The F-14B Tomcat was developed version of the F-14A, with the primary difference being that advanced turbofan engines would be used. These engines would overcome the one significant shortcoming of the basic F-14A. that of being slightly overweight and thus somewhat underpowered. It was anticipated that essentially the same avionics suite used in the F-14A would be employed in the F-14B and the seventh development F-14A served as a testbed for the F401 engines originally intended for the F-14B. The new engine had been expected to be available for installation in the 68th aircraft. It was anticipated that the F-14B would have a 40 percent better turning radius, 21 percent better sustained g-capability, and an 80 percent greater radius of action.
The proposed new engine was required to produce 40 percent more thrust and weigh 25 percent less than the 20-year old TF30 used in the F-111 and F-14A. New lightweight materials and improved designs promised more efficient compressor stage-loading and higher turbine temperatures. The new engine was to generate more than 20,000 pounds-thrust and have a 9:1 thrust-to-weight ratio.
The new afterburning turbofan was developed largely from the P&W JTF16 demonstrator engine of the mid-1960s and the Air Force version was to have less thrust but a longer interval between overhauls because of more stringent Navy emergency thrust requirements during carrier landings. The Air Force F100-PW-100 engine was to use the same gas generator section (core engine) as the Navy F401-PW-400, but the size of the fan (and hence total mass flow and bypass ratio), afterburner, nozzle, and other significant components were not common. In February 1970, a full-scale F-14 inlet was delivered to Pratt & Whitney for compatibility testing with the F401.
On 22nd June 1971, the Navy cancelled its option for the remaining 58 F401 engines for the F-14B and lengthened F-14A production from 67 to 301 and eventually to 557 units (plus 80 for the Iranian Air Force). The Navy’s action opened the engine contract for renegotiation, and significantly increased the unit cost for the F-15. The contract was rewritten in August 1971 to reflect the deferred Navy procurement of the F401, with the two services agreeing to split $110 million in overruns, while P&W absorbed $12.2 million.
Upon completion of this test program, the F-14B prototype was again placed in flyable storage at Calverton, awaiting its use in the F-14D full scale development program.
In the meantime, the Air Force had decided to adopt a competitive engine strategy for both the F-15 and F-16 fighters, splitting engine orders between Pratt & Whitney and General Electric. With each new fiscal year, a new set of engine orders would be issued.
Having a second source would help to ensure a steady supply of engines, and competition between these two companies would, it was hoped, keep prices down. The Navy announced that it too would move to competitive yearly engine evaluations in selecting a new powerplant for the F-14. Initially, the Navy announced that the candidates would be the General Electric F110 and the Pratt & Whitney PW1128 turbotans. However, in the summer of 1983, the Navy abandoned this plan and announced that they would rely on the results of the USAF’s competitive evaluation.
The two USAF candidates were the General Electric F110-GE-100 and a revised Pratt & Whitney F100-PW-220. In February 1984, the USAF announced that General Electric had been awarded with 75 percent of the total contract for engines for the FY85 run of F-16 fighters. All of the FY85 F-15s and the remaining FY85 F-16s would use the upgraded Pratt & Whitney F100. The F110 was to be phased into the General Dynamics F-16 production line as soon as production engines became available, but it was agreed that individual USAF F-16 units would never operate a mix of engine types, the choice of engine being made at the wing level. Future models of the F-15 (like F-15E) are designed to accept both the FlOO and F110.
The Navy believed the F110 was the better engine because it provided greater thrust and promised to have lower overall support costs. Therefore, the Navy adopted the F110 for all future F-14s.
Externally, the F-14B can be distinguished from the F-14A by its larger engine exhaust nozzles, the deletion of the wing glove vanes, and the installation of the new AN/ALR-67 radar warning receiver with antennae below the wing glove area. A new Direct Lift Control/Approach Power Control system and AN/ARC-182 UHFA/HF radios were installed. A fatigue/engine-monitoring system was also added. An improved AN/AWG-15F fire control system was added, providing a faster and more capable processor and allowing easier incorporation of new weapons. Contrary to some published reports, the F-14B does not have the F-14A’s movable glove vanes.
Beginning with the first F-14B, a new gun gas purge system was incorporated, externally evidenced by three flush NACA ducts around the nozzle blister, and a vent on the blister immediately aft of the nozzle blister.
The F-14A/B Upgrade program was intended to consist of a modest capability modernization and service-life extension for 197 F-14A/Bs. In 1995, the upgrade essentially brought the aircraft almost up to the F-14D standard, except the AN/AWG-9(IV) radar and AN/AWG-15 fire control system were retained. Modifications included: a Mil-Std-1553B data bus architecture; enhanced AN/AYK-14 mission computers, programmable Tactical Information Displays; programmable Multiple Display Indicator Group; improvements to the AN/AWG-15, an expendable chaff system; and the AN/ALR-67 radar warning receiver.
The F-14C was to have been a version of the original F-14B fitted with upgraded avionics system that provided for all-weather attack and reconnaissance capability. Like the original F-14B, the F-14C was to have been powered by a pair of F401-P-400 turbofans. However, the high costs of the F-14C caused the Navy to order more Grumman A-6 Intruders instead and to initiate the VFAX program which resulted in the McDonnell Douglas F/A-18 Hornet.
The F-14C was abandoned before any examples could be built.