The Convair B-58 Hustler was the first Mach 2 operational bomber.
The B-58 was developed during the 1950s for the United States Air Force (USAF) Strategic Air Command (SAC). To achieve the high speeds desired, Convair chose a delta wing design used by contemporary interceptors such as the Convair F-102. The bomber was powered by four General Electric J79 engines in underwing pods. It had no bomb bay: it carried a single nuclear weapon plus fuel in a combination bomb/fuel pod underneath the fuselage. Later, four external hardpoints were added, enabling it to carry up to five weapons.

The B-58 entered service in March 1960, and flew for a decade with two SAC bomb wings: the 43rd Bombardment Wing and the 305th Bombardment Wing. It was considered difficult to fly, imposing a high workload upon its three-man crews. Designed to replace the subsonic Boeing B-47 Stratojet strategic bomber, the B-58 became notorious for its sonic boom heard on the ground by the public as it passed overhead in supersonic flight.

The B-58 was designed to fly at high altitudes and supersonic speeds to avoid Soviet interceptors, but with the Soviet introduction of high-altitude surface-to-air missiles, the B-58 was forced to adopt a low-level-penetration role that severely limited its range and strategic value. It was never used to deliver conventional bombs. The B-58 was substantially more expensive to operate than other bombers, such as the Boeing B-52 Stratofortress, and required more frequent aerial refueling. The B-58 also suffered from a high rate of accidental losses. These factors resulted in a relatively brief operational career of ten years. The B-58 was succeeded in its role by the smaller, swing-wing FB-111A.

The genesis of the B-58 was the Generalized Bomber Study (GEBO II) issued in February 1949 by the Air Research and Development Command (ARDC) at Wright-Patterson AFB, Ohio, for the development of a supersonic, long-range, manned bomber aircraft. ARDC sought the best attainable quantitative data, challenging the industry to devise their own solutions to attain the stated goal. Work on the proposed bomber's design was to begin less than two years after sustained supersonic flight had been achieved. According to aviation authors Bill Gunston and Peter Gilchrist, while some military officials were keenly interested in the prospective use of supersonic bombers, others held doubts about the propulsion systems and materials science required for supersonic operations, as well as the much higher fuel consumption relative to subsonic counterparts.

Despite the skepticism, multiple contractors submitted bids for GEBO II, which was viewed as an influential step towards a development contract. These included Boeing, Convair, Curtiss, Douglas, Martin and North American Aviation. The majority of submissions were relatively straightforward, unambitious, and expensive. Convair, which had built the XF-92A and other delta-wing fighters, evaluated swept and semi-delta configurations, then settled on the delta wing, which offered good internal volume for support systems and fuel. It also provided low wing loading for the airframe size, permitting supersonic flight in the mid-stratosphere at 50,000 to 70,000 ft (15,000 to 21,000 m). Most of the configurations studied mated the delta wing to a relatively slender fuselage housing a crew of two and powered by a pair of jet engines.

General characteristics

Crew: Three
Length: 96 ft 10 in (29.51 m)
Wingspan: 56 ft 9 in (17.30 m)
Height: 29 ft 11 in (9.12 m)
Wing area: 1,542 sq ft (143.3 m2)
Aspect ratio: 2.09
Airfoil: root: NACA 0003.46; tip: NACA 0004.08
Empty weight: 55,560 lb (25,202 kg)
Gross weight: 67,871 lb (30,786 kg)
Max takeoff weight: 176,890 lb (80,236 kg)
Zero-lift drag coefficient: CD0.0068
Frontal area: 10.49 sq ft (0.975 m2)
Powerplant: 4 × General Electric J79-GE-5A afterburning turbojet, 10,400 lbf (46 kN) thrust each dry, 15,000 lbf (67 kN) with afterburner
Performance

Maximum speed: 1,146 kn (1,319 mph, 2,122 km/h) at 40,000 ft (12,000 m)
Maximum speed: Mach 2.0
Cruise speed: 530 kn (610 mph, 980 km/h)
Range: 4,100 nmi (4,700 mi, 7,600 km)
Combat range: 1,740 nmi (2,000 mi, 3,220 km)
Service ceiling: 63,400 ft (19,300 m)
Rate of climb: 17,400 ft/min (88 m/s) at gross weight
Lift-to-drag: 11.3 (subsonic, "clean configuration")
Wing loading: 44 lb/sq ft (210 kg/m2)
Thrust/weight: 0.919
Armament
Guns: 1× 20 mm T171 cannon
Bombs: 1× Mark 39 or B53 or 4× B43 or B61 nuclear bombs; maximum weapons load was 19,450 pounds (8,820 kg)
Avionics
AN/APB-2 Bombing radar
AN/APN-110 Doppler navigational radar (part of Sperry AN/ASQ-42 Navigation & Bombing System)
AN/APN-170 Terrain-following radar
AN/APR-12 Radar warning receiver
Hughes Aircraft AN/APQ-69 podded Side looking airborne radar (mounted on RB-58A)
Goodyear AN/APS-73 podded synthetic aperture radar (mounted on RB-58A)

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