Convair B-58 Hustler

https://en.wikipedia.org/wiki/Convair_B-58_Hustler

The Convair B-58 Hustler was the first operational jet bomber capable of Mach 2
flight. The aircraft was designed by Convair engineer Robert H. Widmer and
developed for the United States Air Force for service in the Strategic Air
Command (SAC) during the 1960s. It used a delta wing, which was also employed by
Convair fighters such as the F-102, with four General Electric J79 engines in
pods under the wing. It carried five nuclear weapons; four on pylons under the
wings, and one nuclear weapon and fuel in a combination bomb/fuel pod under the
fuselage, rather than in an internal bomb bay.

Replacing the Boeing B-47 Stratojet medium bomber, it was originally intended to
fly at high altitudes and supersonic speeds to avoid Soviet fighters. The B-58
was notorious for its sonic boom, which was often heard by the public as it
passed overhead in supersonic flight.

The introduction of highly-accurate Soviet surface-to-air missiles forced the
B-58 into a low-level-penetration role that severely limited its range and
strategic value, and it was never employed to deliver conventional bombs. This
resulted in only a brief operational career between 1960 and 1970 when the B-58
was succeeded by the smaller, swing-wing FB-111A.

The Convair design was based on a delta wing with a leading-edge sweep of 60°
with four General Electric J79-GE-1 turbojet engines, capable of flying at twice
the speed of sound. Although its large wing made for relatively low wing
loading, it proved to be surprisingly well suited for low-altitude, high-speed
flight. It seated three (pilot, bombardier/navigator, and defensive systems
operator) in separated tandem cockpits. Later versions gave each crew member a
novel ejection capsule that made it possible to eject at an altitude of 70,000
ft (21,000 m) at speeds up to Mach 2 (1,320 mph/2,450 km/h). Unlike standard
ejection seats of the period, a protective clamshell would enclose the seat and
the control stick with an attached oxygen cylinder, allowing the pilot to
continue to fly even "turtled up" and ready for immediate egress. The capsule
would float, and the crewmember could open the clamshell, using it as a life
raft. In an unusual test program, live bears and chimpanzees were successfully
used to test the ejection system. The XB-70 would use a similar system (though
using capsules of a different design).


Role
Supersonic strategic bomber

National origin
United States

Manufacturer
Convair

First flight
11 November 1956

Introduction
15 March 1960

Retired
31 January 1970

Status
Retired

Primary user
United States Air Force

Number built
116

Unit cost

US$12.44 million


Variants
Convair Model 58-9

The B-58 crews were chosen from other strategic bomber squadrons. Due to some
characteristics of delta-winged aircraft, new pilots used the Convair F-102
Delta Dagger as a conversion trainer, before moving to the TB-58A trainer. The
B-58 was difficult to fly and its three-man crews were constantly busy, but its
performance was exceptional. A lightly loaded Hustler would climb at nearly
46,000 ft/min (235 m/s). In addition to its much smaller weapons load and more
limited range than the Boeing B-52 Stratofortress, the B-58 had also been
extremely expensive to acquire.

Through FY 1961, the total cost of the B-58 program was $3 billion ($58 billion
in 2016 dollars). A highly complex aircraft, it also required considerable
maintenance, much of which required specialized equipment and ground personnel.
For comparison, the average maintenance cost per flying hour for the B-47 was
$361, for the B-52 it was $1,025 and for the B-58 it was $1,440. The B-58 also
cost three times as much to operate as the B-52. The cost of maintaining and
operating the two operational B-58 wings equaled that of six wings of B-52s.
This included special detailed maintenance for the nose landing gear, which
retracted in a complicated fashion to avoid the center payload. Further,
compounding this, the B-58 had an unfavorably high accident rate: 26 B-58
aircraft were lost in accidents, 22.4% of total production. The SAC senior
leadership had been doubtful about the aircraft type from the beginning,
although its crews eventually became enthusiastic about the aircraft. General
Curtis LeMay was never satisfied with the bomber and after a flight in one
declared that it was too small, far too expensive to maintain in combat
readiness and required an excessive number of aerial refuelings to complete a
mission. Although the high altitude ferry range of the B-58 was better than the
B-47, the lack of forward basing resulted in a requirement for more KC-135
tanker support.

By the time the early problems had largely been resolved and SAC interest in the
bomber had solidified, Secretary of Defense Robert McNamara decided that the
B-58 was not going to be a viable weapon system. It was during the B-58's
introduction that high-altitude Soviet surface-to-air missiles (SAM) became a
viable threat, especially the SA-2 Guideline, a SAM system the Soviet Union
extensively deployed. The "solution" to this problem was to fly at low
altitudes, minimizing the radar line-of-sight and reducing exposure time.

Because of the denser air at low altitudes, the B-58 could not fly at supersonic
speeds and its moderate range was reduced further, thereby negating the
high-speed performance the design paid so dearly for. In late 1965, Secretary
McNamara ordered the B-58's retirement by 1970. Despite efforts of the Air Force
to earn a reprieve, the phaseout proceeded on schedule. The last B-58s were
retired in January 1970 and placed in storage with the Military Aircraft Storage
and Disposition Center (MASDC) at Davis-Monthan Air Force Base. The fleet
survived until 1977, when nearly all remaining aircraft were sold to
Southwestern Alloys for disposal. The B-58 as a weapons system was replaced by
the FB-111A, designed for low-altitude attack, more flexible with the carriage
of conventional weapons, and less expensive to produce and maintain.

Specifications (B-58A)

General characteristics
Crew: 3: pilot; observer (navigator, radar operator, bombardier); defense system
operator (DSO; electronic countermeasures operator and pilot assistant).
Length: 96 ft 10 in (29.5 m)
Wingspan: 56 ft 9 in (17.3 m)
Height: 29 ft 11 in (8.9 m)
Wing area: 1,542 ft² (143.3 m²)
Airfoil: NACA 0003.46-64.069 root, NACA 0004.08-63 tip
Empty weight: 55,560 lb (25,200 kg)
Loaded weight: 67,871 lb (30,786 kg)
Max. takeoff weight: 176,890 lb (80,240 kg)
Zero-lift drag coefficient: 0.0068
Drag area: 10.49 ft² (0.97 m²)
Aspect ratio: 2.09
Powerplant: 4 × General Electric J79-GE-5A turbojet Dry thrust: 10,400 lbf dry
thrust (52.9 kN) () each
Thrust with afterburner: 15,600 lbf (69.3 kN) each


Performance
Maximum speed: Mach 2.0 (1,319mph) at 40,000 ft (12,000 m)
Cruise speed: 610 mph (530 kn, 985 km/h)
Combat radius: 1,740 mi (1,510 nmi, 3,220 km)
Ferry range: 4,100 nmi (4,700 mi, 7,600 km)
Service ceiling: 63,400 ft (19,300 m)
Rate of climb: 17,400 ft/min (88 m/s) at gross weight
Wing loading: 44.0 lb/ft² (215 kg/m²)
Thrust/weight: 0.919 lbf/lb
Lift-to-drag ratio: 11.3 (subsonic, "clean configuration")

Armament

Guns: 1× 20 mm (0.79 in) T171 cannon
Bombs: 1× B53 or 4× B43 or B61 nuclear bombs; maximum weapons load was 19,450 lb
(8,820 kg)