F-14A Plus History and Specifications

F-14A Plus History

In the Tomcat's entire history it's biggest and most recurrent problem has been the powerplant. Ever since the start of the VFX program, the TF-30 was recognised as an imperfect engine for the requirements. The original intention was that it would power only the first batches of F-14's. After two years production would switch to the F-14B, featuring the Pratt & Whitney F-401-P400 engine and all F-14A's would be upgraded to F-14B standard. Like most good plans, this fell through for a number of reasons and the Navy was left with theTF-30 to power the F-14. Although more reliable and safer variants of the TF-30 have come along since it is still the F-14's biggest weakness and the Navy was always interested in a better engine. Then in the early 1980's along came the General Electric F-110 turbofan and it is here that the F-14A Plus story begins.
Note: The F-14A Plus is now known as the F-14B, due, I believe, to problems with the Navy's computers in accepting the A+ designation. As mentioned above the F-14B designation had already been used, albeit for a single prototype. Within these pages I shall refer to the F-110 powered F-14 as the F-14A Plus, not by its present designation.

The Development of an Engine

The F-110 entered onto the scene in 1976, when the Navy was considering three different engines as possible replacements for the TF-30. At this time it was known as the F101-X and though both it and the other two engines seemed to offer real performance gains over the TF-30 the program was closed by having zero funding in the FY1978 budget.

The General Electric engine was given another chance due to the wider state of the US aero engine industry. While Pratt and Whitney engines were seen as more advanced than their competitors that put the services, especially the USAF, which would soon be ordering huge numbers of engines for its F-15's and F-16's, at a disadvantage on two counts. Firstly, any major engine problems could hamper large proportions of the inventory, as the USAF was painfully discovering with the F100 going through early difficulties at this time. Secondly it was felt that having only one major engine manufacturer made prices uncompetitive. Thus the USAF decided to bring competition into the engine market. At the same time it was felt that if the USAF and USN could find a common power plant for their main airframes major savings would be made, both in economies of scale in production, and in logistics and spares savings. As a result Air Force Systems Command began a program to further develop the F101-X (soon after known as the F101DFE-Derivative Fighter Engine).
The F101-X was derived from two main sources, the core came from the F101, the powerplant used in the B-1 bomber, while the fan and augmentor came from the F404, although they were scaled up for the F101-X. The F404 also powers the F/A-18 Hornet and is still under development for the F/A-18E/F Super Hornet.
After USAF flight trials were complete two F101-X's were installed in the single F-14B Tomcat (BuNo: 157986), which had been placed in long term storage at Grumman's Bethpage facility after the end of the F-401 program. The first flight of the 'Super Tomcat', as it was dubbed, occurred upon the 14th of July 1981. the engine lived up to its initial promise and testing continued until September 1981. Unfortunately at this time the Navy decided not to proceed with the re-engining and the (second, the first being the F401) F-14B program was cancelled. However testing of the aircraft continued until March of 1982. In October of the same year the F101-X (or F101DFE) entered its FSD (Full Scale Development) phase for the Air Force.
Although the Navy was no longer involved in the program it took interest in the continued development of the F101, which during this time was redesignated the F110. The choice of the F110 over the F100 by the Air Force in February 1984 made the idea of a common engine once more attractive to the Navy. Thus in July 1984 Grumman was issued a contract to install the F110 in the F-14B prototype. The F110 used by the Navy was not exactly the same as that for the Air Force, the main difference being that a 127c m (50in) extension has been included between the rear of the fan and the augmentor nozzle. This is simply to allow the engine to fit into the Tomcat's TF-30 size bays. Also detail changes have been made to the arrangement of components beneath the engine, presumably to make repairs easier in the more cramped confines of an aircraft carrier.
At the same time as it won the contract to install F110's in the F-14B and begin further flight testing Grumman also won the contract to begin FSD of an upgraded Tomcat, which would eventually become the F-14A Plus.

The A Plus

While the F110 was the heart of the A Plus program the new aircraft was to incorporate many other important upgrades as well. Hughes was subcontracted to produce a new fire control system, resulting in the AWG-15F, which is more reliable, easier to mai ntain and has slightly upgraded capabilities when compared to the AWG-9.
Another important upgrade is the installation of the AN/ALR-67 in place of the AN/ALE-39 in the F-14A. The same system as in the F-14D, the AN/ALR-67 covers not only the usual radar bands but extends coverage into the millimeter and laser bands. The new RWR gives the Tomcat a much needed boost in it's abilities to detect and classify threats against itself, even more important when one considers that the F-14 is by no means the stealthiest of airframes.
Other upgrades include the fitment of ARC-182 UHF/VHF radios, a Fatigue/Engine monitoring system (FEMS) and improvements to the Direct Lift Control system (DLC/AFC MOD). First used on the F-14A the DLC allows pilots to alter their approach path without changing their attitude. Before it was installed a change in the approach path did require a change in aircraft attitude, which in turn needed a throttle adjustment to return the aircraft to the correct attitude. By installing a DLC the F-14 made these sort of corrections unnecessary and eased the pilots workload on carrier approach. The DLC works by using the upper wing spoil lers of the F-14, engaging it means the spoilers pop up. Once in the extended position the spoilers become neutral. This means that when they are dropped back into their flush position they generate lift instantaneously, without the need for an attitude c hange. On the F-14A only the outboard spoilers were used, which was found to be giving insufficient lift to enable large corrections on approach. The A Plus uses both inboard and outboard spoilers, enabling much more lift to be generated and thus larger, more effective corrections to be made.
The A Plus also features a new style of vents to clear dangerous gas build ups from the gun bay. This is an active purge system, compared to the F-14A's passive venting system and was successful enough that it has been retrofitted to late production F-14A 's. All F-14's in service now have this gun bay purge system.
Notable for their deletion from the A Plus were the wing glove vanes of the F-14A. Designed to be used at supersonic speeds to help counter trim movements these were found to have little real effect and were thus removed to save weight and complexity.

F-14A Plus Development and Service

The F-14A Plus FSD aircraft was BuNo:162910 and it, along with five others (four more F-14A Plus and the F-14B prototype) were involved in the flight testing. 162910 first took to the air in September 1986, flying from Grumman's Calverton site. It was to be the first block 145 aircraft.
Production F-14A Plus began in March 1987 with the first delivery being to the Naval Air Test Center, Patuxent River in November of that year. 1988 saw missile testing at the Pacific Missile Test Center (PMTC) at Pt. Mugu. VX-4 also received the A Plus in early1988 and flew many of the PMTC test flights. After VX-4 and the other test centres had pronounced the A Plus fir for service airframes began to flow to fleet units. First to receive the new aircraft was VF-101, enabling it to begin incorporating the updated variant into its training syllabus. The first deployable squadron to receive the new type was VF-74, soon followed by its sister squadron VF-103.
Next up to receive the A Plus were VF-211 and VF-24. Both began to receive the new aircraft in April 1989, VF-24's first aircraft arriving on the 14th. However both squadrons later converted back to F-14A's, due to the decision to concentrate all F-14A Plus with the Atlantic fleet. VF-142 and VF-143 were the next squadrons to receive the A Plus, VF-143 receiving its first aircraft (BuNo:161441) on the 26th of May 1989. VF-142's aircraft came from VF-74 while VF-143 got theirs from VF-103, these squadrons presumably receiving replacements fresh off the production line. VF-142 later disestablished and its F-14A Plus aircraft were passed on to other units.
VF-102 is the latest unit to convert to the A Plus. It has recently (late 1996) gained the F-14A/B Update model. This is an updated version of the A plus (now called F-14B) which features new avionics and the provision to carry LANTIRN pods. VF-103 received an interim Update model for its first cruise with LANTIRN. Thus VF-102 will be the first unit to deploy with the fully modified Update. The full Update model has digital bus architecture, a digital TARPS pod using the new Pulnix camera in place of the KS-87B frame camera, NVG's and compatible cockpits, updated radar warning receiver and decoys.
More units are likely to convert to the F-14A Plus in future, as the Navy has been converting small numbers of F-14A's into A Plus aircraft over the last few years. VF-32 is presently rumoured to be the next unit to convert to the A Plus, gaining full capability Update models, like VF-102. Also once the F/A-18E/F starts to come on line there is a strong chance that F-14A Plus' will transfer to other units.

F-14A Plus Blocks

The aircraft in blocks 105 to 140 are all conversions of former F-14A's. Aircraft from block 145 onwards were new build F-14A+. I have several sources for these BuNos and none agree totally. Thus this should not be considered a definite list of F-14A+ production and is likely to be updated in the future.

[Block 30] [Block 105] [Block 110] [Block 115] [Block 120] [Block 125] [Block 130] [Block 145] [Block 150] [Block 155]


Joe Baugher's impressive F-14 history, available online at Elevon
Serial numbers were checked against the World Air Power Journal USN&MC Directory and the listing sent to me by Paul Abadesso of the AWACS Aviation Group.
World Air Power Journal vol 7, Aerospace Publishing 1991
F-14 Tomcat in action, Squadron/Signal Publications 1990
The Great Book of Modern Warplanes, Salamander 1987
Air International, November 1995

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