And so removing armour and wing guns is the basis of all your 1,750 posts? What about the input of the Russians who wanted more armour in certain places to stay alive, which is quite important I am told.
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And so removing armour and wing guns is the basis of all your 1,750 posts? What about the input of the Russians who wanted more armour in certain places to stay alive, which is quite important I am told.Park was no friend of the P-39, but in the other book he made it clear that the biggest fault was too much weight, coming mainly from the wing guns and too much armor plate. In neither book did he say that the plane was difficult or dangerous to fly and was particularly easy to take off and land.
He's read manuals and held up "drawings" for comparison.Please explain the term "construction drawings". I'm familiar with: Detail Drawings, which depict an individual part; Assembly Drawings, which describe an object made up of two or more parts; Installation Drawings, which shows a part or assembly in its installed location, and; Sectional View Drawings, which cut away part of an object to show the shape and construction along the cutting plane. There are also schematics which describe, at some degree of abstraction, systems within an aircraft. So what are "construction drawings"?
I presume you're referring to the "drawings" you cited in this post: XP-39 II - The Groundhog Day Thread. Those are Installation Drawings showing the station positions in the airframe. They ONLY show the distance between stations. They DO NOT show the height or width dimensions.
Just because compartments are "exactly the same length" does not mean that a 3-dimensional object will fit in that space. You need distances across length, width and height...and you also need to reflect any changes to those measurements to see if the physical space is sufficient...and, even then, there may be issues fitting an assembly into the available space because other parts or assemblies might get in the way.
"Construction drawings" A new one...Please explain the term "construction drawings". I'm familiar with: Detail Drawings, which depict an individual part; Assembly Drawings, which describe an object made up of two or more parts; Installation Drawings, which shows a part or assembly in its installed location, and; Sectional View Drawings, which cut away part of an object to show the shape and construction along the cutting plane. There are also schematics which describe, at some degree of abstraction, systems within an aircraft. So what are "construction drawings"?
In my work I was concerned with refineries and oil installations (at times). I frequently heard the expression "approved for construction" or "issued for construction" with regard to drawings, but this is a different branch of engineering. The important drawings in this conversation would be what I heard being discussed as the "as built" drawings."Construction drawings" A new one...
In balance
combat power
tail cone
landing reserve
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At Lockheed we also had "Production Illustrations" (PIs) that had a 3-D view of an installation that might not have been made clear on installation drawings. They were really helpful for wire harness routing within a confined area.Please explain the term "construction drawings". I'm familiar with: Detail Drawings, which depict an individual part; Assembly Drawings, which describe an object made up of two or more parts; Installation Drawings, which shows a part or assembly in its installed location, and; Sectional View Drawings, which cut away part of an object to show the shape and construction along the cutting plane. There are also schematics which describe, at some degree of abstraction, systems within an aircraft. So what are "construction drawings"?
I presume you're referring to the "drawings" you cited in this post: XP-39 II - The Groundhog Day Thread. Those are Installation Drawings showing the station positions in the airframe. They ONLY show the distance between stations. They DO NOT show the height or width dimensions.
Just because compartments are "exactly the same length" does not mean that a 3-dimensional object will fit in that space. You need distances across length, width and height...and you also need to reflect any changes to those measurements to see if the physical space is sufficient...and, even then, there may be issues fitting an assembly into the available space because other parts or assemblies might get in the way.
First time I heard that term is when I was assigned to Canadair as a QA Rep on the CP-140 program many years ago.In my work I was concerned with refineries and oil installations (at times). I frequently heard the expression "approved for construction" or "issued for construction" with regard to drawings, but this is a different branch of engineering. The important drawings in this conversation would be what I heard being discussed as the "as built" drawings.
All nations and industries are different. Sometimes there were various solutions proposed to the client as drawings for approval, at other times many solutions were proposed and fabricated on site (with no client involvement) and the solution to the problem was included in the "as built" drawing submitted to the client. A lot depended on the scope and involvement of the end client, in the oil industry, the end client frequently wants to off load as much responsibility as possible, in case something goes wrong. In WW2 aviation it was usually but not always different.First time I heard that term is when I was assigned to Canadair as a QA Rep on the CP-140 program many years ago.
He doesn't answer my posts either.
As I have shown many times with construction drawings of both planes, the engine compartments are exactly the same length. And the auxiliary stage was installed in a P-39D fuselage to be the P-39E.
P-63 was a new design with the aft fuselage behind the engine compartment lengthened. Wing had to be moved back to balance.
Proof? AHT lists the weights as 1435lb for the P-39D-2 and 1620lbs for the P-63A, a difference of 185lb. These were both production airplanes. The coolant expansion tank would be moved forward to about the CG and the carb should have been on the engine stage like the other Allison production models, providing an extra 3000' critical altitude. Neither of those items weighed much but moving both forward would have helped the CG situation. But mainly CG would have been restored by using a larger (heavier) four blade propeller to handle the extra HP at high altitude.
It certainly would fit inside, it was exactly the same size on both planes. And the structure to withstand the stress was already there. The twin longitudinal beams that made up the fuselage structure provided a very robust mount for the propeller reduction gear, nose landing gear, nose armament, cockpit, and engine compartment which would include the aux stage SC, as it did on the P-63. This structure also provided for attachment of the wing to the fuselage. The tail empennage was of conventional construction.
I don't know. I make one post and get 10 replies and then everyone blames me for the length of the thread.
Great info Greg - and I like the way our friend talks about moving structure and components around as if he was kitbashing a 1/48th scale P-39 model (no disrespect to my modeling friends). No mention of having to place this "Frankenstein" into a jig so the rest of the structure doesn't warp or bend. Sure, at the factory "they" can do almost anything, get that Wayback machine and send our friend to Bell around 1941, he could have been the VP of P-39 Engineering and Production!Hey P-39 Expert. We all KNOW the engine compartment (the part where the power section goes ... you know, the engine block and cylinders) is the same size because the same engine block fits into it. What ISN'T the same size is the compartment aft of the engine compartment, where the auxiliary stage would go. I just got back from the museum and measured things on both the P-39 and the P-63. Go back to post #3,403 and look at the P-39 side views.
Notice the bulkhead just below the antenna mast and the bulkhead just aft of the rearmost exhaust stack. From the bulkhead under the antenna mast to the aft exhaust stack is 3" 9" on a P-39 (the one I used is a P-39N) and 4' 5" on the P-63. If you subtract the smaller measurement from the larger measurement, the difference is 8 inches using the "Measure" app on my cell phone. Doesn't sound like much, but it is the difference between the Aux stage fitting and not fitting. Also, the rear area in the P-63 is big enough for the Aux stage supercharger. In the P-39, it is NOT big enough for the aux-stage to fit inside. As I stated in an earlier post, you COULD knock some sheet metal out to shoehorn it in, but then you'd STILL have the CG issue that requires moving the wing or the pilot and you'd STILL have to supply a bearer mount for the aux stage after you move the existing bulkhead and whatnot back there, like oxygen bottles. Moving the pilot forward would put him firmly in the cannon breech area, so he'd not likely relish that idea. Seems better to move the wings aft a bit for CG purposes.
Hence, the P-63 Kingcobra, with all the changes built in to make a aux-stage Allison work.
You CANNOT fit a 2-stage Allison into a stock P-39 airframe and, if you DID by banging sheet metal around, the aux stage would have no support to mount on, and it would rock back on the tail.
Not sure what you are thinking, but I have had two different museums that own P-39s, one of which has restored both P-39s and P-63s to flight status, tell me a 2-stage Allison won't fit in a P-39. My own measurements confirm that. Now, I can't show you a 2-stage Allison installation in our P-63, because ours is being restored with a single-stage engine, but there are several such pictures floating about. Here is one:
https://ww2aircraft.net/forum/attachments/p-63-ephrata-airfield-july-44-jpg.356901/
You can see the compartment aft of the power section is pretty full.
If you want to insist that you can make an aux-stage Allison fit into a P-39, please feel free. Nobody ELSE can get it done. Perhaps you can get into Mr. Peabody's WayBack Machine and go back to show them all how it is done. Failing that, since Sherman and Mr. Peabody might not be very cooperative, SHOW ME HOW TO DO IT. Get Allison Aux-stage engineering drawings and a Bell P-39 engineering drawings and show that the equipment and the supports fit where everyone else says they won't fit. Show it clearly and with measurements, accounting for everything needed to make a 2-stage Allison run.
Or ... please stop making that claim.
Sorry, I forgot, I'm just a former (not current) pilot. So, my posts must be hearsay.
It's been a while since I knocked around this site, but some great Allison V1710 info.
V-1710-E engines were designed for use with remote gearboxes. Three variants powered single-engine Bell P-39 (LF, RF, Firing), P-63 and XFL-1 fighters, all of which had the engine behind the pilot. This arrangement made room for a 37mm cannon firing through the propeller hub. A fourth variant powered the Douglas XB-42. P-39 engines used single-stage superchargers, while some P-63 engines added a variable-speed auxiliary altitude supercharger stage (LF, RA). The XB-42 employed two V-1710-E23 (L, RF) engines to drive contra-rotating pusher propellers. A turbocompound engine, the V-1710-E27 (L, A, R, T) was built and tested, as were numerous other variations on the shaft-driven remote gearbox (90°, Tandem, Tandem).
V-1710-E Images: F, LF, L, LA, A, RA, R, RF, T, B, with Driveshaft, Gearbox.
I believe this is what the 2 stage V-1710 engine looked like (V-1710-G)
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Here's the stock P-39 engine
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Here's the gearbox - "Just Because"
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S Shortround6 any comments?