AF Operations.
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Another book for the 'ol wishlist.
Looking forward to it. :)
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I think in the end it was the transition to the 51D that fixed the issue. The guns in the B/C were installed slanted in the thinner wing of the B/C. This too contributed to the problem at higher Gs. The solution really was he installation of the guns upright as was done in the D model with had the wing redesigned to allow for this.
Up til then it was the field mods and resourceful crew chiefs that did their best to keep the guns going on the early Merlin 51s.
^^ This is what I read also.
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No - the P-51C was the same as the B except it was made in Dallas and delivered several months later into the ETO.
Having said that, the B/C were very close to the D as far as the BOM is concerned with the major changes of removing turtle deck, installing new more sloped windshield and bubble canopy, changing the wing root and associated inboard wing from station 61.5 to C/L, adding mounts and modifying gun bays to include an extra .50 in each wing, changing the wheel door cover as well as uplock mechanism and one or two more changes,,
Also added a strake in front of the stab for longitudinal stability after cutting down the area behind the canopy.