Vertipedia - McDonnell Model 120 Flying Crane

Developed in 1958, the helicopter is powered by three turbo-compressors; the tip-jet aircraft can operate on two of its three engines, which can function independently. The XV-1 Convertiplane rotor was used for the Model 120. To steer, the engine exhaust was used [Ref Hirschberg. The American Helicopter. Page 62].

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: Skids

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:	2.74 m	9.0 ft
Overall Length:	9.45 m	31.0 ft
Overall Width:	9.45 m	31.0 ft

Airframe Dimensions
Airframe Length:	6.10 m	20.0 ft
Airframe Width:
Airframe Height:	2.74 m	9.0 ft

Landing Gear Dimensions
Landing Gear Base:
Landing Gear Track:	2.79 m	9.2 ft

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

Cruise Speed: 109 mph (175 km/h)

Weights
Max Gross Weight (ground):	2,858 kg	6,300 lb
Max Gross Weight (airborne):
Max Take-off Weight:	2,858 kg	6,300 lb
Empty Weight:	1,111 kg	2,450 lb
Useful Load:	1,746 kg	3,850 lb
Empty Weight Fraction:	0.389

Climb Performance
Max Rate of Climb:	12 m/s	2,400 fpm

Hover Performance
Hover Ceiling IGE:	3,658 m	12,001 ft
Hover Ceiling OGE:	3,048 m	10,000 ft

Limitations
Max Level Flight Speed:	222 km/h	120 kts
Never Exceed Speed:
Service Ceiling:

Range and Endurance
Max Range:	158 km	85 nm
Max Endurance:	1 hrs

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

Powerplant
Number of engines:	3
Designation:	AiResearch GTC-85-35 turbine
Manufacturer:	AiResearch

Normal Ratings
Max continuous:
Take-off / rated:	63 kW	85 hp
Intermediate:
Maximum:

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

Main Rotor Characteristics
Diameter:	9.45 m	31.00 ft
RPM:	410.0 rpm	410.0 rpm
Direction of Rotation:	Clockwise
Hub Type:	Stiff inplane, bearingless, damperless

Main Rotor Blade Characteristics
Blade Construction:
Blade Chord:
Blade Tip Geometry:	Swept Tip-jet
Blade Twist:
Number of Blades:	3

Main Rotor Derived Characteristics
Disc Area:	70.14 m²	755.0 ft²
Disc Loading:	40.74 kg/m²	8.345 lb/ft²
Solidity:

Main Rotor Blade Derived Characteristics
Blade area per blade:
Tip Speed:	202.87 m/s	665.6 fps

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

Helicopters & Autogyros of the World

Paul Lambermont, Anthony Pirie
Cassell & Company Ltd., 1959 (page 339)
Book

Report of Evaluation of the McDonnell Model 120 Flying Crane

United States Army Aviation Board
27 May 1960 (page 2)
Report or Technical Manual

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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Main Rotor Diameter:	9.45 m	31.00 ft
Max Gross Weight (ground):	2,858 kg	6,300 lb
Useful Load (calculated):	1,746 kg	3,850 lb

Number of engines:	3 Turbines
Max Level Flight Speed:	222 km/h	120 kts
Max Range:	158 km	85 nm
Max Endurance:	1 hrs	1 hrs