The USAF Engineering Division Finding Aid
How We Did It
by Kimble D. McCutcheon

This is an account of how the USAF Engineering Division Finding Aid project was accomplished. It is written from a personal point of view because its creation has been, well, personal. I began writing about aircraft engines because no one covered the high-performance liquid-cooled engines developed for the Army Air Corps/Forces between 1930 and 1946 at any significant technical depth. I was dismayed at how little information was available on these engines. Other researchers told me that I should visit the National Archives for a look at the "Sarah Clark Files".

I made a pilgrimage to College Park, Maryland. Bright and early on the first Monday in October, 2000, I presented myself to a member of the Archives staff and announced, "I’d like to do research in the Sarah Clark Files." He replied, "You’ll need to start with the finding aid on the fourth floor." I went to the Microfilm Research Room on the fourth floor and asked to see the Sarah Clark finding aid. I was handed a box and directed to a Microfiche viewer. Inside the box were 100 Microfiche cards, each with 84 images. Each card was numbered sequentially, but also had another cryptic "RD" number. I started with Fiche #1, hoping for some kind of an index. Not only was there no index, but the information on Fiche #1 was in no particular order. I put away Fiche #1 and viewed Fiche #100, which also had no index and no discernable order. I viewed another, and another, and another --- same story.

I’d had considerable experience looking at scrambled data and had usually been able to rapidly discern a pattern. If there was order to this chaos, I wasn’t seeing it. No one in the Microfilm Research Room was able to help. Someone finally suggested there was a paper copy back on the second floor, where I had begun two hours earlier.

Back on floor two I asked a different staff member about a finding aid for the Sarah Clark Files. She showed me a shelf with eight thick three-ring binders. "Now we’re getting somewhere," I thought. The binders were arranged chronologically, but within each year was yet another repeating sequence of arcane "Central Decimal Filing System" numbers. It soon became obvious that "452.8" had something to do with aircraft engines, thereby reducing the amount of reading to be done. However, it was still necessary to flip through the pages of all eight binders in order to find citations for all the engines I was researching. By skipping lunch and working into the early afternoon I was able to identify and request a short list of records. While I waited for my records to be pulled, I continued to work through the eight binders, making additional lists of engines, airplanes, equipment, accessories, etc., each requiring yet another pass through the binders.

In less than an hour the records I had requested arrived. With visions of sugar plums in my head, I moved from the "Researcher Assistance" area to the reading area and opened the first box of records. Inside the box there was indeed a file folder with a title like I had seen in the finding aid, but inside the folder was a single pink sheet of paper — a cross reference to yet another file in yet another box! The file folder with the next title on my list was missing entirely. "Harrumph!" The third file folder I looked into had what appeared to be correspondence between the Army Air Corps and Wright Aeronautical. Good stuff it was! I obtained permission to scan the document and began scanning the pages.

Once the task of scanning was complete, close inspection of the document pages revealed many were cover letters, most of which read something like, "Attached herewith is [everything you ever wanted to know about this engine/airplane/program] … Nowhere could I find any of the very intriguing reports, photographs, drawings, charts, etc., that were mentioned in the cover letter! Subsequent work with the correspondence files showed this to be the norm rather than the exception, which left me with the overwhelming question of, "Where is all the good stuff??" Clearly there must be a mother lode of undiscovered documents, but the question was how to find it. None of the archivists seemed to know how to find the really valuable information, nor could they suggest any underlying order to the collection. They explained that the 100 Microfiche cards were copies of the shipping documents that accompanied the collection from Wright Field, but no one could suggest how to find things by subject or project.

After that first day at the Archives I was off on a quest to discover how the collection was organized. Later I learned that the really interesting airplane and engine data was contained in another part of the collection called the "Research and Development Project Case Files", but I was still unable to discover how the R&D Project Case Files were organized or how to find documents related to any specific subject or project.

I returned to the Archives several times a year, each time bringing home gigabytes of scanned documents and each time picking around the edges of how the progressively more interesting collection of documents was organized. Finally, on October 23, 2003, I hit pay dirt by discovering that the R&D Project Case Files were organized according to something called an "Expenditure Order Number", or EO number. This was apparently a budget line item from each fiscal year’s development budget against which the work done on a project was charged. I wish I could claim I discovered this by the process of elimination, clever deduction, or prescience, but the fact is, I stumbled upon it through blind luck. I had ordered some records I thought were related to one program, but they were not. Instead, they were related to another program that I recognized and whose EO # had appeared in some of its correspondence!!

Unfortunately, this discovery happened late in my visit and I didn’t have time to verify whether I had indeed found the key until my next visit to the Archives, which didn’t occur until the following September! In the mean time I had reviewed all my previously collected information and armed myself with a long list of EO numbers to investigate. Sure enough, I was now able to find scores of folders full of information about the engines and aircraft I had been researching!

Now that I had a handle on how the records were organized, I began thinking in terms of creating a searchable catalog. I figured this would be a big, expensive job and started trying to estimate how much it would cost. I knew there were 100 Microfiche Cards with 84 images on each one. I had representative copies of a few of the images, so I sat down and typed in some of the images. It took about a minute per citation, and it looked like there were probably between 160,000 and 220,000 citations, which equated to between two and three person-years for the transcription, database and web site pages. In addition, an on-line database would have to be designed and built, and programs written to serve up the web pages that would solicit search criteria and display search results.

I wondered if it would be cheaper to have the whole thing scanned and then use optical character recognition technology to convert it into machine-readable form. I sent some samples to several of the top OCR vendors, who all opined that the original images were too poor to OCR. Armed with the knowledge that data transcription for the catalog would have to be done manually and with a rough idea of the cost, I began searching for aerospace corporations that might be willing to fund the effort. This led nowhere.

It finally occurred to me that if the project’s scope were more limited the AEHS might be willing to fund a pilot project. On January 11, 2005 I proposed this to the AEHS Board of Directors, which approved the proposal.

In April 2005, I traveled to the Archives and scanned all 8,400 images that form the 100 Microfiche cards. I then viewed every image, sorting them into either Correspondence or R&D Project Case File groups. I further subdivided the R&D Project Case File images into groups according to the Engineering Division Organization that had originally produced the document referred to by the image information. Viewing all of the images gave me insight into the kind of data that was available, thereby allowing me to design the database and begin writing programs to search the database and display the results.

Now that the images were in some kind of an order, I broke the Correspondence group into "work packages" that were sized so they could be transcribed in between 10 and 20 hours. I then prepared prototype Excel worksheets into which the data from the images was to be transcribed and wrote a set of instructions outlining how to do the transcription process. The AEHS contracted with a few temporary employees to do part-time data transcription, and I mailed each one a work package consisting of an image file, an Excel worksheet, a machine-readable set of instructions (all of this on a single CD-ROM) and a hard-copy set of instructions. Completed Excel worksheets were returned via e-mail. These patient contractors helped work the bugs out of the system.

Satisfied that the process was workable, I announced the project to AEHS members and asked for help, both in the form of volunteers to help with the transcription and donations of money to help cover work not done by volunteers and other associated expense. Volunteers and donors responded enthusiastically. I sent each volunteer a "work package". As volunteers returned the completed Excel worksheet via e-mail, I checked the worksheets for errors and uploaded them into the on-line database.

Once the system for processing the Correspondence group was working well, I turned my attention to the much larger problem of designing a processing system for the R & D Project Case Files, whose shipping document formats differed dramatically from the one organization to another. Some organizations had nicely descriptive titles for each file, while others did not. The Power Plant Laboratory, for example, had only listed the EO numbers for most of its files. This meant that each file would have to be examined by hand and a list of its contents created.

In October, 2005, Sam Ferguson, Dan Whitney, and I traveled to the Archives to make box lists for the Power Plant Laboratory. Another group (David Birch, Gerard Blake, Todd Hodges, James Strobeck, Dan Whitney and I) returned in July, 2006 for another week of making box lists. At that time, we had a good sampling of the most "interesting" Power Plant Lab files, and a fairly good idea of what the EO number ranges represented.

Meanwhile, processing of the other R&D project case files continued. In mid-2006, more volunteers from the American Aviation Historical Society, Society of Air Racing Historians, and the WW1 Aeroplane organization offered assistance. Charles Downs, a retired NARA archivist,  also contributed a detailed transcription of the Air Force Technical Museum and provided enormous insight into the structure and history of the collection.

Cataloging of microfilmed Power Plant Laboratory Memorandum Reports was done in much the same way as the Correspondence and R & D Project Case File groups. As of November 30, 2008, over 95,000 on-line citations allowed more extensive research into the history of US Air Force Materiel development than has ever before been possible. This has since grown to over 102,000 citations.

I wish to thank the following persons for their support of this project. Without their help, it would have never been accomplished.

Postscript, 31 December 2012

After three years of reflection on the value of the AEHS cataloging endeavor, it is fair to conclude that results obtained have been far more useful than anyone ever imagined. It has provided numerous academics, historians, modelers and enthusiasts with valuable material upon which to base their work. As valuable as this earlier cataloging effort has been, the microfilmed memorandum reports of the Flight Test Division, Propeller Laboratory and Aircraft Laboratory may, in the long run, prove to be even more useful.

The Flight Test Division was responsible for flight-testing aircraft, engines, propellers and other equipment from 1929 until the 1960s. The records of these tests were microfilmed by the U.S. Air Force during the early 1970s and original paper copies destroyed, which means that only the microfilmed versions survive. These, like the Powerplant Laboratory memorandum reports, were completely uncataloged. Over 4,000 reports comprise this large records collection, which is extremely rich in content. In addition to providing conceptual, developmental, testing and operational details of specific aircraft, they also document the development of doctrine, underlying science, materials, processes, procedures, and standards. Cataloging of the Flight Test Division was completed during April 2012, and the catalog is now available on-line.

The Engineering Division, Airplane Section, Propeller Branch was created at McCook field during 1917. It built a large propeller testing facility in 1918 and began testing thousands of propeller designs for the US Army, US Navy, and the US aircraft industry. The results of these tests are recorded in the memorandum reports of the Propeller Laboratory, which the AEHS began cataloging in September 2012. This catalog is now on-line.

The Aircraft Laboratory grew out of the Airplane Section that began in 1907. Its memorandum reports cover the paper studies necessary for the development of doctrine, design and procurement of aircraft, support of flight testing, and investigation of problems. Cataloging of Aircraft Laboratory memorandum reports began in September 2012. A small fraction of the catalog is now on-line; additional citations will be added as time and money permits.

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