Engineering data for scratch builders - what is most helpful?

[mozart]

I haven’t investigated your site yet, but I know from personal experience of ploughing through thousands of DH 82a Tiger Moth micro film drawings (right down to nut and bolt, washer/split pin level) that the thing that I was crying out for was an accurate and comprehensive index! 
If it doesn’t already exist it would be a massive task to organise the drawings and compile said index, but that really is the key. 

[dodgem37]

I agree with Mozart.  I have your P-51B Engineering Drawings in electronic form.  Thousands of them.  The are all identified as the examples you provided earlier, alphanumerically.  I spent a solid 6 weeks labeling the drawings with the name and drawing number so I could find a drawing of a part I wanted to make or draft.

 

Having an index of drawing names would be invaluable.  This would allow us to hone our research before making a purchase.

 

Thank you.

Sincerely,

Mark

 

[AirCorps Library]

On 12/24/2021 at 2:45 PM, Landrotten Highlander said:

I am particularly interested in the development planes - experimental craft, or production craft adapted for specific tests.  Any info on this type of knowledge?

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

[AirCorps Library]

On 12/25/2021 at 1:05 AM, mozart said:

I haven’t investigated your site yet, but I know from personal experience of ploughing through thousands of DH 82a Tiger Moth micro film drawings (right down to nut and bolt, washer/split pin level) that the thing that I was crying out for was an accurate and comprehensive index! 
If it doesn’t already exist it would be a massive task to organise the drawings and compile said index, but that really is the key. 

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.

[mozart]

That's a very imaginative way of compiling a type of searchable database Ester - a few potential problems spring to mind about it not least spelling/typos, but it's a good start!  Thanks for letting us know, I could be very interested in searching for the early North American T-6 types so I may well add to the system.

[dodgem37]

I have a P-51D Parts Manual I used to detail a Tamiya P-51D.  The build can be found in my signature below.  In the thread I mention the manual I used.  For me, having a set of drawings that matches the index of drawings for that page which makes up that part or that assembly, would be a time saver.

 

 Thank you.

Sincerely,

Mark

[AirCorps Library]

1 hour ago, mozart said:

That's a very imaginative way of compiling a type of searchable database Ester - a few potential problems spring to mind about it not least spelling/typos, but it's a good start!  Thanks for letting us know, I could be very interested in searching for the early North American T-6 types so I may well add to the system.

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!!??

[AirCorps Library]

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

[mozart]

11 minutes ago, AirCorps Library said:

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!!??

The BC-1 I’m especially interested in because it’s pretty much a Harvard Mk1, no 1/32 scale model exists of this so I have dreams of scratchbuilding one! 
The Tiger Moth drawings are on a cd which was loaned to me by a friend who restores them, though I’m not sure he found them too useful. 

[Sabrejet]

Most/all NAA Parts Catalogs have a PN 'family tree' in the preliminary pages. This would serve as a good start for finding drawing numbers (part numbers). I'll have to check, but I think NAA at least used a system where the first two or three digits of the PN/drawing number related to a structural area or system type. This pre-dates the modern system of using (for example) ATA numbers to identify PN/drawing numbers by structure location or system.

[Sabrejet]

This is the general NAA system for drawing/PN (with further number evolutions within each area/system):

 

00001    3-view drawing

00002    General Airplane Assembly

00003    Inboard profile

01001    Wind Tunnel Models

03001    Handbook Illustrations

04001    Mockup

05001    Field Service

10001    Wing Installation

20001    Empennage Installation

30001    Body Group

40001    Power Plant Installation

50001    Fixed Equipment

[AirCorps Library]

18 minutes ago, Sabrejet said:

Most/all NAA Parts Catalogs have a PN 'family tree' in the preliminary pages. This would serve as a good start for finding drawing numbers (part numbers). I'll have to check, but I think NAA at least used a system where the first two or three digits of the PN/drawing number related to a structural area or system type. This pre-dates the modern system of using (for example) ATA numbers to identify PN/drawing numbers by structure location or system.

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