Aerial convoys: Army, Marines plan improvements for cargo choppers.

As the Army and Marine Corps embark on programs to modernize their medium-heavy cargo helicopters, roadside bombs and ambushes have forced the U.S. military to increasingly rely on the skies to transport supplies and troops in Iraq and Afghanistan.

The Marine Corps has been moving larger quantities of spare parts and supplies by air, said Gen. James Conway, commandant of the Marine Corps. Airlift is the preferred way of moving cargo because it keeps trucks off bomb-infested roadways and reduces the likelihood of armed confrontations at checkpoints, he told reporters.

But the lower risk comes at a price. Like many military assets used in the two wars, the heavy use is wearing down helicopters and fixed-wing aircraft quicker than expected.

The Army alone so far has lost 130 helicopters in combat, said Brig. Gen. Stephen Mundt, director of Army aviation. That is the equivalent of an entire combat aviation brigade, he said at a Pentagon news conference. Replacing those helicopters--which include a mix of cargo and combat variants--could take years or even decades, he noted. It takes contractors on average two years to deliver a new aircraft, and that is way too long, Mundt lamented. "While the military may be on a war footing, our nation's industry is not on a war footing," he said. Contractors make "great products but I sure need them a lot faster."

In the transport arena, three rotorcraft programs--one Marine, one Army and one joint--are in their beginning stages. The stalwart CH-47 Chinook continues to serve as the Army's primary rotorcraft medium-heavy lift option, and deliveries of the revamped F-class began late last year. An updated version of the Marine's CH53E Super Stallion, the CH-53K, is in its first year of development. And all services are eyeing a joint heavy lift helicopter that they hope will tote a whopping 29 tons.

Whether these three programs will have an impact on the current conflicts depends on how long U.S. forces remain in theater. Nevertheless, analysts have pointed out, roadside bombs have proven to be an effective tactic and promise to be employed for years to come. Moving supplies and warriors in aerial convoys will be a vital capability in any future conflict.

The first program to come to fruition will be the Army's revamped Chinook. The service is also rebuilding the aircraft's D-models. Pentagon plans call for 378 remanufactured CH-47Fs and 74 new builds. Boeing Corp.'s rotorcraft division in Philadelphia has delivered 13 aircraft to the Army so far, said Ken Hand, the company's CH-47F program manager. Pilot training and operational tests are being conducted by the 101st Airborne Division at Fort Campbell, Ky.

All of the new builds and most of the D-models now have the Honeywell 714 engine, which will increase fuel efficiency by about 3 percent, he said. The new Chinook can fly at 4,000 feet with a 15,000-pound load on a 150 nautical miles mission. With smaller loads, it can climb as high as 14,000 feet and travel 60 miles.

One of the most important upgrades, Hand said, is the digital flight control computer, which will allow pilots to boost their low-speed handling capabilities, and their ability to hold hover positions as cargo is loaded and unloaded.

While the upgrade doesn't include an improved cargo loading/unloading system, Hand said the cockpit computer allows pilots to hook or unhook an external load with greater ease or hover with only the ramp touching the ground.

"It's a really nice feature," he said.

"When a pilot is trying to pick up a load, he can actually lock a position in." If adjustments are needed, the pilot can ask the computer to move in one-foot increments. Older models require the manual use of the stick, which can be imprecise.

Because the cockpit is now digital, it will also allow for communications software and network systems to be integrated as they become available.

The redesign reduces the number of vibration absorbers from three to two. Since the first fuselage was designed in the early 1960s, Boeing was able to apply what it has learned about "tuning the airframe," Hand said. Reducing the vibrations extends the life of the frame and makes it so "we're not shaking everything to death," he said.

Another major improvement will be the reduction in time it takes to field a Chinook once it is offloaded from a C-5 or C-17 transport aircraft. The F-model includes quick removal fasteners for the aft pylon and quick connect/disconnect for the hydraulics. It currently takes a crew nine hours and 45 minutes to get a Chinook up and running. The new model will be ready to fly in less than three hours, amounting to a 65-percent reduction in time, and a 60 percent reduction in man hours, Eland said.

"Not only did we make it so that you could do it quicker, but it requires fewer people ... We're not just throwing more people at it," he added.

With the F-model in production through 2018 and a projected 30-year lifespan, Boeing speculates that some versions of the Chinook will be in operation at its 100-year birthday in 2061.

The Marine Corps has embarked on a program to replace its main medium-heavy lift rotorcraft, the CH-53E, with an all new K-model.

To the untrained eye, the new model will look like the old version, but it will be a new helicopter, said Dave Haines, CH-53K program manager at Sikorsky Aircraft Corp.

The Marines awarded the contract in April 2006 and Sikorsky broke ground this year in Stratford, Conn., on a heavy lift development center.

Production of the E-model ended in 1999, so there are no aircraft to replace those that are lost in combat. The shortage forced the Marines to use war supplemental dollars to pull three aircraft out of retirement, refurbish them and put them back in the fight, Haines said.

The average CH-53 in Iraq and Afghanistan is flying more than 40 hours per month. In peace time, it typically flies 17 hours per month.

Top of the Marines' wish list was an aircraft with sharply lower maintenance costs, Haines said. The 150 CH-53Es in use today are the most expensive helicopters that the Marines operate, he said.

It takes 40 maintenance hours per flight hour to keep the CH-53E aloft amounting to $8,000 to $9,000 per flight hour in direct maintenance costs. Sikorsky believes it can reduce that by 50 percent, with a 60 to 65 percent reduction in man hours.

To lower the risk associated with incorporating cutting edge technologies, the design will include proven components, said chief engineer Jason Durno.

The K-model will have new rotor blades, a glass cockpit, a General Electric 600 class engine and landing gear. Bits and pieces of the aircraft will be borrowed from other Sikorsky models including the S-92, which is built for civil aviation, the UH-60M Black Hawk, and technologies developed under the now defunct Comanche program, he said.

An automatic cargo rail locking system will allow Marines to load and unload internal cargo pallets quickly. The E-models have a labor-intensive system employing rollers and chains.

The aircraft is being designed to fit in the 2015 Marine expeditionary brigade concept of operations, which is moving away from the traditional ship to shore operations. The service wants to go longer distances, Haines said.

"In places like Afghanistan, you might have to fly up to 9,000 feet and drop people off" in the mountains, Haines said. "It's really being able to deploy equipment to any location--longer distances and higher altitudes."

Sikorsky is aiming to deliver the first models for operational tests in 2014 with the Marines deploying them in 2015.

Specifications call for the E-model to carry up to 18 tons on short hops, and 13 and a half tons on 110 nautical mile missions.

Further out, the Defense Department has a goal of lifting up to 29 tons.

There are currently five studies being conducted by Sikorsky, Boeing, Frontier Aircraft and a joint Boeing/Bell Helicopter team to conceive a joint heavy lift aircraft to be used by the Army, and possibly the Marines.

"It's a quantum leap in payload capacity for these aircraft," said Steve Behnfeldt, Sikorsky program manager for joint heavy lift. Sikorsky is working on two designs, a crane-based system for external lift, and an advanced tandem rotor aircraft that would carry payloads internally.

The desire for a joint aircraft stems from the Army's Future Combats Systems modernization program, and the need to move its heavy components quickly. Whether the other services want to join in the Army's vision remains to be seen.

"The joint heavy lift rotorcraft program is 'joint' in name only," said a GlobalSecurity.org fact sheet. The Marines pushed ahead with the CH-53K because the service couldn't wait for a program that wouldn't come into fruition until the 2020s. It was also concerned that a large aircraft wouldn't fit on Navy ships.

Peter Grant, director of advanced programs at Sikorsky, said if the joint rotorcraft loads equipment internally, the size of the aircraft would increase exponentially.

A crane system, one of the two Sikorsky concepts, would make a considerably smaller aircraft and may placate the Marine's concerns, he said.

The 18-month studies are due this summer. After that, the program's future is unknown, Grant said. The Defense Department has not yet allocated any money for further development.

Meanwhile, Kaman Aerospace Corp. of Bloomfield, Conn. has teamed with Lockheed Martin's System Integration unit in Owego, N.Y. to market a manned and unmanned helicopter capable of lifting 6,000 pounds at sea level and more than 4,000 pounds at 15,000 feet.

Officials of the two companies admitted that the K-Max aircraft, which they are calling an "aerial truck," is not being developed in response to any Defense Department requirements. However, they're hoping a domestic and international market will develop. Lockheed Martin will serve as the integrator for weapons, command and control and logistics systems.

A manned version for non-government customers has been on the market since 1994.

The K-Max can fly 214 nautical miles with an external load and be configured for high-altitude armed reconnaissance at heights of 20,000 feet, the companies said.

Kaman developed its autonomous flight capability in the late 1990s under a demonstration program for the Marine Corps.

"An unmanned resupply vehicle can accommodate getting around the improvised explosive and the ambush situation," said Sal Bordonaro, president of Kaman Aerospace's helicopters division, at an industry conference.

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