Vertipedia - Piasecki H-21B Work-Horse

An alternate gross weight of 14500lb was also available. The Empty weight quoted is for the passenger carrying version.

Overview

Data on design, manufacture and status

Design authority: Piasecki Helicopter Corporation

Primary manufacturer: Piasecki Helicopter Corporation

Parent type: Piasecki H-21

Aircraft status: No longer flying

Configuration

Primary flight and mechanical characteristics

VTOL type: Helicopter

Lift devices: 2 in Tandem (Fore/aft) configuration

Crew required: 2 in Side-by-side 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:	4.69 m	15.4 ft
Overall Length:	26.31 m	86.3 ft
Overall Width:	13.41 m	44.0 ft

Airframe Dimensions
Airframe Length:	16.02 m	52.6 ft
Airframe Width:	3.97 m	13.0 ft
Airframe Height:

Landing Gear Dimensions
Landing Gear Base:	7.51 m	24.6 ft
Landing Gear Track:	4.38 m	14.4 ft

Cabin Dimensions
Cabin Internal Height:	1.78 m	5.8 ft
Cabin Internal Length:	6.10 m	20.0 ft
Cabin Internal Width:	1.73 m	5.7 ft

Weights
Max Gross Weight (ground):	6,033 kg	13,300 lb
Max Gross Weight (airborne):
Max Take-off Weight:	6,033 kg	13,300 lb
Empty Weight:	3,960 kg	8,730 lb

Climb Performance
Max Rate of Climb:	6 m/s	1,080 fpm

Hover Performance
Hover Ceiling IGE:
Hover Ceiling OGE:

Limitations
Max Level Flight Speed:	211 km/h	114 kts
Never Exceed Speed:
Service Ceiling:	2,880 m	9,450 ft

Range and Endurance
Max Range:	544 km	294 nm
Max Endurance:

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

Powerplant
Number of engines:	1
Designation:	Wright R-1820-103 (derated) reciprocating
Manufacturer:	Wright Aeronautical Division, Curtiss-Wright Corporation

Normal Ratings
Max continuous:	858 kW	1150 hp
Take-off / rated:	858 kW	1150 hp
Intermediate:
Maximum:

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

Fwd rotor rotates ant-clockwise, aft rotor rotates clockwise

Main Rotor Characteristics
Diameter:	13.41 m	44.00 ft
RPM:	255.0 rpm	255.0 rpm
Direction of Rotation:	Counter-rotating
Hub Type:	Fully articulated

Main Rotor Blade Characteristics
Blade Construction:	Metal with D section steel spar
Blade Chord:	0.419 m	1.38 ft
Blade Tip Geometry:	Conventional
Blade Twist:	-0.081 rad	-4.617 deg
Number of Blades:	3

Main Rotor Derived Characteristics
Disc Area:	141.26 m²	1520.6 ft²
Disc Loading:	21.35 kg/m²	4.373 lb/ft²
Solidity:	0.0597

Main Rotor Blade Derived Characteristics
Blade area per blade:	2.81 m²	30.3 ft²
Tip Speed:	179.06 m/s	587.5 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

Maintenance Instructions Handbook for YH-21, H-21A, H-21B and H-21C

No stated author
T.O. No. 1H-21(Y)-2, 15 Jun 1954 (page x)
Report or Technical Manual
Revision date 15 Aug 1955

Piasecki Helicopter Corporation

No author stated
Journal of the American Helicopter Society Vol. 1, No. 1, Jan 1956 (page 33)
Periodical

Structural Repair Instructions Handbook for YH-21, H-21A, H-21B and H-21C Helicopters

No author stated
T.O. No. 1H-21(Y)-3, 23 Mar 1953
Report or Technical Manual
Date is original date of issue

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Overview

Attribution

Number of engines:	1 Reciprocating
Max Level Flight Speed:	211 km/h	114 kts
Max Range:	544 km	294 nm
Max Endurance:

Main Rotor Diameter:	13.41 m	44.00 ft
Max Gross Weight (ground):	6,033 kg	13,300 lb