In early 1989, Grumman proposed an upgraded F-14D to the Navy as an alternative to buying the Navy Advanced Tactical Fighter. This program is generally thought of as the Tomcat 21 project, especially after Aviation Week ran a series of articles on that aircraft. However, in reality Tomcat- 21 referred to just one of three proposals for an Advanced Tomcat. In order from the least expensive and quickest upgrade to the most sophisticated, the proposals were called QuickStrike, Tomcat 21, and ASF-14.
The so-called QuickStrike was a proposed long-range strike fighter version of the F-14D, designed to fill in the gap created by the cancellation of the A-12 as a possible A-6 Intruder replacement. It was envisaged as a sort of naval equivalent of the Air Force’s McDonnell Douglas F-15E Strike Eagle.
The QuickStrike was basically an F-14D equipped with FUR capability and provided with more modes for its APG-71 radar. These additional modes included synthetic aperture and Doppler Beam Sharpening for ground mapping, making the radar even more similar to the APG-70 of the F-15E. There would be four hardpoints under the central fuselage which would each carry five munitions substations, whereas the two wing glove pylons would have two munitions substations each. LANTIRN navigation and targeting pods would be similar to those already carried by the F-15E. The cockpit would have FLIR, HUD, and moving-map displays for the crew. The aircraft would be capable of carrying and delivering laser-guided bombs, stand-off SLAM missiles. Maverick air-to-surface missiles, HARM anti-radiation missiles, and Harpoon anti-ship missiles.
However, the selection of the McDonnell Douglas F/A-18E/F as the successor to the A-6, effectively killed the QuickStrike derivative of the Tomcat.
The Tomcat-21 was a proposed multi-role adaptation of the F-14D as a low-cost alternative to the Naval ATF, and drew heavily on the work done on the QuickStrike proposal. Modifications to the production F-14D under the Tomcat-21 proposal included upgraded avionics, increased internal fuel capacity, greater lift through a wing glove modification, and allowances for the aircraft to be employed effectively in the air-to-ground mode. Grumman anticipated the first flight could be conducted as early as 1993 if they had been given authorization to proceed in 1990. Total development costs for the new derivative were estimated at $989 million, and delivery of production aircraft could have begun in 1996. A total of 12 Tomcat-21 s would have been built in the first year of production, followed by 30 in each succeeding year. Grumman projected a need for 490 of the aircraft – 233 new production aircraft at a flyaway cost of $39 million each, and the remanufacture of 257 F-14B/Ds at a cost of $21 million each.
Major changes to the Tomcat-21 included a revised high-lift system which employed a single-slotted Fowler flap as well as modified slats and spoilers. This provided a 30 percent increase in lift at approach angles of attack. The aircraft also features a lengthened glove leading edge which would have allow the aircraft to carry an additional 2,500 pounds of fuel. The new section employed roughly the same contours as the original F-14A glove vane in its fully-extended position. Compared with the F-14D, gross takeoff weight grew from 72,900 pounds to 76.000 pounds, mainly due to the increase in fuel.
Avionics improvements included modifying the aircraft’s AN/APG-71 radar to provide an inverse synthetic aperture capability (similar to the F-15E’s AN/APG-70); enhanced look- down, shoot-down capability over land; and increasing target detection and acquisition ranges by 20% in the fighter environment. Grumman also investigated the possibility of using some ATP (Lockheed F-35 Lightning II) avionics on the aircraft.
Tomcat-21 was also to employ either the Night Owl forward-looking infrared (FUR) system developed by Ford Aerospace, or the existing Martin Marietta LANTIRN system used on the F-15E. The Night Owl system included a laser target designator with a ranging mode, and, along with an improved Northrop TCS, would have been mounted in a dual chin pod in the usual TCS location under the nose.
Alternately, the Tomcat-21 could carry modified LANTIRN navigation and attack equipment mounted in the fairings that previously housed the chilled oil cooling pumps for the AIM-54 missile. Four under-fuselage hard- points would have five munitions substations each, while the two wing glove pylons would have two substations.
In addition, Tomcat-21 was to have been powered by improved F110-GE-129 turbofan engines which offered supercruise’ (the ability to achieve sustained supersonic cruising speeds without the need for afterburning) and might have included thrust vectoring capability. The Tomcat-21 would also have featured enlarged tailplanes with extended trailing edges giving greater area.
The Advanced Attack Tomcat (originally called ASF-14) was based on the Super Tomcat-21 but had thicker outer wing panels that carried more fuel. In addition, the aircraft would have provision for carrying larger external fuel tanks. Further refinements to the leading-edge slats and the trailing-edge flaps were to give a 18-mph reduction in the landing approach speed. The aircraft was to use the Norden radar set that had been developed for the aborted General Dynamics/McDonnell Douglas A-12 Avenger II. The Attack Super Tomcat 21 received quite a bit of attention as a potential alternative to the cancelled A-12, but was never funded.
By 1994, the Navy had seriously evaluated Advanved Attack Super Tomcat 21 (ASF-14) proposal, but it was deemed to be unaffordable. A cost and operational effectiveness analysis was subsequently ordered to identify other F-14 precision strike options. The analysis was finished in December 1994, and one year later a Navy report recommended a stand-alone forward-looking infrared (FUR) and laser designator as the precision strike upgrade. A contract was then issued to Martin Marietta to integrate the LANTIRN system on the F-14 without the other improvements originally offered by Grumman in the Attack Super Tomcat 21 proposal.