Avionics usually come first when it comes to upgrades to military aircraft such as the F-15, F-16 and F-18.

Graham Warwick/ATLANTA

LOCKHEED MARTIN'S F-16 and McDonnell Douglas' F-15 and F-18 represent the single largest constituency of modern Western-built fighters in service worldwide. With some 6,400 F-15s, F-16s and F-18s delivered almost 750 more aircraft on order, and potential for perhaps 2,000 more sales, it is not surprising that they are the focus of attention for avionics companies seeking to sell equipment on to existing and new aircraft.

The US Air Force has requirements for additional F-15Es and F-16s which, if funding can be found, would extend production into the next century, while the US Navy plans to begin replacing its 1,000 F-18s with the upgraded F-18E/F around the turn of the century.

Internationally, these aircraft are being offered in fighter competitions under way in Thailand and the United Arab Emirates. Further such contests are pending in Norway, and are forecast for countries in the Middle East and South America. Upgrade Programmes

Lockheed Martin delivered the 3,500th F-16, a Block 50 F-16C for the US Air Force, in April. A further 450 aircraft are now on order, including 150 Block 20 F-16A/Bs for Taiwan. Deliveries for the USAF end in early 1997, but the Air Force has an un-funded requirement for 120 more aircraft to forestall a fighter shortfall beginning around the year 2000.

The manufacturer has offered to build a further 120 Block 50-standard F-16Cs at 24 aircraft a year for a flyaway unit price of $20 million. It is also studying an enhanced "Block 60" aircraft incorporating avionics upgrades sought by the USAF and an improved "Falcon 2000" which would combine these upgrades with a stretched, delta-wing, airframe.

A major upgrade programme is under way for the European operators of early-model F-16A/Bs. Flight-testing of the MLU F-16 began in April, and deliveries of kits to upgrade 301 Belgian, Danish, Dutch and Norwegian aircraft will begin in August.

The $1.6 billion MLU is intended to enhance the capabilities of the F-16A/Bs, to maintain their operational effectiveness for a further ten to 20 years. The major elements are a modular mission-computer, improved radar and enhanced cockpit. Several MLU features are being incorporated in new-production A/Bs and have been included by the USAF in its Fighter Configuration Plan (FICOP) to upgrade in-service C/Ds.

MDC's F-18E/F, a structural upgrade of the current F-18C/D, will be flown for the first time in December and the US Navy plans to take delivery of its final C/Ds and first E/Fs in 1999. The E/F upgrade will extend the F-18's range, improve survivability, increase payload and provide growth capacity to extend the F-18's service life beyond 2020.

MDC has delivered 1,275 F-18s, and has orders for some 200 more C/Ds. The current aircraft includes, an up- graded radar and mission computer and improved navigation and EW systems. MDC and the USN are discussing a programme to demonstrate improvements to the C/D, including crew station enhancements developed for the E/F. A reconnaissance version of the F-18C is under development for the US Marine Corps.

The baseline avionics suite for the F-18E/F is identical to that of late-model, Lot 19, F-18C/Ds, except for the enhanced crew station. Future upgrades under study include an active-array radar and internally mounted IR targeting system. F-18E/F derivatives under study include an EW version.

MDC has placed the F-15 back in production, and will deliver the first of 72 F-15Ss to Saudi Arabia in September. This order, together with 21 F-15Is for Israel, will extend production into 1999, and the F-15 is being offered in the United Arab Emirates. MDC has offered to build additional F-15Es for the USAF at a flyaway unit cost of $50 million or less to forestall a strike-fighter shortfall.

New-production aircraft incorporate several improvements, principally crew station enhancements, over the two-seat F-15E, the last of which was delivered to the USAF in June 1994. MDC plans to demonstrate upgrades to the F-15C/D which would allow the air-superiority aircraft to be used in a range of roles, including reconnaissance, defence suppression and battle management. Some of these are included in the USAF's FICOP blueprint to upgrade its in-service F-15s. Fire-Control Radar

Westinghouse Electric's upgraded APG-66(V)2 radar, for the F-16A/B MLU incorporates technology from its APG-68(V)5 radar, in the Block 50 F-16C/D. The upgrade increases APG-66 detection and tracking range by 25% and enables the A/B to carry the AIM-120 advanced medium-range air-to-air missile.

New air-to-air capabilities introduced include ten-target track-while-scan, and the simultaneous engagement of up to six targets with up to six fire-and-forget AIM-120s. New air-to-ground modes include medium-resolution Doppler-beam-sharpened ground mapping. A version of the MLU radar, the APG-66V(3), will equip Taiwanese F-16A/Bs, which will carry the less-capable AIM-7 missile.

Improvements under study for the APG-68 include the introduction of a high-resolution synthetic-aperture-radar (SAR) ground-mapping capability. The USAF has identified SAR as a key element of its F-16C/D upgrade plans and is considering the feature for any new aircraft it acquires.

Deliveries of F-18s equipped with Hughes Aircraft's APG-73 radar began in mid-1994. The radar is an upgrade of the APG-65 originally fitted to the F-18 and includes, an increased performance processor and wider band width receiver/exciter to support future growth, including, provisions for the eventual installation of an electronically scanned active array radar. The APG-73 will be installed on F-18C/Ds delivered to Finland, Malaysia and Switzerland and is the baseline radar for the upgraded F-18E/F.

The USAF launched a programme to upgrade the Hughes APG-63 radars in more than 350 F-15C/Ds with the award of a $190 million, 52-month, development contract to McDonnell Douglas in October 1994. The APG-63(V)1 upgrade, will incorporate the transmitter and software, from Hughes' APG-70 radar (in the F-15E) and components from the F-18's APG-73 and is intended to improve reliability and maintainability by a factor of ten. Flight tests are to begin in August 1997, with retrofit of the fleet to begin in 1999.

Japan is evaluating the upgraded APG-63 for use in a programme to update its F-15Js. Also under consideration is the electronically scanned active-array radar being developed by Mitsubishi Electric for Japan's Mitsubishi FS-X, the airframe of which is based on the F-16C.

Another potential F-15 radar is Westinghouse Norden Systems' APG-76, developed and produced for upgraded Israeli MDC F-4Es and offered, unsuccessfully, for Israeli F-15Is. The APG-76 is a multi-mode radar with the capability for simultaneous SAR ground-mapping and moving-target indication. The radar is being flown in an under-wing pod on a USAF F-16 to test its ability to detect Scud-type targets. Electronic Warfare

In May, the US Department of Defense launched the Integrated Defensive Electronic Countermeasures (IDECM) programme to develop an internal electronic-warfare (EW) system for a range of US Air Force and US Navy aircraft, including the F-16 and F-18. The IDECM started as a programme to develop an EW suite for the F-18E/F, and is a follow on to the joint-service Airborne Self-Protection Jammer (ASPJ), cancelled controversially in 1992.

The IDECM is intended to use ASPJ antenna and wiring provisions already in F-16s and F-18s, the Raytheon ALE-50 towed decoy, Tracor ALE-47 "smart" chaff/flare dispenser, and the missile-approach warning system to be developed under the US Army-led Advanced Threat Infra-Red Countermeasures (ATIRCM) programme. The system will interface with existing radar-warning receivers (RWRs).

The ITT/Westinghouse ALQ-165 ASPJ was cancelled in late 1992 after failing its operational evaluation - a verdict which the manufacturers dispute. The system was later approved for commercial sale to export customers, and the ALQ-165 has been selected by Finland and Switzerland for F-18s, and is on offer to South Korea for F-16s. In July, following the shooting down of an F-16, the Pentagon approved the temporary installation of ALQ-165s on 12 Marine Corps F-18s operating over Bosnia to counter the threat from SA-6 missiles. The units were taken from storage.

Individual service efforts to develop missile approach warning systems were combined early in 1995 under the Army's ATIRCM programme to produce a laser-based directed IR-countermeasures (DIRCM) system to "dazzle" infra red (IR)-guided missiles fired at helicopters. The ATIRCM sensor will be used as the common missile-warning system (CMWS) on USAF and USN combat aircraft, controlling the release of flares to decoy IR-guided missiles.

Lockheed Martin company Sanders, produced the prototype ATIRCM, using a Loral passive ultra-violet (UV) sensor. Sanders, is now competing against Litton, Northrop, Grumman and Raytheon, for the ATIRCM development contract. Litton has been developing a missile-warning system using Daimler-Benz Aerospace passive-UV technology, while Raytheon has been working with Cincinnati Electronics on a passive-IR sensor. Northrop Grumman's ATRICM bid is based on the Nemesis DIRCM ordered by the Royal Air Force in the UK, and USAF Special Operations Forces, earlier this year. This uses a Westinghouse IR missile-warning sensor.

The "standard" EW suite on the F-18 consists of the Litton ALR-67(V)2 RWR and the Sanders ALQ-126B internal jammer. The USN plans to begin installing an improved RWR - the Hughes-developed ALR-67(V)3 Advanced Special Receiver - on its F-18s later this decade, and the system will be standard on the F-18E/F. Canadian and Spanish F-18A/Bs are additionally equipped with Northrop Grumman's ALQ-162 continuous-wave radar jammer. The manufacturer is testing an improved ALQ-162 capable of jamming pulse-Doppler radar.

There is no standard F-16 EW suite. The baseline RWR is the Litton ALR-69 on the F-16A/B and the Loral ALR-56M, which is also produced by Litton, on the F-16C/D. The baseline radar-jammer options are the Westinghouse ALQ-131 and Raytheon ALQ-184 pods. Taiwanese F-16A/Bs will be fitted with the ALR-56M receiver, and will carry the ALQ-184 pod.

Customers have a wide range of choice beyond these basic EW options. Belgian F-16A/Bs are being equipped with Dassault Electronique's Carapace RWR, for use with the ALQ-131 pod. Greek F-16C/Ds are to be fitted with the Litton ALR-66 RWR and Raytheon ALQ-187 internal jammer. Israeli and Turkish F-16s are equipped with Loral's ALQ-178 internal jammer.

Danish F-16A/Bs are equipped with a pylon-mounted EW system developed locally by Per Udsen. This consists of Northrop Grumman's ALQ-162 jammer and a Tracor ALE-50 dispenser installed in the weapons pylon, and a TERMA Elektronik electronic-warfare management system (EWMS). The EWMS is part of the F-16 mid-life update (MLU) and is being offered, as is Per Udsen's pylon-integrated dispenser system, for USAF Reserve and Air National Guard F-16A/Bs.

Cancellation of the ASPJ in 1992 led other manufacturers to offer competing integrated jamming systems for the F-16 and F-18. These have included the Loral ALQ-202, which combines the ALR-56M receiver with the ALQ-178 jammer; a repackaged version of the F-15's Northrop Grumman ALQ-135 internal-jamming system; and GEC-Marconi Defence Systems' Zeus.

Israel has selected Elisra to supply the EW suite for its 21 F-15Is. This Israeli-developed system will replace the standard F-15 suite, which combines Loral's ALR-56C RWR with Northrop Grumman's ALQ-135 internal jammer, and consists of Elisra's SPS-3000 RWR and a radio-frequency jammer.

Suppression of enemy air-defences (SEAD) is a relatively new role for the F-16. USAF Block 50 F-16s are operational with Texas Instruments' (TI) ASQ-213 HARM targeting system (HTS). This intake-mounted pod enables TI's AGM-88 high-speed anti-radiation missile (HARM) to be launched against detected emitters in its most-lethal "range-known" mode.

USN plans call for a similar capability on the F-18. Loral tested a pylon-mounted precision emitter-location system on an USN F-18 in 1993, and Litton is developing the Advanced Digital Receiver, which would fit inside the F-18's ALR-67 RWR, and provide a precision direction-finding and identification capability using the existing antennae. Litton plans flight tests in an F-18 this year, and later in an F-15 and F-16.

MDC is seeking USN backing for a command-and-control-warfare derivative of the F-18F, which would replace the Northrop Grumman EA-6B EW aircraft. MDC has teamed with Northrop Grumman, Litton and Sanders to promote the aircraft. The two-seater would be equipped with wingtip wide band-receiver arrays and under-wing jammer pods with steerable transmitter arrays.

MDC continues to work on a SEAD conversion of the F-15C, although the USAF has cut funding for the programme. The aircraft would be equipped with a Hughes or Litton precision direction-finding (PDF) system. As an alternative to the PDF, TI is developing an enhanced version of the F-16 HTS which it hopes to flight-test in an F-15 in 1997. Japan, meanwhile, plans to convert F-15Js to escort jammers for the FS-X and has begun development of the associated EW system. Targeting Systems

The US Air Force has identified an internal targeting system (ITS) as a key requirement for upgraded and new F-15s and F-16s. The ITS is a replacement for the LANTIRN navigation- and targeting-pod system now carried by F-16s, internally mounted to reduce drag and radar cross-section.

Lockheed Martin has flight-tested various ITS configurations including Westinghouse's dual-ball Falcon Eye, which combines a forward-looking infra-red (FLIR) navigation sensor with a head-steered targeting FLIR slaved to the pilot's helmet-mounted display. MDC is also looking at an ITS for the F-18E/F as an alternative to the current pods.

Lockheed Martin's LANTIRN navigation and targeting system was developed for USAF F-15Es and F-16C/Ds and has been widely exported. The system has two intake-mounted pods: the AAQ-13 navigation pod with a FLIR sensor and terrain-following radar; and the AAQ-14 targeting pod with a gimballed FLIR sensor and laser range finder/designator.

LANTIRN customers include Greece, Singapore, South Korea and Turkey for the F-16C/D and Israel for the F-15I. The Sharpshooter export version of the LANTIRN targeting pod has been sold to Bahrain, Egypt and Israel for the F-16C/D and Saudi Arabia for the F-15S. The Pathfinder navigation pod, which lacks the LANTIRN's terrain-following radar, has been sold to Egypt for the F-16C/D and Saudi Arabia for the F-15S.

The equivalent system for the F-18 combines a Hughes AAS-50 navigation pod with a Loral AAS-38 Nite Hawk targeting pod. The intake-mounted Nite Hawk has a gimballed FLIR sensor, laser designator/ranger and laser spot-tracker. Systems have been sold to all F-18 customers.

Loral's Nite Hawk is among several alternative systems for the F-16. The first targeting pod to be qualified on the F-16 was Thomson-CSF's ATLIS II, a daylight-only laser-designator pod, which is operational on the F-16A/Bs of at least two countries. The French company has now developed the Convertible Laser-Designator pod, which has interchangeable daylight television (TV) and night FLIR sensor heads.

Israel has ordered Rafael's new Litening targeting pod for its F-16C/Ds, with deliveries beginning in mid-1996. The Israeli-developed pod provides both navigation and targeting capability, with gimballed FLIR and TV sensors, laser range-finder/designator and laser spot-tracker. Northrop Grumman has agreed to help market the Litening pod, which is adaptable to the F-18. A derivative, the Lite pod mounts the Litening sensor section on the front of an under-fuselage fuel-tank and is offered for early-model F-16A/Bs.

GEC-Marconi Avionics has demonstrated its Atlantic FLIR pod on the F-16, but is now concentrating marketing efforts on its thermal- imaging laser-designator (TIALD) targeting pod. This combines gimballed FLIR and TV sensors with a laser designator. Developed for the Panavia Tornado, the TIALD is under consideration for the Netherlands' F-16 targeting-pod requirement. Reconnaissance

The US Air Force has dusted off its manned tactical-reconnaissance requirement with the pending retirement of its MDC RF-4Cs, and is looking for an interim capability in the shape of 26 to 56 reconnaissance pods to be carried by Air National Guard F-15s or F-16s.

The urgent requirement is the result of the 1993 cancellation of the Lockheed Martin advanced tactical air-reconnaissance system (ATARS) programme to develop a "filmless" sensor suite to be carried by USAF F-16s, in an under-fuselage pod, and USMC F-18s, in a nose-mounted pallet. MDC continues to develop the reconnaissance F-18 for the USMC, using electro-optical and infra red sensors developed by Loral for the ATARS programme.

In response to the USAF requirement, both Lockheed Martin and MDC conducted quick-reaction reconnaissance-pod flight demonstrations early in 1995. The F-16 pod, now being evaluated by the ANG, houses a Recon/optical KS-87 camera modified to an electro-optical sensor. The pod evaluated by MDC on the F-15 carries Loral's ATARS medium-altitude electro-optical sensor. Flight tests included the data linking of imagery to the ground.

Other contenders for the USAF requirement include a Danish reconnaissance pod, developed by Per Udsen, to be evaluated in the USA during 1995. Israel's El-Op has also developed a reconnaissance pod believed to be in use on Israeli F-16s.

COCKPIT DISPLAYS

Cockpit upgrades under way for the F-15, F-16 and F-18 are introducing colour liquid-crystal displays (LCDs) for the first time. A major feature of the F-16 MLU is the introduction of two Honeywell colour-LCD multi-function displays (MFDs). The use of colour is designed to increase pilot situational-awareness, while the LCDs are predicted to be more reliable than the monochrome cathode ray-tube displays used in the F-16. Taiwan's F-16A/Bs will have colour displays.

The USAF has so far resisted Lockheed Martin's offer, of a colour-MFD upgrade for its F-16C/Ds, but under its FICOP blueprint, it has identified a requirement for a large, centrally mounted colour-LCD tactical-situation display. The display is being evaluated in an F-16 FICOP cockpit-simulator at Lockheed Martin.

Crew station enhancements under development for the F-18E/F are now being considered to upgrade the F-18C/D. The Kaiser Electronics display suite for the E/F features a larger, colour-LCD, central MFD and a new up-front control/display panel with a monochrome touch-screen LCD. Another monochrome LCD replaces the F-18's engine/fuel display system.

F-15Ss for Saudi Arabia and F-15Is for Israel will feature cockpit improvements over the USAF F-15E. These include a Kaiser wide-angle head-up display (HUD) and a LCD up-front control/display panel. MDC plans to flight test other crew station enhancements, including large-format colour LCDs, in its F-15D advanced fighter-technology demonstrator.

Another feature of the MLU F-16 cockpit-upgrade is the installation of the F-16C/D's wide-angle HUD, produced by GEC-Marconi Avionics, and the introduction of provisions for a helmet-mounted display (HMD). All F-16s have been fitted with GEC HUDs, although Israel is now flight-testing a wide-angle HUD developed locally by El-Op.

In June, GEC and Honeywell joined forces to develop a helmet-mounted cueing system, initially for the F-16, but ultimately for the F-15 and F-18 also. A prototype of the jointly developed system will be flight-tested by Lockheed Martin on an F-16D in 1996. The manufacturer has previously flight-tested HMDs produced separately by both companies.

The cueing system will integrate Honeywell's HMD with GEC's HUD. The HMD will feature monocular, visor-projected, optics, a colour-LCD display and a magnetic head-tracker.

Flight tests will be performed to evaluate radar-off missile-seeker cueing using the HMD. Early in 1994, a Honeywell/GEC HMD system was used to cue a modified AIM-9 air-to-air missile for a launch almost 70° off-bore-sight against a target drone.

MDC has an agreement with Elbit to market the Israeli company's Dash HMD on the F-15 and F-18. The Dash monochrome, monocular, visor-projected display uses a magnetic head-tracker and is operational on Israeli F-15s. The system has been demonstrated on the F-18. Communication/Navigation/Identification

Several communication-, navigation- and identification-system (CNI) upgrades are included in the F-16 MLU. Principal among these is the introduction of Hazeltine's APX-113 advanced identification friend-or-foe (AIFF) system. This includes a combined interrogator/transponder, and is designed for use with the AIM-120 beyond-visual-range missile.

The AIFF is a development of the APX-111 in service on USAF F-16A air-defence fighters and Kuwaiti F-18s. The APX-113 has been selected for Greek F-16C/Ds and Japan's FS-X. Aircraft equipped with the system have an interrogator-antenna array on the nose forward of the cockpit.

Other MLU upgrades include an E-Systems global-positioning system, a Symetrics improved data-modem (IDM), and a digital-terrain system (DTS). The IDM will be used to provide an intra-flight datalink enabling aircraft in a flight to exchange target information.

The DTS consists of British Aerospace Systems and Equipment terrain-profile-matching software resident in the Fairchild Defense data-transfer cartridge, which is used to load data into the mission computer. The DTS will be used for terrain-referenced navigation, predictive ground-collision avoidance, database terrain following, obstruction warning and cueing and, eventually, passive ranging. The USAF plans to upgrade its F-16s with the DTS.

The only significant CNI upgrade under way on the F-18 is the switch to a Litton LN-100G integrated global-positioning/inertial-navigation system (GPS/INS). The system combines a Litton LN-100 laser-gyro INS with a Rockwell-Collins GPS-receiver module and has been selected for the Lockheed Martin/Boeing F-22.

USAF plans to equip F-15Cs with a low-cost terminal for the Joint Tactical Information Distribution System (JTIDS) have been rolled into a Navy/NATO programme to develop the Multifunction Information Distribution System (MIDS) for the F-18, Dassault Rafale and Eurofighter EF2000. The JTIDS/MIDS, also known as Link 16, is a secure, jam-resistant, datalink.

GEC-Marconi Electronic Systems is leading a consortium consisting of France's Thomson-CSF, Germany's Siemens, Italy's Italtel and Spain's Indra in development of the MIDS terminal. Production is scheduled to begin in the year 2000, against a requirement for some 1,500 terminals. Target unit cost is $200,000, compared with $500,000 for a full-size Class 2 JTIDS terminal.

Source: Flight International