Convair RB-58 Hustler
From the late 1940's, Convair had been engaged in studies to design an advanced long-range subsonic bomber. Over the next few years various proposal by Convair and other firms were considered and the specification for the new bomber was slowly increased. In Dec 51 the USAF published a General Operational Requirement (GOR) for a strategic bombardment system (SAB-51) with a minimum operational radius using the single refuelling concept of 2000 nautical miles, a 2300 nautical mile radius at 50,000 ft, low altitude capability at high subsonic speed and maximum supersonic capability. The GOR for a strategic reconnaissance system (SAR-51) outlined a similar aircraft requirement. After a bid from Boeing was rejected, Convair were given the go ahead for a full scale Phase 1 development contract using as a basis a design known as MX-1964 - this was the aircraft that became the B-58 Hustler.
The B-58 was a highly advanced design for its time and featured a 60º delta wing with 4 GE J79-5A turbojet engines mounted separately underneath. Below the fuselage a large two-piece strike pod was designed to house both fuel and a nuclear weapon. In a later version the pod was split into two, the 54 foot lower element of the pod was designed to be dropped when empty of fuel before the run into the target. The 35 foot long upper pod would then be jettisoned over the target. Many new materials and design techniques were employed in the construction of the B-58. The aircraft carried 3 crew in separate tandem cockpits, a pilot, a bombardier/navigator and a defence systems operator. Each cockpit had an individual escape capsule that could be closed and pressurised in 7 seconds, allowing the crews to operate safely at high level without the need to wear bulky pressure suits. The B-58 first flew on 11 Nov 56 and 116 aircraft were eventually built.
In 1963 it was decided to give 45 B-58 aircraft a reconnaissance capability and these aircraft were modified to allow the carriage of ten modified MB-1C pods, re-designated the LA-331 pod. The LA-331 pod was equipped with a KA-56 low altitude panoramic camera mounted in the nose behind a V shaped optical glass port. The system was designed to provide horizon-to-horizon coverage from low altitudes at high speed. The control panel for the camera was mounted in the bombardier/navigator's cockpit and was interchangeable with the weapon monitor and release panel for the strike pod. The 43rd Bomber Wong at Carswell AFB was selected to operate the LA-331 pods and prove the concept and in Jan 64 the designated crews were checked and declared operationally ready. The reconnaissance capability of the B-58's of the 43rd BW equipped with the LA-331 pod was employed on a number of occasions, mainly to provide quick photographs of natural disasters to enable a rapid assessment of the relief resources required. Other specialised pods were built, such as the MD-1 ECM pod which never flew. However, a radar reconnaissance pod containing the Hughes AN/APQ-69 SLAR was flown in the early 1959. These tests led to a more compact version of the SLAR, the AN/APS-73, being fitted in a pod and during the Cuban Missile crisis a Hustler equipped with this pod overflew Cuba, the only time a Hustler was used on an operational mission.
The last 17 service test aircraft built were completed as RB-58A reconnaissance bombers. It was planned to equip these aircraft with a dedicated reconnaissance pod, designated the MC-1, built by Fairchild Camera and Instrument Company. The MC-1 pod contained three 36" focal length cameras in a stabilised mount to provide vertical and side obliques, a tri-camera system consisting of three 6" focal length cameras to provide vertical and side obliques, one 3" focal length forward oblique camera, a camera control system, a nose mounted television view finder, an operator's console unit, a fan of five 3" focal length cameras, a Melpar recording system, a Sperry navigation system and a Raytheon search radar scope camera. Total sensor weight was 998lbs. The equipment could be carried in two configurations, a high-low altitude configuration or a low altitude configuration. In Jul 55, because of funding limitations, the reconnaissance pod and its various systems were cancelled. Although the programme was reinstated in Sep 55, it was finally cancelled completely on early 58 following completion of a single pod that was never actually flown. The cancellation of the reconnaissance pod to equip the RB-58A is hardly surprising when you consider that by early 1958 the U-2 was operating routinely over the USSR and that planning for the A-12, which eventually led to the SR-71, was already underway. Consequently, with tactical and strategic reconnaissance already well catered for, there was little if any support for the additional costs involved in providing a reconnaissance capability for the RB-58A and the aircraft were eventually converted into standard B-58A's or TB-58A trainers.
The B-58 was a highly advanced aircraft and the first supersonic bomber built in the West. The aircraft set many international records, a number of which still stand. However, as the air defences of the Soviet Union improved the viability of the B-58 came into question, in addition, the wear and tear of operating a heavy bomber at supersonic speeds and high utilisation rates resulted in unusually high fatigue rates. Added to this were the aircraft's range limitations, it's poor safety record and it's significantly higher than anticipated production, maintenance and support costs. The high costs were best illustrated by the fact that the cost of maintaining and operating two B-58 wings equalled that of six wings of B-52's. In the end all these factors, together with a deep rooted dislike of the aircraft by SAC, resulted in a decision in Oct 69 to retire all the aircraft by 31 Jan 70, after only 10 years operational service and by Jan 71 all the aircraft were in storage at Davis-Monthan AFB - two years later, apart from a number of aircraft donated to museums, all the remaining aircraft had been reduced to scrap, a sad end to a spectacular aircraft.