Corsair Blueprint
Finnis Springer
I am trying to model the cowling of a Corsair F4U-4 using Fusion 360. The only scale plans I have access to are the ones in the AJ Press Aircraft Monographs series. I scanned them and used them as canvas to start modeling the cowling in Fusion, but I keep getting inconsistencies between the different views and I have a lot of trouble to get smooth curves.
Unfortunately that happens with scanned and/or photocopied drawings. Each reproduction introduces its own set of distortions. I do a bit of 2D CAD work, mainly producing drawings for my club's magazine, and I've run into some doozies - misalignments, inconsistency left to right, image warping, you name it. One of the best was attempting to draw a Sunderland underside plan using the old Aviation News drawing as a base. I'm sure the original drawings were fine, but by the time they came into my hands they had been copied so many times, and were so distorted, that the keel line looked more like a road up the side of a mountain, wandering off the mean centreline by up to 5mm on either side. Needless to say, a certain amount of fudging adjustment was required to get an acceptable result!
I think you need loft drawings - Air Corps Library have anything? I'd avoid anything that isn't derived from factory drawings - often these incorporate artistic interpretations rather than actual profiles. Many 'scale plans' are not particularly accurate.
I see that the side view in AJ Press is a bit off: the actual forward protrusion of the chin intake lip is very light and there is a noticeable bulge in the lower profile of the cowling, while on the AJ Press drawings it is almost flat.
The Vought heritage site used to have drawings on it (of somewhat variable quality) including a set on the F4U (IIRC of a reputed draughtsman whose name escapes me) but I can't find them...? Other -4 sets I am aware of are by Alf Granger (printed in Wingspan and Squadron's Aerodata USN carrier a/c) and Aero Detail.
The drawings that wellsprop linked to are for F4U-4 (AU-1 cowling is quite different). I actually had found the drawings indicated by tempestfan (and forgotten about it), they are too crude for 3D modelling. I think that I will bite the bullet and subscribe to Aircorps Library (at least for a few months) to get my hands on true factory blueprints,
Hello Christian , write a message to Jumpei Tenma. He just started work on a Corsair, and in the text of his article he makes reference to a japanese guy who has a site discussing Corsair (I suppose with drawings and so on)... For sure Jumpei will produce a whole set of drawings in the next future so you can also wait for them.
satisfactory shape now. I was a bit spoiled because my previous attempt at modelling in Fusion 360 was a Dewoitine 520 radiator housing, and since I had factory blueprints with dimensions available on the web, everything went like a charm,
I did an examination of the Vought blueprints for a post on another modeling website and thought the folks here may like to know what I distilled from looking at them. The upcoming Tamiya kit will have the option of a step in the R/H inboard flap, one closed with a plate and one completely open through the flap. The wing erection drawing (VS-10000) for the F4U-1, F3A-1, FG-1 indicates that at revision O, Vought Engineering authorized the use of the flap p/n VS-37769 (with a step in it) somewhere between April and what looks like May of 1944 (but does not preclude the use of the old flap p/n VS-10069). The microfilm scan is not clear enough to read the exact date when this was authorized. Nor does the blueprint state which aircraft it was installed with. Note 13 on the blueprint says that Engineering will be informed when this change is made but the field of the note is blank with respect to any serial/construction number information. It is my belief (call it a hunch as I have no basis of fact for it) that the war ended before this flap made it to the production line and that it was primarily installed on post war F4U-4's and later. But for the sake of the argument....
Having said that and absent of any photographic evidence (or more definitive information), there is no way of knowing which aircraft (in construction at that date or thereafter) were fitted with this particular R/H inboard flap and which were not. Aircraft manufacturing experience leads me to the opinion that there was a stock of flaps prebuilt for installation on the production line and that would have to be used up prior to this specific flap being installed on the production line (unless the flap stock was pulled and modified but that takes a lot of time and most likely was not done given the exigant circumstances of war). However, if the aircraft was manufactured prior to said authorization (April-May 1944) it is doubtful it would have had such a flap installed from the factory. This also does not indicate that aircraft produced after this date will definitely have the step flap. Like I said, any stock of existing flaps (VS-10069) would have most likely been exhausted prior to this flap (VS-37769) being installed on the production line.
This does not preclude field replacements on older aircraft as it appears as though they were interchangeable. I should think any replacement flap with a step would have stuck out like a sore thumb on a combat aircraft given the fading and wear of the paint job on the airframe vs. the newer flap.
Again, this is my opinion based on examining the actual Vought Corsair blueprints for the subject parts. If there's any errors, they're mine alone and I'm perfectly happy if more/better information is brought to the discussion as it makes us all the better for it.
Well, rather sheepishly, I must admit that I didn't do as thorough a job as I thought I did as the construction number for the step flap is listed on the flap drawings (10069 and 37769) and not on the higher level drawing which I examined. Add to that the fact that Dana Bell had already done this quite thoroughly and is included in his Aircraft Pictoral No. 8. complete with bureau number cross refererences. I should have known he'd be on top of something like this. Anyway, it turns out that the step flap was indeed introduced into the production line in the FG/F4U-1D production line at aircraft number 4425. Refer to Dana's aforementioned book to see what Bureau No. this corresponds to. I have his book but don't have access to it at the moment.
The Thomas L. Blakemore Collection contains blueprints, articles, memos, technical notes and reports regarding Lighter-than-Air aircraft including the U.S.S. Hindenburg, Shenandoah, Los Angeles, Akron, and Macon.
Richard Duiven was a well-known scholar of World War I aviation, writing several books and articles on the German Air Service in World War I, as well as serving as editor/author of the "Mentioned in Dispatches" column for the journal Over the Front.
Kaj L. Nielsen was a mathematician who pursued various professional and academic careers, distinguishing himself at Chance Vought Aircraft as a member of the design teams that developed the Vought F4U Corsair and Vought V-173 Flying Pancake. The bulk of the collection contains his engineering notes for the development of the propellers for the Vought V-173.
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