Developed in 1958 and produced in 1961, the BS-12D1 is the first twin-engine helicopter to be FAA Certificated.  The 5-place aircraft is designed for transport of heavy loads in hard-to-reach places.


Data on design, manufacture and status

Design authority: Omega Aircraft Corporation

Primary manufacturer: Omega Aircraft Corporation

Parent type: No type defined

Aircraft status: No longer flying


Primary flight and mechanical characteristics

VTOL type: Helicopter

Lift configuration: Single main rotor

Dedicated control device: Tail rotor

Crew required: 1-2

Crew seating: Side-by-side

Landing gear: Wheels (non-retractable)

Layout and Dimensions

Data on aircraft size

Overall Dimensions
Overall Height: 3.96 m 13.0 ft
Overall Length: 14.74 m 48.4 ft
Overall Width: 11.89 m 39.0 ft
Airframe Dimensions
Airframe Length: 11.13 m 36.5 ft
Airframe Width: 1.32 m 4.3 ft
Airframe Height: 3.96 m 13.0 ft
Landing Gear Dimensions
Landing Gear Base:  
Landing Gear Track: 3.63 m 11.9 ft
Cabin Dimensions
Cabin Internal Height:  
Cabin Internal Length:  
Cabin Internal Width:  

Weights and Performance

Data on aircraft weight and flight characteristics

Cruise Speed: 85 mph (136.794 km/h)

Max Gross Weight (ground): 2,214 kg 4,880 lb
Max Gross Weight (airborne):  
Max Take-off Weight: 2,214 kg 4,880 lb
Empty Weight: 1,565 kg 3,450 lb
Useful Load: 649 kg 1,430 lb
Empty Weight Fraction: 0.707
Climb Performance
Max Rate of Climb: 6 m/s 1,210 fpm
Hover Performance
Hover Ceiling IGE: 1,219 m 4,000 ft
Hover Ceiling OGE:  
Max Level Flight Speed: 153 km/h 83 kts
Never Exceed Speed:  
Service Ceiling: 2,896 m 9,500 ft
Range and Endurance
Max Range: 257 km 139 nm
Max Endurance:  

Engine Details

Aircraft powerplant (lift and/or propulsion)

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

Number of engines: 2
Designation: Lycoming O-540-F1A5 reciprocating
Manufacturer: Lycoming Engines
Normal Ratings
Max continuous:  
Take-off / rated: 194 kW 260 hp
OEI Ratings
OEI contingency:  
OEI continuous:  
OEI 30-second:  
OEI intermediate:  

Primary Lift Device

Data on primary lift devices such as main rotors

Main Rotor Characteristics
Diameter: 11.89 m 39.00 ft
Direction of Rotation: Clockwise
Hub Type: Two fully articulated two-bladed parts
Main Rotor Blade Characteristics
Blade Construction:
Blade Chord:  
Blade Tip Geometry: Conventional
Blade Twist:  
Number of Blades: 4
Main Rotor Derived Characteristics
Disc Area: 110.98 m² 1194.6 ft²
Disc Loading: 19.95 kg/m² 4.085 lb/ft²
Main Rotor Blade Derived Characteristics
Blade area per blade:  
Tip Speed:  

Primary Control Device

Data on primary control devices such as tail rotors

Unblocked, the tail boom is of truss construction.

Tail Rotor Characteristics
Diameter: 2.41 m 7.92 ft
Configuration: Unblocked
Direction of Rotation: Top blade fwd
Tail Rotor Blade Characteristics
Number of Blades: 2
Blade Construction:  
Blade Chord:  
Blade Twist:  
Tail Rotor Derived Characteristics
Disc Area: 4.57 m² 49.2 ft²
Tail Rotor Blade Derived Characteristics
Tip Speed:  
Blade Area (per blade):  

Related VFS Resources

Resources related to the BS-12D-1 , provided by the Vertical Flight Society.
Forum Proceedings
Vertiflite articles
Enter a search term in the box above.
Web files from
Enter a search term in the box above.
Webpages from
Enter a search term in the box above.

Related Public Resources

Resources related to the BS-12D-1 , provided by public sources across the internet.