Vertipedia - Pitcairn PA-21

CAA (now FAA) Approved Type Certificate 410. All data references are the same as for the Pitcairn PCA-2. The engine is upgraded to the 420-hp Wright R-975-E-2, improving performance.

Overview

Data on design, manufacture and status

Design authority: Pitcairn Autogiro Company

Primary manufacturer: Pitcairn Autogiro Company

Parent type: Pitcairn PCA-2/3

Aircraft status: No longer flying

Configuration

Primary flight and mechanical characteristics

VTOL type: Gyroplane

Compound type: N/A compounded with 1 propulsors

Lift devices: 1 Single main rotor

Dedicated control device: 1 Rudder

Crew required: 1 in Tandem 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:	13.72 m	45.0 ft
Overall Width:	13.72 m	45.0 ft

Airframe Dimensions
Airframe Length:	7.04 m	23.1 ft
Airframe Width:	9.14 m	30.0 ft
Airframe Height:	4.14 m	13.6 ft

Landing Gear Dimensions
Landing Gear Base:
Landing Gear Track:	4.01 m	13.2 ft

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

Weights
Max Gross Weight (ground):	1,361 kg	3,000 lb
Max Gross Weight (airborne):
Max Take-off Weight:	1,361 kg	3,000 lb
Empty Weight:
Useful Load:
Empty Weight Fraction:

Climb Performance
Max Rate of Climb:

Hover Performance
Hover Ceiling IGE:
Hover Ceiling OGE:

Limitations
Max Level Flight Speed:	201 km/h	109 kts
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:	1
Designation:	Wright Whirlwind R-975E-2 reciprocating
Manufacturer:	Wright Aeronautical Division, Curtiss-Wright Corporation

Normal Ratings
Max continuous:
Take-off / rated:	313 kW	420 hp
Intermediate:
Maximum:

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

Main Rotor Characteristics
Diameter:	13.72 m	45.01 ft
RPM:
Direction of Rotation:	Counterclockwise
Hub Type:	Articulated, with flap and lag hinges and interconnecting blade cables and dampers

Main Rotor Blade Characteristics
Blade Construction:	Blade constructed from steel spar, plywood ribs with doped fabric skin
Blade Chord:	0.559 m	1.83 ft
Blade Tip Geometry:	Tapered, unswept
Blade Twist:
Number of Blades:	4

Main Rotor Derived Characteristics
Disc Area:	147.84 m²	1591.4 ft²
Disc Loading:	9.20 kg/m²	1.885 lb/ft²
Solidity:	0.1037

Main Rotor Blade Derived Characteristics
Blade area per blade:	3.83 m²	41.3 ft²
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

Autogiro: The Story of the Windmill Plane

Townson, George
Aero Publishers Inc., 1985 (page 35)
Book
Comprehensive reference about the work of the Autogiro Company of America and its licensees in the years 1928-1943

Helicopters & Autogyros of the World

Paul Lambermont, Anthony Pirie
Cassell & Company Ltd., 1959 (page 361)
Book