Would you say that you have a complete set of the required Mustang manuals? How about comfortably discussing your technical manuals with an FAA inspector if they walked into your shop today? Even if you’re like us and have an extensive library of WWII manuals, the answer to both these questions is likely no – unless you’ve purchased our 4-manual set for the P-51D. We’ve done the work of going through dozens of manual revisions to validate every page of these documents as correct – so you don’t have to. If you own, operate, or maintain a D model Mustang, read on to understand why these manuals are unlike anything currently on your shelf, and why you need them.
In late 2018 and through the summer of this year, I began the lengthy research project, of determining the latest revision -1 through -4 manuals for the P-51D. I knew that answering the question of what the latest revision was would be difficult, but I didn’t know how difficult. 150 hours later, I was finally done, and along the way had acquired a healthy respect for why no one had undertaken this project before, and also how important the work actually was.
We all know how many manuals there are for WWII aircraft, you can find them on eBay, at yard sales, and antique shops, and of course, websites like AirCorps Library, EFlightManuals, Avialogs, and Essco. However, other than growing your personal collection of manuals for collector’s sake, there are several more (very important) reasons why you should be able to identify the latest revision manuals for your aircraft – specifically the P-51D in this case. Safe operation, and FAA compliance are the big reasons, but a deeper understanding of construction and maintenance practices gained by reviewing manuals from a variety of dates is beneficial on a variety of levels. In addition, having access to a verified “latest revision” manual gives operators and mechanics piece of mind when looking for a final answer to technical questions.
If you have ever worked on a P-51D, and have read through its type certificate (TC), you have likely noticed several interesting disclaimers regarding the manuals that pertain to it. TC’s are very specific when it comes to the short Tech Orders that deal with very precise maintenance topics. Short Tech Orders are usually anywhere from 1 to 10 pages, and their document numbers end with high digits (Example: T.O. 01-60-95 or 01-60-116). The TC will tell you all the short TO’s that pertain to your aircraft, along with the correct revision of that TO. However, when it comes to the main manuals, such as the pilot’s handbook (-1), maintenance manual (-2), structural repair manual (-3), and parts catalog (-4), it’s a different story. These high-level manuals are referenced in the mustang TC, but revision dates are not specified, and the manuals are accompanied by disclaimers such as:
“In all cases it will be the responsibility of the applicant to secure a copy of the correct Technical Orders. The FAA does not have these documents available for distribution.”
Disclaimers such as the one above necessitates a knowledge of the revision system for manuals and TO’s – as responsible mechanics, operators and owners, knowing how to answer the question of what resource is correct, not only assures safe operation of our aircraft, but also peace of mind.
Above: P-51D Mustang Type Certificate. Left: Note 3 from P-51D Mustang Type Certificate highlighting FAA disclaimer
Most of us know where to find revision dates on a manual – in the lower right corner of the cover page, or in the upper right corner of a short TO. High-level manuals will often have two dates listed, a larger one (which I call the “basic date”), that indicates the first published version of that manual, and often a smaller date listed below. This second date is the “revised date”, and indicates changes to the original manual from the basic date listed above.
Revisions were issued in packets during the war, which consisted of any pages that were modified, along with a new cover page indicating the new revised date. Each page within a revision packet also had the revised date printed on the bottom margin. When mechanics and technicians received these revision packets, it was their responsibility to remove outdated pages and insert the new ones in the correct place. However, this almost never happened. Often, revision packets were placed on top of the basic manual, or some pages were inserted, and others were not. Because of this, no manuals today can be considered up-to-date without verifying each individual page within a manual to assure that it is the correct version.
The back side of the cover of a military published manual always contains the List of Effective/Revised Pages. This page contains a cumulative list of all the revised pages in a specific manual, along with their latest revision date. The list of revised pages (along with the revision dates listed on the bottom of each revised page) contains half the information necessary to verify a latest revision manual.
The image to the left is from the P-51D maintenance manual, and the image above is from the parts catalog
Every Army aircraft flying in WWII had a manual that was titled “List of Applicable Publications for __” (LAP). While this title might make the content seem as interesting as watching paint dry, these manuals are the second piece of information that is necessary in determining what date makes a manual the latest revision. Any List of Applicable Publications document number always ends in a -01, and many revisions can be found for individual aircraft. When working to determine the latest revisions of the P-51D (-1 through -4) manuals, I utilized every version of the LAP for the Mustang that I could find; 31 different revisions, spanning dates from 1947 through 1955.
LAP’s are important because they tell us every single manual and TO that applies to our aircraft, at the date when that specific LAP was published. Using multiple revisions of LAP’s allowed me to see when specific manuals and TO’s were added as required materials for the P-51D, and the revision dates of each of these manuals.
After looking through all the LAP’s, I was able to determine the last date when the -1 through -4 Mustang manuals were released. Once I knew this information, I then had to find a version with that revision date listed on the cover – mainly because I needed to utilize the List of Revised pages on the back of the cover. Having this latest revision of the List of Revised pages allowed me to go through each manual (page by page) and verify that I had all the correctly revised pages as per the list.
As I mentioned previously, revised pages were almost never inserted into manuals, and because of this it was difficult to find the exact pages I needed to complete the manuals. For example, I had to hunt down nine different versions of the P-51D maintenance manual in order to get the correct revision of each page that I needed.
Having the latest revision of a manual does not mean that no other versions are necessary. I am constantly encouraging the guys in the shop to look at multiple versions of the same manual. Most of us are familiar with the fact that important information was often omitted in later revisions to save space, or because it was thought that a topic was “common knowledge”. Knowing the difference between an omission and a revision/change due to incorrect or outdated information is also a key to safe operation and maintenance practices. However, having the latest revision manual on the shelf means that you can always verify or inform any decision from a verified source.
The main goal of completing this project was to have a set of manuals that could address the disclaimer in the Mustang type certificate about which revision of the high level manuals to use when answering maintenance questions about the P-51D. However, safe operation is a close second to FAA compliance. The internal goal for us was to address these key points, and also make these manuals available to the owners, operators, and mechanics who really do need them on the shelf.
My background in bookbinding came in handy when we sat down to discuss the best way to make these manuals available. We wanted them to look different from other manuals, so it would be obvious they were something special. However, we also wanted them to be high quality and durable so that they could be easily used in the shop environment. In the end I ended up creating a hybrid binding style that allows the manual to lay flat, while being more durable (and more stylish) than a standard 3-ring binder. Each manual is hard bound with a laminated cover, and the manual itself is printed in full color on heavy weight gloss paper. Because I created the binding and design myself, I also make all the individual components and assemble them myself in-house here at AirCorps.
A key component of these manuals is the document I created to illustrate and validate the work that went into compiling each one. This document is attached to the inside cover of each manual, and is the verification that these manuals are in fact the latest revision. After discussing this project with many different people at the FAA, we decided that this document should be comprehensive enough to demonstrate to any inspector the validity of these manuals. This document, along with the unique binding of the set, make the collection stand out on the shelf, and in an inspectors mind.
We have had great feedback on the sets that we have sold, and know that these manuals are a necessity if you either own, operate, or maintain a P-51D Mustang. Many shops have already purchased the sets, and personalized them with the serial number and owner of the aircraft, a service I offer for each set sold. We are excited to offer these sets to others, so that everyone can benefit from this crucial information. The manual sets are for sale on AirCorps Depot, click here, or the graphic to the right for more info and pricing. If you have questions, or would like more information about the manuals or my process, please feel free to contact me at:
or, call the shop at: 218-444-4478
Keep ’em flying!