B2 Bomber A Closer Look at the B2 Configuration

The B2 Bomber is capable of all-altitude attack missions up to 50,000 feet (15,000 m), with a range of more than 6,000 nautical miles (6,900 mi; 11,000 km) on internal fuel and over 10,000 nautical miles (12,000 mi; 19,000 km) with one midair refueling.

b2 bomber

Brief History B2 Bomber 

 

The B2 Bomber is a revolutionary aircraft

Unique flying wing configuration with the following design objectives:

– Serve as a multirole bomber
– Stealth was extremely important
– Had to be able to fly long missions

 Development:

– Began in the 1970s
– First off the line in November of 1988
– First Flight was July 17, 1989
– In 1991, B‐2 design team was awarded the Collier Trophy

 B‐2 in Action:

– 1999 in Kosovo
– 2001 in Afghanistan
– February 22, 2008, first reported accident of B‐2
– Humidity on sensors were yielding skewed pre‐flight checks

Specifications B2 Bomber 

First flight: 17‐Jul‐89
Classification: Bomber
Span: 172 feet
Length: 69 feet
Gross weight: 336,500 pounds
Cruising speed: High subsonic
Range: 6,000 miles plus
Ceiling: 50,000 feet
Power: Four 19,000‐pound‐thust F118‐GE‐100 engines
Accommodation: 2 crew
Armament: More than 40,000‐pound nuclear or conventional weapon payload
Runway Length: 6500 feet
Cost: $2 billion

 

Takeoff and Landing

 Ground effect:

- Large area flying wing
- Sits on cushion
- Has to be “forced” to land
- Not difficult (2nd easiest to the F‐15)

 Stealth design led to great lifting features.

Control Surfaces

B‐2 has 4 pairs of control surfaces on the wing trailing edge.
1) Split drag rudders on outer wing
2) One elevon on outer wing
3) Two elevons on inner wing
4) Beaver tail

b2 bomber

  • Outer elevons provide primary pitch & roll control.
  • 2 inner elevons considered secondary control surfaces (used at low‐speed).
  • Beavertail works constantly to alleviate gust loads. At low speed flight, drag rudders are open.

Low Observable Characteristics

‐RADAR cross section (RCS)
‐Infrared signature
‐Appearance
‐Electromagnetic Signature
‐Acoustic Signature

Stealth

• The key to Stealth is know how RADAR waves are reflected offa body.
• RADAR waves reflect similar to light rays.
• A light ray will reflect off a surface the same angle at which it encountered the surface.
• To get a return a RADAR reflection requires a surface perpendicular to the incoming wave.

b2 bomber

The B‐2 outer profile has a variable radius/ continuous curve that deflects RADAR waves at any angle (non‐tangential surface).

Thus, reducing it’s RCS.

It’s shape also allows for aerodynamic flow.

To further reduce it’s RCS the skin is coated with RADAR Absorbing Materials (RAM)

b2 bomber

b2 bomber