The next Stratofortress version was the B-52C (Model 464-201-6). It was the last Stratofortress version to be built solely at Seattle.
Only 35 B-52Cs were built. Letter Contract F33(600)-22119 of September 1952 had originally covered 43 RB-52Bs, but it was amended in May of 1954 to have the last ten examples delivered as RB-52Cs. At the same time, 25 more RB-52Cs were added to the order. In the event, all the planes were actually delivered as B-52Cs, but with dual bomber and reconnaissance capability. When fitted with the reconnaissance pods, the designation RB-52C was sometimes applied, although this designation was never used officially.
The primary difference between the B-52C and the earlier A and B models was that the B-52C featured much larger auxiliary underwing fuel tanks, with the 1000-gallon units of the B-52A and B being replaced by 3000-gallon tanks. This increased the total fuel capacity to 41,700 US gallons, which significantly extended the aircraft's unrefuelled range.
The powerplants of the B-52C were still the J57-P-19W or J57-P-29WA engines that had been used by the late B-52Bs. The gross weight was now up to 450,000 pounds.
The B-52B had initially been equipped with the Sperry K-3A navigation/bombardment system, which had turned out to be almost useless for high-altitude bombing. A temporary expedient was the IBM MA-6A, which was installed in the later B-52Bs. A vastly improved navigation/bombing system, the AN/ASB-15, initially equipped the B-52C. Later in its career, the B-52C was retrofitted with the AN/ASQ-48 bombing/navigation package at the same time that this equipment was fitted across the entire B-52D fleet.
The defensive armament of the B-52C comprised a battery of four 0.50-inch machine guns, just as it had on most of the B-52Bs. In the B-52B, these guns were directed by an MD-5 fire-control system which had a lot of bugs and had not lived up to expectations. All but one of the B-52Cs used the supposedly improved A-3A fire control system that had been used on the last seven B-52Bs. Unfortunately, the A-3A was itself less than fully reliable, and the last B-52C (54-2688) was fitted with an improved MD-9 fire control system, a system which was fitted to subsequent B-52 models.
The cause of a B-52B crash in February of 1956 had been traced to a faulty turbine-driven alternator. A new Thompson Products Company alternator was installed on the B-52C, which was much better but was still troublesome. Problems were traced to defects in the alternator drive's lubricating system. Another B-52 problem had to do with the trunnion fittings of the main landing gear, and defective fittings were found in nearly all B-52Cs.
The first B-52C flew on March 9, 1956. The last 5 B-52Cs reached the Air Force in December of 1956. All of them went to the 42nd Bombardment Wing based at Loring AFB in Maine and to the 99th Bombardment Wing at Westover AFB in Massachusetts.
Another innovation first introduced on the B-52C was a new paint job. The undersides of the fuselage of the B-52C fuselage and wings were painted at the factory in gloss white anti-flash paint. This paint was intended to reflect away some of the thermal radiation from a nuclear detonation, making the B-52C less vulnerable to damage caused by the release of its own bomb. National markings, USAF lettering, and other markings were not applied over the reflective paint. This system came into vogue in 1956, and was generally applied to most of those aircraft that were capable of delivering nuclear weapons, and some of the earlier B-52Bs were painted in this fashion during subsequent modification programs.
A special project known as Harvest Moon increased the B-52C's combat potential to that of the B-52D. The B-52C was also involved in other large programs that concerned themselves with the overall improvement of the entire B-52 fleet. These improved B-52Cs served in southeast Asia along with the B-52D. The last B-52C was retired in 1971.
The first B-52C (serial number 53-399) was retained for service and modification testing and was assigned to the Aeronautical Systems Division at Wright-Patterson AFB in Ohio. It was redesignated JB-52C or NB-52C, depending on the specific project.
Engines: Eight Pratt & Whitney J57-P-29WA or -19W turbojets, each rated at 12,100 lb.s.t with water injection. Performance: Maximum speed 636 mph at 20,200 feet, 570 mph at 45,000 feet. Cruising speed 521 mph. Stalling speed 169 mph. Initial climb rate 5125 feet per minute. Service ceiling at combat weight 45,800 feet. Combat radius 3475 miles with 10,000 pound bombload. Ferry range 7856 miles. Takeoff ground run 8000 feet. Takeoff over 50 foot obstacle in 10,300 feet. Dimensions: Length 156 feet 6.9 inches, wingspan 185 feet 0 inches, height 48 feet 3.6 inches, wing area 4000 square feet. Weights: 164,486 pounds empty, 293,100 pounds combat, 450,000 pounds maximum takeoff. Armament: Four 0.50-inch M3 machine guns with 600 rpg in tail turret. Maximum offensive payload 43,000 pounds.
53-0399/0408 Boeing B-52C-40-BO Stratofortress c/n 16878/16887 54-2664/2675 Boeing B-52C-45-BO Stratofortress c/n 17159/17170 54-2676/2688 Boeing B-52C-50-BO Stratofortress c/n 17171/17183