The Philadelphia Region:
The Cradle of Rotary-Wing Aviation in the US
By Robert Beggs
Excerpted from the Sept/Oct 2018 issue of Vertiflite [pdf]
The City of Philadelphia, located in the beautiful Delaware Valley of Pennsylvania, is most notable for its rich history, its lawyers, its cheesesteaks and more recently its Super Bowl winning professional football team. In 2019, Philadelphia will again be center stage as it hosts the Vertical Flight Society’s Forum 75! Celebrating the Society’s Diamond Anniversary in Philadelphia is quite fitting and a homecoming of sorts for our Society. Philadelphia is undeniably the cradle of rotary-wing aviation development in the US and was the location of the inaugural meeting of rotary-wing aviation pioneers on April 3, 1945, at the Engineers Club of Philadelphia on Spruce Street, just a few blocks from where Forum 75 will be held.
The aviation history of Philadelphia could fill volumes, but this short summary will help you to appreciate how it all began and why we still say there are more “rotorheads” in Philadelphia than anyplace else in the world.
In 1928, Harold Pitcairn imported a Cierva C.8W Autogiro, which made the first rotary-wing flight in America on Dec. 18 in a small town just north of Philadelphia named Bryn Athyn. The next year, Pitcairn acquired rights to Cierva’s patents and formed the Pitcairn-Cierva Autogiro Company of America. The company began manufacturing and operating Autogiros from Pitcairn Field in Willow Grove, Pennsylvania. In 1931, the Pitcairn PCA-2 became the first certified Autogiro in America. Pitcairn and his associates received the 1930 Robert J. Collier Trophy from President Herbert Hoover in April 1931 — pilot James G. “Jim” Ray landed a PCA-2 on the South Lawn of the White House for the ceremony. Between 1930 and 1940, Pitcairn Aviation was issued 270 US patents.
In 1929, the brothers W. Wallace Kellett and Rod Kellett formed the Kellett Autogiro Corporation and began manufacturing Autogiros, under license from Pitcairn-Cierva Autogiro Company in Upper Darby, Pennsylvania, and later near the Philadelphia Municipal Airport. In 1934, the Kellett KD-1 achieved first flight and was sold to the US Army Air Forces over the next seven years as the first US military rotorcraft to enter into service. In 1939, Eastern Airlines flew the KD-1 Autogiro to deliver mail five times daily from Philadelphia’s 30th Street Post Office to the Camden, NJ, Central Airport.
Between 1928 and 1931, inventors Gerard Herrick and Ralph McClarren of the Franklin Institute in Philadelphia developed the world’s first convertiplane that flew both as a fixed-wing aircraft and an autogyro. The unique craft was a technical marvel for its time, being able to convert inflight. The HV-2A Vertaplane, made its maiden flight in 1937 at Boulevard Airport in northeast Philadelphia; it soon demonstrated the world’s first of more than 100 conversions from fixed-wing to rotary-wing flight.
The year 1938 was an inflection point in the history of rotary-wing development. In a district where Harold Pitcairn’s Autogiro business created scarce jobs, US Representative Frank J. Dorsey from Philadelphia proposed $2M for the War Department to purchase Autogiros for test and research. However, the Navy was not interested because of the craft’s limited speed and endurance, and the Army was disappointed with the Kellett Autogiros they operated. Dr. Alexander Klemin, Dean of New York University’s Guggenheim School of Aeronautics, was an influencer advocating funding for “any aircraft with a rotating wing.” He had been impressed by the public demonstrations of the Focke-Wulf Fw 61 helicopter in Germany.When the Dorsey-Logan Bill became law in June 1938, it was designated for research, development, purchase and testing of “rotary-wing and other aircraft.”
The Franklin Institute of Philadelphia hosted the “First Annual Rotating Wing Aircraft Meeting” in October 1938. It was described as “the first free discussion in this field of science open to all engineers in the aircraft industry.” The event was attended by many of the aforementioned pioneer inventors and engineers of the fledging vertical lift industry, including Dr. Klemin. Flight magazine that year noted that the Rotating Wing Aircraft Meeting was held in Philadelphia because, “this is the town in which practically all the rotary-wing activity in the United States takes place.”
W. Laurence LePage teamed up with fellow autogyro engineer Havilland Platt to form the Platt-LePage Aircraft Company in Eddystone, Pennsylvania, and the team began designing an experimental helicopter, the PL-1.The Platt-LePage Aircraft Company won an Army Air Corps competition to build the XR-1 helicopter using funds provided by the Dorsey-Logan Bill. After many developmental issues, however, the program was cancelled in April 1945, by which time the Army had already been using the much more capable Sikorsky R-4 for more than a year. However, ex-Platt-LePage engineer Robert Lichten went to Bell Aircraft (as it was then known) and developed the tiltrotor idea into the Bell XV-3.
Frank Piasecki began his career as a young engineer at Kellett and Platt-LePage while he attended school at the University of Pennsylvania in Philadelphia. While still in college, he founded the P-V Engineering Forum with a classmate, Harold Venzie. In 1943, Piasecki’s group designed the PV-2, a single-seat, single-rotor helicopter. Piasecki became the second person to design a successful helicopter in the US, and the first person to be issued a federal helicopter-specific license.
In 1945, the P-V Engineering Forum determined that a tandem rotor configuration would best meet the US Navy requirement for a helicopter that carried at least a one-ton payload. The XHRP-1 design was completed in three months in Sharon Hill, Pennsylvania. The Navy ordered 10 HRP-1 helicopters in 1946, and another 10 in 1947. Production was established at a new facility in Morton, Pennsylvania, and P-V Engineering Forum became the Piasecki Helicopter Corporation. The successful tandem rotor designs would form the basis of what is now Boeing Vertical Lift in Ridley Park, Pennsylvania.
In 1931, Arthur Young began experimenting with rotary-wing models at his home in Radnor, Pennsylvania. Later, he bought a farm near Paoli to work on larger models. Skeptical of rotor theories espoused at the 1938 Rotating Wing Aircraft Meeting at the Franklin Institute, Young presented a paper entitled “A New Parameter of Lifting Rotors” at the second meeting, held at the Institute in 1939.
In 1941, Young and his friend Bartram Kelley flew their model helicopter in and out of their Paoli barn by tethered remote control. Later that year, they demonstrated the stability of the model with a teetering rotor and “stabilizer bar” to Bell Aircraft in Buffalo, New York, leading to the creation of the Bell Model 30. The design became the signature rotor system for Bell helicopters, continuing into the 1980s.
These are but a few of the many talented engineers, craftsmen and pilots who shaped the early days of rotary-wing aviation in the Delaware Valley. Their accomplishments went on to influence an entire industry, and that legacy continues to this day. The Delaware Valley remains home to four major design and manufacturing centers including: Boeing Vertical Lift, Leonardo’s AgustaWestland Philadelphia Company, Piasecki Aircraft Corporation and Lockheed Martin/Sikorsky’s Coatesville plant.
This is the history that is preserved and celebrated every day at the American Helicopter Museum & Education Center in West Chester, Pennsylvania. It is only fitting then that the Vertical Flight Society’s 75th Annual Forum & Technology Display is located on the hallowed ground that gave birth to America’s rotary-wing aviation industry.
We look forward to seeing you in Philadelphia!
About the Author
Bob Beggs is a co-founder and trustee of the American Helicopter Museum & Education Center, in West Chester, Pennsylvania: www.americanhelicopter.museum