Allied Gold-Match

[DAVIDICUS]

Oooh, that was nasty.

Someone pass the popcorn.


Seriously though, let's keep our exchanges civilized.

 

[mosquitoman]

Oooh, that was nasty.

Someone pass the popcorn

Thanks, I could do with some right now

 

[Gemhorse]

Wow, this is some 'discussion' you guys are having [I'll have some of that popcorn too!!..], which I'm finding extremely informative...Thankyou for the explanation of the merits of the Industrial histories and differences RG, I've found it very illuminating...

The mention of Packard Merlins stirred a memory, and I've tracked it down, it's actually concerning Lancasters in this instance....

Cliff Allen started at 21 as an Engine Fitter working on Lancasters for RAF No.'s 467,463[RAAF] and 617 Sqns. in WWII, and wrote;
''The wooden tool box issued to each mechanic contained a rachet screwdriver; a few open-ended spanners, which were too soft and soon useless; a hacksaw; file; engine brush; pliers and hand-vice; a set of BA spanners, also soft; and a feeler gauge...All these looked insignificant in the huge box...- When Lancasters entered service fitted with American Packard Merlins, highly sophisticated tool kits were supplied with them; but alas, only one of these ever reached the flights. This was kept in the Flight Office under the eagle-eye of our flight sergeant. NCO's in charge of groundcrews were alone authorised to use this toolkit, which contained the very versatile universal box spanner with attachments, and socket-heads, precision-made to fit aero-engine nuts bolts. A wide range of open-ended and ring spanners, toughened for the job they had to do, and a host of other useful gadgets, completed this masterpiece of engineering.
Secrecy kept these labour-saving devices locked away for some time until a hard-pressed groundcrew really needed them: then all of the flight knew of their existence, so the rule ''NCO's only'' was fixed...''

That's not the first time I'd read of this sort of thing, all Commonwealth Groundcrews may have had similar difficulties, and in reading what you chaps are discussing, I have to concur that although both Allies had different manufacturing processes, there appears that American quality was of a very high standard. Where the Servicing process was different, the Commonwealth groundcrews were very thorough but lacked suitable equipment, the US groundcrews tended not to 'tinker' unless something was radically wrong; and possibly their Spares were more quickly accessible too.

This is tough for me, I love both these aircraft !!...But I am respectful of both your comments, they are indeed enlightening, I don't think I could make a choice here.......

 

[Nonskimmer]

That's not the first time I'd read of this sort of thing, all Commonwealth Groundcrews may have had similar difficulties...

"Yeah", in the case of the RCAF. Grandad mentioned that the boys had a helluva time finding proper tools on occasion. Sometimes they'd just improvise, but they always managed to get the job done to keep the big birds in the air.
One thing he never mentioned were hidden specialty tool kits. If the fellas had found out about that, I'm pretty sure you'd have seen a few dead Warrant Officers lying around.

 

[KraziKanuK]

Some corrections Luni.

109 production was not 45,000 but 33,000.

You are correct, I used the 45,000 number without verifying it. However there were actually 39,000 109's built during the WWII period - 6000 were two seat trainers.

In the Pacific, it was 145PN fuel, not 150PN fuel, and it arrived very late.

In 1943/44 the intent was to divert 150 grade fuel to the PTO. Later, as I said, this plan changed. I agree the high test fuel did not arrive until very late - about July 1945 with a few minor exceptions earlier.

The fuel rating system is kinda impossible to judge. As you probably no, there is really no such thing as 150 octane fuel - 100 is the highest possible "octane" rating.

The RR Merlin, whether by RR or BY one of the other UK manufactures, was the preferred engine, not the Packard Merlin. The Packard was not that reliable.

Where do you find this. Everything that I've seen says the Packard Merlin was more reliable because it was made from superior alloys and it was built to more exact tolerances.

109 construction was no more than 35,000 and that included Hungarian war time construction and Spanish post war construction. Where did you get this 6000 trainers? Not from WNr serial blocks I hope. There was only the G-12 built as 2 seat trainers and NO MORE than 500 were built(converted).

Fuel for the Pacific was 115/145 PN, to use the correct terminoligy. The lean-rich mixture should be shown.

Made to more exact tolerances. Packards had tolersances more sloppy than the UK Merlins. That is the way assembly lines work > sloppy tolerance so everything fits. You reading material requires some broadening that does not toot the American horn so much.

The best thing about Packards was the tool kit that came with it.

A family friend, who passes away a couple of years ago was a ground crew on Mossies and then became flight crew. He stated that they dreaded getting a Mossie with Packards to fdly on a mission.

 

[FLYBOYJ]

That's not the first time I'd read of this sort of thing, all Commonwealth Groundcrews may have had similar difficulties...

"Yeah", in the case of the RCAF. Grandad mentioned that the boys had a helluva time finding proper tools on occasion. Sometimes they'd just improvise, but they always managed to get the job done to keep the big birds in the air.
One thing he never mentioned were hidden specialty tool kits. If the fellas had found out about that, I'm pretty sure you'd have seen a few dead Warrant Officers lying around.

As a maintainer by trade I must state that this is true even today!

 

[Nonskimmer]

As a shipboard electronics maintainer, I can tell you we've always had access to any specialty tools we needed. If not, you risk damaging the equipment and just maybe yourself or your buddies. There have been times when a tool or two may have been misplaced and we've had to improvise, but that's a far cry from deliberately withholding the proper tools from the maintainers. Especially during a war.

 

[FLYBOYJ]

As a shipboard electronics maintainer, I can tell you we've always had access to any specialty tools we needed. If not, you risk damaging the equipment and just maybe yourself or your buddies. There have been times when a tool or two may have been misplaced and we've had to improvise, but that's a far cry from deliberately withholding the proper tools from the maintainers. Especially during a war.

I guess you guys got to be extra careful because of your equipment

 

[Nonskimmer]

True enough I guess, but even the mechanical gear has certain tolerances that have to be met. That often requires specialty tools like torque wrenches and such. It just irks me to think that the boys wouldn't have been given something necessary to the job, when it was in their possession the whole time.

Still, they managed I suppose.

 

[FLYBOYJ]

I know what you mean, I hate when someone uses a "calibrated elbow."

 

[Anonymous]

Packard Merlins were made of superior metals. They were also made to more exacting tolerances - whether these were "looser" than the RR's I don't know, just that they were more consistant. RR's also lacked the cleanup that the Packards recieved, the flashing was not ground off the inside of the block for instance, where on the Packards it was.

Look at the number of "spares" per squadron... for the Brits, it was 20 planes per squadron to keep 12 flying. For the P-51's, it was 20 to keep 16 flying. Of course, there was more than engines involved but the engines were by far the biggest maintainence component.

=S=

Lunatic

 

[trackend]

I'm not trying to stir the S... or anything as this is a genuine question RG do you think the location of the factory's would have had an influence on the production quality of the lumps, I don't know what the production figures are in terms of labour resources too productivity, but do you think having the threat of bombing had a direct influence on the need for speed over quality control?

 

[Anonymous]

Soren,

About the BHP of the Spit XIV vs. the F4U-4. I've combine the Vought April 1944 graph with the Spit XIV graph on Mark William's 4th Fighter group website. While it could be argued that Vought's graphs are company graphs and therefore might overstate the power ratings some, the graph on Mark William's site gives no ref. to the orginal source and WE KNOW HE HAS A VERY HIGH PRO-SPITFIRE BIAS! Also, the graph represents performance from the Griffon 61, 65, 66, 85, 86, and 90 - only the 61 and 65 are relavent for WWII, so the Griffon power ratings are probably overstated. These are the only BHP graphs I can find, so they will have to do.

For the Spitfire I've show the BHP for +18, +21, and +25 lbs boost. The solid green line shows +21 lbs boost, and it is the relvant power output since the original graph indicates the mains/bearings were not strong enough to support +25 lbs boost and would have to be reinforced which never happened in WWII.

Evidently British max power ratings reflect takeoff power, which for the Griffon was ~2050 HP. As you can see the Griffon actually made about peak 2200 BHP at ~9800 feet. For the USN, the standard was "combat power" which was defined as power output at 15,000 feet, which gives ~2450 BHP for +70 lbs boost, about 2350 BHP for the lower boost setting used with lower grade avgas used in the PTO in early 1945.

Finally, the RPM for the Spitfire is 2750 rpm which is what is shown, and this is the maximum allowable RPM. The F4U-4 figures are at 2800 rpm and 70" of boost, though the engine could actually run up to 3000 rpm and up to 72" of boost (though this was never approved).

As for your comment about the wing airfoils - umm, I don't think so. I will try to post these soon.

The Supermarine 369 Spitfire F XIV wings used NACA 2213 root and NACA 2209.4 tip airfoils. The Vought V-166 F4U Corsair used NACA 23015 root and NACA 23009 tip airfoils. Unfortunately the Spitfire aifoil data is not available in a windows program compatible format, I'm trying to figure out how to convert the data now but the software is not well documented. I can however put both up in a dos program (which I cannot screen grab), overlayed on top of one another, and it is very clear that there is only a little difference in the wing root airfoils (max chord point of the F4U sits a little further back from the leading edge, perhaps 5%), and ALMOST NO DIFFERENCE AT THE TIPS. Furthermore, the F4U wing chord is a bit longer at the root and quite a bit longer out beyond the guns.

When it comes to the props, the 5'2-1/2" inch blades of the Spitfire are 1'4-1/2" shorter than the 6'7" blades of the F4U-4. 4 x 1'4-1/2" = 5'6". Therfore the total blade length of the F4U-4 is a few inches greater than that of the Spitfire. Furthermore, the blades of the F4U-4 have a greater chord (i.e. they are thicker) and are more optimally shaped (they have no eliptical form to the leading or trailing edge and the chord does not taper off so quickly near the tips). And of course the prop becomes increasingly efficient the further it is from the hub.

=S=

Lunatic

 

[KraziKanuK]

You do have your problems Luni. The boost for the Griffon was 21ln NOT 22lb.

 

[Anonymous]

I'm not trying to stir the S... or anything as this is a genuine question RG do you think the location of the factory's would have had an influence on the production quality of the lumps, I don't know what the production figures are in terms of labour resources too productivity, but do you think having the threat of bombing had a direct influence on the need for speed over quality control?

Round trip distance from Calais to Birmingham was about 400 miles, well outside the range of the Bf109E/F to provide escort during early years of the war, and later the Germans didn't even try to bomb aircraft factories. I'm not sure how much night bombing of Birmingham took place, but I don't think the Vickers plant was ever hit by a bomb.

I certainly agree the British priority was for quantity over quality of production, within reasonable limits. As long as it was combat worthy, it was good to go. The logic was probably that 3 planes where one rolled well, one rolled satisfactorally, and one rolled not so well (but not horribly), were probably deemed to be of more value than two planes that rolled well.

Anyway, this whole part of the discussion just has to do with the fact that on the Spit III, V's (2), IX, and XII's (2) tested in March 1943 there was a very noticable variation between rolling quality from unit to unit. Those that rolled well with the non-clipped wings did not benifit signifcantly when tested with the wings clipped. However, those that did not roll well with non-clipped wings did benifit from having the wings clipped. This indicates a quality control issue - simple as that. Clearly the conclusion of the report was that wings should not be clipped on future versions of the Spitfire, which it must be assumed meant that they were indicating the quality variation needed to be rectified. Given that even on the Spit XIV wings were still being clipped, we must also assume this quality control issue was not fully rectified at least for Spit XIV production.

=S=

Lunatic

 

[Anonymous]

You do have your problems Luni. The boost for the Griffon was 21ln NOT 22lb.

Grr... you are correct. I keep making that mistake

Hey, it is not easy making these graphics. The stupid british chart puts altitude across the bottom and BHP vertical.

I'll fix the post and the graphic.

Thanks,

=S=

Lunatic

 

[Soren]

As for your comment about the wing airfoils - umm, I don't think so. I will try to post these soon.

You don't think so ??!!!

RG a plain wing will always produce more lift than a bent one ! And those intakes on the Corsair's leading edge also reduces the lift even further.

 

[Anonymous]

As for your comment about the wing airfoils - umm, I don't think so. I will try to post these soon.

You don't think so ??!!!

RG a plain wing will always produce more lift than a bent one ! And those intakes on the Corsair's leading edge also reduces the lift even further.

The bent part of the wing will reduce lift a little. The oil cooler intakes will hardly reduce the lift at all, as that area of the wing root does not produce much lift in any case. Moving them was seriously considered, but tests showed it would not make a noticable difference.

The chord is longer, and the wing a little thicker, and that will make a difference.

But what I was commenting on was your claim the basic airfoil shape for the Spit wings was somehow superior because of its curvature - there is very little difference at the root and practically none at the tip.

=S=

Lunatic

 

[Soren]

The bent part of the wing will reduce lift a little.

It takes away much more lift than the small decrease of the Spits wing thickness in comparison to the Corsairs ! Those two bent wing sections take up a good part of the Corsair's wing-area !

The oil cooler intakes will hardly reduce the lift at all, as that area of the wing root does not produce much lift in any case.

It still decreases the lift even further.

The chord is longer, and the wing a little thicker, and that will make a difference.

The increase in thickness will hardly make any difference as the Spit's airfoil gets its max thickness earlier along the chord, and although this adds more drag it also adds more lift.

But what I was commenting on was your claim the basic airfoil shape for the Spit wings was somehow superior because of its curvature - there is very little difference at the root and practically none at the tip.

No but the difference is there, and the curvature is superior with the Spit's wings.

I can't believe your trying to tell me the Corsair will turn with a Spit ! Its ludacris !

 

[Schöpfel]

I can't believe your trying to tell me the Corsair will turn with a Spit ! Its ludacris !

Umm, its obvious, RG_Lunatic said it and WE KNOW HE HAS A VERY HIGH PRO-AMERICAN BIAS! Can't trust a word those arrogant american's say. It is funny though to think he thinks any American plane could out-turn a Spit. He probably thinks P-40 is better than BF 109 too All British all liers and cheats, so you know that Griffon chart is nonsense too, probably a fraudulent forgery