cvairwerks
Staff Sergeant
Air Corps library is a mix of 75, 81 and 87 prefix drawings.
Curtiss P-40B, C or Tomahawk MkIIa or IIb Manuals/T.O.s (3 Viewers)
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- #22
I have a subscription to the air corp library, their scans are really good. I haven't found a drawing master list yet but that may just be me. It is interesting the majority of the structural drawings for the P-40B and C are 87 drawings. I will have to extract the data from the parts catalogue and do an analysis to tell you the exact percentage but most seem to be 87 drawings. I don't understand exactly how the Curtiss drawing system works but there are obviously 75, 81 and earlier drawings as well as the 87 drawings.
If there is a CAD model of the P-40C available that would be incredibly useful and save me a lot of work!
cvairwerks
Staff Sergeant
The prefix on a drawing, for most manufacturers, will tell you what basic aircraft the drawing was originally done for. WACO and pre-WW2 Lockheed were great reusers of previous parts designs. For example with WACO, some of the drawings were used on more than a dozed different model aircraft. Early Lockheed and Detroit-Lockheed did the same thing. The Vega, Sirius, Altair and Orion share numerous part numbers.
What will help you, even without a master index, is reading the effectivity or use on blocks. Here's an example from my AT-21 stuff. This particular drawing was only effective for the XAT-13 and 14 and what would have been the production verion of the AT-13. It was the quickest one I found that was for multiple models and was legible when zoomed. Also, in this case, the parts get used on the 751000L and R assemblies for the XAT's and would have been used on the same for the AT. Doesn't always work that way though.
What will help you, even without a master index, is reading the effectivity or use on blocks. Here's an example from my AT-21 stuff. This particular drawing was only effective for the XAT-13 and 14 and what would have been the production verion of the AT-13. It was the quickest one I found that was for multiple models and was legible when zoomed. Also, in this case, the parts get used on the 751000L and R assemblies for the XAT's and would have been used on the same for the AT. Doesn't always work that way though.
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- #24
Yes I am familiar with this from Piper Cub drawings that I have. I have found that this isn't always up to date. We obviously don't necessarily know what the final revision state and potential modifications were and we can have earlier versions of the drawings with an earlier modification state, but for earlier models that is helpful. The Parts Catalogue explains the high level drawing system but obviously the P-40C should in theory be 81 or earlier but it isn't? My plan is to analyse what drawings from the parts catalogue are contained within the drawing library. Interestingly for British aircraft there are also a lot of standards used. We have AGS for example which is Aircraft General Stores, this in broad terms is equivalent to ANS. There are also manufacturer standards, for example A std drawings for Hawker Aircraft, this can encompass fasteners, extrusions, rolled sections, forgings etc. believe it or not there are some A std components that are fitted to Hurricanes and Harriers! There is also cross references between manufacturers, for example Vickers made various units like oil filters, fuel cocks etc known as Vicker General Spares (VGS). You can find VGS in Hawker Aircraft like the Hind and Hurricane. I have no idea if this is the case for US manufacturers and more specifically Curtiss Wright in this case. If there are any draughtsmans handbooks for Curtiss Wright available that would answer a lot of the questions.
cvairwerks
Staff Sergeant
Something to keep in mind is that the IPC's and master parts indexes are not always created as the aircraft is in production. Often, the most correct versions are ones that are put together after the model is out of, or nearing the end of production. I've got the IPC for my Stinson and my Fairchild, but there are definately differences for both, based on document revision dates. There are about 4 or 5 different wing designs for the L-5, and not all are in the IPC, but they are backward interchangable. There are lots of installation changes based on both model and serial number. The only way I found out about the additional wing designs was going thru the effectivity blocks and assembly BOM's. The Fairchild has things like drawings for battery installations in both nacelles, but the production AT got batteries in the forward bomb bay.
Working on the F-16 was my first aircraft where Application Lists and Parts Lists were current for every aircraft in production. You had to get good at reading the AL's and PL's, because they incorporated Block numbers, ownership designinations and type-version identifiers. Same drawing might cover as many as 10-15 different type-versions, only differing by part dash number or hardware callouts. It would take us about 10-12 weeks to get a new hire to the point they could reliably read them.
Working on the F-16 was my first aircraft where Application Lists and Parts Lists were current for every aircraft in production. You had to get good at reading the AL's and PL's, because they incorporated Block numbers, ownership designinations and type-version identifiers. Same drawing might cover as many as 10-15 different type-versions, only differing by part dash number or hardware callouts. It would take us about 10-12 weeks to get a new hire to the point they could reliably read them.
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- #26
Yes I am aware of the L-5 wings, only because a super nice chap in Alaska helped me interpret the Aircraft movement card for my L-4 who is an L-5 expert. I can well believe the F-16 takes some getting your head around after being in service for nearly 50 years now. I used to work for Airbus and legacy technical reference systems present a challenge for a product that can stay in operation for half a century. Some currently supported models started out with microfiche and hard copy print libraries that were manually updated by humans. That has all long gone and everything needs to be IT based, but that is a challenge with IT systems having a maximum lifecycle of a decade and some far less. I think some of the modifications in the later P-40 models could be safely incorporated into a restoration. I know of a P-40K-10 that was restored as a -5 which has a complete different rear fuselage and tail. I suspect there would be very little change to weight and balance as a result.
Perhaps you think of this?
P-40B (based on the original Curtiss blueprints)
Recreating geometry of a historical aircraft is usually a painstaking, iterative process. You can see this in my work on the SBD Dauntless. During the long hours of studying the photos and trying to figure out the precise shape of this plane I often wished to have its source blueprints! For many...
ww2aircraft.net
