All New Warthog

By David Jensen | December 1, 2005
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The U.S. Air Force's A/OA-10 Thunderbolt II has never been regarded as a pretty aircraft--ergo its nickname, Warthog, and its pilots' nicknames, Hog drivers. And the largest-ever A/OA-10 modernization program, currently in a $67.7-million engineering and manufacturing development (EMD) stage, won't make the close air support aircraft any prettier. But it will make the 30-year-old Warthog (first production model flown in 1975) a lot more capable.

Precision Engagement (PE), a primary component of an ongoing modernization effort, will give A/OA-10 pilots all-weather combat capability with "smart" weapons, as well as greater situational awareness and an entry into the network centric warfare environment. These new capabilities derive from the updated hardware and avionics that employ existing technologies. They won't change the A/OA-10's primary missions of close air support and forward air control, and the General Electric 30-mm GAU-8/A Gatling gun will remain the aircraft's primary weapon. However, the PE program will give the A/OA-10 "greater flexibility...the ability to tie more target information to additional weapons," according to Roger Il Grande, A/OA-10 program director at Lockheed Martin.

The upgrade will allow the standoff delivery of precision-guided weapons, such as the Joint Direct Attack Munitions (JDAMs) and Wind Corrected Munitions Dispensers (WCMDs), both GPS-calibrated smart bombs in the Air Force inventory. With these weapons, plus a targeting pod and data link that delivers targeting data, A/OA-10 pilots will be able to engage targets in all weather and at safer distances and higher altitudes. Their precision also will help limit fratricide and collateral damage during engagement.

Program Schedule

In 1997 Lockheed Martin Systems Integration in Owego, N.Y., won the competition to become prime contractor and systems integrator for A/OA-10 modernization. In 2001 the Air Force awarded Lockheed Martin the Precision Engagement EMD contract, and in February 2005 the headquarters, Ogden Air Logistics Center, at Hill AFB, Utah, issued to Lockheed Martin a $37.8-million production contract to build 72 Precision Engagement production kits. The company plans to begin delivering PE kits in March 2006 to the 508th Attack Sustainment Squadron at Hill AFB, home of the A/OA-10 system program manager.

Fitted aircraft are to be fielded later that year and then receive software upgrades and incorporate JDAM and WCMD, beginning in 2007. Precision Engagement kits are to be installed in the Air Force's entire fleet of 356 operational A/OA-10s over a five-year period, beginning in the second half of 2006, for an estimated total contract value of $168 million. (Fairchild Republic produced a total of 713 Warthogs between 1975 and 1984.)

PE Kits

The PE kits include the following:

  • Two new color multifunction displays,

  • New pilot control,

  • A new central interface control unit (CICU) that provides digital stores management and overall A/OA-10 avionics systems integration,

  • Upgraded processors,

  • Up front controller (UFC),

  • New stick grip,

  • New instrument panel,

  • Upgraded power system,

  • New wiring, and

  • The hardware and Mil-Std-1760 weapons system interfaces necessary to accommodate the new smart weapons.

In 2006 Lockheed Martin plans to add digital mapping, as well as the hardware and interface for the Northrop Grumman Litening and Lockheed Martin Sniper reconnaissance and targeting pods, which house optical sensors and laser designators. These pods, existing in the Air Force inventory, are first to provide "powerful visuals" to A/OA-10 pilots, who largely have had to "look out the canopy" to spot targets, says Il Grande.

Lockheed Martin has delivered PE kits for eight aircraft. Five have been installed in dedicated flight test aircraft--two at Eglin AFB, Fla., and three at Nellis AFB, Nev. The remaining three systems have been installed in operational A/OA-10s, which also are being used for flight test.

The PE kits are part of the initial, Spiral 1 in the A/OA-10 modernization program. Spiral 2, currently in the definition phase, will involve the integration of the joint tactical radio system (JTRS), which will provide A/OA-10 pilots with network centric connectivity. "We foresee flight testing the JTRS package in the 2008/09 timeframe," says Il Grande.

Meantime, there is a "short-term plan" to install a situational awareness data link (SADL) in the Thunderbolt II, which will provide both air-to-air and ground-to-air digital communications of target data. SADL uses the enhanced position location reporting system (EPLRS) waveform, which will provide secure, jam-resistant data communications, such as friendly force data from Army units, in near real time. SADL is now in the development stage and scheduled to enter a flight test program, "probably at Eglin," in the second half of 2006, according to Il Grande.

"We also have, in the conceptual stage, the incorporation [into the A/OA-10] of improved communications systems," Il Grande adds. These upgrades--part of the aircraft's avionics roadmap--will add to other proposed upgrades, including integrated combat search and rescue locator systems and improved early warning and antijam self-protection systems.

New Life

Launched in 2001, the Precision Engagement program rescues a tough combat aircraft that the Air Force probably would begin phasing out in about 2019. The A/OA-10's original service life was to be 8,000 hours, a milestone that many Warthogs are about to meet, if they haven't already done so. The modernization effort, however, is expected to extend the aircraft's service life to 2028.

What rescued the A/OA-10 was its performance during Operation Desert Storm (first Gulf War), particularly in destroying Iraqi armor. According to an Air Force fact sheet, the 144 Warthogs sent to Iraq in 1991 flew only about 30 percent of the sorties but were responsible for more than half the Iraqi equipment losses. That equated to more than 1,900 tanks and artillery plus more than 1,100 trucks. In addition to these impressive statistics, the Warthogs hunted Iraqi Scud missile sites, destroyed a large number of Iraqi radar installations, and lent assistance in numerous search and rescue missions. The Hog drivers were able to exploit their aircraft's low-speed and low-altitude performance to execute close air support missions as low as 50 feet above the ground when flying under the thick clouds of smoke pouring from the Kuwaiti oil fields.In more than 8,000 sorties the A/OA-10s flew during the operation, just six aircraft were lost in combat, while the Warthogs acieved a mission availability rate of 97 percent. Such effectiveness prompted the U.S. Congress to extend the A/OA-10 program until at least 2008 and initiate the modernization effort.

Weapons Delivery System

The new PE-equipped aircraft is sometimes described as "a Warthog on steroids" to emphasize its increased mission capabilities. The new system's backbone is the central interface control unit, which replaces most of the old armament control system and also interfaces with other mission subsystems to provide an integrated solution for the pilot and maintainance technician.

The CICU takes various sources of information from the aircraft's subsystems--such as targeting pods, radios, processors and displays--and integrates and displays the information in a manner that is meant to reduce pilot workload. The massive increase in data provided by the PE system can be complex and confusing, which is why Lockheed Martin engineers are working with A/OA-10 pilots to "look for ways to improve and add information that the pilot needs to see," says Il Grande. This has been an ongoing process at Lockheed Martin's systems integration lab (SIL) in Owego.

One of the subsystems to be included with the CICU is the integrated flight and fire control computer (IFFCC). The IFFCC replaces the A/OA-10's current low-altitude safety and targeting enhancement (LASTE) system. BAE Systems produced the LASTE and is developing the IFFCC.

Shortened 'Kill Chain'

LASTE provides computer-aided capabilities for the low-flying Warthog, including ground collision avoidance, enhanced attitude control for aircraft stabilization during gunfire, and a low-altitude autopilot system, as well as ballistic weapons control and target detection and tracking. Hardware and software upgrades to LASTE resulted in IFFCC. And as part of the Precision Engagement program, BAE Systems is upgrading the IFFCC software to add HUD symbology in support of targeting pods, data link and smart weapons integration.

The new smart weaponry, in conjunction with data link, will allow digital machine-to-machine connectivity between the troops on the ground and the A/OA-10 in the air. This connectivity will help shorten the "kill chain," delivering bombs on target in a shortened timeframe.

The Precision Engagement upgrade also will support improvements to mission planning. The mission planning system (MPS) will allow the pilot to plan his route, the weapons employed and drop sequences, and target information on the ground. He then uses a cartridge to load the mission plan onto the aircraft. As part of the Precision Engagement EMD program, the Southwest Research Institute is upgrading the MPS. Warthog pilots also will be able to program the weapons and check the weapons' status, while in fight.

For the maintenance technician, the A/OA-10's CICU and an existing control display unit (CDU) have been fitted with upgraded software to improve the detection and isolation of avionics subsystem failures. Southwest Research Institute is providing an upgraded operational test system (OTS) with a diagnostic interface to the aircraft avionics and weapon systems. These enhancements are expected to improve the system's maintainability and, thus, its availability.

In addition to BAE Systems and the Southwest Research Institute, Lockheed Martin has subcontracted Northrop Grumman to exploit the latter's knowledge of the A/OA-10's legacy weapon system and structrual engineering.

Cockpit Displays

The two new 5-by-5-inch liquid crystal, multifunction color displays in the Thunderbolt II's PE kit replace analog switching devices and round dials, and require installation of a new instrument panel. The displays, supplied by Elbit Fort Worth, are interchangeable and provide various control menus that provide the pilot-vehicle interface. The displays also will present a digital map on the tactical awareness display (TAD), produced by Lockheed Martin. The data link information and other tactical data are automatically oriented and scaled in order to be correctly overlayed on the map. This will "show where the good guys are and where the bad guys are," Il Grande explains.

Pilots thumb through the menus on the displays, using the surrounding bezel keys or the HOTAS (hands on throttle and stick). The PE kit will add the up front controller, which is positioned just below the HUD, so that Warthog pilots can keep eyes up while inputting data. The UFC has the same keyboard as on the CDU and typically would be used to input menu items, navigational information and weapons delivery data.

Software Suites

Installation of software upgrades, defined as "suites," has been ongoing for A/OA-10. Currently, the modernization effort includes five suites:

  • Suite 1, installed in preparation for Warthog modernization, rehosted the legacy software, function by function, replacing the old Jovial language with Ada.

  • Suite 2, which was fully fielded in August, includes new weapons guidance algorithms.

  • Suite 3 provides integrated software for the Precision Engagement kits.

  • Suite 4, providing maintenance and diagnostic improvements, is to be fielded beginning in late 2005.

  • Suite 5 is in the requirements stage. "We're working with the Air Force to define the requirements," says Il Grande.


Key to the Precision Engagement program's development, as well as to ongoing systems evaluation and integration, is the A/OA-10 systems integration lab. The lab includes a simulator that incorporates an A/OA-10 cockpit with actual aircraft and weapon hardware and software, so that Air Force pilots can provide early feedback on systems and display presentations. These pilots have been working with Lockheed Martin on the aircraft's modernization program "throughout the contract," says Il Grande. Made operational with Precision Engagement modifications in February 2004, the SIL is the only integration lab established for the Thunderbolt II.

Warthog: A Brief History

The A/OA-10 Thunderbolt II, aka Warthog, may have proven its worth during Operation Desert Storm, but the close air support aircraft traces its routes to the Vietnam War. The small arms fire, ground-to-air missiles and other lethal threats to aircraft flying close air support missions in Southeast Asia prompted the U.S. military to consider a heavily armed jet aircraft able to fly low and maneuver at low speeds, with long range and loiter times. A request for proposals was issued in 1967, and the requirements for a new aircraft were soon expanded in response to the Cold War threat of Soviet armor. An "Attack Experimental" (A-X) competition was narrowed to a face-off between Northrop and the Republic Aviation Division of Fairchild-Hiller. The U.S. Air Force chose Republic in January 1973, about seven months after the company's candidate aircraft made its maiden flight. The first production A-10 flew in October 1975, and Warthog deliveries began about six months later. The adaptable Thunderbolt II has proven its worth in two Persian Gulf conflicts. The Air National Guard claims it was "the dominant weapon when coalition forces raced for Baghdad during Operation Iraqi Freedom." Many simply call the attack aircraft the A-10, but it also is an observation aircraft, hence its designation, the A/OA-10.

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