6th April 2015 (Content added 24 December 2018) | Lakeland, Florida. The current (April 2015) issue of Air Force Magazine contains a photograph on the first two pages (Sac’s Heyday, pages 50-51) of a U.S. Air Force Boeing B-47 Stratojet ‘leaping’ into the air with the supplemental thrust generated by RATO (Rocket-Assisted Takeoff).
A little known fact is that RATO (in the past often referred to as JATO or ‘Jet-Assisted Takeoff’) ascents became practicable in America only after successful U.S. Army Air Corps (USAAC) tests in August 1941 demonstrated the safety and efficacy of the augmenting power source.
The airplane selected for the RATO studies was none other than the ERCO (Engineering and Research Corporation) Ercoupe. As Fred E. Weick, the Ercoupe’s designer, and James R. Hansen noted (page 188) in From the Ground Up: The Autobiography of an Aeronautical Engineer, the “Ercoupe established a special sort of record: it made the first jet-assisted take-off (JATO) airplane flight in history.” With 2015 marking the 75th anniversary of the Ercoupe 415-C’s debut (75 Coupes for 75 Years! Ercoupe Owners Club, Coupe Capers, January 2015, page 1), it is only fitting that this small, safe aeroplane’s contributions to military aviation be recalled.
In 1935, Frank J. Malina was a graduate student who was interested in rocket propulsion. He and others at the Guggenheim Aeronautical Laboratory of the California of Technology (GALCIT) realized that propeller propulsion of aircraft was reaching insurmountable obstacles as rotating speeds neared the speed of sound. The revolutionary gas turbine and rocket engine seemed to offer a way around the limitations. Therefore, Malina and three colleagues formed the GALCIT Rocket-Research Project.
It was in December 1938 that Malina issued a report for U.S. Army Air Corps commander Henry ‘Hap’ Arnold and Army Air Corps Research at the National Academy of Sciences (NAS). During the summer of 1939 NAS gave GALCIT a contract for JATO research. The military desired the capabilities for swifter level-flight speeds, faster rates of climb and shorter and quicker takeoffs.
Devising methods of attaining these goals was the focus of the studies. In January 1941 CalTech’s Clark Millikan and Homer J. Stewart completed calculations which indicated that JATO should result in a significant reduction in takeoff roll distance and an increase in climb performance. Their work continued.
Elsewhere, by May 1941, Britain and Germany had already conducted tests. The British had developed and tested a form of RATO to counter the threat posed by Luftwaffe Focke-Wulf Fw 200 ‘Condors’ (the Condor / Kondor was also known to the Allies as the ‘Kurier’) Focke-Wulf Fw 200 long-range patrol bombers. The planes possessed a phenomenal range of some 2,000 nautical miles, and once Nazi Germany had captured France the Condors began operating from airfields in western France.
The Fw 200s tracked British and British Commonwealth merchant and naval vessels in the Atlantic Ocean well beyond the range of Royal Air Force fighters. At the time the Royal Navy did not possess escort aircraft carriers, and the Condors were raiding commerce on the high seas, attacking convoys and feeding Kriegsmarine (Nazi Germany’s navy) U-Boats with information that was leading to an alarming number of sinkings.
To quickly counter the Condor threat, the Admiralty devised and developed fighter catapult (Catapult Aircraft Merchant Ship — ‘CAM’) ships, which were converted freighters that carried a Hawker Sea Hurricane Mk. I (referred to commonly as ‘ a Hurricat” or “Catafighter’) fighter. Convoys containing CAMs were initially restricted to North American to United Kingdom routes, and Sea Hurricane maintenance was performed by the Royal Canadian Air Force at Dartmouth, Nova Scotia.
When German bombers were sighted by escorting Royal Navy or Royal Canadian Navy warships, a Royal Air Force pilot would be rocketed into the air to engage or drive off the bomber. After encounters the aviator bailed out or ditched in the sea near ships of the convoy and hopefully be rescued. The system enjoyed some success as seven enemy planes were tallied as being downed by Hurricats. RATO had proved to be practical and effective.
Meanwhile, in the United States, theoretical RATO studies progressed. Clark Millikan had previously made the acquaintance of Fred Weick and was familiar with his work on the Ercoupe design. Millikan chose the Ercoupe for the scheduled August 1941 U.S. Army Air Forces (USAAF) tests because, as Stanley G. Thomas states (page 65) of the “Ercoupe’s small size, tricycle gear, and easy handling characteristics. . .”
20th Century Aviation Magazine Ercoupe 415-C pilot and staff photojournalist John Stemple remarked, “The revolutionary Ercoupe was an excellent choice. Visibility forward is excellent due to its low profile and tricycle undercarriage, and the airplane is easy to fly and steer on the ground.”
Air Materiel Command at Wright Field, Ohio (near Dayton), obtained an Ercoupe equipped with rudder pedals and Fred Weick supplied aircraft structural data for the mounting of the RATO units. USAAF Captain Homer A. Boushey, Jr., who was assigned to Wright Field, was ordered to March Field, California, as project test pilot. RATO units were to be located under both wings and mounted on racks.
Ground tests commenced and airborne firing testing subsequently took place at an altitude of about 8,000 feet. A fairly detailed description (Rocket-Powered Ercoupe, pages 64-66) of the Ercoupe RATO tests may be found in Stanley G. Thomas’ book The Ercoupe. Finally, on 6 August 1941 three RATO rockets were installed beneath each wing. Captain Boushey climbed to the prearranged altitude and engaged the boosters. Fred Weick and James R. Hansen in From the Ground Up: The Autobiography of an Aeronautical Engineer noted that the RATO rockets fired as the airplane’s internal reciprocating powerplant was running. At that moment he became the first American to fly under rocket power, and. the mild-mannered Ercoupe had simultaneously made military history.
On 12 August Boushey successfully completed the first RATO takeoff. Stanley G. Thomas indicates in The Ercoupe that the “RATO assist had cut the Ercoupe’s takeoff roll by half, from a normal 580 feet to 300 feet. It had reduced takeoff time from 13.1 seconds to 7.5 seconds.”
On 23 August 1941 civilian technicians and USAAF mechanics removed the Ercoupe engine’s prop. Twelve RATO rockets were installed, six beneath each wing. With a pickup truck towing the Ercoupe until the airplane reached 25 miles per hour. The Ercoupe was thrust into the air and ascended under rocket power. After a few seconds the RATO boosters expended their fuel and Boushey safely performed a dead-stick landing.
A color film record of several of the key 1941 tests exists. “Before the U.S. — and ERCO, and its people — entered the war, the Ercoupe had already made its first contribution to the war effort,” Thomas notes.
The Ercoupe’s short-field takeoff capability is impressive even without RATO. The performance provided by the GALCIT boosters was incredible. The fruits of the USAAF flight testing successes were that American military aircraft in World War II and for decades afterward utilized RATO or JATO when additional thrust was needed for takeoff.
With regard to U.S. Military uses of Ercoupes, it is documented that the USAAC/USAAF did buy and evaluate a few ‘Coupes.’ One 415-C (Serial Number 41-18875) was ordered on 4 January 1941. It entered service on 26 February 1941. The sample was evaluated as an observation aircraft and designated YO-55.
Two others (Serial Numbers 41-25196 and 41-39099), the first entering service on 8 December 1941, powered by Franklin engines, were bought and tested as target drones; these carried the designation XPQ-13. Ercoupe 415-C N37143 is the eldest warbird Ercoupe in existence.
None of the test examples were found adequate for envisioned roles. Nevertheless, the Civil Air Patrol (designated ‘U.S. Air Force Auxiliary’ when actively tasked by the U.S. Air Force) made use of a number during WWII for coastal patrol, transportation and liaison missions.
Others were utilized at Civilian Pilot Training (CPT) program facilities where many aspiring pilots earned wings prior to active military service.
After the war, in 1948, the Royal Air Force evaluated a 415-C (Serial Number VX147) Ercoupe for primary training purposes, but there would be no further acquisitions.
Yet, the ERCO Ercoupe’s military legacy was not over. In fact, it ended only about a decade ago when the 491st Aviation Regiment, Alaska State Defense Force (a component of the Alaska National Guard), Department of Military and Veterans Affairs retired the unit’s seven PQ-13s (415-Cs and 415-Ds).
Colonel M.E. Reeves, now retired, wrote about his unit’s Ercoupes to the Ercoupe Owners Club. His text and photos were published on the Webpage Ercoupes Still Flying for Uncle Sam! Interestingly, the Alaska State Defense Force Ercoupes’ stars reflected 1941 U.S. national markings. According to Col. Reeves, “The planes were privately owned; however, the 491st maintained them. They were ‘assigned’ to the 491st.” The 415s were utilized to support military police and for aerial photography and officer transport.
Considering the above, the often overlooked ERCO Ercoupe has indisputably and justifiably earned the frequently seen ‘stars and bars’ liveries and the respect of historians and owners alike.
The author (John T. Stemple) thanks retired ASDF Col. M.E. Reeves, CAP Historian Col. Frank A. Blazich, Jr., and the Ercoupe Owner’s Club for their cooperation and assistance during the preparation of this article.
Below: First U.S. Military JATO/RATO takeoff – August 1941.
Below: Consolidated Privateer RATO takeoff during WW2
Sources, Suggested Readings & Viewings
75 Coupes for 75 Years! Coupe Capers, January 2015, Volume 44 No.1, Ercoupe Owners Club.
Alaska State Defense Force
Alaska State Defense Force
Alaska Department of Military and Veterans Affairs
Colonel M.E. Reeves, Ercoupes Still Flying for Uncle Sam!
Directory of U.S. Military Rockets and Missiles, Appendix 1: Early Missiles and Drones, PQ Series – ERCO PQ-13
ERCO 415-C XPQ-13 (Gordon W. Hubbard Collection)
No. 3545. Erco 415C XPQ-13 (41-25196 c/n 110) US Army Air Corps
ERCO Ercoupe 415-C
ERCO 415-C Ercoupe
Ercoupe 415 (YO-55)
Ercoupe Owners Club
Ercoupes Still Flying for Uncle Sam!
Ercoupe VX147 by Robert Moore
Fearless Flying: The Ercoupe Story, DVD, Ercoupe Owner’s Club.
F-0568 Focke-Wulf FW 200 Bomber Attacking Shipping
Focke-Wulf Fw 200 Condor
Focke-Wulf Fw 200
Franklin Engines and XPQ – 13’s
History of Rocketry World War II (Other Nations)
Merchant Ship Fighter Unit
N37143 (1941 415-C s/n 110)
RAF Ercoupe discussion
RAF Serials VA-VZ, XA-XZ
Thomas, Stanley G. The Ercoupe, Blue Ridge Summit: Tab Books, 1991.
Weick, Fred E. and James R. Hansen. From the Ground Up: The Autobiography of an Aeronautical Engineer, Washington: Smithsonian Institution Press, 1988.