Old Rhinebeck Aerodrome:
Technical Corner

AVRO 504K Trainer

Alliot Verdun Roe built his first airplane in 1908, a triplane powered with a 24 hp. French Antoinette engine. Becoming airborne on June 8 he was the first Briton to fly in England. This was the beginning of British aircraft design and manufacturing. Royal Navy contracts for biplanes followed in the next few years and his 5th biplane, named the 504, subsequently achieved true greatness in the history of aviation. A.V. Roe & Co. went on to earn every manner of success through WW2 and beyond. Mr. Roe died in 1958.

The Aerodrome finished restoration of its British built Avro 504K in August of 2007. It is powered with an original Le Rhone rotary engine of 110 hp. A complete rebuild of the airframe and engine was undertaken after a forced landing put it into our parking lot with considerable damage in the spring of 2003. Later that summer restoration was begun in western Pennsylvania by Fred Murrin, Rick Bennet and Al Cvelbar. Aerodrome staff trucked it back to Rhinebeck for final assembly, reworked all the engine accessories, and made its first flight on September 23rd, 2007.

The Avro is a large, double bay biplane, meaning it has two sets of vertical struts on each side to brace the long wings. Avro’s were used by the British during World War One as trainers and afterward as "barnstorming" airplanes, much as the famed Curtiss Jenny was used in America. (The Curtiss Jenny was also used to train British pilots in England during the war.) It has two cockpits in tandem, solo generally being from the front seat. Designed by A.V. Roe in February of 1913 as an enlarged and more powerful version of the successful Type 500, the 504 was an incredibly long lived design. It was a successful racer and long distance flyer before the war, notably winning races against supposedly faster monoplanes. It had an impact as a reconnaissance and bomber airplane in the early part of WW1 in that it performed the first organized bombing mission only 3 months after the war began. In November of 1914 two ships flew 100 miles to successfully drop bombs on the great Zeppelin hangars in Friedrichshaven in the Alps between Austria and Switzerland. Carrying only four 20 pound bombs each, they damaged one of the huge Zeps and destroyed the hydrogen generating plant to the astonishment of the Germans. But though its use as a combat aircraft was short it was so highly regarded that it became the designated training airplane of the war when in February of 1918 it was ordered to be adopted as "the sole purely training machine" that would replace over a dozen other types in training squadrons, even for initial flight instruction.

So well liked that it remained in production with various modern radial engines until the 1930's, it was the only prewar airplane design anywhere in the world to do so. Mr. Roe said he originally hoped to sell "a dozen or so," but instead production reached over 8300 during the war and so many more afterward that Avro had to build a new factory to handle the increased output. Eventual production exceeded 10,000. Significant orders were recieved from Canada, Australia and the US. In 1919 it served in Russia against the Red Army but a 504K captured in Bolshevik territory was disassembled and sent to Moscow. A young Nikolai Polikarpov prepared the working drawings that allowed the Red Army to build 737 units powered with the 120 hp M-2 Russian rotary engine. These were also used as flying school airplanes.

During WW1 it served as a test bed for every kind of rotary and fixed engine, and was the first airplane to have a universal type motor mount specifically designed to accommodate various engines. This was considered a breakthrough at the time, as engine mount plates were normally specific and structurally part of the fuselage of the aircraft to which they were fitted. Accomodating to modifications as it was, it is not then surprising that many served with sea floats and snow skis. Stripped of its wings and fitted with rotor blades it even became the core for the world’s first successful gyroplane, designed by Juan de la Cierva. It was therefore instrumental in the eventual design of the helicopter. Its success was largely due to wonderful handling characteristics;

"The AVRO 504 had an intangible charm. It felt right. This subtle question of feel made or marred an airplane of those days, and the controls of the Avro seemed ideally suited to its purpose. Takeoff was
simplicity itself. In an amazingly short distance the Avro became airborne and climbing at 65 mph. It could get out of quite small fields with a feeling of complete security. In level flight it flew with docile steadiness. In retrospect it's behavior seemed perfect. It was a thing that came together like a work of art comes together, by a sudden inexplicable harmoniousness of parts. It is the supreme example of the aeroplane as the work of art. Sir Alliot Verdon Roe achieved in the old Avro one of those works of genius whose essential quality is that they spring complete from their creator's brain." Harald Penrose, Chief Test Pilot, Westland Aircraft.

About 50 Avro's were imported into the US during 1921-22 by famed early pilots Clarence Chamberlin and Lawrence Sperry (Sperry gyroscope) to be used as barnstorming airplanes. A young Roscoe Turner attempted a 48 state tour in one of them. Like most of their counterparts of this early period, they disappeared in rotting wrecks across the farms and sod airports where they flew long ago. The Aerodrome's Avro was built in 1966 in England by Maurice Robinson (see photos on our website News section, October 2007) from factory plans and purchased by Cole Palen to replace the original Avro 504 which Cole had sold to Canada. It was flown at the Aerodrome for many years by famed aerobatic performer Stan Segalla, who still flies his Piper "Cub" in our air shows every weekend. Stan was billed as "One Shot Gatling" when he was terrorizing the skies, or more often trying to escape being shot down by the blood red Fokker Triplane flown by "The Evil Black Baron of Rhinebeck." Of course the machine guns are fakes, but the slinging of castor oil and an entire 400 pound engine that spins around its own crankshaft is very real. The flying characteristics of our Avro are solid and predictable. First there is a 3 step climb up the tall fuselage, then forward beyond the rear cockpit where some necessary folding is required to gain access to the front seat, all a reminder that the Avro is a towering airplane. The broad span and generous dihedral provide great lateral stability. The fuselage is unusually extended for a short nosed rotary engined airplane, longer than all its contemporaries at 29 ft. This allows good longitudinal stability. Performance is excellent with the powerful and friendly 110 hp. Le Rhone, an engine which is easy to throttle and behaves predictably. With a St.Croix climb propeller of 106" diameter the angle of climb is steep and the airplane accelerates and flies off very quickly. Though this is typical of many rotary powered airplanes it is a revelation in an airplane so weighty. The cruise speed is still quite good for a ship with many wires and struts, about 85 mph at 1150 rpms. Flying from the front seat there is little draft behind the compact Avro style windscreen and the slow turning propeller. You are sitting far forward in a snug cockpit with the nose only a short reach in front of you, but the long moment arms to the side and behind remind you that it is the largest showplane flying at the Aerodrome. The airplane responds slowly but deliberately about all axes and can be flown hands off. Rudder control with the comma shaped rudder (sans fin) is responsive but the great length of the slab sided fuselage again prevents quick results. Despite its bulk the angle of glide is very flat. Approach is done at the stately speed of 50-55 mph with the engine virtually blipped full off, as only the slightest power is necessary to control descent rate. It tends to float slightly in ground effect and one must be careful to approach and land short or the runway end is quickly in sight as the airplane is capable of rolling a long way on its own momentum since the tailskid offers little drag. Shutdown results in satisfaction that this imposing rotary powered airplane is not manhandled like the fighters, but rather majestically navigates through the air. It plays no tricks, and merits the name of a fine trainer.

Some may comment on the unusual color scheme on our Avro but both during the war and after, such color schemes were quite common. Though British combat airplanes were officially discouraged from sporting any but the standard military schemes, instructors at flight schools during the war had much greater latitude and many Avros in these squadrons wore exotic markings and colors apparently based on whim. After the war in barnstorming use, a veritable riot of color, markings and humorous accoutrements such as horns, clotheslines, and even chimneys (!) were added to Avros to attract the most possible attention for airshow and rides work. Our Avro is doing the same duty today so seems perfectly fitting that it be brightly painted.

If you missed this magnificent machine in 2007 be sure and come see it on the flightline and in action again during our airshow season.

Chad Wille, Chief Pilot.
Director of Maintenance, Old Rhinebeck Aerodrome.