NAA P-51B/C/D Mustang: Radiator Coolant Mount

NAA P-51B/C/D Mustang: Radiator Coolant Mount

I discussed in my last post the development of a comprehensive drawing register for the P-51 and my rather ambitious intent to derive the list of parts associated with each sub assembly and main assemblies.

This could indeed be quite a task as for example on the P-51C alone we have 348 assemblies listed, some are sub assemblies and some are top level assemblies. The challenge is organizing the drawing parts list according to their assembly and retain the order of links on my filing system as per the main document register.

2015-06-15_18-18-30The NAA Numerical part lists (AN01-60JE-4 Section 2) give us some idea of how this data can be collated but the chart lists the top level assemblies and does not follow the hierarchy to the individual part. The individual parts though are listed in subsequent chapters of the parts list.

The part files themselves also contain information to assist with establishing the hierarchy of assembly; similar to the following for the Radiator Coolant Mount.

2015-06-15_01-15-12    2015-06-15_00-46-18

As you can see from the scans this part drawing typically lists the associated next level assembly, quantity and the aircraft variants to which they belong.

2015-06-15_01-19-41This image on the left is the next level assembly (sub assembly) which shows the inclusion of fittings and bushings and again lists another next level assembly.

Typically this is how the hierarchy works and its great that we can track the target assembly from the individual part drawings.

2015-06-15_00-56-52This is the top level assembly as noted in the above drawing. Our Coolant Radiator Mounts are highlighted in red.

In this example we don’t have all the drawings for the parts listed and though it would seem unlikely to be able to build this assembly with incomplete information it may be possible to interpolate sufficient data from what we know to develop the parts that are not available.

This is typical of these types of projects as the majority of scan drawing sets are incomplete and many parts can only be developed from physical examples or interpolated where we have the requisite data from other sources.

This approach is similar to how I plan to tackle this document register in identifying the links between the part files and the assemblies. We have the NAA register; which is a great starting point; and the part and assembly files themselves. There may be instances where the information from the drawings or the NAA register is unclear, in which case I would refer to other drawings in the series that may reference this information in the notes or comments.

2015-06-15_23-39-34At this stage I have transposed the NAA register assembly chart (noted above) into a spreadsheet format so that I can add additional key information.

The image shown here is a partial screenshot of how the fuselage data has been organised, showing the hierarchy level of the main assemblies according to their respective position in the NAA chart.

The first column is a reference number I use for hierarchical lists of this nature. There is still a lot of work to be done to collate the parts associated with these assemblies; hopefully most of which I will be able to transpose from the NAA scanned register.

In the interim I shall continue to develop some of these part drawings into accurate 3d cad models.

2015-06-15_00-48-28

TechNote: MS Excel Drawing Register P-51

TechNote: MS Excel Pivot Tables: Drawing Register P-51

The drawing archive collection for the Mustang P-51 includes an NAA Document register in PDF that lists all the Scan Index Numbers, Drawings Number, Aircraft Type and Change (Revision)Number.

To make sense of this large archive; containing thousands of scanned images; it is necessary to first transpose the comprehensive NAA document register into a spreadsheet in order to analyse and filter the data according to requirements.

My requirements are simply to be able to group the data per content; Fuselage, Wings, Equipment etc; and per aircraft type; P-51A, P-51B, P-51C etc.

Further breakdown of data would involve isolating the main assemblies and then parts or sub assemblies belonging to each.

2015-06-12_22-06-44From Adobe Acrobat I extracted the pages of data as spreadsheet tables to which I added a Drawing Description and grouped the data sets together by “Content”…that took a long time to do as the extracted data first had to be checked and then sorted accordingly.

The drawing descriptions came from an index already created by Norman Meyers at Chanute Air Museum, so it was relatively easy to enter this data into my spreadsheet. Its a real pity I had not had access to Normans data earlier; could have saved me a lot of work.  My thanks to Norman Meyers.

2015-06-12_23-39-41After sorting the data and inserting descriptions I now have separate worksheets for the content similar to this one.

What I really want now is to identify and organize the drawings belonging to each type of aircraft. For this exercise I use the Pivot Table function in Excel. Pivot Tables are great for organizing and summarizing data according to specific criteria.

2015-06-12_22-34-13Here I have initiated the Pivot Table function and selected the entire data-set of information relating to the Fuselage; as you can see we have a large number of drawings just for this one area!

When working with large data-sets it is good practice to select a new worksheet for inserting this new table.

2015-06-12_22-38-07What we end up with is a new worksheet with the pivot table outline on the left and a selection box on the right. We now select from the latter the columns of data we want…in this case all the main ones plus the P-51D; which will populate the outline table on the left.

Pivot tables by default include a summary row under each entry; I suspect this is more useful for statistics than organizing a document register; which we don’t want.

2015-06-12_22-49-34To remove the summary from the table we just need to select each column in turn using the small arrow as highlighted and turning off this option in “Field Settings” and select “None”.

The final step is to filter the data according to the required criteria; in this case I want all the drawings that have an “X” value in the P-51D column.

2015-06-12_22-54-42This is done by selecting this value from the header drop-down options; which lists by default the unique values in each column from the master table.

We now have a list of all the fuselage drawings and their location in the archive belonging to the P-51D aircraft.

The next step would be to extrapolate all the “assembly” drawings and from there the components that make up each assembly…but that’s for another day.

Pivot Tables are great for this type of job.

  • 846 fuselage drawings for the P-51A
  • 890 fuselage drawings for the P-51B
  • 833 fuselage drawings for the P-51C
  • 923 fuselage drawings for the P-51D
  • 950 fuselage drawings for the P-51H

Many drawings of course are a shared resource for all variants. This drawing register has recently been updated with hyperlinks to all the drawings listed. See this post for details.

For further information on any of these projects please feel free to drop me a line via my contact page or email me at hughtechnotes@gmail.com

North American P-51 Mustang: NAA Profiles

NAA P-51 B/C/D Mustang:

The majority of parts created for aircraft like the P-51 are derived from a library of standard section profiles, not unlike the steel and ship building industries. Fortunately for this project we have an extensive collection of these original NAA standard drawings, numbering 208 in total.

To facilitate the long term goal of recreating the P-51 part drawings as 3D models and associated 2D drawings I figured it may be prudent to first recreate the standard profiles as 2D CAD profiles for this purpose.

So far I have drawn the first 24 profiles exactly as shown on the original drawings but with dimensions in dual format inch & mm…many more to go!

NAA-1E1          NAA-1E1a