McDonnell XH-20 Little Henry

XH-20 Little Henry

Role	Experimental ramjet-rotor powered helicopter Type of aircraft
National origin	United States
Manufacturer	McDonnell Aircraft
First flight	29 August 1947
Primary user	United States Air Force
Number built	2

The McDonnell XH-20 Little Henry was a 1940s American experimental lightweight helicopter designed and built by McDonnell Aircraft.^[1]

Development

The McDonnell Model 38 was a lightweight experimental helicopter sponsored by the United States Army Air Force to test the concept of using small ramjets at the tips of the rotor blades.^[1] As a functional helicopter it was a simple open-frame steel-tube construction.^[1] Allotted the military designation XH-20 the first of two first flew on the 29 August 1947.^[1]

Although the XH-20 flew successfully the ramjets were noisy and burnt a large amount of fuel and plans to build a larger two-seat XH-29 were abandoned.

Variants

Data from: U.S.Military Aircraft Designations and Serials since 1909^[2]

Model 38 XH-20 Little Henry: experimental lightweight helicopter, two built.
Model 79 XH-29 Big Henry: proposed two-seat ramjet-powered development, canceled.^[3]

Operator

United States

United States Air Force

Aircraft on display

46-689 the first XH-20 is on display at the National Museum of the United States Air Force

Specifications

Data from ^[1]

General characteristics

Crew: 1
Length: 12 ft 6 in (3.81 m)
Height: 6 ft 8 in (2.03 m)
Empty weight: 290 lb (132 kg)
Powerplant: 2 × McDonnell Ramjets
Main rotor diameter: 20 ft (6.1 m)

Performance

Maximum speed: 50 mph (80 km/h, 43 kn)

References

Media related to McDonnell XH-20 at Wikimedia Commons

^ ^a ^b ^c ^d ^e "XH-20 Little Henry Research Helicopter". Boeing. Archived from the original on 2009-12-17. Retrieved 2009-12-20.
^ Andrade, John (1979). U.S.Military Aircraft Designations and Serials since 1909. Midland Counties Publications. pp. 119–121. ISBN 0-904597-22-9.
^ "McDonnell Model Numbers" (PDF). McDonnell Douglas. July 1, 1974. Retrieved September 3, 2023.

McDonnell and McDonnell Douglas military aircraft and spacecraft

Fighters

USAAF / US Air Force	XP-67 XF-85 Goblin XF-88 Voodoo F-101 Voodoo F-110 F-4 Phantom II F-15 Eagle F-15E Strike Eagle F-15EX Eagle II Northrop YF-23
US Navy / USMC	FH Phantom F2H Banshee F3H Demon F-4 Phantom II F/A-18 Hornet F/A-18E/F Super Hornet
Export	F-4 Phantom (RAAF) F-4K Phantom · F-4M Phantom · F-4J(UK) Phantom CF-18 / CF-188 Hornet
Licensed	F-15J Eagle (Mitsubishi)

Attack

US Navy / USMC	A-4 Skyhawk AV-8B Harrier II A-12 Avenger II
Export	A-4G Skyhawk

Trainers

US Navy	T-45 Goshawk

Transports

US Air Force	Model 119 C-9 KC-10 Extender YC-15 C-17 Globemaster III
US Navy	C-9
Licensed	Model 188 (Bréguet 941)

Helicopters

US Army / US Air Force	XH-20 Little Henry AH-64 Apache
US Navy	XHJH Whirlaway XHCH XHRH
Other	McDonnell 120 Flying Crane MD500 Defender

Drones (UAVs)

US Air Force	ADM-20 Quail
US Navy	KDH Katydid KUD
Other	Aquiline

Experimental

US Army / US Air Force	XV-1 X-36 F-15 STOL/MTD Bird of Prey DC-X

Spacecraft

NASA	Mercury capsule Gemini capsule Skylab
US Air Force	Blue Gemini

United States helicopter designations, Army/Air Force and Tri-Service systems

Numerical sequence used by USAAC/USAAF/USAF 1941–present; U.S. Army 1948–1956 and 1962–present; U.S. Navy 1962–present

Army/Air Force sequence
(1941–1962)

Prefix R-, 1941–1948	R-1 R-2 R-3 R-4 R-5 R-6 R-7 R-8 R-9 R-10 R-11 R-12 R-13 R-14 R-15 R-16
Prefix H-, 1948–1962	H-5 H-6 H-9 H-10 H-11 H-12 H-13 H-13J H-15 H-16 H-17 H-18 H-19 H-20 H-21 H-22 H-23 H-24 H-25 H-26 H-27 H-28 H-29 H-30 H-31 H-32 H-33 H-34 H-35 H-36¹ H-37 H-38¹ H-39 H-40 H-41 H-42 H-43 H-44¹ H-45¹

Tri-service sequence
(1962–present)

1962 redesignations	H-13 H-13F H-13J H-19 H-21 H-23 H-25 H-34 H-37 H-43
New designations	H-46 H-47 H-48 H-49 H-50 H-51 H-52 H-53 CH-53/E/K HH-53/MH-53 H-54 H-55 H-56 H-57 H-58 H-59 H-60 UH-60 SH-60 HH-60 MH-60 H-61 H-62 H-63 H-64 H-65 H-66 H-67 H-68 H-69¹ H-70 H-71 H-72 H-73
Alternate sequence	H-1 AH-1/J/T/W/Z UH-1/N/Y H-2 G H-3 CH-3/HH-3 SH-3 H-4 H-5 H-6 AH-6 MH-6 OH-6
Non-sequential	H-90 H-92 CH-92/VH-92 H-139