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.