Vertipedia - McDonnell Model 38 Little Henry (XH-20 USAF)

Developed in 1947, designated XH-20 by the U.S. Air Force. The ram-jets are powered by propane.

Overview

Data on design, manufacture and status

Design authority: McDonnell Aircraft Corporation

Primary manufacturer: McDonnell Aircraft Corporation

Parent type: No type defined

Aircraft status: No longer flying

Configuration

Primary flight and mechanical characteristics

VTOL type: Helicopter

Lift devices: 1 Single main rotor

Crew required: 1 in Single seater arrangement

Landing gear: Wheels (non-retractable)

Key Characteristics

Data on key physical features

Aircraft Details

Data on aircraft configuration, weights, flight performance and equipment

Layout and Dimensions

Weights and Performance

Engine Details

Primary Lift Device

Overall Dimensions
Overall Height:
Overall Length:
Overall Width:	5.49 m	18.0 ft

Airframe Dimensions
Airframe Length:
Airframe Width:
Airframe Height:

Landing Gear Dimensions
Landing Gear Base:
Landing Gear Track:

Cabin Dimensions
Cabin Internal Height:
Cabin Internal Length:
Cabin Internal Width:

Cruise Speed: 50 mph (80.4672 km/h)

Weights
Max Gross Weight (ground):	254 kg	560 lb
Max Gross Weight (airborne):
Max Take-off Weight:	254 kg	560 lb
Empty Weight:	129 kg	285 lb

Climb Performance
Max Rate of Climb:

Hover Performance
Hover Ceiling IGE:
Hover Ceiling OGE:

Limitations
Max Level Flight Speed:
Never Exceed Speed:
Service Ceiling:

Range and Endurance
Max Range:
Max Endurance:

Provided powerplant data is for uninstalled, sea level, static operations.

Powerplant
Number of engines:	2

Normal Ratings
Max continuous:
Take-off / rated:
Intermediate:
Maximum:

OEI Ratings
OEI contingency:
OEI continuous:
OEI 30-second:
OEI intermediate:

Main Rotor Characteristics
Diameter:	5.49 m	18.00 ft
RPM:
Direction of Rotation:	Clockwise
Hub Type:

Main Rotor Blade Characteristics
Blade Construction:
Blade Chord:
Blade Tip Geometry:	Tip-jet
Blade Twist:
Number of Blades:	2

Main Rotor Derived Characteristics
Disc Area:	23.64 m²	254.5 ft²
Disc Loading:	10.74 kg/m²	2.201 lb/ft²
Solidity:

Main Rotor Blade Derived Characteristics
Blade area per blade:
Tip Speed:

Tail Rotor Characteristics
Diameter:
Configuration:	Unknown
Direction of Rotation:	Unknown
RPM:

Tail Rotor Blade Characteristics
Number of Blades:
Blade Construction:	N/A
Blade Chord:
Blade Twist:

Tail Rotor Derived Characteristics
Disc Area:
Solidity:

Tail Rotor Blade Derived Characteristics
Tip Speed:
Blade Area (per blade):

References

References and sources used

S-47 | S-47/R-4 Helicopter

Vinny Devine
Sikorsky Archives | Product History, Sep 19, 2017 (page 9)
Website
Very thorugh description and details of the R-4 series helicopter

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Resources related to the Model 38 Little Henry (XH-20 USAF), provided by public sources across the internet.

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Number of engines:	2 Unknowns
Max Level Flight Speed:
Max Range:
Max Endurance:

Main Rotor Diameter:	5.49 m	18.00 ft
Max Gross Weight (ground):	254 kg	560 lb