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This article was Originally Published on Oct 01, 2002 in Volume: 1  Issue: 5

Marine Helicopters to Share Facelift

Leveraging economies of component commonality, the U.S. Marines will get their new attack and utility helos.

By Patrick Chisholm

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Swifter. Higher. Stronger. Not only is that the motto of the Olympic games, but it is an apt description of the Marine Corps’ next generation attack helicopter, the AH-1Z Super Cobra. With triple the range and twice the payload of the existing AH-1W Super Cobra, the new AH-1Z, manufactured by Bell Helicopter Textron, is the most advanced attack helicopter in the world. Major upgrades include improved maneuverability, a new helmet-mounted flight display system, enhanced battlefield survivability, and increased mechanical commonality with the UH-1Y Huey utility helicopter.

The AH-1Z is part of the H-1 Program, the Marine Corps’ overall effort to modernize its existing fleet of AH-1W and UH-1N helicopters. Working with Bell Helicopter Textron, the program will produce 280 new “zero time” aircraft (consisting of 180 AH-1Zs and 100 UH-1Ys) for the Marines to operate through 2020. “Zero time” refers to the fact that the older versions of the helicopter will be remanufactured and configured as if built from scratch, resulting in an essentially new aircraft.

Both helicopters are currently in the engineering, manufacturing and development phase, or EMD, at Maryland’s Patuxent River Naval Air Station. Testing on the new helicopters began in December 2000 with production expected to begin sometime in 2004. The initial operating capability date—when the Marine Corps will have use of the first squadron of the upgraded aircraft—is slated for March 2008. Project completion is estimated to be sometime in 2014, when the last AH-1Z and UH-1Y helicopters are expected to have been delivered.

A key feature of the H-1 Program will be the 84 percent parts commonality between the Cobra and Huey platforms. Over the 30-year expected lifespan of these aircraft, this commonality is projected to save the Marine Corps about $3 billion in operating and support costs.

In addition to the advantages of commonality, the H-1 program lifecycle costs are substantially less than that of any other aircraft combination.

The AH-1Z’s predecessor, the AH-1W Super Cobra, is the frontline attack helicopter for the Marines. Since its introduction to the fleet in 1986, the AH-1W has seen action in every conflict involving Marines, from Desert Storm to Afghanistan. While the AH-1Ws currently in service in Afghanistan are performing well, the upgraded AH-1Z will enhance the Marines’ ability across a range of requirements. Of the AH-1W, NAVAIR public affairs officer John Milliman said, “They’re carrying the fight to the enemy and doing everything that we’ve ever asked that aircraft to do. It’s a warrior and it’s one of the Marines’ best friends when it comes to close air support. But they’re operating at the edges of their envelope—its pretty high over there, the density altitude they’re operating at.”

The AH-1Z, however, will allow for better performance at higher altitudes, in addition to many other enhancements, program officials said.

Stability, Survivability

One of these enhancements is certainly aircraft stability.

“One of the first things I noticed about the aircraft as compared to the ‘W’ is it’s a significantly heavier aircraft,” said Marine Major Tom Post, an AH-1Z test pilot.” It’s a lot more stable than the ‘W,’ and the ‘W’ is a fairly stable aircraft anyway. Vibration levels are lower, particularly because of the four-bladed systems versus the two-blade system.”

On the numbers side, the new AH-1Z will see about a 25 percent increase in payload capacity, with a maximum gross lift-off weight of 18,500 pounds. Its top airspeed will jump 17 percent to 222 knots, and its maximum altitude will increase to 20,000 feet, improving upon the 14,700-feet maximum altitude of the AH-1W. In addition, the aircraft’s survivability has been substantially improved. Redesigned parts and new composite structured components have increased the odds that the new Super Cobras will return from their missions intact. “The new AH-1Zs [and UH-1Ys] are designed to sustain 20 Gs vertically, 10 Gs laterally, and 20 Gs longitudinally. Up, down, sideways, and back and forth. What that does for us is significantly improve crew and passenger [in the Huey] protection during hard landings and certain crashes,” Milliman said.

Crash-worthy seats, which were absent from previous versions of the Cobra and Huey, have now been added for all pilots, crew and passengers on the new aircraft. These seats absorb much of the energy that would otherwise be transmitted to the occupants in the event of a crash. And not only are the passengers better protected, the aircraft itself has been enhanced with a composite rotor head, which can withstand small anti-aircraft fire. “It can take a licking from a 23mm or smaller round, and that’s because of a composite structure,” remarked Milliman.

Other enhancements include:

  • Redesigned landing gear to increase survivability. By using rectangular cross tubes instead of round ones, the landing gear weight is reduced by 20 pounds.
  • New intermediate and tail rotor gear boxes, which have been tested to run dry (without lubrication) for more than 30 minutes. In fact, during testing one box ran a full 77 minutes before the test was stopped.
  • Crash-worthy fuel cells.

Helmet Control

Among the first improvements Cobra pilots will notice will be a new helmet-mounted mission display system. Bell Helicopter selected Thales Avionics’ “Top Owl” helmet-mounted display system for use in the H-1 Program. This flight navigation/targeting/safety tool presents essential flight data to the pilot and co-pilot in a head-up fashion.

The Top Owl, already in use in the Eurocopter/Augusta/Fokker NH-90, the Eurocopter Tiger and the South African Rooivalk helicopters, was chosen for its expected ease of integration with the AH-1Z and UH-1Y.

“The primary thing is flight safety, head-up situational awareness,” said Marine Major Harry Hewson, H-1 Upgrade’s deputy for operations. “The secondary thing it does is it puts night vision, weapons sighting, and weapons control, all in one integrated package on the pilot’s head.”

And the upgraded system on the AH-1Z puts necessary information in front of both the pilot and co-pilot, allowing them to concentrate on engaging the enemy and flying the aircraft without the need to look away.

The Top Owl has received high marks for its ergonomic design and light weight. Fully assembled, the Thales helmet weighs about 4.5 pounds. “They actually measure your head with a laser scanner,” said Dan Wright, H-1 Avionics Upgrade leader. “So, when you put the liner in the visor, which among other things is your sight, it’s perfectly fitted to your eyes and your head shape.”

Another advantage of the Top Owl is its ease of transition between day and night uses, accomplished with the touch of a button. One test pilot compared night vision on the old AH-1W to “looking through binoculars.” Tubes on the side of the helmet project night vision images onto the visor. These images are then superimposed over what is normally seen.

“With night vision goggles you have a very difficult time getting depth perception because essentially it’s giving you a two-dimensional image,” Hewson said. “Now you have built-in depth perception because what this does is put green and black, scaled night color, over top of those images. Wherever you’re looking, it gives you the picture over the top so it creates depth perception.”

According to Thales Avionics, Top Owl makes use of the only technology available today that offers gain and resolution suitable for low-level and tree-top night flying. An integrated back-up battery provides an additional safety measure for pilots. If the helmet electronics fails, night vision capabilities would still be supported.

Additionally, Top Owl features virtual head-up display selections. If the pilot is looking one direction and the helicopter is flying another, the system recognizes the difference and reports both positions on the display.

Then there is a safety feature that engages when the pilot has a weapons system selected. While the pilot scans the horizon, the weapons reticule will only appear when it is safe to use.

A Revamped Cockpit

Another key aspect of the Cobra/Huey upgrade is the new “glass cockpit”—i.e., LCD (liquid crystal display) screens and keyboards rather than gauges and needles. While many pilots have a fondness for the outgoing AH-1W, its cockpit won’t be missed. “The biggest complaint most people have about the (AH-1W) aircraft is the cockpit,” Post said. “It’s really busy, and it’s always been a bit of a problem to manage. But that’s one of the things we’re hoping to address in the upgrade.”

An integrated software package in the new cockpit will run everything from the weapon systems to the mission computer and other avionics systems. This automation will free up the pilot and greatly reduce the workload.

Milliman described the new cockpit as “a much friendlier place to work. [The pilot]  has a lot on him, especially in a combat situation.” Together with the Top Owl display system, program proponents said, the pilot and co-pilot will have head-up access to necessary information, as well as enjoying automated mission/weapons control and computer-driven avionics management.

Ounce of Prevention

Furthermore, the “buffed” and ruggedized Cobra is expected to enjoy a longer service life thanks to a new Integrated Maintenance Concept or IMC, already in use with the AH-1W Cobra. Unlike pre-AH-1W Cobra maintenance schemes where aircraft had to fly long distances for regular servicing, IMC provides depot-level-quality preventive maintenance just off the flight line. And just as preventive maintenance on a car can save money by warding off costly overhauls, IMC provides similar benefits to the Marines’ helicopter fleet. The program is expected to save the Corps more than $600,000 per aircraft, while providing increased operational availability.

“The team has reduced the time the aircraft are out of service from 38 weeks every eight years in the SDLM (Standard Depot Level Maintenance) cycle to 12-16 weeks every eight years in IMC,” stated H-1 IMC manager Scott Nast.

Improving the Logistical Footprint

On the other side of the H-1 Upgrade Program house, the UH-1Y Huey utility helicopter recently made its first flight at Patuxent River Air Station. Like the new Super Cobra, the UH-1Y also has undergone dramatic improvements in its capabilities. With the H-1 upgrade, the Huey’s maximum gross takeoff weight increases from 10,500 pounds to 18,500 pounds.

And additional enhancements include a 32 percent gain in airspeed to 198 knots as well as an increased maximum altitude to 20,000 feet.

From a logistical viewpoint, however, the most talked-about improvement in the overall H-1 Program is the almost total component commonality between the Cobra and Huey helicopters. This includes the state-of-the-art “glass cockpit”; the GE-T700 engines; an all-composite, four blade, hingeless, bearingless main and tail rotor system; and identical drive trains, hydraulics and electrical distribution systems.

The commonality will improve the platform’s logistical “footprint” and free up critical shipboard space as fewer spare parts and support equipment are needed for the two helicopters. Additionally, the shared parts mean less aircraft-specific training will be needed for the Marines operating them. “This makes life easier all the way,” Milliman concluded.

It is a remark that could stand as a byword for the whole H-1 Program. For by improving Cobra and Huey’s operational performance, survivability, ease of flying, maintainability, and sustainability, this innovative upgrade program has indeed made life easier—and more assured—for those Marines who will fly the world’s leading attack and utility helicopters into harm’s way well into the 21st century.



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