MILTARY MACHINES

Radical helos, V/STOL vehicles and UAVs are on US Army's shopping list

Complexities of future warfare lead to purchase of wide variety of unconventional aircraft.

By Jay Chandler
ATP/Helo. Learjet, Shorts 360, Sikorsky S54, Boeing Vertol 234


Building on X2's success, Sikorsky plans to demonstrate the S97 Raider to the US military. The coaxial counter-rotating main rotor and pusher propeller will allow speeds up to 220 kts and dash speeds to 240 kts. Other advances include low acoustic signature, agility for close air support and FBW controls.

Small arms fire dances alongside the off-road vehicle as it speeds along the high desert trail. SSG Jordan and his team provide suppressive fire to allow the lead vehicle to transform into flight mode and extract the precious cargo. As if on cue, 2 flying humvees swoop down and neutralize the threat, allowing SSG Jordan to transform to flight mode himself so the entire SOF team can depart the danger zone and fly toward safety.

The above vignette may sound like a scene from an action movie, but it may in fact be reality in the not too distant future if the Dept of Defense (DoD) and Special Operations Command (SOC) have their way. Having the right tool for the right job is a slogan many operate by, including US Special Operations Forces (SOF).

Foreseeing a need for future SOF capabilities, there is an active push not just for making current helicopters faster and more capable (see "Innovation for the rotorcraft of tomorrow," Pro Pilot, Jan 2012) but for fresh new vertical-lift aircraft for all arms of the military and for multiple missions.

Research is well under way for a radically new vertical-lift aircraft with little resemblance to current helicopter designs and more similarities to the vertical-lift aircraft in the movie Avatar. These sport 2 or 4 fully articulating ducted-fantype rotor systems and come in gunship, troop transport and C17 sizes.

At a recent SOF industry conference, several presentations made it clear that a rotary-wing transformation program was badly needed to meet the needs of future SOF operations. Considering the expanded responsibility of Special Ops and the recent increased use of SOF units, according to a Congressional report dated Mar 23, 2012, SOF will be increasing in size. Demand for newer high-tech equipment is sure to follow.

The report references the White House's plan to reduce Army end strength by 27,000 soldiers and the US Marine Corps by 15,000–20,000, with increased reliance on SOF units worldwide.

Advanced designs

DOD's Joint Multirole program invites designers to think outside the box of normal rotor equipped aircraft.

A stunned world watched the aftermath of the attack on Osama bin Laden's compound in Abbottabad, Pakistan. While everyone wanted to learn the outcome of the mission, aviation experts clamored for the identity of the advanced helicopter that crashed during the successful SOF attack. Helicopter experts and the rest of the world had no idea the US already had stealth helicopter technology in use.

Many speculate the advances are the result of the cancelled 2004 Boeing–Sikorsky RAH66 Comanche stealth program that spent $6.9 billion to produce 2 prototype helicopters. Military officials did say at the time the technology would be used in future stealth projects, and perhaps Comanche tail rotor technology was mated to an existing Sikorsky UH60M for this special ops mission in Pakistan.

The Army hopes eventually to replace the now legacy Boeing CH­47 Chinook, Sikorsky UH60 Black Hawk and Boeing AH64 Apache with the next generation of vertical-lift aircraft. As Maj Gen Anthony Crutchfield, commanding general of the US Army Aviation Center of Excellence and Fort Rucker AL, said at a briefing recently, "I do not want my son flying a Block 80 AH64 Apache."

The Pentagon and US Army have already begun the early stages of a broad-reaching science and technology program to develop the next generation of vertical-lift aircraft. Led by the Army, this program is labeled the Joint Multirole (JMR) program. It will receive input from all branches of the military, NASA, SOC and the office of the Secretary of Defense.

Piasecki's X49A obtained significant speed increases and reduced noise signatures using a vectored thrust ducted propeller (VTDP) system on a highly modified Sikorsky UH60.

Three primary categories will make up the JMR program—light, medium and heavy, with a possible 4th category—ultra—for cargo operations. PEO Rotary Wing, Army Aviation Applied Technology Directorate Col Doug Rombough has stated in many briefings that "only new technology can make significant increases in range, speed, payload, survivability and reliability."

Incremental improvements, according to Rombough, have run their course for rotorcraft development. New aircraft need to be lighter, faster, with increased lethality and situational awareness and reduced crew member workload.

DARPA Tactical Technology Office Program Mgr Stephen Waller at a separate aviation technology conference confirmed DoD's intent to pursue advanced vertical lift by both military and industry design teams.

Waller stated, "Right now the plan is to go through the first phase to define what the state of the possible would be, followed by a down-select to build 2 demonstrators. The idea is to identify, develop and demonstrate the best trade solution that covers the attribute matrix."

AVX Aircraft's proposal incorporates a counter-rotating rotor system to overcome high-speed rotor system aerodynamics and a ducted fan system for increased forward speed.

These futuristic studies will be reviewed by the end of FY2012 and design specifications created and released by early FY2013. Design teams from either individual companies or consolidated corporations will then use the design specs to create an actual aircraft demonstrator.

Again, the designers are not limited to a helicopter-type aircraft but are free to design any vertical-lift aircraft with significant increase in speed, payload and range. The Army hopes to make design awards for build and test phases by Sep 2013 and first aircraft flights by 2017.

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