FEATURE ARTICLE

September 2001

Air Force Eyes Replacement For Aging Pave Hawk Helos

by Bethany Stott

The Air Force expects, by 2004, to select a new medium-lift helicopter to replace its current workhorse, the Pave Hawk. Even though the contract award is three years away, companies already are jockeying for position, for what could be a $6 billion, 132-aircraft acquisition.

The HH-60G Pave Hawk is the Air Force’s current combat search and rescue helicopter. It has helped rescue downed pilots behind enemy lines and capsized fishermen from freezing oceans. It has supported NASA missions and flood-relief operations in Mozambique. It can do all this under virtually any weather conditions. The Pave Hawk’s modern tech-nologies include night-vision capabilities, Global Positioning Satellite (GPS) and other navigational systems, as well as anti-icing rotor blades and engines.

This twin-engine, medium-lift helicopter has been a reliable platform for nearly 20 years. The Air Force, however, wants to begin searching for a Pave Hawk replacement and begin fielding it by 2010. The reason, said Air Force officials, is the aging of the fleet. The Pave Hawk, which is a modified version of the Sikorsky-built Black Hawk—used by the U.S. Army—has proven to be a safe and effective combat search-and-rescue (CSAR) platform. It served during operations in Western Iraq, Saudi Arabia, coastal Kuwait and the Persian Gulf during Desert Storm, as well as in operation Allied Force in the Balkans, where Pave Hawk aircrews were responsible for the safe extraction of two downed pilots in hostile territory.

Currently, 64 are on active duty, 18 in the Air National Guard and 24 in the Air Force Reserves. These seemingly small numbers can be deceiving. When three Pave Hawks were sent to Mozambique for flood-relief operations, they flew 240 missions in 17 days and delivered more than 160 tons of humanitarian relief supplies.

When it first deployed in 1982, the Pave Hawk’s operational life was estimated at 7,000 flight hours. The oldest Pave Hawks in the fleet will reach that milestone in 2001.

Air Force Gen. John Jumper, head of the Air Combat Command, told National Defense that the entire Pave Hawk fleet will have exceeded its 7,000 flight-hour life expectancy by 2019.

But that is not the only reason why a replacement is needed. In January 1999, the Joint Requirements Oversight Council (JROC) noted that the HH-60G was deficient in areas such as survivability, range/combat radius, payload capacity/cabin volume, battle-space/situational awareness, mission reaction (deployment) time, adverse weather operations and service life limit.

As a result, the Air Force decided to begin an Analysis of Alternatives (AoA), to explore possible options to upgrade or replace the Pave Hawk. One of the options considered was a service life extension program (SLEP) for the baseline HH-60G. A SLEP would extend the service life of the helicopter from 7,000 to 20,000 flying hours. That would make the Pave Hawk operable until 2030, as opposed to 2010.

Another possibility is a modernization/upgrade program. It would involve a combination of a SLEP, plus other improvements, such as new wire-cord rotor blades, more cabin space, external fuel tanks, higher performance engines, advanced avionics and defensive systems.

Two other options considered under the AoA—both of which would replace the Pave Hawk altogether—are to purchase a new medium-lift helicopter or a tilt-rotor aircraft such as the Osprey. A final alternative considered by ACC was the notion of a mixed fleet, combining any of the above alternatives.

These options were evaluated based on several criteria: deployability, mobility footprint, survivability, terminal area performance, reliability and maintainability. On June 28, the Air Force announced that it had opted for the purchase of a new medium-lift helicopter.

As with any major acquisition program, the CSAR helicopter procurement is contingent upon JROC approval of the so-called operational requirements document (ORD) for the vehicle, as well as receiving the funds needed. The AoA simply started the process to create an ORD—outlining and compiling the desired criteria for the new helicopter.

Assuming the process moves forward as planned, the Air Force could award a contract as early as 2004. As is often the case with any big-ticket acquisition program, there is a chance of delays due to funding problems. A well-known cliché within the Air Force is that the CSAR community is the service’s “red-headed stepchild.”

According to Air Force Maj. David Morgan, who is in charge of the Pave Hawk modernization effort, an acquisition program could start in 2004, if the so-called operational requirements document is approved.

The Air Force will need “something that can do everything the HH-60 can do, and more,” he said. The HH-60 performs many missions. It is designed to conduct day or night operations into hostile environments and to recover downed air crews or other isolated personnel during war. The HH-60G also participates in military operations other than war, such as civil search and rescue, emergency aeromedical evacuation (MEDEVAC), disaster relief, international aid, counterdrug activities and NASA space shuttle support.

The Pave Hawk carries two pilots, one flight engineer, and one gunner who operates the 7.62mm machine guns. It is about 64 feet long, 16 feet high and can go 184 miles per hour. When it takes off, it can weigh up to 22,000 pounds and go 504 nautical miles without refueling. Its range can be extended, if refueled in flight.

In charge of conducting the AoA was Mike Agin, of Pioneer Technologies, a systems engineering firm. In an interview, he explained that the most important performance factors in selecting a CSAR platform are response time, capacity and survivability. The ability to withstand enemy fire is especially important, Agin said, because the Air Force A-10 fixed-wing aircraft, which traditionally provides rescue-escort support, is aging and may not be around by the time a new CSAR helicopter is fielded.

A ramp also could become a valuable selling point. It offers a quick way to load evacuees on and off the aircraft. The current helo is too small to accommodate a ramp. Additionally, said Agin, a ramp would make it possible to install a gun in the back of the aircraft, to cover that vulnerable “six o’clock” area, behind the pilot. The AoA did not recommend a specific type of gun, but Agin said it should not be too heavy.

Another important factor in a future CSAR helo is range, said Agin. The original H-60 could fly 100 nautical miles and back, unrefueled. “We need to fly farther,” he said. A new CSAR platform should have an unrefueled range of more than 250 nautical miles, according to Agin. The exact range requirement is classified.

Ideally, he said, a CSAR helicopter should be capable of sister-ship rescue operations. That means that if one of two helos goes down, the other one should be able to rescue every crew-member and evacuee traveling on the other aircraft. Currently, that is not possible, because there is not enough room, said Agin. The two fuel bladders take 32 inches of the cabin, and there are 2,100 pounds of gear. If two casualties have to be treated on two stretchers in the back of the aircraft, they could be stacked in a 6-foot cabin and there would be enough room to treat both patients. That is not achievable in the 4.5-foot cabin in the Pave Hawk.

A problem with the old Pave Hawk was the poor survivability odds in a crash situation for para-rescuemen (PJs) belted to the floor. Additional cabin space would help to improve that situation by allowing the addition of seats for the PJs.

If the program is approved and funded, the Air Force could buy up to 132 CSAR helicopters to replace the Pave Hawk. There are competitors already showing interest in the competition, given the size of the program. Among them are AgustaWestland—based in the United Kingdom—and Sikorsky, in Stratford, Conn.

The AoA estimated that each new helicopter would cost about $45 million. Revamping the existing Pave Hawks would cost $8 million per aircraft.

GKN Westland’s EH-101 has a range of more than 750 miles, as well as mid-air refueling capability. It can reach speeds of 168 knots and can carry 30 troops. In addition to its performance specifications, the EH-101 is rumored to be less expensive than other competitors. Company officials were not available to comment on the price of the EH-101. One advantage of the EH-101, said an industry source, is that it is already operational. It has logged 18,000 flying hours.

The Sikorsky H-92 also will be among the competitors. The H-92 airframe is common with the S-92 commercial helicopter, but the H-92 has a higher gross weight and includes customized features, especially designed for the Air Force CSAR competition, said Christopher W. DeWitt, Sikorsky’s chief engineer.

Like the Pave Hawk, the S-92 is a twin-engine, medium-lift helicopter. Although speed and distance vary with load and other factors, its maximum speed is 151 knots, and it can fly 475 nautical miles without refueling. It has 22 troop seats and an external lift capability of 10,000 pounds. The aircraft comes with a large stand-up cabin—6x6x20 feet—and a large aft ramp.

The six-foot cabin—compared to the Pave Hawk’s 4.5-foot—makes it possible to stand up in the cabin and easier to accommodate and treat wounded patients. The S-92 meets Federal Aviation Administration regulations, which is not required for military aircraft. The rotor head was designed to provide 50,000 hours of service and it is “ballistically tolerant,” said DeWitt.

He declined to provide any pricing information on the H-92, but said that it should be “in the range that the Air Force is looking for.” He said it would be cheaper to operate—on a per-flight hour basis—than the Pave Hawk. Finally, the H-92—unlike the Pave Hawk—has a ramp going into its cabin, which would facilitate loading and unloading equipment.

Although the H-92 first flew in 1998, it is not scheduled to be certified for use until 2002. Sikorsky expects that it will have adequate time to have it ready for an Air Force competition in 2004.

Sikorsky also is proposing, in addition to the H-92, a new member of the H-60 family, called the H-60X. This variant would provide increased lift by incorporating the S-92 drive train and rotor systems and a new engine developed under the Army’s common engine program (CEP). The CEP is supposed to develop a 3,000-shp class engine for the Black Hawk and Sea Hawk that delivers both more power and reduced fuel consumption.

The H-60X aircraft is based on a UH-60L or HH-60G, “depending on whom you talk to,” said DeWitt. “In the H-60X, we add a 20-inch cabin plug and a 16” plug to the tailcone. A plug is an extension of the airframe. The cabin plug creates more cabin volume and the tailcone plug brings the tail rotor 16 inches further away from the rotor center to accommodate the 16-inch longer main rotor blades.”

Even with the length added, the H-60X is smaller than the S-92. One of the lessons learned from Vietnam was that CSAR helicopters need to be small and maneuverable. This could prove to be an advantage for the H-60X.

The smaller size, however, does reduce the prospect of a ramp, but there are other ways to protect the aircraft, Agin noted. Gun systems such as the Navy’s Phalanx, which steers itself in the direction of an incoming projectile and stops it with a virtual wall of lead, could be mounted in the rear of an HH-60X.

In the event that a new medium lift helicopter is not available to begin replacing the Pave Hawk in 2010, the option of a SLEP is always there, Air Force officials said.

For the AoA, other helicopters that would have been analyzed, but were not, because the companies did not provide information, were the Agusta-Bell AB139, NATO’s NH-90 and the Eurocopter AS532 Cougar.

Bethany Stott is a cadet at the U.S. Air Force Academy.

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