Flight of the Pterodactyl

Photographs are fragile things, and some of the ones I come across have almost succumbed to age and elements. It's always a joy to find a unique one and digitize before it completely crumbles to dust, and such is the case with this photo, of the very unique 1932 Westland-Hill Pterodactyl Mark V.

A lot of people died in stall-spin-crash accidents in the early decades of aviation, making the idea of a safe, stall-proof airplane something many inventors strove for. (It still is a goal today - for instance, that's the primary reason Burt Rutan pursued his early canard designs). British inventor Captain Geoffery T. R. Hill believed that the answer lay in the concept of a flying wing, as opposed to the more traditional aircraft configuration. Hill was, no doubt, influenced by the earlier development of the Dunne flying wings, which sought the same safety goals, and which ultimately led to a Curtiss attempt at developing a safe "everyman's" airplane in 1930 (See our April blog post The Birth of the American Flying Wing).

Hill began small, and called his series of aircraft the Pterodactyl. The first one was initially tested as a glider in 1926, and then modified to incorporate a 30 hp engine. The British Air Ministry was suitably impressed, and offered to fund the development, as long as Hill worked through Westland Aircraft, where he then hired on. Subsequent versions, beginning with the Westland-Hill Pterodactyl Mark I, refined the concept through the beginning of the 1930s, but all were relatively small, low-powered aircraft. 

This all changed with the Mark V. The Air Ministry specified a fighter plane based on the concept, to be powered by a huge (given the size and weight of the plane) 600 hp Rolls Royce V-12 Goshawk engine. The tailless design allowed for a defensive machine gun turret to be mounted behind the pilot (missing from this photo), and there were plans to build a complementary version with a pusher prop and a turret in the nose.

Unlike the previous models in the Pterodactyl series, the Mark V included a stubby, straight sesquiplane lower wing. Roll and pitch control was through elevons and yaw control was through wingtip fins, each of which could only move outward. Initially, the fins were almost all rudder, but this design evolved to include a lower fixed fin.

The contract was awarded by the Air Ministry in 1931 with serial number K2770 being assigned to the project, and work started in 1932. By fall of that year, the plane was put through its paces in taxi tests and during one of these, the Pterodactyl hit a bump in the turf which caused the left wing to crumple due to a miscalculation in the structural stress analysis. By the time the wing structure was redesigned, another sixteen months had gone by, and the plane finally took its maiden flight in May, 1934.

The Mark V failed to impress the Air Ministry, however. It suffered from excessive pitch sensitivity inherent in flying wing designs, and was not nearly as fast as had been expected, turning in a top speed of only 165 mph. The RAF's Hawker Hart light bomber was a good 20 mph faster than this supposed fighter. The nose and engine were then extended forward in order to try to solve the pitching issues, and additional vertical fences were added to the bottom of the wings. The problems continued, however, and work on the Mark V was finally cancelled, after which plans for larger versions, including a twin-engine sea plane and a four-engined airliner capable of transatlantic flights, were abandoned.

YouTube has some footage of the earlier Mark 1A, which is the only plane of the Pterodactyl to survive, now preserved in London's Science Museum.

Waldo Waterman's Whatsit

This has got to be one of the most creative names of an aircraft: people showing up to see Waldo Waterman's novel flying wing design, they'd invariably ask "What is it?" Whether he was intrigued or annoyed with the constant question isn't clear, but what is know is that Waterman named the plane the Whatsit.

Original Caption: "A New-Type Plane Makes Debut": Because everyone who has
seen it fly has gasped, "What is it?", Waldo D. Waterman, ex-Air Mail pilot and
aeronatuical veteran of Santa Monica, California, named his unique new flying
wing plane just that, "Whatsit". The novel two passenger tailess craft, which
travels more than one hundred miles an hour, powered with a small radial air
cooled engine, appears to be one answer to America's need for a low priced,
simply and economically constructed everyman's flivver plane. Photo shows
Waldo D. Waterman in cockpit of his new plane at the Grand Central Air
Terminal, Glendale. 2/17/34

In the late 1920s and early 1930s, two men, Jack Northrop and Waldo Waterman, were independently working on the concept of a flying wing aircraft design within but a few miles of each other. While Northrop was doing his work at Burbank, Waterman set up shop nearby at the Los Angeles Metropolitan Airport, what is today known as the Van Nuys Airport.

The two designers had very different motives for pursuing such a radical design: Waterman thought that the configuration held promise for a "flivver", a small every-man's airplane, like a car for the sky, and just as easy to operate. Jack was driven by the desire to refine aircraft design to achieve the lowest possible drag, and he saw a tailless wing as the ultimate solution to that problem. Northrop's design first flew in 1928 (we'll be covering that in a future post), and he went on to fame. Waterman's wing flew in 1932, and though his designs evolved over the next few years, he was never able to come up with the breakthrough design that would provide him with fame and the common man with an airplane that would be as ubiquitous as the automobile.

Waterman had worked in various locations around Southern California for years. In 1910, while based at North Island, San Diego, he designed a variation on a Curtiss pusher that included an innovation where a pull of a lever folded the planes wheels out of the way so that it could land on its skids, making it quite possibly the first retractible landing gear in aviation history.

After WWI, Waterman found work in Glendale custom-building first a JN-4 Jenny and then a Packard-LaPere for millionare L. C. Brand. While there was a huge war surplus of hastily-assembled Jennys available on the market, Waterman found a small niche for customized and precision-built - and thus quite a bit more expensive - aircraft. From these, he acquired a reputation for producing aircraft that were highly reliable.

Construction on the Whatsit, NX12272, started in 1929 and included a number of notable design innovations, including the first documented use of "elevons" for both roll and pitch control. A trim plane, which was adjustable on the ground, protruded on short booms in front of the nose. The wings featured a 15 degree sweep, and the tips supported small rudders. Unlike most planes of the era (but just like Northrop's AE-1 wing), the Whatsit used tricycle landing gear complete with a steerable nose wheel.

Work on the aircraft was completed in May, 1932, and Waterman commenced taxi tests at LA Metropolitan. After several abortive flight attempts which ended in several minor incidents with the aircraft, Waterman finally got the plane airborne in July, although he quickly found that it was somewhat unstable in pitch. This was due to the close-coupled vertical relationship between the pusher engine's thrust line and the wing's center of pressure (this relationship affects an aircraft's longitudinal static stability, and while it is less noticable in traditional fuselage/tail aircraft designs, it is especially critical in tailless swept flying wing designs; even modern designs struggle with such problems, and the complex relationships of center of pressure and thrust line, as well as pitch control moment led to the crash of the Lockheed RQ-3 Dark Star, as well as pitch instability issues with Boeing's Phantom Ray, which only flew twice before being relegated to storage).

In October 1932, the aircraft was almost destroyed in an landing accident (Waterman wasn't flying at the time). Discouraged, Waterman shelved the project and took a job as an airmail pilot for Transcontinental & Western Airlines. Then, in late 1933, when the US Bureau of Air Commerce's director Eugene Vidal initiated a competition to encourage designers to come up with safe, reliable and inexpensive aircraft that the average person could fly, essentially Model-Ts of the air. Vidal stated, "that if some manufacturer could produce a foolproof airplane in large quantities and market it at a low figure, a new phase of the aircraft industry could be developed"

Waterman realized that a number of aspects of the Whatsit design fit the requirements of the Bureau's challenge, and so flight testing resumed in Feburary 1934, with only minor modifications. At some point, he landed at Grand Central where this photo was shot (the Whatsit was powered by a Kinner radial engine, and Kinner was based at Glendale). He even received mention in the May 1934 issue of Popular Science. 

However, the pitch instability remained, and it quickly became apparent that such a sensitive aircraft was not consistent with what was needed for a novice pilot. Thus, Waterman completely redesigned the plane, adapting a high-wing design (a change that solved the pitch stability problem by putting the wing's center of pressure more in line with the engine's line of thrust), which became the Arrowplane, produced under a the auspices of the newly incorprated Waterman Arrowplane Corp.

Ultimately, out of the 30 entrants in the Bureau's contest in 1935, the Arrowplane was one of only two that took prizes (depending on the source of information, either a Pitcairn AC-35 autogyro or a Hammond Y was the other prize winner). Later, the Arrowplane was refined into the Arrowbile, and then the Aerobile. However, despite the Bureau's romantic visions of the future direction of the aviation industry, neither of these...or any other "flivver", for that matter...made it into large-scale production. WWII and other modern realities pretty much killed the idea of a flying car in every garage. Waterman himself passed away in 1976, in relative obscurity.

The Whatsit, surprisingly, has survived in the collection of the Smithonian's Air and Space Museum, and what's left of it can be seen here.

America's First Rocketplane

Acme Telephoto wirephoto with an embedded caption. This is the only known
photo of the MX-324 during powered flight, although there are a number of images
extant that were taken during the initial glide testing. Back "in  the day", it was
fairly common for photos to be retouched (yes, even long before Photoshop became
a verb!), and this one is quite heavily retouched, so much so that the caption writer
had to note that "this is an actual photograph". The actual flight took place on July
5, 1944, so presumably this dateline is February 13, 1946.

In 1942, Jack Northrop began to pursue one of his most persistent dreams: to perfect the flying wing. This version, the XP-79, was to be a rocket-powered flying-wing fighter aircraft. To test some of the concepts, he first built three MX-324 test aircraft. One of these was later powered by a rocket motor built by Aerojet Corp. In order for the pilot of both the XP-79 and the MX-324 to withstand the anticipated high-G loads, he would fly lying prone.

The first flight of a MX-324 glider took place on October 2, 1943, at the remote Harper Dry Lake, not far from today's Edwards AFB and Mojave Air and Space Port, where modern rocket plane development is underway. The small aircraft were towed aloft behind a P-38 Lightning. There were several incidents that seriously jeopardized the program. During one of the glide test flights, the pilot pulled the wrong handle when it came time to jettison the tow rope...he had grabbed the escape hatch release by mistake! The aerodynamic changes that this caused led to severe buffeting, but he was able to land safely. On another test flight, one of the MX-324s was lost when the tiny glider got caught in the P-38's prop wash, and entered a spin. When the pilot recovered, he was inverted and lying on the ceiling, unable to reach the flight controls. Instead, he bailed out and parachuted to safety. The -324 continued its gliding descent inverted and was damaged beyond repair on hitting the lakebed.

The engine used on the MX-324 was a 200-pound-thrust Aerojet XCAL-200 liquid-fuel compound rotary rocket, which actually was comprised of several smaller rockets that rotated about an common axis. The fuel was monoethylaniline and red fuming nitric acid.

The first powered flight of the MX-324 took place on July 5, 1944 (some accounts state that it was on July 4, other say it was July 22; date confusion is not surprising, since even the photo of the then-top-secret aircraft wasn't release for two years!) with Northrop test pilot Harry Crosby at the controls. The plane was towed to 8,000 feet, and Crosby then release the tow rope and ignited the engine. The flight lasted only four minutes, 3:30 under rocket power, but was considered a success.

Just over a year later, on September 12, 1945, Harry Crosby was at the controls of the XP-79 prototype when it went out of control during its maiden flight. He was killed while trying to bail out.

Historian's note: there's a lot of confusion about this plane, as would be expected from a secret project conducted during this time period. Besides the variation of first flight dates, even the model designation is in dispute. Northrop historian Ira Chart states that the MX-324 was the unpowered glider and the MX-334 was the powered version. Author Andreas Parsch states the opposite. It is clear, though, that in the official news release accompanying our photo, two years after the flight the powered version was being referred to as the MX-324.

Update: After this posted this morning, I received the following note from one of my Mojave rocket plane friends: "Well... America's third rocketplane, but arguably America's first military rocket plane, as the caption claims. In 1931, William G. Swan flew a rocket glider at Bader Field in Atlantic City. In 1941, Lt. Homer Boushey took off in a JATO-equipped Army Air Corps Ercoupe from which the propeller had been removed. The MX-324 was probably the first airplane designed from the outset for rocket power." Thanks, Randall!