Ride on the Ray: Boeing’s X-45 UCAVs

X-45C, F/A18F, F-15E
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In 1998, Boeing began a revolutionary development program: create an unmanned aircraft that was about the size of the USAF’s F-117 stealth fighter, with similar performance, better stealth, and better range. DARPA’s J-UCAS program launched Boeing’s X-45A and Northrop Grumman’s X-47B Unmanned Combat Air Vehicles (UCAVs), which went on to perform tests that included multiple UCAV flights, bomb drops, and other aviation firsts.

J-UCAS was effectively killed in 2006, though it went on to spawn the Navy’s UCAS-D competition. NGC’s X-47B Pegasus won, but the Pentagon’s back-and-forth over the USAF’s Next-Generation Bomber program gave Boeing an incentive to remain active. The bomber program will either create a big opening for UCAVs, or allow Boeing to lever any new advances in stealthy UCAV design for its bomber bid. Not so coincidentally, Boeing is using company funds to put its X-45C back on track, as the “Phantom Ray”.

Boeing’s X-45s

X-45A’s 1st flight
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UCAVs currently have no real situational awareness of the airspace around them, which makes them sitting ducks for any attack that doesn’t use radar guidance, and isn’t picked up by their radar warning receivers. Even an alerted UCAV currently has few options but to try and change course, which can work against ground threats but not against mobile aerial opponents. That may be why high-end strike UCAVs like the X-45 Phantom Ray, X-47 UCAS-D, European nEUROn, and Russia’s MiG SKAT all use the maximum stealth configuration of tailless subsonic blended wing bodies, with shielded air intakes and attenuated exhausts.

The original X-45A used a swept-wing stealthy design and composite construction, with a wingspan of 33.8 feet/ 10.31m and an overall length of 26.34 feet/ 8.03m. It was powered by a Honeywell F124-GA-100 non-afterburning turbofan, producing 6,300 pounds of thrust for its 2-dimensional yaw-vectoring exhaust. The vehicle carried a payload of 1,500 pounds/ 680 kg, but it had underwing hardpoints for carrying auxiliary fuel tanks or additional weapons. It was designed to take off and land autonomously, and was reportedly capable of operating to an altitude of 35,000 feet at a cruise speed of Mach 0.75.

The X-45A’s most interesting feature was its ability to detach the wings from the fuselage so the air vehicle can be stored and transported in a storage container. A single C-17 Globemaster could reportedly carry up to 6 containerized X-45As to forward bases.

X-45C concept
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While the X-45A was undergoing testing, work began on an advanced version, the X-45C. It would be a larger aircraft with a different body layout, about 39 feet long with a 49-foot wingspan. The same kind of modified F404 engine that powered the F-117 Nighthawk will power the X-45C. It was expected to cruise at 0.85 Mach at up to 40,000 feet, with a mission radius of about 1,300 nautical miles.

Despite being only a few feet thick, its maximum payload will be 4,500 pounds and it will carry 8 250 lb. Small Diameter Bombs, or GPS-guided JDAMs and other ordnance, using 2 internal weapons bays. Other payload types under consideration in the follow-on Phantom Ray program include radar and/or optical surveillance, and electronic jamming equipment.

A high-end strike UCAV can be controlled using line-of-sight links, but its range almost guarantees the need for satellite relay. The USA already flies missions of this type, piloting MQ-1 Predators and MQ-9 Reapers on combat missions over Afghanistan from Creech AFB near Las Vegas. The near-guaranteed presence of jamming around the X-45A’s high-end targets also raises the need for autonomous decision-making as a backup, which raises interesting issues of control in the robotic age.

The program was planned with a series of overlapping spirals, each incorporating more technology and adding capabilities. The UCAVs will be able to operate independently or be fully integrated with manned aircraft operations, and will incorporate next-generation stealth technologies. Capabilities demonstrations were begin in 2007 to provide several program options for future production and fielding, but the program was strangled in March 2006 when the USAF declined to pick up the program. J-UCAS range was considered too short to meet the USAF’s Pacific requirements, and initial dreams of 50% cost savings over manned fighters had been refined to a more likely figure of about 10%.

The USAF elected to focus on its Next-Generation Bomber instead, and the X-45 lost to Northrop Grumman’s X-47B in the UCAS-D program for a carrier-capable UCAV. The X-47B had been developed from the outset for naval capability, which gave it a critical edge.

The X-45C gained new life in 2009, however, as a Boeing-funded advanced prototyping platform for its top-secret Phantom Works advanced technology group. As an added bonus, that program is likely to have the same effect as the initial X-45C capabilities demonstrations. With the USAF’s Next-Generation Bomber still a big question mark, even as the need for a long-range strike platform grows in the Pacific theater, defense manufacturers are thinking hard about their potential offerings.

Boeing is already contracted for key R&D programs involving unmanned aerial refueling, which would greatly extend the X-45C’s operational possibilities – so long as the base UCAV platform remains in existence to exploit it. Hence Phantom Ray.

Key Phantom Ray suppliers include:

• General Electric Aviation (F404-GE-102D non-afterburning turbofan, power distribution)
  
• Crane Hydro-Aire (brake controls)
  
• Heroux-Devtek (landing gear)
  
• Honeywell (brake system)
  
• Woodward-HRT (flight control actuation system)

Contracts and Key Events

Note that some research contracts for Boeing may support the Phantom Ray program indirectly. The US Navy’s UCLASS research studies are the most obvious example. They won’t be covered here, unless there’s a clear impact on the Phantom Ray platform.

I’m leavin’, on
a jet plane…
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Aug 12/13: UCLASS Specs. Aviation Week reports that the US Navy is having a hard time with the specifications for their UCLASS program RFP, which will be delayed into September 2013.

The biggest question is how much stealth the drone requires. Despite recent manufacturing advances, like the radar-absorbing materials baked right into the F-35’s composite skin, more stealth tends to make planes more expensive to buy and to maintain, while dropping their endurance and payload. On the other hand, current drones would have a very short life expectancy against advanced air defense systems, which creates a gap outside of the military’s unknown “black” programs.

Aviation Week reports that Northrop Grumman and Lockheed Martin are emphasizing stealth, while General Atomics and Boeing are willing to raise the radar cross-section somewhat in exchange for payload and endurance. General Atomics’ Sea Avenger, with its winged body and tail, does seem to fit this description. On the other hand, Boeing’s X-45 Phantom Ray is a tailless flying wing design, just like its NGC and Lockheed competitors. If Boeing is really prioritizing range and payload, it means they’re changing their base platform. Aviation Week: “Uclass: How Much LO is Enough?”

April 27/11: 1st flight of the Phantom Ray, from NASA’s Dryden flight center at Edwards AFB, CA. During the 17-minute flight, it flies to 7,500 feet and a speed of 178 knots. Boeing release | feature || NASA.

Jan 10/11: Boeing announces that the Phantom Ray is now at Edwards AFB. It made the trip piggybacked on NASA’s Boeing 747 SCA, which is registered to fly in civil airspace.

Dec 13/10: Test flight of a NASA Shuttle Carrier Aircraft (SCA) with the Phantom Ray attached. The 747 takes off from Lambert International Airport in St. Louis, MO. Boeing release | feature || NASA.

Rollout.
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July 20/10: Boeing says that its Phantom Ray will fly to NASA’s Dryden, CA flight test center as a piggyback passenger on NASA’s Shuttle Carrying 747, as part of a Boeing-funded Commercial Space Act Agreement with NASA. Boeing decided that the Shuttle Carrier would be the most cost-effective way to transport the Phantom Ray, and developed an attachment to allow the Ray to connect to the structure that normally carries the much larger Space Shuttle. Boeing.

May 10/10: Boeing rolls out its Phantom Ray demonstrator aircraft. The demonstrator is scheduled to begin taxi tests in summer 2010, with a planned 1st flight in December 2010, about 2 years after the project began. The craft will then conduct up to 9 additional test flights over approximately 6 months, with further flights determined by customer interests.

The most significant aspect of this rollout, however, may be corporate and industrial. Boeing’s Phantom Ray program manager, Craig Brown, said that:

“We’re really excited about this because Phantom Works is back as a rapid prototyping house, operation and organization. This is the first of what I expect to be many exciting prototypes, and they’re all with exciting technology.”

Lockheed Martin’s Skunk Works is the industry’s most famous – and arguably its most successful – rapid prototyping and advanced design house. Boeing appears to be pushing hard to improve in that area, in order to ensure its future competitiveness, and is putting resources behind that commitment. Phantom Works President Darryl Davis underlined Brown’s message:

“Phantom Ray represents a series of significant changes we’re making within Boeing Defense, Space & Security. For the first time in a long time, we are spending our own money on designing, building and flying near-operational prototypes. We’re spending that money to leverage the decades of experience we have in unmanned systems that span the gamut from sea to space.”

See: Boeing release | Full Boeing Feature.

March 2/10: Aviation Week quotes Boeing Phantom Works president Darryl Davis, who says that an unnamed “classified program” will delay X-45C testing, by laying claim to special stealthy exhaust systems for the drone’s F404-GE-102D non-afterburning jet engine. Taxi tests for the demonstrator have slipped to July 2010, but at this point, Boeing is sticking to December 2010 as its first flight date.

This type of project risk is more common than many people outside the industry would think, because it’s rarely covered. Boeing is following long-established procedures by beginning with flight-worthiness tests, including basic component tests for reliability, durability, etc. That’s why the absence of key components affects testing schedules, and forces ground and aerial testing back. A 2nd testing phase would expand the flight envelope and, potentially, conduct automated aerial refueling trials, electronic warfare, or other tests.

The article also mentions that Boeing’s partnership with Lockheed Martin to compete for any next-generation bomber project is “in pause mode,” and may not be revived.

It’s baaack…
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May 8/09: X-45C revival. Boeing announces that they’ll revive the X-45C as a company-funded, unmanned flying test bed for rapid prototyping of advanced air system technologies. In the process, of course, they’ll bring the X-45C up to speed as a viable combat UAV. With the 2018 bomber’s effective cancellation in the proposed FY 2010 defense budget, air-refuelable UCAVs with no operator-endurance limits are the best hope to fill the gap.

Lab testing for the “Phantom Ray” air vehicle is scheduled for late 2009, followed by ground testing and first flight in December 2010. It is scheduled conduct 10 flights over a period of approximately 6 months, supporting missions that may include intelligence, surveillance and reconnaissance; suppression of enemy air defenses; electronic attack; hunter/killer; and autonomous aerial refueling:

“Phantom Ray will pick up where the UCAS program left off… the X-45C… will serve as the basis for the Phantom Ray demonstrator. “What is particularly exciting about Phantom Ray is that we will incorporate the latest technologies into the superb X-45C airframe design,” said Dave Koopersmith, vice president of Boeing Advanced Military Aircraft, a division of Phantom Works. “As we gradually expand the vehicle’s flight envelope, potential users will have access to a full range of unique capabilities that only this type of autonomous platform can provide.”

See: Boeing release | Aviation Week.

April 7/09: As part of his recommendation regarding the Pentagon’s FY 2010 budget, US Secretary of Defense Robert M. Gates effectively kills the USAF’s Next Generation Bomber program, saying:

“We will not pursue a development program for a follow-on Air Force bomber until we have a better understanding of the need, the requirement, and the technology.”

X-45A flight
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October 2/06: After 64 flights and numerous firsts in autonomous combat aviation along with its Northrop Grumman competitor the X-47B Pegasus, Boeing’s 2 X-45A UCAVs are sent to 2 prominent aviation museums: the National Museum of the U.S. Air Force at Wright-Patterson Air Force Base in Dayton, OH; and the Smithsonian National Air and Space Museum in Washington, D.C. Boeing release.

Aug 10/05: Graduation Day. A pair of X-45As complete a graduation exercise at NASA’s Dryden Flight Research Center, Edwards Air Force Base, CA. This would be the X-54A’s final-ever set of test flights, though Boeing did not know that at the time.

For test flights 63 and 64, the X-45As departed from the base, climbed to altitude, and used their on-board decision-making software to determine the best route of flight within the 30 mile x 60 mile area of action (AOA). The pilot on the ground approved the plan, and the 2 unmanned vehicles entered the AOA to perform a simulated mission that involved identifying, attacking and destroying pre-identified ground-based radars and associated missile launchers before they could be used to launch anti-aircraft missiles.

During the test flight, the X-45A unmanned aircraft faced a simulated “pop-up” threat, used evasive maneuvers to avoid it, and autonomously determined which vehicle held the optimum position, weapons and fuel to attack the higher priority simulated target. Once the pilot authorized the attack, the unmanned aircraft simulated dropping weapons on the target. After engaging and destroying a 2nd simulated target, the X-45As completed their mission and safely returned to Edwards. Boeing release.

July 8/05: Boeing Co. subsidiary McDonnell Douglas Corp. in St. Louis, MO receives a $2.65 million increment of a $175 million modification to the prototypes agreement. In exchange, Boeing will conduct a robust autonomous aerial refueling demonstration with the X-45C robot plane, and extend the current flight test effort by 18 months. The autonomous refueling effort will continue ongoing Air Force Research Laboratory and Boeing development activities and is scheduled to culminate in an in-flight X-45C refueling by a KC-135 Stratotanker aircraft in 2010.

The firm will continue previously funded work to design, develop and demonstrate 3 full-scale, flight-worthy air vehicles and 2 mission control elements under the J-UCAS program.

Work on the preparations for the extended flight test regimen and air-air refueling demonstration will be performed in St. Louis, MO and will be completed in December 2012. Funds will not expire at the end of this fiscal year. This is a follow-on to a competitive award. The Defense Advanced Research Projects Agency issued the contract (MDA972-99-9-0003). See also Boeing’s corporate release.

June 14/05: Boeing’s X-45A J-UCAS (Joint Unmanned Combat Air Systems) program receives the Flight International Aerospace Industry Award for 2005 in the category of Missiles and Military Aviation. Boeing release.

May 11/05: The X-45A completes a System Requirements Review, involving DARPA, Boeing and the US Air Force. Boeing release

Feb 4/05: A pair of Boeing X-45As flew a simulated combat mission, codenamed “Peacekeeper,” at NASA’s Dryden Flight Research Center, Edwards Air Force Base, CA. It was the program’s 50th flight.

The two X-45As climbed to 24,500 and 25,500 ft respectively, separated by approximately 25 miles and operating at Mach .65 (225 knots) while providing airborne alert over the exercise area. Tasked with suppression of enemy air defenses, the two vehicles were given 2 simulated pop-up ground threats to eliminate. The X-45As autonomously determined which vehicle held the optimum position, weapons and fuel load to properly attack the target, whereupon one of the X-45As changed course and the pilot-operator allowed it to attack the simulated ground-based radar. Following a successful strike, another simulated threat emerged and was subsequently destroyed by the 2nd X-45A. The two X-45As completed their mission and safely returned to Edwards.

The X-45A demonstration was preceded by a lengthy software integration and test process. Peacekeeper software underwent more than 2800 hours of testing in a high fidelity System Integration Laboratory. Boeing release.

X-45A ground control
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Dec 9/04: A Boeing X-45A unmanned is controlled via satellite by a pilot-operator in Seattle, WA, after launching from NASA’s Dryden Flight Research Center at Edwards Air Force Base, CA. The X-45A departed in the morning with a pilot-operator controlling the jet from its home in Southern California, using line-of-sight controls. Once airborne, the pilot-operator handed control of the unmanned vehicle over to another Boeing pilot 900 miles away in Seattle. After controlling the X-45A for 6 minutes via UHF satellite communications (SATCOM) link, command was turned back back to the California-based team, which returned it to Edwards AFB safely after nearly an hour in the air. Boeing release.

Dec 3/04: Known by the call signs “Stingray 01 and 02,” a pair of X-45As operate together for over an one hour. The UCAVs demonstrated the ability to autonomously enter and exit coordinated flight based on pre-identified points. The X-45As executed several different formations, showing the ability to dynamically alter the formation in all 3 axes simultaneously. Boeing release.

Nov 12/04: A pair of X-45As with new Block 3 software demonstrate “4-D” navigation, which allows the vehicles to accurately control time-of-arrival over specified geographic locations in addition to maintaining relative position – a critical capability in tactical operations. Source.

Nov 10/04: Boeing accepts the first 2 F404 engines for its X-45C aircraft program, in a ceremony held at a General Electric plant in Lynn, MA. At this point, the first X-45C flight is scheduled for early 2007. Boeing release.

Oct 21-28/04: Boeing begins began testing its X-45A’s Bock 3 flight and mission software for the X-45A unmanned aircraft at NASA’s Dryden Flight Research Center, Edwards Air Force Base, CA. The program’s 36th and 37th flights follow a series of successful ground and taxi tests in August and September.

The Oct 28/08 flight was the first test of the unmanned system’s capability to rapidly respond to a changing environment. The “Automated Dynamic Mission Replanning” function responded to a simulated “pop-up” ground threat during the flight by defining a revised route to avoid the threat, communicating it back to the pilot-operator, and following it after the pilot-operator concurred. After avoiding the pop-up threat, the X-45A resumed its primary route and continued on its direct attack mission. Boeing release.

Oct 12/04: Boeing subsidiary McDonnell Douglas Corp. in St. Louis, MO received a $766.7 million modification to a previously awarded prototypes agreement. Under this modification, Boeing will design, develop and build 3 full-scale X-45C Joint Unmanned Combat Air Systems (J-UCAS) air vehicles and 2 mission control elements, integrate them with the J-UCAS Common Operating System to meet Air Force and Navy mission capability objectives, and conduct an operational experiment and assessment.

Work will be performed in St. Louis, MO (80%), El Segundo, CA (4%), Cincinnati, OH (2%), Goleta, CA (2%), Lynn, MA (2%) and multiple other locations (1% or less at each location) and will be completed in March 2010. Funds will not expire at the end of this fiscal year. This is a follow on to a competitive award by the Defense Advanced Research Projects Agency (MDA972-99-9-0003).

X-45C UCAS (3 views)

Aug 1/04: A single operator at Edwards AFB, CA controls 2 Boeing X-45As, in a coordinated flight completing the first ever multiple air vehicle control flight demonstration.

Both J-UCAS X-45As departed in succession from NASA’s Dryden Flight Research Center at Edwards AFB. After joining up over the test range, the air vehicles demonstrated coordinated operations by flying preset formations that involved autonomous maneuvering to hold their relative positions. The 2 X-45A aircraft were able to fly the same mission plan on their own which significantly reduced their pilot-operator’s workload. Boeing release | Video [RealPlayer]

“Our X-45 team has demonstrated that a single pilot can manage multiple unmanned aircraft during all phases of a coordinated flight,” said Darryl Davis, Boeing J-UCAS X-45 program manager, “This event is very significant because it is the first step in demonstrating the ability of this distributed weapons system to coordinate operations in a high-threat environment.”

Once the demonstration was completed, both unmanned combat air vehicles (UCAVs) returned safely to the base, landed on a common runway and taxied to the shutdown location.

July 19/04: Boeing unveils a full-size model of its X-45C at the Farnborough International Air Show in England. Photo release.

June 8/04: Boeing starts assembling its follow-on X-45C J-UCAS aircraft, loading the aft “carry-through” frame into a holding fixture inside the company’s St. Louis, MO manufacturing facility. The 86-pound aluminum part, which spans the back end of the vehicle, will soon be mated with the two X-45 engine keels. Boeing’s release quotes Darryl Davis, Boeing J-UCAS X-45 program manager:

“Thanks to advanced design and manufacturing techniques coupled with our lean processes [and learning from the X-45A program], we expect the X-45C parts to come together easily and quickly… On both the A and C vehicles, we’ve greatly reduced the amount of expensive hard tooling needed and we are using laser tracking for more efficient assembly.”

X-45As, 2005
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June 7/04: Two Boeing X-45As taxi together at 20 knots on the runway of NASA’s Dryden Flight Research Center, Edwards Air Force Base, CA, autonomously maintaining their positions relative to each other through an inter-vehicle communication link. Boeing release | Boeing video [RealPlayer format].

May 7/04: An X-45A successfully communicates with a manned T-33 aircraft while in flight over NASA’s Dryden Flight Research Center, Edwards Air Force Base, CA. It exchanged data through the secure Fighter Data Link protocol while operating at 14,000 ft and 228 mph, as the T-33 maneuvered around it.

This flight lays the groundwork for a 2-ship X-45A flight, and will be followed by an X-45A/ T-33 flight with a ground operator managing both aircraft, as the T-33 is flown by on-board J-UCAS avionics software. Boeing release.

X-45A drops JDAM
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April 18/04: The X-45A UCAV demonstrator hits a ground target with a 250-pound inert GPS-guided weapon released from its internal weapons bay.

March 11-14/04: Boeing’s X-45A completes a pair of flights at NASA’s Dryden Flight Research Center, Edwards Air Force Base, CA. These were the first tests of the final build of the Block 2 software, flying to the aircraft’s maximum demonstration envelope of 0.75M and 35,000 ft. The flight also included transmitting a (stored) synthetic aperture radar (SAR) image to the ground operator, demonstrating the capability to do so within the operational timeline and bandwidth constraints.

During that flight, it opened and closed the weapons bay, clearing the vehicle to conduct the rest of the Block 2 flights. Boeing release.

May 22/02: The X-45A’s first flight. It flew for 14 minutes at NASA’s Dryden Flight Research Center at Edwards Air Force Base in California. The UCAV reaches an airspeed of 195 knots, and an altitude of 7,500 feet.

March 24/99: Boeing Phantom Works in Seattle, WA won a $14.8 million increment under a $131 million other-transaction-for-prototypes contract. They will design and fabricate an Unmanned Combat Air Vehicle demonstrator system, and conduct a series of demonstrations to validate the technical feasibility of their design. The government is funding $110 million of the effort; the balance is cost-shared with Boeing.

That demonstrator was known as the X-45A, and went on to tests that included the dropping of live bombs. This contract involved 2 X-45A air vehicles and a mission control station.

Work will be performed in Seattle, WA (38%); St. Louis, MO (53%); Huntington Beach, CA (3.2%); Long Beach, CA (2.8%) and Mesa, AZ (2.4%) and is expected to be complete by Sept 30/00. This was a limited competition, with 3 proposals received by the Defense Advanced Research Projects Agency (MDA972-99-9-0003).

Additional Readings

• Air Force Technology – X-45 J-UCAV Joint Unmanned Combat Air System, USA

• NASA Dryden Flight Center – Past Project – X-45 Unmanned Combat Air Vehicle (UCAV). These flights involved the X-45A.

• Boeing – History section: X-45 Joint Unmanned Combat Air System

• DARPA – Joint Unmanned Combat Air Systems

• GE – Model F404-GE-F1D2 (engine)

• Honeywell Aerospace – F124 (engine)

• DID – $49M for Boeing to Advance UAV Aerial Refueling. Even when J-UCAS was canceled, UAV aerial refueling research continued.

• Boeing’s All Systems Go magazine – X-45 Transforming the Future of Flight.” Includes a program timeline to date.

• DID FOCUS – Carrier UCAVs: The Return of UCAS. The UCAS-D competition, won by Northrop Grumman’s X-47B.

• DID – USAF Wants a New Bomber By 2018… Or Does It?