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Aviation History
1989
1989 - 2310.PDF
HEADLINES B-2 in flight reveals new details The curtain of security sur rounding the Northrop B-2 bomber lifted slightly with the aircraft's first flight on July 17. With the world's press there to witness both the take-off from Palmdale and the landing at Edwards, it was hard to keep secret the B-2's external details. Even after the successful 112min flight at the hands of Northrop chief test pilot Bruce Hinds and director of the B-2 combined test force Col Richard Couch, however, the US Air Force remained tight-lipped about the bomber's performance. In command for the maiden flight, Hinds said afterwards that the B-2's performance had been "very close to the simulation that we have done," and added: "It's a very simple aeroplane aero- dynamically. Everyone is going to enjoy flying it." Col Couch, director of the 6510th Test Group at Edwards Air Force Base, says the B-2 lifted off at approximately 160kt, after a 4,500ft to 5,000ft ground roll: We attempted a 7\° attitude for rotation, but we never got there. The aircraft just very smoothly lifted off the ground." Take-off weight was not revealed, but would be less than the B-2's 350,0001b design maximum. The B-2 "was rock steady on finals," says Col Couch. "It needed a very slight aft pressure on the stick, and it touched down very smoothly. Pitch attitude on landing was approximately 7° and landing roll was 5,000ft." The B-2 has a distinct birdlike profile Nose gear Weapons bays Phased-array radar antennas Undercarriage bays Cusp leading edge Doppler/altimeter antennas? Access doors for engines Beaver tail The B-2's "sawtooth" trailing-edge shape is echoed on the span-wise edges of doors and panels In ground effect, the aircraft apparently handled better than simulation had anticipated. The entire flight was com pleted in approach configuration, with gear down. Two doors on each engine nacelle were open throughout the flight, possibly feeding extra air at low speeds to each pair of 19,0001b-thrust General Electric unreheated turbofans buried in the wing. High-lift devices were not used. The B-2's distinctive W-shaped trailing edge has simple flaps inboard, split ailerons outboard, and a beaver tail, apparently articulated, at the rear of the "fuselage". The split ailerons appear to perform several func tions: the lower sections deflect downwards symmetrically to increase lift and asymmetrically for roll control; and both sections open symmetrically for air- braking and asymmetrically for yaw control "drag rudders". On lift-off, the flaps were deflected only slightly, if at all, and the split ailerons were opened partially, suggesting that their upper sections can be deflected upwards to act as elevators. The beaver tail appeared to be deflected slightly downwards, suggesting it can be used to increase camber of the aerofoil-shaped "fuselage". As the aircraft took off, obser vers gained their first glimpse of the B-2's black-painted under side. Plainly visible were the double doors of two longitudinal weapon bays, one either side of the centreline. These will house the Boeing-developed Advanced Applications Rotary Launcher which will carry both nuclear and conventional weapons. Outboard of the weapon bays are removable panels providing access to the buried engines, alongside which are the main undercarriage wells, covered by a single large door on each side. Just outboard of each door hinge are what appear to be antennas for the Honeywell radar alti meter, part of the B-2's covert terrain-following system. The leading and trailing edges of the weapon-bay doors, engine access panels, and nose-gear doors exhibit the same radar- scattering sawtooth shape as the B-2's overwing inlets, their splitter plates, and the wing trailing edge itself. Visible just behind the cusped leading edge, either side of its apex, are the conformal phased- array antennas, two each side, for the Hughes Aircraft radar, which is probably used for terrain- avoidance, ground-mapping, and target location. Viewed along its leading edge, the B-2 "wing" undergoes several profile changes, with distinct cusps at the apex and tip and a more-conventional curved aero foil nose at about mid-span. The FLIGHT INTERNATIONAL 29 July 1989
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