Helio Courier

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(Redirected from L-24 Courier)
A restored Helio Courier in flight
Role STOL utility aircraft
Manufacturer Helio Aircraft Company
First flight 8 April 1949
(Helioplane #1)
Introduction 1954
Status In use as of 2022
Number built 500 (approximate total)
Variants Helio AU-24 Stallion
Helio Courier H-295 on floats, Lake Hood Seaplane Base, Anchorage, AK

The Helio Courier is a cantilever high-wing light STOL utility aircraft designed in 1949.

Around 500 of these aircraft were manufactured in Pittsburg, Kansas, from 1954 until 1974 by the Helio Aircraft Company. The design featured four leading edge slats that deployed automatically, and large trailing edge flaps. The engine was the 295 hp Lycoming GO-480, which had a gearbox that lowered the output RPM and allowed for the use of a large three-bladed propeller to further improve takeoff performance. Couriers were famous for their takeoffs, which often took only a few plane lengths and then climbed at very high angles. During airshow demonstrations, it was common for the aircraft to actually take off across a 100 - 200 foot wide runway. The geared engine, however, required constant maintenance and was a major downside to the design.

During the early 1980s, new owners (Helio Aircraft Ltd.) made an attempt to build new aircraft with direct-drive Lycoming engines, to replace troublesome and expensive geared engines. In a further effort to reduce weight, a new composite landing gear was featured. The new models also featured modest winglets. Two models were produced, the H-800 and H-700. A total of 18 aircraft were built. The rights to the Helio Stallion and Helio Courier were acquired by Helio Aircraft of Prescott, Arizona.[1]

Design and development[edit]

Professor Otto C. Koppen designed aircraft for the Stout Metal Airplane Division of the Ford Motor Company, including the Ford Flivver, an aircraft that was supposed to be mass-produced by Ford. Koppen went on to design the Helio Courier.[2]

The demonstrator for the Courier's concept, "Helioplane #1", was converted by the then-local Wiggins Airways firm from a Piper PA-17 Vagabond Trainer, one of the so-named "short-wing Pipers" in production following World War II. Only the cabin area of the PA-17's original airframe remained unmodified, with the fuselage lengthened by four feet (1.2 meters), given a taller fin-rudder unit, clipped the Vagabond's stock 29 ft-3 inch (8.92 meter) wingspan down to only some 28.5 feet (8.7 meters), fitted the shortened wings with full-span leading-edge slats, long-span wing flaps that forced the ailerons to be much diminished in their span - only occupying the two outermost rib bays inboard of the wingtip; and a longer-travel main landing gear of a taller design, not unlike that of the 1930s-origin Fieseler Fi 156 German military short take-off and landing (STOL) pioneer aircraft. The powerplant for the demonstrator was switched to the Continental C85 boxer-four cylinder air-cooled engine, upgraded with fuel-injection, and uniquely equipped with a multi-belt speed reduction unit to drive its Aeroproducts nine-foot (2.75 meter) diameter, variable-pitch two-blade propeller, which contributed greatly to the amazing STOL flight characteristics of the demonstrator aircraft.[3][4] The demonstrator's first flight took place on April 8, 1949, flying from what was then called the Boston Metropolitan Airport.[5]

For the construction of the production Courier aircraft, its all aluminum-clad airframe features a welded 15G steel-tube center section fuselage, with shoulder harnesses that protect the occupants in an emergency. The wings are of conventional aluminum construction, but feature Handley Page leading-edge slats that deploy automatically when the aircraft's airspeed falls below a certain value — 55 to 60 miles per hour (89 to 97 km/h). The slats contribute to the Helio's outstanding short takeoff and landing capability, and allow for stall/spin-proof controllable flight. In conjunction with the leading-edge slats, 74% of the trailing edge incorporates high-lift slotted flaps, which together with interrupter blades atop each wing when roll control is lost at very low airspeed, allows for a tight turning radius. The Helio Courier could maintain control at speeds as low as 27 miles per hour (43 km/h).[6]

The design of the Helio features a large vertical tail surface and rudder for control at very low flight speeds. However, on conventional geared aircraft (taildraggers), the airplane tends to be sensitive to crosswinds, thus a crosswind gear option is available, allowing the main tires to caster left or right 20 degrees, increasing the crosswind component to 25 miles per hour (40 km/h). The Helio has its main gear placement far forward of the cabin, enabling hard braking on unprepared landing areas. A tricycle-gear model was produced, but is unsuitable for unprepared rough terrain.

Helios are also capable of being equipped with floats; both straight and amphibious floats being offered.

Operational history[edit]

Helio Courier slow flight
Helio Courier in hangar at JAARS
A USAF U-10B from the 5th Special Operations Squadron in Vietnam, 1969.
A U-10D with a C-119
Richard Bach, author of Jonathan Livingston Seagull, and Lynn Garrison with Helio Courier G-ARMU used for Von Richthofen and Brown, 1970

With a minimum-control speed of around 28 mph, the Courier is perfectly suited for confined off-airport operations. The first one was certified in July 1954 and powered by the 260 hp Lycoming GO-435-C2B2. The first production Courier (Serial Number 001, dubbed "Ol' Number 1")C-G001 was previously owned and operated by JAARS as N242B until 2010.[7] Jaars Helio Courier has been a frequent airshow performer at EAA AirVenture Oshkosh for decades, displaying its slow flight capability in front of thousands and serving as a drop plane for the Liberty Parachute Team.[8]

In 1957, a "Strato Courier" set an altitude record over Mexico City, Mexico at 31,200 ft powered by a geared Lycoming GSO-480-A1A5 (340 hp), only one was built. The Super Courier, a more powerful derivative, was used by the U.S. Air Force from 1958 onward, by the U.S. Army Special Forces in the 1960s and 1970s and by Air America during the Vietnam War as the U-10. In U.S. Army and Air Force service, the U-10 Super Courier was used for liaison work, light cargo and supply drops, psychological warfare, forward air control (Air Force), insertion and extraction by land and sea (Army), and reconnaissance. Various versions were produced up through the 1980s, including turbine-powered variants.

The Super Courier saw military service in the United States as the U-10 (ex L-28). Over 120 were built: The L-28A (2, later redesignated U-10A), U-10A (26), U-10B extended range and paratrooper doors (57), and the U-10D with a higher gross weight(36). There was no U-10C.

Helios remain very popular among bush pilots in Canada (32 current) and Alaska and missionaries who fly into rough, relatively unprepared jungle airstrips because of its superior STOL abilities. Some operators use the Helio Couriers for aerial observation. Both Winged Vision Inc. of Gaithersburg, Maryland and the Pima County, Arizona, Sheriff's Department each operate two of the rare tri-gear model and mount gyro-stabilized cameras under the wing for aerial observation.[9] Pima County mounts a FLIR camera for law enforcement, and Winged Vision mounts a high definition television camera for coverage of major sports events.[10]


Koppen-Bollinger Helioplane[11]
Original prototype soon re-named Helio Courier.
Helioplane Four
unknown possible variant.
Helioplane Two
unknown possible variant.
Hi-Vision Courier
unknown possible variant.
Prototype, one built.
H-295 Super Courier
Variant with a Lycoming GO-480-G1D6, purchased by USAF as U-10D, 173 built.
HT-295 Super Courier or Trigear Courier
H-295 with tricycle undercarriage, 19 built.
H-250 Courier
H-295 with lengthened fuselage and Lycoming O-540-A1A5 engine, 41 built.
H-391 Courier
Prototype with Lycoming GO-435-C2 engine, one built.
H-391B Courier
Production version of H-391, 102 built.
H-392 Strato Courier
High-altitude version of H-391 with Lycoming GSO-480-A1A5 engine (340 hp).
H-395 Super Courier
H-391B with Lycoming GO-480-G1D6, purchased by USAF as U-10A and U-10B, 138 built.
H-395A Courier
Variant of the H-395 with a Lycoming GO-435-C2B6 engine, seven built.
H-500 Twin Courier
Twin-engined H-395 for the CIA. Very little information available except seven delivered to the CIA under front designation U-5.
H-550 Stallion
Turboprop powered development
H-580 Twin Courier
A longer nosed H-500 with twin wing mounted piston engines, five built.[12]
H-634 Twin Stallion
Planned twin Allison C250 powered Stallion.
H-700 Courier
H-295 with redesigned wing and undercarriage and Lycoming TIO-540-J2B engine.
H-800 Courier
H-700 with Lycoming IO-720-A1B engine, 18 built (H-700 and H-800 together).
L-24 Courier
Military version of the H-391 Courier.
L-28 Courier
Military version of the H-395 Courier.
U-5 Twin Courier
Probable front designation for CIA Twin Couriers.
U-10 Courier
Re-designation of L-28 Courier
Helio AU-24 Stallion
Military designation for H-550 Stallion


Helio U-10B of The Royal Thai Air Force

Military operators[edit]

 United States

Civil operators[edit]

Aircraft on display[edit]

Helio Courier flying in the United Kingdom in 2016.
United States

Specifications (U-10D Super Courier)[edit]

Data from Operation and Maintenance Manual : Helio H-395 Super Courier[23]

General characteristics

  • Crew: 1
  • Capacity: 5 pax / 1,320 lb (599 kg) payload
  • Length: 30 ft 8 in (9.35 m)
  • Wingspan: 39 ft 0 in (11.89 m)
  • Height: 8 ft 10 in (2.69 m)
  • Airfoil: NACA 23012[24]
  • Empty weight: 2,087 lb (947 kg)
  • Max takeoff weight: 3,000 lb (1,361 kg)
  • Powerplant: 1 × Lycoming GO-480-G1D6 6-cylinder air-cooled horizontally-opposed piston engine, 295 hp (220 kW) at 3400 rpm for take-off
285 hp (213 kW) at 3000 rpm, maximum continuous power
  • Propellers: 3-bladed Hartzell HC93Z20-1B/10151-C (or HC-B3Z20-1/10151-C), 8 ft 0 in (2.44 m) diameter constant-speed propeller


  • Maximum speed: 148 kn (170 mph, 274 km/h)
  • Never exceed speed: 164 kn (189 mph, 304 km/h)
  • Maximum structural cruising speed: 130 kn (150 mph; 241 km/h)
  • Maximum manoeuvring speed: 85 kn (98 mph; 157 km/h)
  • Maximum flaps extended speed: 65 kn (75 mph; 120 km/h)
  • Maximum rough air speed: 130 kn (150 mph; 241 km/h) flaps up
  • Maximum rough air speed: 80 kn (92 mph; 148 km/h) flaps down
  • Range: 950 nmi (1,090 mi, 1,760 km) with 120 US gal (100 imp gal; 450 L) fuel
  • Service ceiling: 20,500 ft (6,200 m)
  • g limits: +3.8 flaps up, +2 flaps extended
  • Rate of climb: 1,200 ft/min (6.1 m/s)

See also[edit]

Related development

Aircraft of comparable role, configuration, and era



  1. ^ "Helio Courier." Archived 2011-11-20 at the Wayback Machine Helio Aircraft. Retrieved: October 3, 2011.
  2. ^ Peterson, Norm. "There's a Ford in your Future." Sport Aviation, August 1991.
  3. ^ a b "Smithsonian National Air & Space Museum - Collections - Helioplane - Long Description". airandspace.si.edu. National Air & Space Museum. Retrieved December 27, 2016. Professor Koppen was not a newcomer to the so-called affordable safe light plane design field as he was the designer of Ford's 1925 Flivver Plane and designed the pre-World War II two-control, spin proof General Skyfarer airplane. The professors tried several sources for financial support in government, academia, and industry for the experimental project but eventually they put up their own money. They arranged for Greater Boston Metropolitan Airport fixed base operator, E.W. Wiggins Airways and volunteers to convert a Piper PA-17 Vagabond to the two-place Helio No.1, and, in the end, the investment of the professors was about $6,000. The only unmodified part of the Vagabond was the fuselage cabin area. The original 65 hp Continental engine was replaced with a fuel-injected 85 hp Continental fitted with a multi-belt reduction unit that drove a specially designed nine-foot Koppers Aeromatic propeller. This extra large diameter propeller with its large thrust component was a major contributor to the success of the Helio-1. The propeller's wide slipstream coverage of the wing slats and slotted flaps provided a substantial added lift component during the take-off, landing and the slow/near hover flight regimes. The large propeller size dictated a higher-than-normal main landing gear with long throw shock struts to achieve sufficient propeller ground clearance...The fuselage was lengthened by nearly four feet and the Vagabond's already short 29-foot 3-inch wing was shortened by another nine inches. The wing had a complete array of the high lift devices available at that time, including leading edges with retractable full span Handley Page automatic slats and trailing edges with the equivalent of full-span slotted flaps. The ailerons could be drooped in the slow speed configuration to act as flaps and still perform for banking purposes. In addition to these devices, a later development called a lateral roll control augmenter was installed at the wing leading slat gaps. This device was aerodynamically positioned at the slat gap so that it provided excellent slow speed roll stabilization.
  4. ^ "Simplicity and Safety, Features of the Helioplane, a Promising American Light Aircraft Prototype". Flight International. United Kingdom: Flightglobal. October 20, 1949. Retrieved September 3, 2017.
  5. ^ Freeman, Paul (July 3, 2015). "Abandoned and Little-Known Airfields - Massachusetts, Southwest Boston Area - Massachusetts Air Terminal & Arena / Canton Airport / Massachusetts Air Terminal / Boston Metropolitan Airport, Canton, MA". www.airfields-freeman.com. Paul Freeman. Retrieved December 27, 2016. The last aircraft-related company at Canton Airport was Helio Aircraft Corporation. In the late 1940s, Otto Koppen of MIT & Dr. Lynn Bollinger of Harvard developed the first Helioplane experimental prototype, a short take off & landing light aircraft...The professors arranged for Greater Boston Metropolitan Airport fixed base operator, E.W. Wiggins Airways & volunteers to convert a Piper PA-17 Vagabond to the 2-place Helio No.1. The successful first flight was in 1949.
  6. ^ "Small Plane Copies Copter." Popular Science, August 1949, p. 135.
  7. ^ "Very First Helio Courier Alive and Well in Canada." Archived 2012-02-13 at the Wayback Machine EEA, February 13, 2012.
  8. ^ Koepenick, Jim. "Antiques and Classics at Oshkosh '91." Sport Aviation, November 1991.
  9. ^ Thomas Horne (June 2014). "Eye on Sport". AOPA Pilot: 64.
  10. ^ "News & Press Coverage." Archived 2011-09-29 at the Wayback Machine Helio Aircraft. Retrieved: October 3, 2011.
  11. ^ "Leaps Off Lawn." Popular Science, October 1949, pp. 109, 110.
  12. ^ Flying, March 1984, p. 54.
  13. ^ Hatch, Paul F. (July 1985). "Air Forces of the World: Bophuthatswana Defence Force Air Wing". Air Pictorial. Vol. 47, no. 7. p. 249.
  14. ^ "Helio H-295 Super Courier | Guyana Defence Force".
  15. ^ aeroflight
  16. ^ "Building 1". Royal Thai Air Force Museum. Archived from the original on 26 October 2013. Retrieved 16 January 2017.
  17. ^ "Airframe Dossier - Helio U-10B, s/n 66-14332 USAF, c/n 576". Aerial Visuals. AerialVisuals.ca. Retrieved 17 January 2017.
  18. ^ "Hurlburt Field Memorial Air Park Guide" (PDF). Hurlburt Field. Archived from the original (PDF) on 27 December 2016. Retrieved 16 January 2017.
  19. ^ "Airframe Dossier - Helio U-10A Super Courier, s/n 62-3606 USAF, c/n 540, c/r N11619". Aerial Visuals. AerialVisuals.ca. Retrieved 16 January 2017.
  20. ^ "U-10B "SUPER COURIER"". Museum of Aviation. Museum of Aviation. Retrieved 16 January 2017.
  21. ^ "Helio U-10D Super Courier". National Museum of the US Air Force. 18 May 2015. Retrieved 16 January 2017.
  22. ^ "1966 H-295 HELIO COURIER". Alaska Aviation Museum. Archived from the original on 13 September 2016. Retrieved 28 November 2020.
  23. ^ Operation and Maintenance Manual : Helio H-395 Super Courier (PDF). Helio Aircraft. 17 November 1958.
  24. ^ Lednicer, David. "The Incomplete Guide to Airfoil Usage". m-selig.ae.illinois.edu. Retrieved 16 April 2019.


  • Elliot, Bryn (March–April 1997). "Bears in the Air: The US Air Police Perspective". Air Enthusiast. No. 68. pp. 46–51. ISSN 0143-5450.
  • Ogden, Bob. Aviation Museums and Collections of North America. Tonbridge, Kent, UK: Air-Britain (Historians) Ltd, 2007. ISBN 0-85130-385-4.
  • Simpson, R. W. Airlife's General Aviation. Shrewsbury, UK: Airlife Publishing, 1995, pp. 208–210. ISBN 1-85310-577-5.
  • Taylor, Michael J. H. Jane's Encyclopedia of Aviation. London: Studio Editions, 1989. ISBN 0-517-69186-8.
  • World Aircraft Information Files. London: Bright Star Publishing, File 896, sheet 18.

External links[edit]