NNS020821-10 First All-up AH-1Z, 2nd UH-1Y Make Initial Ground Runs
Release date: 8/21/2002 3:04:00 PM
By John C. Milliman, NAVAIR Public Affairs Officer, PMA-276
NAVAIR PATUXENT RIVER, Md. (NNS) -- The first all-up AH-1Z made its initial startup and ground run Saturday following remanufacturing from its original AH-1W configuration.
The aircraft, designated Zulu Three, is the first Z-model Super Cobra with an integrated, all-digital cockpit featuring LCD display panels to fly. Zulu One, the first Z-model Super Cobra to begin flight testing, retains the AH-1W avionics.
Both new aircraft were restrained during runs to allow use of full power without actually taking off.
"We do a restrained ground run to check that the aircraft produces rated power and to check the rotor system," explained Robin Locksley, H-1 Integrated Test Team Lead. "It's a ground check to make sure everything works right before you go flying."
The check is similar to a fixed-wing aircraft's full-power check but different in that a helicopter must be restrained to keep its rotor system from lifting the aircraft off the ground, according to Locksley.
"It's a Bell Helicopter best practice to do this with each new or remanufactured helicopter, and we think a good one," he explained. "The rotor system goes to 100 percent RPM and then [the test pilot] pulls collective," he said. "If you weren't tied down, you'd be flying."
Specifically, the testers checked for fluid leaks and the track and balance of the rotor blades.
"Imagine a ceiling fan that wobbles because it's a little out of balance," Locksley explained. "Now, imagine that with a blade that's 24-feet long, spinning at about 300 RPM. During track and balance evolutions we install the equivalent of pennies on the rotor blades. We adjust weights on the blades and make adjustments to each rotor blade's angle of attack until it's smooth - typical helicopter stuff."
Zulu Three has more track and balance work to do, but Yankee Two has moved on to an in-hangar phase of electrical tests before it will actually fly, Locksley explained.
"(Yankee) Two comes back to the hangar for three weeks for electrical demonstration," Locksley said. "That's where we check that the generators make the right amount of power, the circuit breakers pop when they're supposed to, and the power system degrades gracefully in the event of failure."
With two aircraft now flying (Zulu One and Yankee One), and two in ground-run stage, only Zulu Two has yet to have its first ground run. Because it is more heavily instrumented, it follows its siblings in the schedule, according to program officials. All five aircraft are scheduled to be actively flying test sorties by the end of the summer.
The H-1 Upgrade Program is improving the Marine Corps' aging fleet of combat-utility and attack helicopters by remanufacturing UH-1N Hueys and AH-1W Super Cobras to share a common drive train, rotor head, tail boom, avionics, software and controls.
Over the 30-year expected lifespan of the aircraft, this commonality is projected to save the Marine Corps approximately $3 billion in operating and support costs.
This commonality will also reduce the logistical "foot print" of Marine light-attack helicopter squadrons, or HMLA's, that operate both aircraft. The common features of the aircraft mean less spare parts will be required to be kept on hand. Also, training for aircrew and maintainers will be simpler.
The UH-1 "Huey" has been in service since 1956. With more than 16,000 produced by Bell and it's foreign licensees, in more than 35 variants, it is the most successful military helicopter ever built.
The Corps' current Huey fleet, the UH-1N, is expected to exceed its planned service life of 10,000 hours in fiscal year 2004. Designed in the 1960's and fielded in the 1970's, the current fleet has never had a service-life extension or major upgrade.
While not as "experienced" as the Huey, the Corps' current fleet of Super Cobras is also showing its age and is facing increasing challenges on the 21st Century battlefield. The upgrades being made to both aircraft, in addition to making them easier to field and maintain, will also make them easier to fly, faster and more capable.
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