Back to Marker Dedication Event

Historical Overview of the Main Line Airport

Originally a small farm dating from the 1700s, its pastures began to attract local aviators soon after World War I. By 1929 an entrepreneur purchased the farm, renaming it the Philadelphia-Main Line Airport, and began innovative design work on an early helicopter called an Gyroplane. Before relocating to larger quarters in 1932, routine test flights were being conducted across the Great Valley, and those pioneering developments from this field would have a world-wide influence on rotary-wing flight.

Fixed-wing aviation continued unabated during the Gyroplane period, and throughout the 1930s the popularity of the Main Line Airport (also called the Paoli Airport) knew no bounds. On almost any Sunday during that decade (weather permitting), airshows, air races, parachuting and glider events drew huge crowds from across the Delaware Valley.

Many hundreds learned to fly at this field, including a young man from Wayne named Charles "Pete" Conrad who, years later as a NASA astronaut in 1969, became the third man in history to walk on the moon. Also, beginning in 1940, the Main Line Airport taught scores of young men to fly under a government initiative called the Civilian Pilot Training Program. Volunteers from Villanova and West Chester State Teachers College became licensed pilots at no expense in return for their commitment to serve as military aviators if and when America went to war.

When America joined the fight in World War II, all non-essential aviation ceased. But a Civil Air Patrol squadron quickly established at the Main Line Airport in December, 1941 did much to support America's battle against German submarine attacks on coastal shipping along our mid-Atlantic coast a battle for which our military was initially unprepared.

Peace brought back a short-lived popularity in aviation at the Main Line Airport, but by 1950 the field was no longer financially viable. So when Bethlehem Steel Corp. purchased the airport for its eventual conversion to an immense limestone quarry, regular fixed-wing aviation ended in 1952. But an aviation engineer leased the old airport's hangars and other buildings to design and manufacture a small personal helicopter. While the endeavor ultimately failed for financial reasons, the flight innovations would again make rotary-wing history. And what became known as the Main Line Heliport would serve as a flight service center for the legendary Bell 47 helicopter.

In the fall of 1977 a disastrous hangar fire finally ended a half century of aviation in the Great Valley, and enabled the major expansion of the Great Valley Corporate Center.

For more in-depth information, there are several very informative artcles in our History Quarterly online archive:

Selected Main Line Airport Photographs

Image 001 - An aerial image from 1929 shows Swedesford Road snaking east down the Great Valley toward Tredyffrin Township, Chester County, PA. The 80-acre dairy farm in the center, farmed since the 1700s, was called Twin Brook, and owned by William Devaney. A discerning look at the corner of one of the pastures reveals a biplane at rest belonging to William's son Charles — a portent of a half-century of aviation to come.

Image 002 - Soon after World War I, Charles purchased an unassembled, war-surplus Curtiss JN-4 Jenny bi-plane. Constructing the plane in the barn of his father's Twin Brook Farm, he taught himself to fly the plane between 1920-22, fearlessly taking off and landing from his father's pastures. Devaney became the first in Chester County to own and fly an airplane. In this 1930 image, Charles stands beside his green Waco 10 bi-plane, ready to fly with other local aviators from the farm's pastures.

Image 003 - In 1929, Devaney sold Twin Brook Farm to a businessman and inventor named E. Burke Wilford from Merion, who deeded the farm as the Philadelphia-Main Line Airport, Inc. Wilford planned to create a variation of a helicopter predecessor called a gyroplane, and in December 1930, began ground testing a strange-looking twin-propeller, single-seat, open-cockpit ship called “Configuration No. 1.” Discovering that his four overhead rotating blades were an insufficient substitute for wings, Wilford added wing panels to his “Configuration No. 2,” and on August 5, 1931 that ship completed its maiden flight, becoming the world's first rigid (or hingeless) rotor gyroplane with cyclic pitch variation. These pioneering developments would have a world-wide influence on rotary-wing flight.

Image 004 - After almost 200 flights over the airport and the Valley in “Configuration No. 2” during August 1931, Wilford then created a much more powerful “Configuration #3” with a radial engine, as shown in this August 1932 image outside the large barn modified to serve as a hangar and work space (note PAOLI painted on the roof of the barn as a visual aid for passing aviators). Encouraged by his innovative successes, Wilford leased a much larger facility near Philadelphia and moved his development operation there in November 1932. However, Wilford retained ownership of his Philadelphia-Main Line Airport until 1936, and negotiated for local pilot John Jacob to lease the field for fixed-wing flying.

Image 005 - Throughout Wilford's gyroplane development at the Philadelphia-Main Line Airport, the former Great Valley farm remained open to general aviation. Here, Charles Devaney opens the throttle on his Waco 10 biplane at what was informally being called the Paoli Airport. The 1930s saw no bounds to local interest in fixed-wing aviation at the field, and on almost any Sunday during that decade (weather permitting), air shows, parachuting, air races and glider events drew tremendous crowds from across the Delaware Valley.

Image 006 - In June 1936, Charles Devaney, with friends and fellow aviators Nicholas Morris and Morton Caldwell, incorporated Demorr Aeronautical Corporation, and began providing flying lessons and aviation services at the field. In April 1937, Demorr acquired their first Ryan ST-A, shown here in the Demorr hangar, one of only 73 built through 1938 and still considered one of the classic airplanes of all time. In April 1938, Demorr became the East Coast distributor for the world famous Ryan Aeronautical Company of San Diego.

Image 007 - In November 1936, Wilford sold his airport to the famous Curtiss-Wright Aviation Co., and they hired A. L. Schachterle as their manager for the Main Line Airport. In this 1938 image, despite the frigid winter morning, pilots were out early and good flying was expected.

Image 008 - One of the most notable women at the Main Line Airport was Joan King, who started taking flying lessons at the field in 1935 when she was 17. She earned her private pilot's license that September a day before she left for Stanford University to pursue a chemistry degree. But aviation was in her blood. In May 1938, a campaign called National Air Mail Week was held nationwide to promote America's air mail service, and five pilots from the Main Line Airport, including Joan, were selected to fly the mail during this promotion. Joan was the only female participant from Pennsylvania, and during the campaign she flew her own red Fairchild 22 monoplane which she hangared at the Main Line Airport. By the end of 1938, Joan King had been cited as one of the forty-four outstanding female pilots in America. In this late 1930s image, Joan King is shown at the Main Line Airport refueling a Taylor E-2 Cub.

Image 009 - With Swedesford Road running horizontally, this 1939 image looks north at the Main Line Airport's buildings and well-defined grass runways. With the prevailing winds blowing from the northwest, it was typical for a pilot to make a final approach into the airport over the telephone wires along Swedesford Road and land onto the NW runway.

Image 010 - In April, 1940, with the looming threat of a world at war, Curtiss-Wright Aviation Co. sold the Main Line Airport to Demoor Aeronautical, with Charles Devaney as its president. Two months later, construction began on a modern 100' x 60' hangar. The airport, by now accommodating 22 planes in residence, was reported to be "one of the busiest and best-equipped airfields of its size in the entire Commonwealth of Pennsylvania." In this classic image from the high summer of 1940, the Main Line Airport spreads out with its new hangar now fully roofed.

Image 011 - If war was coming, the United States needed trained pilots. Beginning in 1939 the U.S. government began sponsoring a Civilian Pilot Training Program, established as a civilian program but its potential for national defense was undisguised. The program paid for a 72-hour ground school course followed by 35 to 50 hours of flight instruction. Volunteers would become licensed pilots at no expense to them in return for their commitment to serve as military aviators if and when America went to war. Beginning in the spring of 1940 and continuing into 1942, the Main Line Airport conducted flight training for scores of young men from Villanova College and West Chester State Teachers College. In this image, with Demorr's Ryan SC-W in the foreground, six Piper or Taylorcraft airplanes used as CPTP flight trainers can be seen in August 1940.

Image 012 - In the days after the attack on Pearl Harbor, a Civil Air Patrol squadron was quickly formed at the Main Line Airport. The CAP had been created on December 1, 1941, and now volunteer pilots and mechanics were actively recruited for national defense. For the first year-and-a-half of World War II, the Main Line Airport served as a crucial logistics center supporting Coastal Patrol bases as the Civil Air Patrol helped America's military spot marauding German submarines along the mid-Atlantic coast. The Paoli squadron also provided flight crews to Coastal Patrol squadrons as far away as Virginia. In this image, taken in the summer of 1942, three unidentified members of the CAP Paoli squadron stand ready to do their duty, with the farmhouse/flight operations center of the Main Line Airport in the background.

Image 013 - With the end of the war came a pent-up surge of interest in civilian aviation, encouraged by the G.I. Bill of Rights that would help pay for flight training. Demorr Aeronautical had become a Piper dealer in December 1945, and received a Cessna franchise in 1947. And to streamline the laborious job of aircraft fueling, Demorr installed a state-of-the-art underground fueling station at the Main Line Airport. This 1947 photo shows Demorr vice-president Nick Morris refueling a Piper J-4 Cub Coupe at the new station.

Image 014 - Hundreds had learned to fly at the Main Line Airport before the war, including many young men who would show up at the field willing to do odd jobs in exchange for a flying lesson. In 1946, another of those fellows showed up at the field this one a bright but wild kid from Wayne, PA named Charles Conrad. Charles learned to fly from instructor Nick Morris. But after a juvenile stunt while flying, Nick refused to 'solo' Charles because he thought him too reckless. Conrad was finally flight certified by the Princeton, N.J. Flying Club. Years later Charles “'Pete” Conrad went on to become a NASA astronaut, and in 1969 became the third man in history to walk the moon's surface. Morris and Conrad remained friends until Nick's death in 1991.

Image 015 - By 1950, the postwar aviation boom had evaporated, and Demorr Aeronautical was barely “making ends meet.” It was in that year that Bethlehem Steel Corp. paid Demorr to drill test bores which confirmed an extremely high-quality limestone substrate beneath the airport. Bethlehem needed limestone for making steel, and offered to buy the property for future use as a quarry. Demorr agreed to sell their airport, and to vacate the field by the summer of 1952. An aviation chapter had ended, and routine fixed-wing flying in the Valley ceased forever.

Image 016 - As one chapter ended, another began. In November, 1952, a helicopter designer named Haig Kurkjian approached Bethlehem to negotiate a year-by-year lease of the now-abandoned airport's buildings and hangars, and a small portion of the land. Haig's wanted to develop and market a revolutionary personal helicopter, and after five years of research and testing, Kurkjian's company, Haig-K Aircraft Corp, successfully completed the maiden flight of his 2-place HK-1 prototype in November 1957 at the former Main Line Airport.

Image 017 - On a frigid morning in January 1958, with the Holland farm in Tredyffrin Township in the distance, Haig Kurkjian is shown piloting his HK-1 to demonstrate the ship's reliability and flight characteristics to a group of potential investors. Kurkjian had successfully created the world's first helicopter to have all the controls in a “steering wheel,” enabling the pilot to move up, down, turn, hover, all by means of a single control wheel. It was also the first helicopter to utilize a multi-vee belt drive for both main and tail rotors. Regrettably, Haig-K was unable to raise sufficient capital to certify his ship, and for these financial reasons the aircraft was never produced commercially.

Image 018 - In this 1958 aerial image of the former Main Line Airport, looking north across the bisecting Swedesford Road, one spots the white farm house/operations building with its surrounding Linden trees, and the large 1940 hangar and three small tee-hangars. The old PAOLI barn had been ruined during Hurricane Hazel in October 1954, and stood mostly demolished. The new Burroughs Corporation plant, with its distinctive radar tower and large parking lot, can be seen across Swedesford Road.

Image 019 - When Kurkjian's HK-1 project died a financial death, Haig-K Aircraft Corp. was contracted by Bell Aircraft to develop a new variable diameter rotor for future Bell rotary-wing aircraft. In 1963 Haig-K was licensed as an FAA-approved repair station for the legendary Bell 47 helicopter. This photograph from 1971, in which Haig's son Daniel is testing a HK experimental ultralight, is the last known to exist showing the structures of the former Main Line Airport. The tee-hangars (on left) burned to the ground in 1974, and the large hangar was consumed by fire in 1977. Haig-K Aircraft Corp, had occupied the former airport for 26 years, and its demise in 1978 opened the way for development of the Great Valley Corporate Center.


Page last updated: 2017-09-06 at 17:42 EDT
Copyright © 2006-2017 Tredyffrin Easttown Historical Society. All rights reserved.
Permission is given to make copies for personal use only.
All other uses require written permission of the Tredyffrin Easttown Historical Society.