The primary weakness of the F-14A was its TF-30 engines, which left the Tomcat distinctly underpowered and which were prone to frequent stagnation stalling. The Air Force was also less than fully satisfied with the Pratt & Whitney F100 engines used in the F-15 and F-16 fighters. Concerned that the dominant position held by Pratt & Whitney in the high-thrust fighter engine market would leave the Defense Department without a second source for aircraft engines, and responding to political pressure, the Navy and Air Force both agreed to give General Electric a contract to build a next-generation engine which would power the F-14, F-15, and F-16.
In March of 1979, General Electric was given a contract for what came to be known as the F101 Derivative Fighter Engine (DFE). The F101-DFE used the core engine from the F101, which had originally been developed for the Rockwell B-1A (which had been cancelled by President Jimmy Carter in 1977), and was modified by adding a scaled-up fan and augmenter nozzle taken from the F404 engine used by the F/A-18A Hornet.
Ground tests of the F101-X demonstrator had started in 1977, and were followed by three F101 test engines. They were subjected to rigorous simulations and running conditions before flight testing in the F-14, F-15, and F-16 began in December 1981.
Following the cancellation of the F-14B, F-14A BuNo 157986 had been put into storage. In 1981, it was taken out of storage and re-engined with two General Electric F101 DFE (Derivative Fighter Engine) turbofans, each rated at 16,400 lb.s.t. dry and 27,400 lb.s.t. with afterburning. The first flight of the "Super Tomcat" (as the aircraft was unofficially known) took place on July 14, 1981 at Calverton. Grumman test pilot Chuck Sewell called this aircraft "a fighter pilot's dream". The test program showed significant performance gains, including a 62 percent increase in intercept radius, and such vast improvements in takeoff performance that non-afterburning carrier takeoffs were now a distinct possibility.
In the meantime, the Air Force had decided to adopt an alternative 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 two USAF candidates were the General Electric F101 DFE (now redesignated F110) and a revised Pratt & Whitney F100. In February 1984, the USAF announced that General Electric had been awarded with 75 percent of the total contract for engines for the FY1985 run of F-16 fighters. All of the FY 85 F-15 Eagles and the remaining FY 85 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 would be designed to accept either the F110 and F100.
The Navy announced that it too would move to competitive yearly engine evaluations in selecting a new powerplant for the Tomcat. Initially, the Navy announced that the candidates would be the General Electric F110 and the Pratt & Whitney PW1128 (a high-thrust derivative of the F-100) turbofans. 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 Navy liked the F110 better than the F100 since the F110 had greater thrust and promised to have lower overall support costs. In February of 1984, the Navy announced that they would be adopting the F110 for all future Tomcats, and would not be doing USAF-style annual procurement competitions.
In August 1984, the Navy awarded Grumman a contract for improved versions of the F-14 and A-6. The new Tomcat would be known as the F-14D. The troublesome TF30 would be replaced by the F110-GE-400, the avionics would be upgraded from analog to digital, the aircraft would receive an enhanced radar, a new computer, a stores management system, new controls, new displays, and a digital INS. While the full F-14D avionics suite was being developed, an interim aircraft, designated F-14A(Plus), would be produced which would introduce the F110 engines but keep the F-14A electronics suite. However, it was planned that all F-14A(Plus) aircraft would eventually be upgraded to full F-14D status.
The go-ahead for the interim F-14A(Plus) and the definitive F-14D program was given in July of 1984, when Grumman was awarded a contract. Both these versions were to be powered by General Electric F110-GE-400 turbofans, rated at an afterburning thrust of 27,000 lb.s.t. each. The engines were to be fitted with a computerized fuel control system to prevent compressor stalls in all flight regimes. In addition, the F-14A(Plus) was to be fitted with the AN/ALR-67 threat warning and recognition system.
The basic F110 was considerably shorter than the TF30 which it replaced. In order to avoid having to completely redesign the air intake ducting, the Navy version of this engine was "stretched" in length by adding a new section between the engine and the afterburning section. Apparently, this created no significant engineering difficulties. The nozzle is positioned 11 inches further aft, which should reduce the aerodynamic drag of the boat-tail area of the rear fuselage. Very few structural changes were needed to adapt the F-14A to the new F110 engine. Almost the only changes needed were the rearrangement of the engine accessories and their drive gearbox, plus minor modifications of the surrounding F-14 secondary structure.
F-14A BuNo 157986 (which had also served as the F-14B prototype) was chosen as the engine development aircraft for the new aircraft and was fitted with a pair of F110-GE-400s in 1986 and took off on its first flight on September 29, 1986, piloted by Joe Burke. This engine offered considerable extra thrust over the old TF30 turbofan, and offered a considerable better performance. The new F110 engines offered the additional benefit of fewer compressor stalls, a more unrestricted throttle movement throughout the entire flight regime, and improved fuel economy. In addition, the F110-GE-400 had over 80 percent commonality with F110 variants used by the Air Force.
The increased power of the F110 engine dramatically improved all-round combat performance. It also made it possible to perform catapult takeoffs from carriers without afterburner. The fuel consumption of the F110 was also much better than that of the TF30, increasing the mission radius by 62 percent. Time to reach high altitudes was reduced by 61 percent. Last and by no means least, the pilot could at long last forget about his engine during combat maneuvers and move the throttles shut or wide open no matter what the angle of attack or airspeed without having to worry about the danger of a compressor stall.
The F-14A(Plus) program called for the manufacture of 38 new aircraft and the rebuilding of 32 existing F-14As. BuNo 158630, the first F-14A(Plus) rebuilt from a TF30-powered F-14A, flew on December 11, 1986, and the first new-build F-14A(Plus) (BuNo 162910) flew on November 14, 1987. A second new-build F-14A(Plus) was accepted in 1987, 17 were delivered in 1989.
The first Navy squadron to receive the F-14A+ was VF-101 at NAS Oceana, which received its first planes in April of 1988. The first F-14A+ carrier landing took place aboard the USS Independence on April 15, 1988. VF-24 and VF-211 converted to the F-14A+ in the spring of 1989, followed by VF-142 and VF-143 in the late spring of 1990, and by VF-74 and VF-103 in the summer of 1990.
Externally, the F-14A(Plus) can be distinguished from the F-14A by its larger engine exhaust nozzles, the deletion of the wing glove vanes, a modified door near the gun port, 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 was installed, and the gun bay was redesigned, incorporating a gas purging system with NACA-type inlets replacing the original grilles. A fatigue/engine-monitoring system was added and AN/ARC-182 UHF/VHF radios are installed. The modernized and modified radar fire control system was redesignated AN/AWG-15F.
On May 1, 1991, the Navy decided to redesignate the F-14A(Plus) as F-14B, using the same designation as that of the stillborn F401-powered aircraft of 1973. A total of 38 F-14Bs were newly built from scratch, and 32 additional F-14Bs were produced by conversion from existing F-14A airframes. These conversions were allocated the sequential KB-series identifications KB-1 to KB-32 respectively. About 17 more conversions have since been funded, but it is now unlikely that these conversions will actually be carried out.
VF-24 and VF-211 subsequently transitioned back to the F-14A to allow the F-14B to be an Atlantic Fleet aircraft, with the new F-14D being limited to the Pacific Fleet.
The following squadrons have operated the F-14B:
Transitioned from F-14A to F-14A+ in summer of 1989.
Transitioned back to F-14A in 1992.
Disestablished August 31, 1996.
Transitioned from F-14A to to F-14A+ in 1990.
Disestablished April 28, 1994.
Transioned from F-14A to F-14B in 1994.
Transitioned from F-14A to F-14A+ 1990.
Transitioned from F-14A to F-14A+ in mid-1989. Disestablished
April 30, 1995.
Transitioned from F-14A to F-14A+ in mid-1989.
Transitioned from F-14A to F-14A+ in summer 1989. Transitioned back to F-14A in 1992.
Most F-14Bs were to be upgraded to F-14D standards under a general depot-level update program that was used for some of the earlier F-14As. However, post-Cold War cutbacks make this an extremely unlikely event.
157986 Grumman F-14A-30-GR Tomcat modified as F-14B and then as F-14A(Plus). 161270/161299 Grumman F-14A-115-GR Tomcat 161287(KB-5) converted to F-14A(Plus), later redesignated F-14B. 161416/161445 Grumman F-14A-120-GR Tomcat 161424(KB-1),161426(KB-2),161429(KB-3), 161418(KB-4),161428(KB-6),161433(KB-7), 161417(KB-8),161419(KB-9),161440(KB-10), 161444(KB-11),161427(KB-12),161416(KB-13), 161442(KB-14),161437(KB-15),161441(KB-16), 161421(KB-17),161422(KB-18),161425(KB-19), 161430(KB-22),161432(KB-24),161434(KB-25), 161435(KB-26),161438(KB-27) converted to F-14A(Plus), later redesignated F-14B. 161597/161626 Grumman F-14A-125-GR Tomcat 16159?(KB-20),161610(KB-21),161608(KB-23), 161610(KB-30) converted to F-14A(Plus), later redesignated F-14B. 161850/161879 Grumman F-14A-130-GR Tomcat 161851(KB-28),161871(KB-29),161870(KB-31), 161873(KB-32) converted to F-14A(Plus) and later redesignated F-14B 163217/163229 Grumman F-14B-150-GR Tomcat 163407/163411 Grumman F-14B-155-GR Tomcat
Engines: Two General Electric F110-GE-400 turbofans, each rated at 14,000 lb.s.t. dry and 27,000 lb.s.t with afterburning. Performance: Maximum speed (with four semi-recessed Sparrow missiles) Mach 1.2 (912 mph) at sea level, Mach 2.34 (1544 mph) at 40,000 feet. Combat air patrol loiter time 2.05 hours (at 173 mile radius with two 280 US gallon drop tanks). combat air patrol radius (with 1 hour loiter) 423 miles. intercept radius (Mach 1.3) 319 miles. Weights: 42,000 pounds empty, maximum takeoff weight, 75,000 pounds. Dimensions: wing span 64 feet 1 1/2 inches (unswept), 37 feet 7 inches (fully swept), length 61 feet 11 7/8 inches, wing area 565 square feet. Fuel: Maximum internal fuel 2385 US gallons. A 267 US-gallon drop tank can be carried on a hardpoint underneath each air intake. Armament: One 20-mm General Electric M61A1 Vulcan in the nose with 675 rounds. Provision for six AIM-7F/M Sparrow and two AIM-9L/P Sidewinder air-to-air missiles, or six AIM-54A/C Phoenix long-range air-to-air missiles and two AIM-9L/P Sidewinders, or four AIM-54A/C Phoenix missiles underneath the fuselage and two AIM-7F/M Sparrow and two AIM-9L/P Sidewinders on the wing glove pylons.