AirCorps Library

The NAA part numbering system is the best that I have ever seen for organizing drawings into similar categories. It's a topic that I've presented on multiple times, and one that continues to fascinate me. I find it amazing that during one of the most chaotic periods of America's history, companies that were churning out thousands of aircraft a month were also able to keep their engineering data incredibly organized! You are correct that the introduction of most parts catalogs detail the part numbering system (if the manufacturer had one), and that this is the best place to start for information on how to find a drawing you are looking for. For NAA aircraft the part numbering system consists of a two or three digit prefix followed by a 5 to 6 digit suffix that are separated by a dash. The prefix is a model designation that tells you what model of aircraft that part was originally designed to be used on - even if it was later used interchangeably on other models. Here are some NAA prefix examples: 19-____ = BT-9 26-____ = BC-1 36-____ = BC-1 77-____ = AT-6A 82-____ = B-25C 87-____ = B-25D 97-____ = A-36 99-____ = P-51A Etc, etc, etc... The list goes on and on! You are also correct that the first number of the suffix indicates the general area of the aircraft that the part belongs to. __-00001 3-view drawing __-00002 General Airplane Assembly __-00003 Inboard profile __-10000 Wing installation __-20000 Empennage Installation __-30000 Fuselage Installation __-40000 Powerplant installation __-50000 Fixed Equipment __-60000 Armament __-71000 Communications equipment installation __-72000 Navigation equipment installation __-73000 Safety equipment The second digit after the suffix gets even more detailed about that part - for example in the armament series: __-61000 Fixed gun installation __-62000 Flexible gun installation __-63000 Bomb installation __-64000 Torpedo installation __-65000 Pyrotechnics installation __-66000 Gun camera installation __-67000 Tow target installation Here is a link to a part number prefix chart that I created several years ago: https://www.aircorpsaviation.com/wp-content/uploads/AirCorps-Aviation-NA-Part-Number-Prefixes.pdf

Mark - One of the ideas I had was to create an "interactive" parts catalogs for model builders. Think about viewing an exploded view image from the PC and being able to click on an area to view the drawing directly! You'd start at the general assembly exploded view and drill down from there. I think it would be amazing (and will of course take a TON of programming time) Ester

One of the most tedious aspects of my job is being the one who has to approve each description entry submitted by our members . However, I'm continually impressed with the level of accuracy that I get - go figure that people who are this into the details are pretty accurate when it comes to adding descriptions! Many of the T-6 drawings we have do apply to early variants like the BT-9 and BC-1 Also, you mentioned looking though Tiger Moth drawings - where were you able to find those!!??

Hi Mozart - one of the things that we've done on the site to try to make things easier is having our site members enter the descriptions on drawings, rather than only having them identified by their part number. Part numbers are the most efficient way to locate a drawing you are looking for (see my blog about this if you haven't already), but we wanted another way to navigate the site. You know from looking at drawings that there is a description of the part or assembly in the title block. When I initially upload a set of drawings to the site, they are only identified by part number, 89F71104 in the example P-47 drawing below. From there, any member can add the description, or title, to this file = "Bracket Assembly Gun Sight Support". Once that is done, if you were to search within the P-47 area for the term "Gun Sight" or "Bracket" etc, then this drawing would come up as a result, along with any others with those words in the title. This has been our way of making an "index" of sorts, but of course there are difficulties - the main one being that you have to know a bit about how the draftsmen were labeling drawings in order to get the right term for a part. When thinking about data packages for modelers, I suppose I could export a list of all the part numbers and the descriptions that people have added as a reference. Then they could just be in numerical order by part number (which would group similar assemblies together - if the manufacturer had a part numbering system) and would function in the same way that a numerical parts list does at the end of a parts catalog - only with descriptions.

In my experience, the information pertaining to experimental and development aircraft was kept separate about half the time from production data. For example, there are plenty of parts and assemblies that were designed for the X73, the prototype P-51, and these drawings can be found on the microfilm for the Mustang. However, when part or assemblies were changed for the production models, the drawings for those parts were removed from the data set. In our recently acquired set of original NAA drawings I found many drawings for the X73 that were previously unseen. From looking at these drawings it seems like the only place to find this data is by chance (like we did) or by researching in a collection that holds the original manufacturer data, which is always difficult. Most modern companies who own historic manufacturers, or were manufacturing during WWII themselves, don't really want people digging through their archives. It's been my constant goal for the last 5 years to change this mentality, but it's slow going. Ester

If anyone is interested in historical airport info - I have a three volume set of airport directories from April of 1944 that are readable (with a site membership) via AirCorps Library. They are really fun to look through, and most have a picture that goes along with the entry. I've had a good time comparing the images and date with info on Flightaware etc. I also wrote a blog about the volumes and included some comparison photos: https://www.aircorpsaviation.com/viewing-history-wwii-airport-directories/ If you want to see previews of each volume: Volume 1 (Alabama to Kentucky) Volume 2 (Louisiana to North Dakota) Volume 3 (Ohio to Wyoming) Ester

That is correct, this is just standard laminated glass in the photo

To date, I have only found a handful of drawings that relate to the F-86 in the Ken Jungeberg collection. It seems to follow a pattern that when Boeing took what they wanted from the archive at Columbus, they were concerned with the aircraft that were still in service (or most recently in service) rather than the WWII stuff. In a similar fashion, I have some info on the T-28, but the bulk of the drawings are for the P-5, B-25, P-82, and T-6. Ester

I'm so happy that the drawings on the site are of use to you! Combining the information on larger assembly drawings with the dimensions on more specific part drawings seems to be the way for me to go. I have also had the suggestion that including photos from our restoration projects would be invaluable. Having the engineering drawings in addition to photos of the built components/assemblies as they are installed on the aircraft would give the most well rounded picture. Plus I know you builders love to see original photos!! Ester

Hi Kevin, Sadly, no - I don't currently have any drawings for the Typhoon. Engineering data for non-US manufactured aircraft is MUCH harder to come by. We have it lucky because data (manuals and drawings) for our American manufacturers is relatively easy to come by. One of my goals for the site is to branch into including more info on Axis and Allied aircraft. But I have to be patient! Ester

As promised, here are a few pictures of the glass in our P-47 restoration:

You are very correct - an assembly drawing is great for seeing how things fit together, but to understand exact dimensions you need to drill down to a more individualized part drawing. The engineering drawings we have are accurate enough that we use them on our restoration projects, but from what I've heard, it would be nice to use this original data to compile scale info for model builders in a way that is easier to understand, rather than making you sort through 20,000 individual drawings for the B-17 let's say And yes, Boeing does have their own specific way of doing things.

I have heard that cross section views are as good as gold, especially when they are direct from the manufacturer - I'll make a note of that. A station diagram in conjunction with dimensional data seems like it would be much appreciated?

I'm new to LSP, so I wanted to get opinions from you seasoned veterans out there! I manage a website called AirCorps Library that gives digital access to original engineering drawings from WWII. The site was originally designed to cater to warbird restoration shops (which is the bread & butter of my parent company, AirCorps Aviation). However, the number of scratch builders using the site for their projects has grown so much in the past few years, that I'd like to start focusing more on the needs of the scale model community. I do know that as a model builder that you don't need the tens of thousands of engineering drawings that are available for any given warbird. However, I'd like to put together some packages of information aimed at modelers, and don't want to leave out a bunch of important drawings. So, my question is this: Other than overall dimensions of an aircraft (general arrangement / 3-view), what specific areas/topics would be helpful to see from an original factory drawing? My initial thoughts are as follows: wing installation, wing tip, aileron, flap assembly, empennage, horizontal and vertical stabilizer, elevator, rudder, landing gear installation, tail wheel, power plant, cowling install, instrument panel. I also thought including an original parts catalog would be helpful, as they include exploded views of most of the assemblies in an aircraft, along with the associated drawing numbers. This could help users drill down even further and find additional drawings that they needed. See some example drawings below - I've got hundreds of thousands of these, and need help sifting through to find the ones that you think would be useful in a build! Ester

They are doing an amazing job of digitizing their collection and bringing it to the public. Doing it right in San Diego

An example with a reference to the manufacturer's engineering data: We are currently working on the canopy of our P-47D-23 restoration, and even with the protective film still on the glass, there is a slight greenish cast. The engineering drawing for this specific panel (Republic drawing 89F11808) notes that the glass panel is to be made out of Type I, Grade A laminated glass. The specification listed on this drawing with reference to the glass is: AN-DD-G-551. This spec is titled "Glass, Laminated", and details the manufacturer specs required by the Army/Navy in 21-Feb-1940 for this type of glass. This includes information on light transmission, light exposure, scatterability, and visibility distortion tests, among many other things. This spec also defines Type I, Grade A glass as "A laminated glass that is intended for use where perfectly undistorted vision is necessary to insure minimum error in navigation and other accurate observations." We utilized this original spec, and the tolerances it provided, when we had these glass panels manufactured for our restoration, so presumably the green tint is normal when dealing with this thickness of glass. However, we are of course using modern materials, so there is a possibility that during WWII the tint may have been different. Once the official pictures of this part of the project are posted, I will link to them if anyone is interested.

Thank you all so much for the kind words about the site! I'm a new member to Large Scale Planes, and have been learning the ropes, but I am very excited to get more involved in the modeler community. As for the B-24... I would absolutely love to add more information to the site related to the Liberator. All of the info we have available is donated to us for scanning, and then returned to the original owner. Because of this I am a bit at the mercy of whatever it is that people decide to share. I have often wondered where the trove of B-24 materials are, because they're certainly not floating around for general use! If anyone knows where some manuals or drawings are located please share the contact!