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Discovered in an elephant barn in India, two World War I bombers have been brought back to life in the UK.

In the 21st century, finding a long-undiscovered World War I airplane in a barn is more than a rarity; it’s a near impossibility. Thus when UK-based aircraft restorer  Guy Black heard about two 1918 Airco D.H.9 bombers hidden in a Rajasthan elephant stable, he just had to investigate. In 1999 he set out for India to see for himself if the rumor was true. Once Black examined the disassembled aircraft, he determined that they were eminently suitable for restoration.

While the D.H.9 was hardly in the league of the Sopwith Camel or Bristol Fighter, it nonetheless made a significant contribution to WWI. Until recently only four of the bombers were known to survive. The D.H.9 represented a gap in the aviation collections of major UK museums, and there were certainly no flying examples anywhere in the world. It’s likely the last time one of them flew was in the early 1920s, when the D.H.9 was withdrawn from RAF service. But how did any of these rare birds end up in India?

At war’s end, the RAF had some 20,000 surplus airplanes, many of them factory-fresh. Many were scrapped or burned, but some were shipped to Britain’s overseas dominions and territories, in a scheme called “The Imperial Gift.” The goal was to either establish individual air forces in those regions or equip them with airplanes suited to civilian use. At least three D.H.9s went to the Raj of Bikaner. Without pilots to fly them or the means to maintain them, however, they ended up in storage in the Red Fort at Bikaner. Their engines were later removed, allegedly to provide power for an irrigation system.

It was immediately clear to Black that the restoration challenges would be enormous. First, there were no engines. Second, there were no longer any drawings extant for the D.H.9. And third, there was the problem of sourcing authentic instruments, fixtures, fittings and materials. Nonetheless, Black purchased the fragile hulks and shipped them back to Britain in 2000. The Imperial War Museum, recognizing the value of having a D.H.9 in its collection, commissioned Black’s UK-based Retrotec company to rebuild one of the airplanes for static display. Meanwhile, Retrotec committed to returning the other bomber to airworthy status.

It helped that the IWM’s reserve collection included the correct Siddeley Puma engine, along with a propeller. Drawings still had to be produced, though, since the termite-eaten timbers of the planes were largely beyond saving. Fortunately one of the airframes was complete, providing the basis for the schematics. Every part was photographed, measured and drawn. Even though the IWM aircraft would not have to meet airworthiness standards, the museum wanted it to include as many original components as feasible. For the restorers, working on the static-display version provided a valuable learning curve in advance of the more exacting second project.

One of the most significant challenges was finding a potentially airworthy engine. Black estimated that only eight examples of the correct power plant survived. After an extensive search, he tracked down a 200-hp BHP engine at the Canadian Aviation and Space Museum in Ottawa. (The BHP powered the earliest D.H.9s before being replaced by the Puma.) Another lucky break came when he remembered that he had bought a sundry collection of WWI-era wing struts. Digging them out of storage, he found he had one complete set of D.H.9 struts. Next he discovered that the Smithsonian Institution had many drawings of the D.H.4, which shared numerous parts with the D.H.9. And so it went: Instruments and fittings were located at “aero-jumble” sales and on Internet auction sites; a tail skid came from the U.S., ammunition chutes from Australia and even a pair of exhaust manifolds from a scrap yard in Afghanistan. The restoration team enjoyed one notable advantage: Nobody else was looking for D.H.9 parts.

The D.H.9 had not been a great success in its day, in part because there were reliability issues with the Siddeley and BHP engines. The airworthy D.H.9 has been fitted with the latter. Despite the reliability issues, Black is adamant on the matter of originality: “I have a dislike of re-creations of early aeroplanes fitted with modern engines. What is the point? Surely, the whole idea of constructing a period machine is to relive the experience of our forebears—both in construction and its operation, and with all the inherent flying characteristics, both good and bad.”

While he was stripping and rebuilding the BHP, Black made a surprising discovery with respect to one of its known faults: a tendency for the connecting rods to fail. He realized that the point of failure on the rods was exactly where the engine number had been crudely stamped into each one. Clearly, the stampings had weakened them at that point. Though it was an obvious flaw, it had never been discovered while the bomber was in service. Now, almost a century later, Black had new rods manufactured in higher-grade metal without the stamping. Thus the integrity of the engine’s design and originality was retained, albeit with 21st-century improvements for enhanced safety and reliability.

Sadly, the Indian company charged with transporting the D.H.9s had chopped up the airframe and wings for transit. The wings had all been cut in half in order to fit them onto their trucks, which could not accommodate the specially made crates supplied for that purpose. This meant that any of the timbers that might have been salvageable for the Duxford display aircraft had been ruined, since they couldn’t be spliced back together. More damage was done when the wings, horizontal stabilizers and control surfaces were crammed together in packing cases, smashing ribs and other internal elements. What the crosscut sections revealed, however, was that many timbers were little more than shells, their interiors eaten away by termites.

Time had also taken a toll on the fabric covering, but enough samples remained to facilitate study of its type, how it had been applied and even paint schemes. While there is a record of period color schemes, there were also variations, resulting in debate about the correct upper surface color for RFC and RAF aircraft. Known as PC 10 (Protective Covering Type 10), it was intended to be a dark brown made up of 250 parts yellow ochre to one part lamp black. The resulting shade varied with the addition of oils and cellulose, also depending upon the surface to which it was applied. In some cases there was considerable “color shift,” resulted in a dark green appearance. Paint samples from the Bikaner aircraft indicated their original paint was more green than brown. The undersides were unbleached fabric.

There were also questions about the roundel colors. For example, the white paint originally used appeared off-white, since modern titanium dioxide paints were not then in use. Even the method of paint application needed to be replicated: Markings were painted by eye and hand, as masking tape wasn’t used during WWI. Black pointed out that the finish was all-important: “It is a sad fact that third-party criticism after the aircraft is finished always centers on color schemes, which overall are less than 5 percent of the actual effort put into the restoration! In this case, we are 100 percent we got it right.”

Attention to detail has been the watchword in both of these stunning restorations, from sourcing the correct grade-A spruce from Canada to finding the authentic pattern of “Irish” linen from a supplier in Belgium. Black resolved a problem with one impossible-to-find component, frayed-edge fabric tape that covered the aircraft joints and stitching, when he discovered 1917 Ministry of Munitions documents describing the manufacturing process. It was just another example of the detective work involved in restoring these ultra-rare airplanes.

The static D.H.9, D5649, went on display at the IWM at Duxford in April 2007. The airworthy example, E8894, is on track to make its maiden flight at the end of this summer. The flying version will doubtless be operated for a short while by Retrotec’s sister company, the Duxford-based Historic Aircraft Collection. But Black doesn’t anticipate the bomber will be a long-term stablemate of the HAC. “For me, the fun is in the challenge of the research and rebuilding of historically unique airplanes like this, and in getting them flying,” he said. “When that is achieved, it is time to move on to the next project. Sadly, that often means parting company with old friends like the D.H.9 in order to make the next project possible.”

Our knowledge of WWI aviation technology has been enhanced by Guy Black’s drive and determination in tackling these challenging restorations. Both D.H.9s are valuable additions to Britain’s rich aviation heritage.

 

DH9: From Ruin to Restoration, by Andy Saunders and Guy Black, will be published by Grub Street after E8894’s first test flight.

Originally published in the September 2013 issue of Aviation History. To subscribe, click here.