Vertipedia - Sikorsky S-72 RSRA Compound

Equipped with an Emergency Escape System, severing the rotor blades to allow the crew of the 3-place aircraft to escape topside; afterward, it enters the Airplane Configuration.

Hover flight is not possible; take-off and landings are STOL/CTOL. In addition to the turbofan propulors, the main transmission and tail rotor are powered by General Electric T58-GE-5 / T58-GE-10 engines. The equipped main rotor is that of the S-61 (H-3) while a conventional 5-blade tail rotor is used.

Overview

Data on design, manufacture and status

Design authority: Sikorsky Aircraft Corp.

Primary manufacturer: Sikorsky Aircraft Corp.

Parent type: Sikorsky S-72 RSRA

Aircraft status: No longer flying

Configuration

Primary flight and mechanical characteristics

VTOL type: Compound Helicopter

Compound type: Lift and Thrust compounded with 2 propulsors

Lift devices: 1 Single main rotor

Dedicated control device: 1 Tail rotor

Crew required: 2-3 in Side-by-side arrangement

Landing gear: Wheels (some 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

Primary Control Device

Note: Only the main wheels were retractable

Overall Dimensions
Overall Height:	4.72 m	15.5 ft
Overall Length:	23.14 m	75.9 ft
Overall Width:	18.90 m	62.0 ft

Airframe Dimensions
Airframe Length:	19.41 m	63.7 ft
Airframe Width:	13.72 m	45.0 ft
Airframe Height:	4.57 m	15.0 ft

Landing Gear Dimensions
Landing Gear Base:	11.56 m	37.9 ft
Landing Gear Track:

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

Weights
Max Gross Weight (ground):	11,884 kg	26,200 lb
Max Gross Weight (airborne):
Max Take-off Weight:	11,884 kg	26,200 lb
Empty Weight:	9,440 kg	20,812 lb
Useful Load:	2,444 kg	5,388 lb
Empty Weight Fraction:	0.794

Climb Performance
Max Rate of Climb:

Hover Performance
Hover Ceiling IGE:
Hover Ceiling OGE:

Limitations
Max Level Flight Speed:	556 km/h	300 kts
Never Exceed Speed:
Service Ceiling:

Range and Endurance
Max Range:
Max Endurance:	1 hrs

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

Powerplant
Number of engines:	2
Designation:	GE TF34-GE-400A turbine
Manufacturer:	GE Aviation

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

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

NACA 0012 airfoil; RPM (S-72 RSRA): 209.09

Main Rotor Characteristics
Diameter:	18.90 m	62.00 ft
RPM:	203.0 rpm	203.0 rpm
Direction of Rotation:	Counterclockwise
Hub Type:	Fully articulated

Main Rotor Blade Characteristics
Blade Construction:
Blade Chord:	0.464 m	1.52 ft
Blade Tip Geometry:	Conventional
Blade Twist:	-0.140 rad	-8.000 deg
Number of Blades:	5

Main Rotor Derived Characteristics
Disc Area:	280.48 m²	3019.2 ft²
Disc Loading:	42.37 kg/m²	8.678 lb/ft²
Solidity:	0.0781

Main Rotor Blade Derived Characteristics
Blade area per blade:	4.38 m²	47.1 ft²
Tip Speed:	200.86 m/s	659.0 fps

Tail Rotor Characteristics
Diameter:	3.23 m	10.60 ft
Configuration:	Pusher
Direction of Rotation:	Top blade aft
RPM:

Tail Rotor Blade Characteristics
Number of Blades:	5
Blade Construction:
Blade Chord:
Blade Twist:

Tail Rotor Derived Characteristics
Disc Area:	8.20 m²	88.3 ft²
Solidity:

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

References

References and sources used

An Evaluation of Vertical Drag and Ground Effect Using the RSRA Rotor Balance System

Robert J. Flemming, Reuben E. Erickson
May 1982 (page 44)
Meeting paper or Presentation

RSRA Flight Control and Stabilization

Linden, Arthur W
May 1976 (page 2)
Meeting paper or Presentation

RSRA Flight Development Test in the Airplane Configuration

Reuben E. Erickson, Robert M. Kufeld, Jeffrey L. Cross, C.W. Acree
May 1985 (page 692)
Meeting paper or Presentation

Sikorsky Archives | S-72 RSRA

Linden, Arthur W
American Helicopter Society paper Fifty Years of Sikorsky High Speed Concepts, Arthur W. Linden. Presented at the 64th AHS Annual Forum, Montreal, Canada, April 29 - May 1, 2008., SEPTEMBER 11, 2012
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