The experimental stage for small unmanned aircraft systems capable of 20h endurance at low altitude in military service is soon drawing to a close.

The Boeing/Insitu Scan Eagle proved its worth in four years of operational service in Afghanistan and Iraq as an asset leased by the US Marine Corps. It cemented the utility and the concept of operations for the class of vehicle that occupies the last major gap in the unmanned aircraft systems inventory for the US Department of Defense.

Now, the DoD is gearing up to formally acquire and institutionalise what the US Navy calls the small tactical UAS (STUAS) and what the USMC calls the Tier II system, which fits in the inventory between the hand-launched AeroVironment DragonEye and the Tier III RQ-2 Pioneer.


Both the USMC and the USN expect to issue a draft request for proposals in the third quarter, launching the competitive phase for the STUAS/Tier II contract. The US Air Force has signalled its intent to acquire the same aircraft later for base surveillance missions.

The opportunity to sell hundreds - and perhaps thousands - of vehicles and associated equipment to the US military has attracted wide interest from industry. The US defence industry is also mindful that STUAS/Tier II represents the last major UAS contract expected to be awarded by the DoD for several years.

Both incumbents Boeing and Insitu plan to compete, but it remains unclear whether they will remain partners. Insitu has developed the larger and more capable Integrator UAS, which features a twin-boomed tail and provisions for surveillance systems and small weapons.

Another major candidate is the Raytheon/Swift Engineering team, which is offering the blended-wing body KillerBee-3 UAS. AAI, a Textron subsidiary, is readying the Aerosonde Mk4 aircraft to compete for STUAS/Tier II.

Finally, General Dynamics Armament and Technology Products and Elbit Systems announced on 30 April a new partnership to offer the Israeli company's Skylark II UAS for the STUAS/Tier II requirement. The team has held a demonstration of the aircraft's capabilities at Redstone Arsenal, Alabama.

Other potential bidders yet to clarify which vehicle they would offer include BAE Systems, Lockheed Martin and Northrop Grumman.

Northrop has previously held talks with Aurora Flight Sciences to offer the Golden Eye-80 ducted fan. The company says it is also considering new internally developed options, although no Northrop-made small UAV designs have been publicly released.

Aurora, however, maintains that "we do continue to have a relationship with Northrop Grumman" on the STUAS/Tier II programme.

Northrop engineers are "weighing the possibilities of both. A final determination has not been made on whether they will build or partner", the company says.

Northrop's position has been undecided since last year when the company dissolved its partnership with Swift's KillerBee-3.

Lockheed's maritime systems and sensors (MS2) division, meanwhile, reports that it is "continuing to evolve our approach, recognising the complexity of this competition, to ensure that we can provide a solution that meets the needs and requirements of our customers".


Last year, Lockheed was preparing to bid using the SkySpirit II UAS, a converted testbed vehicle designed by researchers at a college near MS2's offices in Eagan, Minnesota.

BAE has no comment about its plans for the competition. Only a year ago, the company was preparing to compete for the USMC Tier II contract with the SkyLynx II UAS.

In addition, BAE is in the process of acquiring MTC Technologies, which previously planned to offer the SpyHawk UAS.

MTC says it has abandoned development of the SpyHawk, but is continuing to develop its ground station that can be applied to any unmanned aircraft. "Discussions have not taken place yet about operational pursuits [after] closing our merger with BAE Systems," he adds.

A key discriminator in the competition hinges on a new requirement to power the UAV with a small, heavy fuel engine. The competitors have a choice between two options. An example of the first option is the Insitu Integrator, which has an exclusive deal with Sonex to adapt a motor gasoline engine to the heavy fuel standard. The Raytheon/Swift team is taking the opposite approach, designing a new, purpose-built engine for a small UAV.

Source: Flight International