Vertipedia - Bell AH-1G Cobra

Overview

Data on design, manufacture and status

Design authority: Bell Helicopter Company

Primary manufacturer: Bell Helicopter Company

Parent type: Bell Model 209/AH-1 Cobra

Aircraft status: No longer flying

Configuration

Primary flight and mechanical characteristics

VTOL type: Helicopter

Lift devices: 1 Single main rotor

Dedicated control device: 1 Tail rotor

Crew required: 2 in Tandem arrangement

Landing gear: Skids

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

Airframe width includes stub wings. While there is some variation among Cobra variants, most fuselage widths without stub wings are .914 m (3 ft).

Overall Dimensions
Overall Height:	4.10 m	13.5 ft
Overall Length:	16.14 m	53.0 ft
Overall Width:	13.41 m	44.0 ft

Airframe Dimensions
Airframe Length:	13.77 m	45.2 ft
Airframe Width:	3.15 m	10.3 ft
Airframe Height:	3.11 m	10.2 ft

Landing Gear Dimensions
Landing Gear Base:	3.27 m	10.7 ft
Landing Gear Track:	2.13 m	7.0 ft

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

Weights
Max Gross Weight (ground):	4,309 kg	9,500 lb
Max Gross Weight (airborne):
Max Take-off Weight:	4,309 kg	9,500 lb
Empty Weight:	2,499 kg	5,510 lb
Useful Load:	1,810 kg	3,990 lb
Empty Weight Fraction:	0.580

Climb Performance
Max Rate of Climb:	9 m/s	1,680 fpm

Hover Performance
Hover Ceiling IGE:	3,015 m	9,892 ft
Hover Ceiling OGE:	1,219 m	4,000 ft

Limitations
Max Level Flight Speed:	270 km/h	146 kts
Never Exceed Speed:	352 km/h	190 kts
Service Ceiling:	3,505 m	11,500 ft

Range and Endurance
Max Range:	575 km	310 nm
Max Endurance:	2 hrs

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

Powerplant
Number of engines:	1
Designation:	Lycoming T53-L-13 turbine
Manufacturer:	Lycoming Engines

Normal Ratings
Max continuous:	933 kW	1250 hp
Take-off / rated:	1045 kW	1400 hp
Intermediate:
Maximum:

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

B540 blade for two-bladed Cobra main rotors.

Main Rotor Characteristics
Diameter:	13.40 m	43.96 ft
RPM:	324.0 rpm	324.0 rpm
Direction of Rotation:	Counterclockwise
Hub Type:	Flex-beam, stiff-in-plane teetering hub

Main Rotor Blade Characteristics
Blade Construction:	Bonded aluminum spar and skin; nomex honeycomb core
Blade Chord:	0.686 m	2.25 ft
Blade Tip Geometry:	Square-edged tips
Blade Twist:	-0.175 rad	-10.000 deg
Number of Blades:	2

Main Rotor Derived Characteristics
Disc Area:	141.03 m²	1518.0 ft²
Disc Loading:	30.56 kg/m²	6.258 lb/ft²
Solidity:	0.0652

Main Rotor Blade Derived Characteristics
Blade area per blade:	4.59 m²	49.5 ft²
Tip Speed:	227.33 m/s	745.8 fps

Some images show the tail rotor in a 'tractor' type configuration so it appears that configuration changed at some point

Tail Rotor Characteristics
Diameter:	2.59 m	8.50 ft
Configuration:	Pusher
Direction of Rotation:	Top blade aft
RPM:	1654 rpm	1654 rpm

Tail Rotor Blade Characteristics
Number of Blades:	2
Blade Construction:	Bonded aluminum skin with abrasion strip
Blade Chord:	0.213 m	0.70 ft
Blade Twist:

Tail Rotor Derived Characteristics
Disc Area:	5.27 m²	56.7 ft²
Solidity:	0.1049

Tail Rotor Blade Derived Characteristics
Tip Speed:	224.30 m/s	735.9 fps
Blade Area (per blade):	0.276 m²	2.97 ft²

References

References and sources used

Bell AH-1 Cobra Variants

Peoples, Kenneth
Aerofax, Arlington TX, 1988 (page 37)
Book
Aerofax Datagraph 4

Cobra

GEN Hamilton H. Howze (USA Ret.)
Vertiflite, Vol. 13 No. 9, 1967 (page 9)
Periodical
"Special Report: World's First Attack Helicopter"

Dirty Little Secrets of the Vietnam War

Dunnigan, James
St. Martin's Griffin Publishing, May 2000 (page 110)
Book

Helicopter Gunships: Deadly Combat Weapon Systems

Mutza, Wayne
Specialty Press, 2010
Book

Operator's Manual, Army Model AH-1G Helicopter

U.S. Dept. of the Army
Technical Manual TM 55-1520-221-10, 1967 (page 53)
Report or Technical Manual

Production Validation Test - Government: Kaman K747 Improved Main Rotor Blade

Diekmann, Vernon L. et al
US Army Aviation Engineering Flight Activity, Edwards Air Force Base, October 1979 (page 1)
Report or Technical Manual
Defense Technical Information Center / USAAEFA Report No. 77-38. Contains specifications on K747 and B540 main rotor blades.

U.S. Army Aircraft Since 1947

Harding, Stephen
Schiffer Publishing LTD, Atglen PA, 1997 (page 54)
Book