Convair B-58A Hustler

Last revised July 1, 2000



A total of 86 production B-58As were built.

Fuselage

The fuselage of the B-58 was of semi-monocoque construction and had the standard bulkhead, former, and longeron construction that was typical of most other military aircraft of that era. There were 19 bulkheads. The area between bulkheads 1 and 5 carried the crew compartments. The volume aft of bulkhead 5 and all the way to bulkhead 19 was devoted exclusively to fuel except for the navigation system stable table area between bulkheads 8 and 9. The portion of the fuselage aft of bulkhead 19 contained the deceleration parachute, the tail armament, and electronic equipment.

Crew

The crew of the B-58 consisted of a pilot, a navigator/bombardier, and a defensive systems operator (DSO), all seated in tandem in three separate compartments. The pilot sat in front, the navigator/bombardier in the middle, and the DSO in the rear. A crawlway between the pilot's station and the second crew station on the right side of the fuselage could only be used for maintainence of electronic equipment, but a crawlway between the second and third crew stations could be used for passage during flight. The navigator/bombardier's panel was equipped with bomb and pod dropping instrumentation, bombing system indicators and monotors, plus the navigation equipment. The DSO's panel contained passive and active defense system monitors.

Structurally, the three crew compartments comprised a single pressurized cabin, but structal bulkheads and equipment created a compartmentalization effect. Each compartment had a separate canopy hinged at the rear for entry and exit. The compartmentilization prevented direct vision or physical contact between crewmembers during flight. The pilot had a windshield with six adjacent panels, plus one panel on each side of the canopy. This afforded excellent outside vision, and the pilot could see parts of the exterior of the aircraft as well as the engine nacelle inlets. The navigator/bombardier and the DSO only had small side windows.

The crew members were seated on individual ejector seats which were catapulted out of the top of the aircraft by a rocket engine. Problems with the originally-fitted SAC-type ejector seats when they were called upon to be used for emergency exit in the supersonic regime led to the development of an encapsulated ejection system developed by Stanley Aviation of Denver, Colorado. The unit protected the pilot against supersonic wind blasts, supplied oxygen and pressurization during an ejection at high altitude, absorbed landing impact and had survival equipment installed. Each capsule was an independently operating unit which required no outside power source. The second and third crew stations were identical and were both ejected on vertical rails. The pilot's capsule was similar, but included a flight control stick and was ejected on slightly leftward-canted rails. A three-piece telescoping clamshell door was pivoted on each side of the seat. It was stowed above the crew member's head during normal flight. It was actuated by raising the ejection handle, causing the doors to rotate downward to form a pressure-tight capsule. The doors could be closed in about a quarter second after actuation. Emergency oxygen and pressure were automatically actuated by door closure. After the doors were closed, each crew member manually ejected his own capsule by squeezing the trigger on the ejection handle, which jettisoned the canopy and fired the rocket catapult initiator. During high speed ejection, capsule stability was provided by the stablization frame and by a stabilization parachute. The recovery parachute was automatically deployed at a preset altitude. Landing impact was cushioned by crushable cylinders and stablization fins. For water landings, flotation bags were provided. During an emergency, the aircraft could still be flown while the pilot was encapsulated, and a small window in the capsule clamshell door provided a view of the instrument panel, while the pilot's control stick permitted controlled flight.

Wings

The wings of the B-58 were of fully cantilever, modified delta type with cambered leading edges and outboard tips. They incorporated multispar construction with a sandwich panel covering that was secured with titanium screws. The leading edges were of sandwich-type skin construction preformed to shape without any internal bracing.

The internal structure of the wing consisted of multispar construction with bulkheads at the points of major load. The two inboard bulkheads located in the wheel well area were large channels that were flanged away from the wheel well to allow maximum clearance for the main landing gear retraction. The spars were made so that contact with the wing skin was on a curved surface to allow the wing skin to more closely approach the contour of the desired airfoil. The wing sandwich panel was made up of aluminum sheet skins, adhesives, fiberglass and aluminum honeycomb core, and a machined aluminum grid.

The entire wing served as an integral fuel tank which was sealed from the outside during construction. Free-flow openings in other spars and bulkhead allowed fuel to flow between sections. Check valves prevented fuel flow between left and right wing sections when one wing was high. The wing panel figerglas cores served to insulate the fuel in the wings from the external heat.

Rudder

The vertical tail was a sweptback, truncated structure with spars and ribs providing the internal framework. The fin cap was fabricated of laminated fiberglas. The rudder had a full-depth aluminum core with an aluminum alloy skin bonded to it. It was hinged at 11 points along the front spar. The elevons were made of steel sandwich panels with a brazing alloy used as a bonding agent.

Flight Control System

The control surfaces consisted of a rudder and two elevons. The pre-production B-58s also had two resolution surfaces, located inboard of the elevons. These were used to mask out the effects of mechanical backlash in the longitudinal control system and were completely automatic. However, they were found to be redundant to the primary trim system and were eventually eliminated from all production aircraft, and were removed from existing pre-production aircraft as well.

The flight control system incorporated three-axis damping, constant stick forces throughout the entire speed range, and continuous g protection, making it virtually impossible to manually overstress the airframe when in automatic flight mode. An artificial feel system was installed, and altitude and Mach number control was providded for station keeping, approach control, landing, and flareout.

The flight control system included an automatic trim system which had three modes of operation: takeoff and landing, manual, and automatic. In the takeoff and landing mode, the trim system was locked at 3 degrees up elevator. In the automatic mode, the automatic trim system provided the elevon deflection required for 1-g flight. The auto trim system was closely associated with the ratio changer or g-protection system.

There was an aileron-rudder interconnect system that served to cancel out out the yawing that normally resulted from aileron deflection. Artifical pitch, roll, and yaw damping were supplied to minimize variations in flight characteristics and to provide satisfactory damping. There was also a "wing heavy" control system which sensed lateral accelerations and provided corrective rudder through the rudder damper servo to prevent lateral fuel shift and subsequent wing heaviness.

The Eclipse Pioneer autopilot system provided a constant Mach number by automatic control of the elevators. The aircraft was maintained at the desired altitude and Mach number by automatically controlling the elevators and throttles. The heading was maintained by automatically steering the aircraft along a constant track or a computer ground track.

Landing Gear

The main landing gear assemblies consisted of 8-wheel bogies, four wheels on each axle. Between each pair of tires there was a steel non-frangible wheel which was installed after mid-1961 in response to the continual problems that the B-58 had encountered with tire failure during landing and takeoff. The main gear was fitted with a set of multiple disk-type anti-skid brakes The main gear bogies were attached to large legs which were in turn connected to the underwing attachment points by large u-shaped connecting units. The main gear assemblies retracted into faired wing wells located inboard of the inboard engine pylons and nacelles. In order to provide sufficent space for the retracted wheel units within the thin wing, the wing wells projected significantly above the wing upper surface, being encapsulated under a wedge-shaped aerodynamic enclosure. The gear retraction mechanism was fairly complex, with the main unit retracting backwards into the wing recesses. During retraction, the main leg folded at the point where it joined the u-shaped connector in order that the whole unit could fit inside the bay. In spite of the complex retraction scheme, main landing gear retraction or extension failures were fairly rare. However, strut, bogie, and axle assemblies did occassionally break, resulting in damage to the aircraft and at least one complete writeoff.

The nose landing gear consisted of a pair of tires attached to a rather complex strut that retracted into a a well covered by a pair of doors. The complexity of the strut was in part due to the fact that the gear had to clear the nose of the ventral pod during extension or retraction. The strut was hinged so that the main strut rotated up and back into the well while providing clearance for the pod. The nose gear was fully steerable from the front cockpit.

The full sequence of landing gear retraction and extension took about 10 seconds.

The deceleration parachute system was housed underneath the rear fuselage just in front of the tailgun installation. It was a 28-foot ring slot parachute assembly housed inside a stowage compartment enclosed by dual clamshell doors. The pilot could jettison the parachute at his discretion.

Engines

The B-58 was powered by four General Electric J79 turbojets, housed in separate pods. The two inner pods were suspended underneath the forward part of the delta wing underneath pylons, whereas the two outer pods were attached directly to the wing undersurface.

The YJ79 was an axial-flow turbojet with a 17-stage compressor and a three-stage turbine. It was equipped with a variable exhaust nozzle, and air entering the compressor section was automatically controlled by variable positioning inlet guide vanes.

The variable exhaust nozzle system automatically controlled the exhaust area to provide for optimum thrust and specific fuel consumption under varying engine operating conditions. It also protected the engine from overheating. The system consisted of primary and secondary nozzle flaps, plus associated control units and actuators. Each primary nozzle control was mechanically interconnected with the engine throttle and synchronized so that throttle movement would automatically result in proper primary engine nozzle setting. The secondary nozzles were used to provide maximum thrust and reduced drag during cruise and military operating ranges. These were opened during idle and afterburner operation, and were closed for operations in the cruise and military ranges.

Each engine nacelle was equipped with a variable-position intake spike which could be moved forward or aft in the inlet to maintain an efficient airflow to the engine throughout the speed range of the aircraft. During normal operation, control of the spike was completely automatic. The spike remained in the aft position until an airspeed of Mach 1.42 was reached. At that speed, a switch in the air data computer closed and activated the system. The transducer then moved the spike forward to the appropriate location for the particular airspeed.

Engine cooling was provided by using two scoops located in the air inlet of each nacelle. Ram air was passed via these scoops through a series of bypass flaps into the hydraulic oil cooler, then aft between the engine and the nacelle walls to be expelled into the engine exhaust gases.

Fuel System

The fuel system of the B-58 was the most complex and sophisticated yet installed in an operational aircrft. The JP-4 fuel was stored in four main tanks, termed forward, aft, reservoir, and balance units. Two more fuel tanks were installed in the underfuselage pod (a total of 4172 US gallons in the MB or LA pod and 3885 US gallons in the TCP pod). The fuel system could operate with or without the pod being installed. The forward portion of both wings, as well as the fuselage volume between bulkheads 5 and 6 comprised the forward tank, which could accommodate up to 3202 US gallons of fuel. The aft portion of both wings and the fuselage volume between bulkheads 9 and 12 comprised the aft tank, which was capable of carrying up to 5893 US gallons of fuel. The fuselage section between bulkheads 6 and 8 comprised the 610-gallon reservoir tank, and the fuselage section between bulkheads 12 and 19 comprised the 1219-gallon balance tank. The reservoir tank acted as an accumulator tank by utilizing an autotransfer system which maintained a specified tank level until the other tank supplies had been depleted. The balance tank was not used for direct engine supply, but fuel could be transferred from the balance tank to the forward tank when needed. The center of gravity could be maintained either automatically or manually by transferring fuel between the forward, aft, and balance tanks.

The B-58 was equipped with a mid-air refueling system, mounted in the upper portion of the nose radome some 45 inches ahead of the pilot's windshield. It consisted of a receptacle for a KC-135A flying boom probe. When not in use, the system was covered by a door which was normally flush with the contour of the radome. When the slipway door was opened, it formed a guide for the entry of the flying boom.

The B-58 was equipped with an emergency fuel dump system. The fuel could be dumped via a a probe which extended two feet outward from the left side of the balance tank just aft of the wing trailing edge.

Defensive Systems

The defensive armament of the B-58 consisted of a General Electric T-171E-3 six-barrel 20-mm rotary cannon with a maximum firing rate of 4000 rounds per minute. The gun was mounted inside the extreme tail, on the axis of an articulated cone which consisted of tapered, concentric aluminum rings which were spring-loaded against each other. The tailgun assembly was aerodynamically faired to conform to the rest of the aircraft.

The Emerson MD-7 radar for the tail gun was located in a bullet fairing above the tail cone. The MD-7 radar was a Ku band unit. Data from the radar was fed to a computer mounted directly behind the gun and was then relayed electromechanically to the gun itself. Mach number and relative air density information were automatically supplied to the fire control system by the air data computer. The gun was aimed remotely by the fire control system in the tail, but there was a radar (automatic) fire control panel and a manual fire control panel located at the DSO's station, and the gun was actually fired by a button located there.

A total of 1200 rounds could be carried. Ammunition was drawn from a box in the fuselage just forward of the turret. The firing zone was any target within a 30-degree cone. During firing, spent ammunition shells were ejected through a ventral door.

The defensive electronic countermeasures system provided an early warning of the presence of enemy radar systems and could be used to deceive, confuse, or jam them. The system consisted of AN/ALR-12 radar warning equipment and an AL/ALQ-16 radar track breaking equipment. An AN/ALE-16 chaff dispensing system was installed in each upper main gear fairing, with chaff being ejected through mechanically-acutated slots in the tops of each wing fairing. The AN/ALQ-16 radar track braker was a repeater type jammer that generated deceptive radar jamming signals as a function of RF energy received from enemy tracking radars. When tracking radar signals were received, the track breaker generated and transmitted deceptive angle and range information, causing the tracking radar servo system to generate false antenna positioning information which in turn caused the tracking radar to compute false range information.

Electronic Systems

The aircraft was equipped with a Raytheon Ku band (16-17 GHz) search radar, with the antenna mounted in the extreme nose. There was also a daytime-nightime Lollsman Instruments KS-39 astro-tracker which automatically tracked a preset celestial body via a photocell mounted in a telescope and was so designed that it held the observed body in the center of the field of view.

The navigation/bombing system was a Sperry AN/ASQ-42 system. This system consisted of six major subsystems.

  1. An aft-fuselage mounted AN/APN-113 Doppler radar which determined the ground velocity of the aircraft and also calculated airspeed and wind.

  2. The heading subsystem including the astrotracker and the remote compass transmitter which determined the true heading of the aircraft.

  3. A navigation subsystem which continuously computed the latitude and longitude of the aircraft.

  4. A sighting subsystem which consisted of the nose-mounted search radar and radio altimeter which established the position of the aircraft relative to a given point on the earth.

  5. An indicator subsystem which contained controls used by the navigator and pilot in the operation of the primary navigation system. In addition, it generated the pod release signal during the bombing run.

  6. A malfunction system used to detect failures in the primary navigation system while also providing for alternative methods for completing the mission.

The primary navigation systems were provided by Bendix and Motorola. It was basically a Doppler inertial system using the astro tracker for a primary heading reference. While enroute, the position and course were continually computed by a precise dead reckoning system. Periodic search radar sightings were used to check the accuracy of the dead reckoning, and corrections were made as necessary.

Midway through its operational career, the B-58 was fitted with a voice warning system with a pre-recorded female voice that would inform the crew when an emergency was taking place. Every major event from an engine fire to a hydraulic failure was included in the set of events, and a total of 20 emergencies could be programmed into the system from 50 inputs.

The Magnavox communication system provided a means of crew intercommunication, plus normal and emergency air-to-air and air-to-ground communication. An AN/APX-47 IFF system was installed. Also included were AN/ARN-69 TACAN, AN/ARN-50 VHF navigation equipment, as well as AN/APN-136 and AN/APN-135 beacons.

Offensive Weapons

The primary offensive armament of the B-58 Hustler was caqrried in an underfuselage centerline pod, a pod which was almost as large as the fuselage itself.

The MB-1C pod was the standard free-falling pod unit that was carried underneath the B-58 fuselage on the centerline. It was basically a finned aerodynamic shell that carried a pair of fuel tanks plus a variable-yield thermonuclear bomb. The pod was 75 feet long with a diameter of about 5 feet. Empty weight was 2500 pounds without the fuel and the warhead being installed, but when fully loaded with fuel and carrying the standard W39Y1-1 warhead it weighed 36,087 pounds. The pod was attached to the aircraft by three hooks. The pod had an equipment bay, a forward fuel tank, a bay for the thermonuclear weapon, an aft fuel tank, a tail cone and fins, plus an attachment pylon. The four fins were mounted at 45 degrees from the horizontal centerline and were slightly offset to give the pod a slow spin during free-fall. The warhead was fused by a set of barometric switches, set to trigger the weapon when the preset pressure was reached. Fuel and fuel pressurization disconnects were released and were closed instantly when the pod was released.

AN/ASH-15 Indirect Bomb Damage Assessment equipment was installed inside the aircraft fuselage to give continuous pod position data to the aircraft after pod release. This data was saved on an inflight recorder inside the aircraft. At the time of warhead detonation, a photocell in the aircraft recorded the light intensity of the burst, and from the data recorded the yield, pressure, the altitude of the burst, the pod-to aircraft range, and the azimuth from the aircraft could be determined.

Some MB-1C pods were modified to incorporate a Fairchild KA-56 camera in a forward compartment. When so modified, the pod was redesignated LA-1. The system consisted of the camera and magazine, a scanner and converter, a control panel, and associated air conditioning and electrical systems. The pod camera control panel was located at the navigator's position and repleced the weapons monitor and release panel when the photo recon pod was installed.

The MB-1C pod had a relatively short service life because there were persistent problems with fuel leakage into the weapon bay. Several years of fighting with this problem lead to the introduction of the two-component pod.

The Two-Component Pod (or TCP) had the same overall profile as the older MB-1 and used the same attachment points. However, it was built in two separate sections. The TCP was actually two pods, an upper BLU 2/B-1 bomb pod and a lower BLU 2/B-2 fuel pod. The warhead unit could be retained while discarding the lower fuel pod.

The 35-foot long upper component contained two fuel tanks, separated by a warhead cavity. Maximum diameter of the upper component was 3.5 feet. A pylon and three fins were fitted. Two of the fins were mounted on the sides of the pod at 30 degrees above the horizontal, and the third (lower) fin was retracted within the upper pod while the lower pod was still attached. This lower fin deployed automatically upon lower pod release. The gross weight of the upper component when equipped with maximum fuel and a Mk.53 nuclear warhead was 11,970 pounds.

The lower component was also divided into two tanks, separated by a common bulkhead. It was supported underneath the upper pod by one forward and one aft releaser. There were no fins, but a pivot strut was mounted on the aft end of the pod to facilitate proper separation from the aircraft during release. The large lower pod was expendable and was released during flight when all the fuel in both the upper and lower components was consumed. The bomb pod remained with the aircraft for release during the delivery run. The empty weight was 1900 pounds, whereas the gross weight was 26,000 pounds.

Both the MB-1 and the TCP remained in the active inventory until the end of the B-58 program. Because of its several advantages, the TCP was the preferred pod, but the MB-1 pod accommodated a much larger warhead.

The MA-1C pod was a proposed rocket-propelled version of the MB-1 free- fall pod, designed to give the B-58 a stand-off capability. The pod was to be powered by a Bell Aerospace LR81-BA-1 rocket engine, fueled by a combination of JP-4 and red fuming nitric acid. The maximum range was expected to be 160 miles. During the flight to target, a maximum altitude of 108,000 feet and a maximum speed of Mach 4 was to be obtained. A Sperry guidance system was to control the pod during its flight to the target. However, the MA-1C pod was cancelled before it could be deployed.

The MC-1 was a proposed dedicated photo-reconnaissance pod. In 1953, the Fairchild Camera and Instrument Company was given a contract to develop a dedicated photo-reconnaissance pod for the B-58. The system could be installed within the standard MB-1C pod, and the only actual airframe modification would be the replacement of the package and bomb system equipment in the second crew station by photo navigation equipment. The MC-1 was to have a multi-camera system consisting of three 36-inch format cameras installed in a stabilized mount, a tri-camera system consisting of 3 6-inch cameras, one 3-inch forward oblique camera, a camera control system, a nose-mounted television view finder, a fan of five 3-inch cameras, a Melpar recording system, a Sperry navigation system, and a Raytheon search radar scope camera. However, in early July of 1955, the reconnaissance pod was cancelled due to funding limitations. The program was reinstated in September of 1955, when funding was again made available. However, the program was cancelled for good in early 1958, after only one pod had been completed. This pod was never actually flown under a B-58, although 55-0671 had been scheduled as the testbed aircraft.

The MD-1 was a proposed electronic reconnaissance pod which used many of the shell components of the standard MB-1 free-fall pod. It was equipped with a wide range of electronic sensors to analyze and record all enemy radar signals that reached the aircraft. Only one example was actually completed, and it was never actually flight tested.

Midway throughout its career, the B-58 was reconfigured to carry four Mk.43 thermonuclear weapons on external pylons underneath the wings between the fuselage and the main landing gear bays. Two weapons were carried on either side of the fuselage in tandem. The Mk.43 weapon was about 12 feet long, 1.5 feet in diameter, weighed about a ton, and had a variable yield of up to 1 megaton.

Specification of Convair B-58A Hustler

Powerplants: Four General Electric J79-GE-5A/5B axial flow turbojets, each rated at 9700 lb.s.t. normal power, 10,300 lb.s.t. military power, and 15,600 lb.s.t. maximum afterburner. Performance: Maximum speed: Mach 2.2 at 40,000 feet, Mach 0.91 at sea level. Cruising speed 521 knots. Takeoff ground roll 7850 feet at 160,000 pounds. Landing ground roll 2615 feet at 63,100 pounds. Maximum initial climb rate 38,650 feet per minute at sea level. An altitude of 30,000 feet could be attained in 11.2 minutes. Normal cruise altitude 38,450 feet. Target area altitude was 55,900 feet. Combat ceiling 63,400 feet. Maximum ferry range 4100 nautical miles. Weights: 55,650 pounds empty (without pod). Maximum gross weight 176,890 pounds (in flight). 63,100 pounds landing weight. Dimensions: Wingspan 56 feet 9.9 inches, length 96 feet 9.4 inches, height 29 feet 11 inches, wing area 1364.69 square feet. Armament: One General Electric T-171E-3 remotely-contolled cannon in tail with 1200 rounds. Offensive weapons consisted of one MB-1C pod containing a W39Y1-1 variable-yield thermonuclear warhead, or a a Two-Component Pod with a Mk.53 thermonuclear warhead. In addition, four Mk.43 thermonuclear weapons could be carried on external pylons underneath the wings between the fuselage and the main landing gear bays.

Serial Numbers of Convair B-58 Hustler:

55-0660/0672	Convair YB-58A-1-CF Hustler 
			All later redesignated B-58A.
58-1007/1023	Convair Y/RB-58A-10-CF Hustler
58-1024		Cancelled contract for RB-58A Hustler
59-2428/2463	Convair B-58A-10-CF Hustler
60-1109		Convair B-58B Hustler - cancelled contract
60-1110/1129	Convair B-58A-15-CF Hustler
60-1130/1148	cancelled contract for Convair RB-58A Hustler
61-2051/2080	Convair B-58A-20-CF Hustler

Sources:


  1. American Combat Planes, Third Enlarged Edition, Ray Wagner, Doubleday, 1982.

  2. Post World War II Bombers, Marcelle Size Knaack, Office of Air Force History, 1988.

  3. United States Military Aircraft Since 1909, Gordon Swanborough and Peter M. Bowers, Smithsonian, 1989.

  4. Convair B-58 Hustler: The World's First Supersonic Bomber, Jay Miller, Aerofax, 1997.