Plug-and-Play Strike Weapons

by Michael Puttré
Sep. 7, 2005

A consortium of US strike weapons manufacturers will be meeting at Wright Patterson AFB (Dayton, OH) in late September to finalize specifications for a "plug-and-play" interface between such weapons and US Air Force aircraft. The Universal Armaments Interface (UAI) program, run by the Aging Aircraft Systems Squadron, has the goal of developing common software that will allow the Air Force to incorporate new precision-guided munitions onto its aircraft without requiring major changes to each aircraft's operational-flight-program (OFP) software. This capability is expected to enable the integration of weapons independent of the block-upgrade process, cutting as much as five years from a given integration effort.

"The Air Force recognized that most aircraft have an OFP cycle that runs three to five years, and you start the second cycle midway through the first one," said Jerry Duke, deputy director of Aging Aircraft Systems Squadron and manager of the UAI program. "If your weapon comes onboard in the middle of one of those cycles, you have to wait until the beginning of the next cycle before you even start integrating the weapon onto that platform."

Saving time is cited as the major justification for the UAI program. With a standardized interface between the platform and the store, any new weapon that supports this interface could be integrated onto that platform without having to make changes to its OFP. "The dollar savings will be there in the long run," Duke said. "In the short run, it might cost you a little extra to put UAI in. But then the next time you crack that OFP, you won't have to do any weapons integration."

The UAI is an extension of Mil Std 1760, which specifies the number and type of connections between aircraft platforms and a class of precision-guided weapons that includes Joint Direct Attack Munition (JDAM), the Paveway family, the Wind Corrected Munitions Dispenser (WCMD), the Joint Standoff Weapon (JSOW), and the Joint Air-to-Surface Standoff Missile (JASSM) (see "Hammers of the Gods"). What the UAI standard defines is a message set that 1760-class weapons and compatible platforms use and recognize. It is not much of a stretch to say that the UAI is functionally similar to the Universal Serial Bus architecture used in the consumer electronics industry in that it enables compatible hardware to be connected and operated without any additional hardware or software changes.

Duke credited Judy Stokley, deputy for acquisition at the USAF’s Air Armament Center, Program Executive Office for Weapons, for launching the initial efforts that would eventually coalesce as the UAI program. After Stokely's group finished a risk-reduction study in July 2004, the Aging Aircraft Systems Squadron was directed to organize the UAI program that would receive its funding through the Air Armament Center. The funding came through in early December 2004, and the Aging Aircraft System Squadron contracted Raytheon, Boeing, Lockheed Martin, and Northrop Grumman to develop the UAI. Each OEM has its own individual contract to create the platform stores initial capabilities document (ICD), the mission planning ICD, and perform validation activities.

The UAI effort has been proceeding at a brisk pace. A baseline ICD was released on June 30, 2005, for the F-15 System Program Office at Warner Robbins AFB to use for planning purposes. The F-15 Eagle is to be the threshold platform for UAI. August 31 was the deadline for quality-assurance checklists from the OEMs. These checklists are being issued to all appropriate program offices for platforms and stores so that each can certify that the UAI can be used. A final design review for the UAI is scheduled for Sept. 28-29 at Wright Patterson. If all goes well, the final UAI specification will be released by the end of December.

Although the four OEMs are not a true consortium in the business sense of the word, Duke said that they perform that function in that the effort is cooperative, not competitive. What's more, the resulting UAI standard will be non-proprietary. "The OEMs have been cooperating very, very well," Duke said. "I couldn't be more pleased with their enthusiasm and effort."

JASSM: A Case Study

One of the reasons the individual weapons vendors find the notion of a UAI standard so appealing is that it opens up new potential markets for their wares -- internationally as well as domestically. Lockheed Martin (Orlando, FL) announced on Aug. 24 that it had developed the capability for its JASSM cruise missile to be integrated onto aircraft that have the existing capability to carry and launch the Raytheon (Tuscon, AZ) JSOW. Unlike the UAI, this capability requires no change to the aircraft OFP software at all. Lockheed Martin has altered the JASSM software so that an aircraft recognizes the weapon as if it were a JSOW. Thus, in theory, all existing aircraft that are capable of launching relatively low-cost JSOWs now constitute ready potential users for the upmarket JASSM. International sales of the JASSM are taking on increasing importance for Lockheed Martin as the weapon faces opposition from the US Congress.

While Lockheed Martin developed the JASSM-on-JSOW interface as an internal effort to improve the marketability of its weapon, the program can be seen as a "dry run" for a more far-reaching and non-denominational UAI. "The effort to make JASSM compatible with the JSOW interface certainly gave us an understanding of how to utilize other similar interfaces," said Casey Contini, Lockheed Martin's JASSM technical director, who cited the UAI program specifically.

Lockheed Martin's work on behalf of its JASSM interface, while proprietary, could offer something of a case study in how useful the UAI might be. In a practical sense, the ability to load JASSM missiles on aircraft stations equipped to handle JSOW is of little consequence for US platforms, many of which have already had their OFP software modified to "speak JASSM." However, international customers have not done so for their aircraft, and Lockheed Martin is trying to remove a hurdle between its weapon and a foreign sale.

"From a business standpoint, the initiative targets the JASSM marketplace, and to accelerate our path into, most importantly, the international marketplace by being more readily adaptable to existing inventories of aircraft with our international customers," said Mike Inderhees, Lockheed Martin's JASSM program director. "We now are providing a path for what has traditionally been a very expensive and schedule-driven event, to bring a weapon into the aircraft cycle of its software build. We now have freed ourselves and the customer of this cycle."

It is difficult to exaggerate the complexity and expense of the block-upgrade cycle. Typically, high-performance jet fighter-bombers are introduced into service with baseline capabilities that are improved and added to as technology and budgets permit. Increasingly, the software aspects of integration projects consume the lion's share of the time and money. For this reason, aircraft operators limit the number of times they allow integrators to "crack" or modify the OFP software to enable new functionality. Improvements are saved up and tackled as a group, with each group of upgrades constituting a block -- sometimes called a "batch" or "tranche" in some circles. As noted preciously, block upgrades are scheduled years, sometimes decades, in advance, and competition for what new systems and improvements will make the cut is fierce. Moreover, an air force is prone to changing its requirements as missions evolve and lessons are learned. Sometimes a planned integration for a new system or weapon is postponed or even discarded in favor of another with a higher priority.

"Typically, a customer is not just going to spend $30 million on JASSM. They're going to spend upwards of $100 million, because they're going to get other upgrades at the same time," said Contini. "And that bill's getting kind of scary even for those of us who are used to dealing in those kinds of numbers. So if we can say, 'you don't really need to do the JASSM work because we'll just use your JSOW interface,' well that knocks $20 million to $30 million off that bill. Plus, it simplifies the software-development effort, and so the timeline gets a little shorter and the risk goes down. And risk is a factor that everybody is concerned about – schedule risk, capability risk. They don't have to worry about that, because we've already demonstrated that you can talk to the JASSM across the JSOW."

Of course, there are still flight-dynamics issues related to weapons carriage and launch speeds that have to be tested, but these activities are trivial compared to the integration effort. Contini noted that countries that are willing to accept the US Air Force's "Seek Eagle" evaluations of weapons carriage and launch dynamics on its platforms can reduce their costs for those weapons and aircraft combinations that have already been tested and cleared.

Expanding the Market

The US Air Force's Duke said that while the UAI standard currently only addresses 1760-class precision-guided munitions, in the future, his program office will look at expanding it to include air-to-air missiles, training pods, sensors, and other pods and stores. Duke said that he was also looking at getting release authority to give the UAI to some Foreign Military Sale (FMS) partners. Thus, the non-proprietary UAI standard might conceivably be made available to non-US manufacturers of strike weapons and operators of US-source aircraft. This would enable vendors to develop UAI-compatible weapons and air forces to incorporate UAI into their platforms' OFPs.

The US Navy is currently performing a baseline cost analysis to see what the benefit of the UAI is for the F/A-18s in particular. From the Navy's point of view, one of the obstacles to adopting UAI at the moment is that the service is not looking to integrate any new weapons for the F/A-18. But that could change.

"Mission requirements change," Duke said. "We took a look at projections for weapons integration as of 1994, and at that time, we had only projected that there would be 16 new weapons integrated across the fleet onto Air Force platforms. In reality, during that period we integrated 33 weapons. The UAI will allow the Navy, if they go this way, the flexibility to integrate weapons on the F/A-18 that they haven't thought about or that they passed by in the past because it was too expensive or whatever. But if those weapons are UAI compatible and if the F/A-18 becomes UAI compatible, then they can go back and do those weapons if they want to, and that will increase their mission flexibility."

The likelihood that the UAI or some derivative of it will be adopted across the services and even internationally seems quite good. The UAI program office is in talks with the F-35 Joint Strike Fighter (JSF) program. "UAI will be a true joint program if JSF embraces it," Duke said.