A Mystery? Not So Much, Maybe

My friend Do-Ming sent me a link this morning to a YouTube video by Adam Savage, one-time Mythbuster and all-round hoopy frood. Savage was interviewing Peter Jackson about one of the latter's many dozens of first-world-war aircraft, and the discovery Jackson (or his staff) made when they removed the fabric from the wings of the (original) SE-5a biplane.

(Note that the images in this post are not those of the machine in question. They're just pix I found in Wikimedia Commons, of museum-display aircraft.)

Museum SE-5a (in what looks like a Bessonneau hanger)
Image by Barry Lewis, from Wikimedia Commons

The story thus revealed was interesting... but perhaps not quite as profound a mystery as messieurs Savage and Jackson implied.

There are two reasons for this... and I suppose I ought to summarize the "mystery" first. Briefly, it was that Jackson's team discovered a rolled-up pencil sketch tucked into what I assume was the leading edge of one of the ribs on the lower plane of the wings. The drawing was of an RFC pilot, and the big mystery was the identity of the pilot. Jackson implied that someone had removed the fabric from the wings for repair, and a person or persons unknown had slipped this drawing into the rib before the fabric was restored.

Who was the mystery pilot?

Not really much of a mystery, because the drawing turned out to be a close copy of an early-war photo of Edward "Mick" Mannock, one of the RFC/RAF's leading scout pilots of the Great War. As hundreds of YouTube commenters pointed out very rapidly.

My reason for posting this, though, is to correct what I think was a faulty impression Jackson may have given. Far from being a rare occurrence, the removal of fabric from Great War aircraft happened pretty much every time a machine was flown through combat. To understand why, you have to know a little about how these aircraft were built.

The structure of a Great War fighter was, superficially, astonishingly flimsy. The fuselage and wings were light-weight structures of wood (primarily ash and spruce, I believe), covered with linen fabric that was given some tenuous protection from the elements by multiple coats of "dope" made up of highly flammable nitrocellulose. What gave these machines their structural integrity and strength was a third component on top of wood and linen: wire.

An SE-5a with fuselage fabric removed
(Image from South African Museum of Military
Technology by way of Wikimedia Commons)

The framework of both fuselage and wings was put into a true shape by the use of wire (not the "piano wire" of cliche), attached at key points in the structure and then tightened with turnbuckles. If you look at the image at the top of this post you can see some of the wires used externally to control the angle of the wings; there was a much more extensive set of wires under the skin, as it were.

This structure, while flexible and quite strong for its weight, was quite delicate. And the stresses of aerial combat, in which aircraft were thrown about by their pilots, were such that small (or sometimes not-so-small) changes were forced on the structure. As such, it was RFC policy that whenever a machine had been involved in combat, it had to have its basic structure trued-up again on landing. This procedure was known as "rigging," and an RFC squadron employed two different types of aircraft mechanics ("ack-emmas" in the alphabetical slang of the period): riggers to handle the structure, and fitters to handle the mechanical elements (engine, fuel tanks and supply, etc.)

So for a typical front-line SE-5a there would have been plenty of opportunities to tuck a small piece of paper into a wing rib. As for the drawing itself, my guess is that it was intended as some sort of talismanic tribute to Mannock, who was killed in combat in July 1918. (The photo from which the drawing was copied was taken in 1917 or early 1918; my guess is 1917, because Mannock's face shows little of the strain that several months of combat imposed on pilots of the period.)

Really, the true mystery of this drawing is that the SE-5a itself (or at least its wings) survived for nearly a century after the machine's manufacture. Over five thousand SE-5s and 5as were built; the survivors can be counted on the fingers of a hand or two.

(One of the big thrills of my life was seeing—and, more important, hearing—an SE-5a flying over my head as I was walking along a country road in England in 2001.)