F-22A - Sharpening the Raptor's talons

Currently in developmental testing at Edwards Air Force Base (AFB) in California is the new Increment 3.1 upgrade package for the Lockheed Martin F-22 Raptor. This set of upgrades will significantly increase the aircraft’s air-to-ground strike capability. When fielded in 2011, these modifications will enable Block 30 capabilities for the Air Force’s small operational fleet of Raptors. All F-22s presently flying with the United States Air Force (USAF) are fitted with the current Increment 2 package, enabling a fleet-wide Block 20 capability.

Increment 3.1, which is the first of three incremental upgrades programmed for the Raptor, is well into developmental testing and is scheduled to enter its operational test phase with the 422nd Test and Evaluation Squadron (TES) at Nellis AFB, Nevada, sometime next year, says Cara Miller, Deputy Director of F-22 Modernization at the USAF’s F-22 System Program Office (SPO). The completed package, tentatively scheduled to become operational in fiscal year 2011, adds a Synthetic Aperture Radar (SAR) mapping feature along with an Electronic Attack (EA) capability to aircraft, Miller said.

The Northrop Grumman-built APG-77 active electronically scanned array (AESA) radar is composed of thousands of transmitter/receiver elements that replace the traditional mechanically scanned dish found in older radar systems. This new type of antenna allows the radar to scan in multiple modes simultaneously and offers precise control of the radar’s scanning beams. The addition of a SAR mapping capability will allow the Raptor to make detailed photograph-like images of the terrain below, significantly increasing the F-22’s air-to-ground strike potential. SAR mapping will also afford Raptor pilots the ability to designate their own ground targets on the fly, a capability currently not found on the F-22.

The EA feature, meanwhile, will allow the F-22 to attack an enemy’s radar systems. This is made possible by the AESA’s precision radar beam focusing ability and improved threat emitter geo-location capability afforded by improved passive sensor systems. The radar would focus its energy on a threat radar emitter, either jamming it, or potentially even physically damaging the enemy hardware. The integration of additional radar processing power was required for the Increment 3.1 upgrade, said Doug Ebersole, F-22 Technical Director at the F-22 SPO.

Lastly, Increment 3.1 introduces the capability for the Raptor to carry the GBU-39 Small Diameter Bomb (SDB), Miller said. The SDB is a small precision-guided 250 lbs glide bomb, which allows the Raptor the ability to strike targets at standoff ranges. Another benefit of the SDB, largely due its small warhead and increased precision, is the reduction in potential collateral damage. Ebersole added that under Increment 3.1, the Raptor would only be able to strike two fixed targets with the eight SDBs the aircraft will be able to carry. A more comprehensive SDB capability is slated for Increment 3.2, he said.

The second major upgrade for the Raptor will be Increment 3.2, which Miller says, is currently in the planning stages. This package is focused on improving the Raptor’s air-to-air capability as well as integrating an advanced SDB capability.

As currently envisioned, Miller said Increment 3.2 will include the integration of the new close range AIM-9X Sidewinder missile and the new long-range AIM-120D AMRAAM missile. The integration of the new AIM-9X variant will remedy the current lack of a high off-bore sight (HOBS) missile capability in the Raptor’s arsenal. HOBS capability is considered crucial in modern aerial combat as it allows an aircraft to launch a missile off-axis from its direction of travel. Many pilots have commented that with the advent of HOBS missiles, entering into a traditional visual range fight becomes an exercise in mutually assured destruction.

Unfortunately, while Increment 3.2 includes a HOBS capable weapon, it does not include provisions for a helmet mounted cueing system (HMCS), which some consider as being essential. “The JROC validated F-22 Capabilities Production Document, which defines requirements for all Increment 3 changes, does not include provisions for a HMCS. A HMCS may be considered as part of the post Increment 3 trade space”, Miller said. However, the addition of the AIM-9X will significantly increase the Raptor’s within visual range combat prowess even without such a helmet.

The AIM-120D, meanwhile, will afford the Raptor increased long-range firepower. The new missile generally offers increased performance over previous incarnations of the AMRAAM presently in service. Increment 3.2 also affords the Raptor the ability “to dynamically retarget up to eight Small Diameter Bombs”, Ebersole said, which exponentially increases the F-22’s potential as strike aircraft.

Arguably, the most significant upgrade contained in the Increment 3.2 package is the addition of the Multi-Function Advance Data Link (MADL). The MADL is the primary data link for the F-35 Lightning II Joint Strike Fighter, however, the system is being adopted to connect all of the USAF’s 5th generation and stealth assets, Ebersole explained. The idea, Miller adds, is to “provide interoperability. At some point it’ll link the F-22, F-35, and the B-2 together”.

Despite the addition of the MADL, the F-22 will retain its own proprietary Intra-flight Data Link (IFDL). The one major shortcoming of the new MADL data link is that it does nothing to address the inability of the Raptor to transfer data off-board to legacy fourth generation aircraft such as the F-15s or F-16s except by means of voice communications.

The addition of the new MADL data link will require the addition of new hardware to the F-22. Currently, Ebersole explains, the Raptor fleet consists of three configurations. The training aircraft at Tyndall AFB and a portion of the early operational test fleet at Nellis AFB were built to the early Block 20 standard. This group of 34 planes is capable of operating under the current Increment 2 package. However, due to their older hardware configuration, in the future they will only receive minor upgrades wherever possible, Ebersole said.

A further group of 63 aircraft, comprising the earliest production Lots of operational Raptors, were built to the later Block 30 configuration. While this group of aircraft will receive the full Increment 3.1 upgrades, these F-22s will not receive the full Increment 3.2 modifications, Ebersole said. He explained that these older aircraft are not “hardware enabled” to receive the Increment 3.2 package. Ebersole added, however, that wherever possible, select capabilities found in Increment 3.2 would be incorporated into these machines.

“The selected capabilities from Increment 3.2 that can be immediately retrofitted into the earlier jets are software only updates, Electronic Protection, Combat ID, and Link-16 improvements”, Miller said. Retrofitting other Increment 3.2 improvements requires a “few minor hardware changes necessary for AIM-9X and major changes are necessary to the Raptor's Stores Management System to accommodate these weapons”, Miller explained, referring to the AIM-9X and the AIM-120D. She added, “There is a study on-going to assess the feasibility of pushing the weapons capabilities to the earlier jets”.

Ebersole, expanding on the issue, explained, “The AIM-9X and AIM-120D are not currently programmed to be retrofitted into the Block 30 aircraft. These capabilities are enabled by the Enhanced Store Management System (ESMS) that is unique to the Block 35 aircraft. The Air Force and our industry partners are currently executing design trade studies to identify cost effective options to flow this capability back to the Block 30 aircraft without the ESMS enabler”.

The last 87 Raptors to be built for the USAF, starting with the Lot 6 aircraft stationed at Elmendorf AFB, Alaska, have added processing power and are “hardware enabled” to receive the full Block 35, Increment 3.2 configuration, Ebersole said. He emphasized that these aircraft are still Block 30 machines in terms of their current hardware configuration. “There are no Block 35 aircraft yet”, Ebersole stated bluntly.

A total of 37 of these improved “hardware enabled” machines have been handed over to the USAF at the time of this writing. There are 50 more planes still on order before production of the Raptor is scheduled to end in 2011. These 87 improved aircraft will still require “some hardware retrofits” when being upgraded to the Increment 3.2 capability, Ebersole explained. The addition of the MADL data link, for example, is one such system that will require additional hardware modifications. It is important to note that all F-22s currently operational with the USAF are Increment 2 enabled aircraft operating with Block 20 level capability.

While Increment 3.2 is in the planning stages, the even more advanced Increment 3.3 is in the notional pre-planning phases. “It’s way out there”, Miller said, explaining that the Joint Requirements Oversight Council (JROC), which is charged with validating capability requirements for all the services, is currently vetting the requirements for this advanced configuration. Ebersole, adds, “There isn’t any new revolutionary technology being considered, but there are new capabilities”.

Article provided courtesy of Dave Majumdar and examiner.com