Hunting insurgents or covering convoys, the U.S. Army’s first digital aircraft remains its most heavily used combat helicopter. To hike Kiowa Warrior availability and trim operating costs, the Army itself is integrating a Cockpit And Sensor Upgrade (CASUP) that turns OH-58Ds into more capable OH-58Fs with longer-ranged sensors, intuitive color displays and a more powerful avionics architecture. The Army Aviation and Missile Research Development and Engineering Center (AMRDEC) at Redstone Arsenal in Alabama will integrate the Bell helicopter with the Raytheon Common Sensor Payload (CSP) and the latest Honeywell Control and Display Subsystem (CDS5).
“From the system level, the PM Kiowa Warrior is the lead system integrator for the overall program,” said Kiowa Warrior pilot and assistant product manager Maj. Jeffery McCoy at the Army Aviation and Missile Command (AMCOM).
The first CASUP Engineering and Manufacturing Development airframe was “depopulated” at the AMRDEC Prototype Integration Facility (PIF) in early summer and should fly again as an OH-58F in late 2012. (Bell has another OH-58D for structural analyses associated with the nose-mounted CSP.) Plans call for the PIF to assemble three of the seven OH-58F Engineering and Manufacturing Development aircraft before conversions transition to Bell in Amarillo, Texas. The Army expects a first unit equipped with the Fox-model Kiowa Warrior in 2015 and plans 368 CASUP helicopters to team with Shadow Unmanned Air Vehicles (UAV) in attack-reconnaissance squadrons.
The CASUP will put Level 2 Manned-Unmanned interoperability (L2MUM) into the Kiowa Warrior cockpit. “You can’t control where the UAV is looking or where it needs to go, but you can see that video live,” said Bell Army Business Development Manager Stephen Eppinette. MUM capability was first fielded on VUIT-2 Apaches in Iraq, but the productionized OH-58F package promises to extend range beyond the original 40+ kilometer range. The CASUP will also enable scout crews to record and downlink unmanned aircraft systems and CSP imagery for ground commanders.
Trading the distinctive OH-58D Mast Mounted Sight (MMS) for a nose-mounted AN/AAS-53 CSP will let the OH-58F crew look directly below the helicopter in urban combat. The laser-designating CSP is already flying on the Gray Eagle UAV and gives the armed scout helicopter infrared, day TV and Image-Intensified TV imagery with probability of target recognition about 55 percent greater on infrared and 20 percent better on TV than that of the MMS. “That sensor package brings a great deal of capability into a smaller, lighter-weight package,” said McCoy. The CSP can also fuse infrared and electro-optical imagery. “That allows you to overcome different atmospheric conditions that you couldn’t do with the MMS” ( Avionics, August 2008, page 24). CSP high-definition video and target location accuracy improvements are already in the works.
To enhance the connectivity of the battlefield scout, CASUP adds a second Raytheon ARC-231 VHF/UHF/SATCOM radio integrated with crew displays. CDS4 introduced Joint Variable Message Formats (JVMF) to the Kiowa Warrior via the Improved Data Modem, but CDS5 can show the latest JVMF icons enhanced with color. The OH-58F cockpit also retains the Blue Force Tracker II now in the fleet to enhance the situational awareness of the scout crew. A new Rockwell Collins data loader is compatible with the Aviation Mission Planning System.
Throughout its service life, the OH-58D cockpit has had two monochrome multifunction displays augmented with stand-alone Aircraft Survivability Equipment and electromechanical engine instruments. The cleaner CDS5 cockpit has three color multifunction displays that eliminate the vertical scale instruments and give the OH-58F pilot and observer primary flight symbology and access to multi-sensor imagery or digital maps simultaneously or independently. “You can see your sensor and the UAV sensor at the same time to confirm a target,” noted McCoy. The split-screen displays will also post threat warnings from Aircraft Survivability Equipment on intervisibility maps alongside flight and systems symbology. “When the data is there, it’s very easily discerned,” he said.
The OH-58F is the latest chapter in the Army Helicopter Improvement Program that started turning Vietnam-vintage OH-58A/C Kiowas into databused OH-58Ds in the early 1980s. The Bell Aeroscout with McDonnell Douglas MMS, Automatic Target Handover System and digital cockpit was designed to locate and laser-designate targets from defilade for artillery and attack helicopters. Operation Prime Chance integrated Hellfire and Stinger missiles, 70 mm rockets and 0.50 caliber machine guns on the Kiowa Warrior for the Persian Gulf and led to CDS2 around 1989. CDS3 with twin Master Control Processor Units appeared in 1996, and a Safety Enhancement Program begun in 1998 standardizes the last OH-58Ds on CDS4 with an Improved Master Control Processing Unit (IMCPU). OH-58D conversions for the U.S. Army ended in 1999, but the armed scout became a valued player in Operations Enduring and Iraqi Freedom. (Deliveries of 40 new war replacement aircraft start again in 2012 to replenish the fleet.) Kiowa Warriors in Afghanistan and Iraq average 75 flight hours per aircraft per month with surges to 110 hours a month five times peacetime operating tempos. Mission-capable rates run about 85 percent.
When rising costs killed the Bell ARH-70 Arapaho with its CSP and Rockwell Collin cockpit in 2008, the Army initiated an OH-58D Life Support 2020 program with CDS5 and CSP to remedy Kiowa Warrior component obsolescence and reduce operating costs.
“The MMS, due to its age, is a very maintenance-intensive piece of equipment,” noted McCoy.
In April 2009, the Secretary of the Army approved the CASUP, awaiting some higher-performance armed aerial scout based on existing helicopters or a new platform. (The Bell Xworx flew its Kiowa Warrior Block II demonstrator in April 2011 in anticipation of an armed aerial scout competition.)
OH-58F CASUP requirements were formalized in a Capabilities Development Document in late 2010. Today’s OH-58D CDS4 still has two monochrome displays and dual 1553B databuses, but wartime threats have loaded the Kiowa Warrior with the Common Missile Warning System. “It really is a federated system, modded onto the aircraft and hard-wired into the aircraft,” said Bell CASUP Project Manager Paul Watts. The OH-58F CDS5 provides a third databus and a new architecture to tie CMWS into the multifunction displays. “On the F, it really is an integrated system, integrated into the mission computer and all the other systems.”
CDS5 also collects data from the Honeywell Health and Usage Monitoring System (HUMS) to move the OH-58F closer to the Army’s goal of Condition-Based Maintenance. “That’s really the beauty of HUMS,” said Honeywell CDS5 Program Manager Mike McDowell. “You can do maintenance when it’s appropriate, not when it’s timed to go do it.” The HUMS system currently draws on 15 aircraft sensors to record vibration that warns of component wear. OH-58D maintenance test crews today use a separate laptop computer for data collection. The CASUP puts data collection in the cockpit and provides sufficient growth to add temperature or other sensors as CBM is refined.
For CDS5, Honeywell upgraded the IMCPU from a single PowerPC 603 processor to four 7448 chips. The new IMCPU has five times the processing speed and 32 times the flash memory of its predecessor. The 200 percent growth margin in the new IMCPU made it possible to integrate the AN/AAR-57 Common Missile Warning System, APR-39A(V)4 radar warning receiver, AN/AVR-2B laser warning receiver into cockpit displays and still have 100 percent processor and memory growth for future systems. In addition, the new processor unit switched from a proprietary backplane to a PCIe backplane that increased redundancy for the 1553B and ARINC 429 buses.
The new CASUP wire harness provides three 1553B data buses to tie in the CSP, three pieces of Aircraft Survivability Equipment, four radios, an embedded GPS/Inertial navigator, a digital intercom, a Common Mode Transponder and Mil-Std-1760 weapons launchers. The 1760 launchers will accommodate the Joint Air-to-Ground Missile, Modernized Rocket Launcher and future ordnance. “We want to posture ourselves to integrate the latest weapons on the aircraft, and that’s the interface,” said McCoy. The CASUP system will also use a high speed/high bandwidth Ethernet connection to link the dual IMCPUs and other black boxes including the new data loader.
Honeywell engineers developed the OH-58F Pilot-Vehicle interface with extensive input from Kiowa Warrior pilots in the product manager’s office and numerous cockpit working groups. “Every single time we’ve had a meeting with all the teammates, I’ve been impressed with the response from the user community and how much input they’ve had on the design of this aircraft,” said Watts at Bell. The AMRDEC System Simulation and Development Directorate is using the converted ARH-70 simulator for OH-58F cockpit display development with familiar symbology.
“We’ve been on the platform so long, the user has found the data provided to them is intuitive. When pilots get on board, all the pages behave the same way,” said Honeywell’s McDowell.
Though CASUP designers are working on cyclic switches for the co-pilot/observer to control the CSP other changes to Kiowa Warrior hands-on interface re minimal. “For the most part, we’re trying to retain the same switchology so there’s not a large learning curve,” said McCoy. Initial pilot reports from CASUP simulators indicate workload in the new cockpit is within Army requirements.
Honeywell had Systems Integration Labs from CDS3 and CDS4 and assembled a new Software Integration Lab in Albuquerque, N.M., for CDS5. “Everything we interface with is part of the SWIL, less the engine,” explained McDowell. The Common Sensor Payload and other Government Furnished Equipment are already tied to CASUP displays.
Elbit Systems of America provides the two “dumb” 5- by 7-inch active matrix liquid crystal displays allocated to moving maps and sensor video, and the 6- by 8-inch central display that eliminates OH-58D engine instruments and provides a split-screen format for threat warnings and aircraft information. A Honeywell optical display assembly pipes flight symbology into Night Vision Goggles.
OH-58F performance and handling are expected to be similar to the characteristics of today’s Kiowa Warrior despite removal of the Mast Mounted Sight and introduction of dual-channel Full Authority Digital Electronic Control on the existing Rolls Royce 250C-R3 engine. “We attempt to make everything weight-neutral or reduced weight,” said McCoy. Projected weight savings from the CASUP are now around 50 pounds. “That may not seem like much, but that’s 50 pounds more gas, 100 rounds of 50 caliber ammunition. That’s two more rockets I can carry on every mission.”