As Lockheed Martin prepares to fly the first F-16E/F Block 60 it is stepping up efforts to secure additional customers for the fighter, currently under commercial development for the United Arab Emirates

Thirty years of experience are reflected in the muscular profile of the fighter standing on the rain-damp concrete at Lockheed Martin's Fort Worth, Texas plant. Under its fresh coat of two-tone grey camouflage, the Block 60 F-16 bears a family resemblance to the lithe red, white and blue YF-16 prototype Falcon that rolled out 30 years ago this month. But the resemblance is barely skin deep.

The Block 60, now formally designated the F-16E/F, is the most substantial upgrade of the best-selling fighter since the F-16C/D followed the original A/B model in 1984. Equally significant, the aircraft now being prepared for its first flight - hoped for during next week's Dubai air show - bears not the stars-and-bars of the US Air Force but the roundels of the United Arab Emirates (UAE) air force, which signed a $6.4 billion commercial contract with Lockheed Martin in 2000 covering development and production of the Block 60.

Compared with the USAF-standard F-16C/D Block 50, at least 70% of the structure is changed; the core avionics are new, as are the active electronically scanned array (AESA) radar, integrated forward-looking infrared and targeting system (IFTS) and electronic-warfare (EW) suite; and the cockpit and fly-by-wire flight controls are significantly enhanced. Compared with the original F-16A/B, maximum take-off weight is increased by 50% to 22,700kg (50,000lb) and engine thrust by 35% to 32,500lb (145kN).

"Development and production of the entire aircraft is commercial," says John Bean, vice-president for F-16 programmes. "Five systems on the aircraft, all involving encryption, are provided by the US government. Everything else is commercial, including training and support." The US government is providing pilot training and weapons, but Lockheed Martin is providing the pylons and fuel tanks as well as maintenance training.

Even flight testing is being run commercially. Half the flying will be out of Fort Worth; the rest, including supersonic and weapons testing, will be on US Air Force ranges at Edwards, Eglin and Holloman, with some in the UAE itself. "We ran a competition between USAF test ranges - based on time, infrastructure and cost - and Holloman won most," says Bean. The USAF will also provide aerial-refuelling support for flight testing on a commercial basis.

Paradigm changes

One of the "paradigm changes" under the commercial contract is the use of production-standard aircraft for all flight testing, which has driven an increase in ground testing. The conformal fuel tanks and uprated General Electric F110-132 engine have been qualified by flight testing on Block 50 F-16s, but the new avionics and flight controls will fly for the first time in the Block 60. RF01, the "proof" aircraft, is the first of 55 single-seat F-16Es and 25 two-seat F-16Fs scheduled to be delivered to be UAE by 2007.

"We couldn't modify an existing aircraft," says Bean. So the first three Block 60s, all two-seaters, are fully instrumented, and after completion of development will be delivered to the UAE with flight-test instrumentation still installed. The gun pack, which is replaced by the instrumentation package, will be delivered in a box so that the aircraft can be converted to tactical configuration if required. A fourth, back-up aircraft will have limited instrumentation for avionics testing.

RF01 is being prepared for a first flight this month. The second aircraft is to fly in January and the third in February. "Schedule is the biggest challenge - we knew that when we signed up," says Block 60 programme manager Jim Franks. "The programme is doing fine on cost, and the product is coming out as expected, but there are still unknowns. The first flight is already delayed, and could be later in December. But the key milestone is aircraft delivery."

Lockheed Martin needs to ensure flight testing is as efficient as possible, Franks says. "The slippage had made some things higher risk, but I don't see any capabilities that we won't provide." The Block 60's capabilities are being developed and delivered in blocks, or standards. Standard 0 is the initial release that will allow the UAE to begin training in the USA, while Standard 3 is the full operational capability specified by the commercial contract and scheduled to be achieved by 2008.

Flight testing

Flight testing will begin in Standard 0 configuration. Lockheed Martin plans to complete verification of all the functionality in the specification for Standard 0 by March next year, allowing aircraft deliveries to begin in April. Standard 0 is the first production release, but Standard 1 is the full hardware configuration and is scheduled for the end of next year.

Standard 1 provides capabilities equivalent to the Block 50 F-16: Standards 2 and 3 are software-only upgrades that will be performed in-country. "The breakthrough capabilities hit the aircraft with Standard 2," says Bean.

The aircraft will begin flight testing plumbed and wired for all the hardware and with the Northrop Grumman APG-80 AESA radar and IFTS sensors installed. Capabilities that will be added in stages include radar and autoflight modes - terrain following will come in with Standard 2, for example - and datalink functions. The Block 60 has the same Thales-supplied UHF/VHF datalink radio as the UAE's Dassault Mirage 2000s to provide interoperability.

EW integration

Northrop Grumman's Falcon Edge integrated EW system, which includes onboard jammers and a towed decoy, will come along later because of development delays. "The EW story is starting to come around, but is still considered a pacing item," says Franks. "It's a good development as EW programmes go, and smoother than most. But it's a significant integration effort, as it spans a lot of the aircraft." EW testing will be conducted in an anechoic chamber at Fort Worth and on US and UAE ranges.

All design work on the pilot-vehicle interface through to Standard 3 has been completed and the full operational capability demonstrated in the simulator, says Bean. Flight International was able to preview some of the capabilities planned for the Block 60 in the simulator at Fort Worth (see accompanying panel). These include safety-enhancing features such as automatic recovery from deep stall and automatic ground collision avoidance.

Possibly the biggest change in the Block 60 from earlier F-16s is in the core avionics and flight controls, in which the unique military processors are replaced with commercial PowerPCs. There are 1.3 million lines of new software. Existing F-16 mission computer and flight control software has been rewitten from Ada and Jovial into the C++ commercial high-order language, then built on to provide the additional capabilities of the Block 60.


A fibre-optic high-speed data network using commercial Fibre Channel technology ties the new avionics together. "Fibre Channel is the biggest breakthrough on the aircraft," says Bean. "It allows federated boxes to communicate and provide the same benefit as the F/A-22's integrated avionics. The same technology is used in the Joint Strike Fighter."

Dual Fibre Channel networks, each with 1,000 times the bandwidth of the 1553B databus, link sensors, mission computers and displays.

The new digital flight-control system uses the same F-16 control laws, rewitten from Jovial into C++ and rehosted on to commercial processors. The basic structure of the software has been changed to add the advanced autopilot and enhanced safety modes. The new flight-control system has been qualified in high-fidelity ground simulations, and will fly for the first time in the Block 60.

Avionics have been undergoing testing for several months in the system integration laboratory at Fort Worth, and Lockheed Martin has completed a full-up ground test of the Standard 0 configuration. "It passed all the tests," says Franks. "The software is not as stable as we would like, but it is stable enough to begin flight tests and there will be some improvement before production release."

Final assembly

While the first Block 60 is being prepared for flight, the second is in final assembly at Fort Worth alongside Block 50/52 Plus F-16C/Ds for Greece and Israel. Despite the number of changes, the first two aircraft have come together well, says Nathan West, Block 60 air vehicle team director. Largely this is because Lockheed Martin was able to evolve the airframe incrementally, changing 35% of the structure going from the USAF Block 50 to the Greek Block 50 Plus, and another 30% going to the Israeli F-16I.

Half of the structural changes in the Block 60 are for increased strength, and half are for systems installation and routing, says West. Changes include thicker bulkheads, stronger aluminium-lithium skins and unitised structures.

Space is at a premium in the F-16, and the dorsal spine developed for the two-seater is fully used in the UAE's F-16F, housing the secondary environmental-control system (ECS) that provides liquid cooling to the active-array radar, as well as the engine start controller, datalink radio, crash data recorder, and EW receiver, aft transmitter and chaff/flare dispensers.

In the single-seater, the secondary ECS is mounted in an enlarged fin fairing.


Notable differences between the Block 60 and Block 50/52s also in final assembly include the liquid cooling lines running to the radar in the nose, which pulls forward to disconnect the lines before swinging out for access. The fibre-optic bundles of the Fibre Channel network, inside loose protective sleeves, are also new. So is the orange wiring of the flight test instrumentation. "We are going into flight test with a production aircraft," says West. "We have to embed instrumentation on the factory floor, which means making the instrumentation guys work alongside the production guys."

As the Block 60 is prepared for its maiden flight, the UAE Air Force is preparing to take delivery of its first aircraft. A 25-man team of engineers and pilots at Fort Worth is a full-time, integrated part of the programme, to ensure the UAE has insight into every aspect. They will go on to stand up the Block 60 force in the UAE, where work has begun on preparing the main operating base.

Training is already under way at a location in the USA, where UAE pilots will initially qualify on the Block 50 F-16 before beginning Block 60 conversion training.

An initial cadre of instructor pilots is being trained, using the training system under development by Lockheed Martin for delivery to the UAE as well as the engineering simulators at Fort Worth. The UAE is expected to train in the USA for a period, sending over both moderate-time Mirage pilots and new pilots trained on the Pilatus PC-9 and BAE Systems Hawk. Maintenance training is also under way in the USA.

Complex contract

Under the commercial contract, Lockheed Martin is responsible for validating that the Block 60 meets the specification agreed with the UAE. "It is a very detailed and complex contract, with very high levels of definition of the capability contractually required," says deputy programme manager Del Spann. "How we will validate the requirement is in the contract."

Spann says the working relationship with the UAE since programme go-ahead in June 2000 has been good, and is based on transparency. "They were a very intense customer during negotiations. They knew exactly what they wanted in terms of missions, capability and technology. Now they are an extremely good customer to work with, and they have worked with us to resolve issues." The UAE team involved in defining the contract is still in place. "The UAE has kept consistency in its team, and Lockheed Martin is trying to do the same," he says.

With flight testing about to begin, Lockheed Martin is stepping up efforts to find additional customers for the F-16E/F Block 60, although the aircraft did not make the shortlist in Singapore. "The customer wants to fly before they buy," says Franks. "And with the aircraft about to enter flight test it will become more attractive." Several customers are showing interest, he says. At $50-55 million, the Block 60 costs $10-15 million more than the Block 50 Plus.

Prospects for the F-16E/F are tied to availability of the international variant of the F-35 Joint Strike Fighter, with the Block 60 being promoted as an interim aircraft for existing F-16 operators who may have to wait until 2015-20 for the JSF. "It offers pilot commonality, engine commonality, and the same maintenance concept, but with new-technology, more-reliable support equipment and as much capability as a customer is likely to need," says Franks.

US interest

The exception could be the US Air Force, which could require even more capability in an interim fighter if the Joint Strike Fighter is delayed. Lockheed Martin, meanwhile, has begun looking at ways to retrofit key Block 60 systems - including the active-array radar - into earlier blocks of F-16s. The Block 60 development programme has also provided a number of solutions for obsolescence issues with the more than 4,000 F-16s already in service worldwide.

Source: Flight International