Military

Century Chinook?

By James T. McKenna | October 1, 2005

Heavylift, Search and Rescue

With planned acquisitions and improvements keeping its production lines busy for years to come, Boeing is preparing for the CH-47 to become the first helicopter to still be flying 100 years after the type entered service.

Boeing’s CH-47 Chinook started flying in 1962, when helicopters were in much demand, relatively inexpensive and designed and built with the expectation that new and improved replacements were not far off.

Nearly 40 years later, the aircraft are not only still in service, but are being remanufactured, upgraded and even built new. Lay out the timeline for the U.S. Army’s CH-47/MH-47 program’s planned acquisition of new or remanufactured aircraft and you’ll find deliveries planned for as far off as 2018. Add up the numbers (current service life plus new delivery date) and an obvious, startling question comes to mind.

Will the Chinook be the helicopter industry’s first century-old aircraft?

Boeing expects so and is continuing to overhaul its design and production processes to make that a reality.

"If you had a C model delivered in 1975, it’s going to have 40-45 years before it gets made into an F model and its airframe has obviously lasted that long," said Jack Dougherty, director of Boeing helicopter programs.

The CH-47 really is the Energizer Bunny of the rotary-wing world; it just keeps going and going and going and . . .. In addition to the commitments from the Army for new-build F and G airframes, Boeing is pitching the Chinook for the U.S. Air Force’s Combat Search And Rescue-X competition for 200-400 combat SAR aircraft. While Boeing officials admit the V-22, which the company builds with Bell Helicopter, is the ideal aircraft for the CSAR mission, they note it is a bit pricey, at least $75 million per aircraft.

The Chinook entrant in the competition, the HH-47 CSAR-X, would be equipped with advanced countermeasures and survivability enhancements similar to those on U.S. Special Operations MH-47G heavy assault rotorcraft, according to Boeing. The special operations helicopter is capable of multiple missions and has significant combat experience at high altitudes, in austere environments and with limited visibility. It is flown by air forces in Australia, Egypt, Japan, the Netherlands, Singapore, the United Kingdom, and many other services, according to Boeing.

"This aircraft has a history of performing search, rescue and humanitarian missions around the world," said Mike Tkach, vice president, Boeing Rotorcraft Systems. "The configuration that meets the customer’s requirements is in active production and, as such, is a low-risk choice for the U.S. Air Force."

In addition to its low price, the Chinook would have another advantage in the competition, Dougherty said. "Everybody knows there’s no helicopter but the Chinook that can take people where they need to go in Afghanistan."

For Boeing, the Chinook may be proof that all good things come to those who wait. The Improved Cargo Helicopter upgrades of CH-47Ds (themselves upgraded As, Bs and Cs) to the F configuration was intended as a stopgap measure until the Joint Transport Rotorcraft was fielded. But that never happened.

In the interim, combat at high altitudes in Afghanistan re-established the value of the Chinook. Also, lean-manufacturing practices were shaken out in other Boeing aircraft programs.

"We realized it was a great opportunity to apply the lean tools we’d been developing on the Comanche and V-22 and 787," Dougherty said.

Boeing helicopter leaders decided to try their hand at building a better Chinook.

The lean-manufacturing techniques, combined with the outsourcing of production of the main and aft fuselage sections, helped slice the price of the Chinook airframe roughly in half, to just over $5 million.

That work occurred during a lag in CH-47F remanufacturing. The first of those aircraft were delivered in July 2004; the next isn’t due until September of next year. The production line in the interim is focused on delivering MH-47G special-forces aircraft and remanufactured Egyptian air force CH-47Ds.

The aircraft was redesigned for improved producibility, not better performance or strength (although the changes should boost maintainability and reliability). The cost savings on the airframe and production were enough to convince Army officials to opt for new-build airframes. All the D models scheduled for remanufacture will get new airframes. Once those are done, Boeing expects to be producing 2-3 new-build Chinooks a year, barring additional contract awards. Flight tests of a remanufactured F began last April. That aircraft is fitted with the configuration’s Rockwell Collins Common Avionics Architecture System (on which the Army is standardizing its Chinook, Black Hawk and special-operations rotorcraft) and a BAE digital Automatic Flight Control System.

The company is now looking at other improvements to the Chinook. It is developing a Low-Maintenance Rotor, which uses a dry rotor hub with all elastomeric bearings. That has been completing qualification tests.

The rotor hub is the Chinook’s weak link, Dougherty said. The current hub requires rotation of bearings in the field at 1,200 hr., "which is a pretty lengthy job," he said, and an overhaul of the hub at 2,400 hr.

"When we started out" with the existing hub, he said, "we were literally melting bearings." The new hub shouldn’t require overhaul until about 4,500, "which is probably good for 20-30 years."

In addition to operations in Afghanistan, which gave the Chinook program "a very big boost," Dougherty said recent events have showcased the aircraft. Chinooks flown by Singapore, Japan and Thailand were used extensively in relief operations after the Indian Ocean tsunami last December. That "raised visibility of the aircraft with the governments of India, Indonesia, Malaysia and Pakistan."

Likewise, the aircraft was very active in relief operations after Hurricane Katrina in the U.S. Gulf Coast last month, shoring up levees, rescuing thousands of victims and even fighting residential fires from the air in New Orleans. That exposure may eventually boost international sales, which could only increase the Chinook’s longevity.

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