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Home : News
NEWS | Dec. 28, 2011

Colorado National Guard high-altitude aviation training: local school, global impact

By Master Sgt. Cheresa Theiral Colorado National Guard

This story is the first in a series of three about Colorado's High-altitude Army National Guard Aviation Training Site

One of four Army National Guard aviation training schools, the High-altitude Army National Guard Aviation Training Site in Gypsum, Colo., is the only Department of Defense school specifically focused on teaching high-altitude power-management environmental training to military rotary-wing pilots from around the world.

Among the four aviation schools, this one is considered to be the only graduate-level training course, providing life-saving combat aviation skills to pilots serving in Afghanistan and other mountainous regions around the globe.

"We don't teach people to fly; we teach them to fly at altitude," said HAATS executive officer Army Maj. Tony Somogyi. "The more experience you have, the more you'll get out of the course, the more concepts you'll understand."

HAATS primarily uses U.S. Forest Service and Bureau of Land Management property, along with some privately-owned areas surrounding the Eagle County Regional Airport near Vail, Colo., to conduct training at altitudes ranging from 6,500 to 14,000 feet.

HAATS is operated by the Colorado Army National Guard and is staffed by 27 Soldiers, two contractors, and one Coast Guard member.

Four UH-60A Black Hawk helicopters, four OH-58 Kiowa helicopters and two CH-47 Chinook helicopters are available for use by students traveling from overseas locations or as backups. Students traveling from anywhere in the continental United States are required to bring their own aircraft.

The course is one week long for U.S. students and two weeks long for international students. Monday is all ground school, and Tuesday through Thursday are mostly flight days. Friday requires a written test in the morning, and oral and flight tests in the afternoon.

Humble beginnings, international appeal

The course started in 1985 as CHATS - Colorado High-Altitude Training Site - to teach Colorado Guardsmen to fly in their "back yard." Then, as word of the program spread, National Guard units in North Dakota and West Virginia, facing deployments to Honduras and similar environments, began requesting to train their crews prior to deployment.

"Honduras is high and hot, and they were flying heavy," Somogyi said. "They asked to train with us and it's grown since then."

In 1991, the school became a federal training site and was renamed HATS under the command of the Western Army National Guard Aviation Training Site.

In 1995, HATS became HAATS - and a stand-alone school. It currently falls under the command of the adjutant general of Colorado and is funded by the National Guard Bureau.

During the later part of this month, it officially became a joint school, when a memorandum of agreement between the Army National Guard and the Coast Guard was signed, allowing a Coast Guard instructor pilot to be assigned to the schoolhouse.

Coast Guard Lt . Cmdr. Shane Hill will begin teaching in January, and with his contribution, the Coast Guard will nearly triple its annual student throughput and further improve support for its inland search-and-rescue missions, Somogyi said.

To date, in addition to U.S. service members, instructors have trained students from Germany, Norway, Netherlands, Denmark, United Arab Emirates, Slovenia, Jordan, England, Sweden and Estonia.

Power management

In aviation, the three H's - high, hot and heavy - reduce aircraft performance. So how does a pilot combat those conditions? Power management.

"We teach students how to manipulate the power they have available to maximize the utility of the aircraft," Somogyi said. "We also teach them a little bit about themselves - their ability to manipulate the controls has just as much to do with power management as knowing how much power's available."

Simply put, if you're coming in on an approach and you don't have your power loaded in within about 10 percent for the last 50 feet or so, that's when bad things happen because you'll ask too much of the aircraft before safely landing, he said.

"We teach them about the aircraft - that's the math part of it, the tabular data - and then the environment, how to read and maximize the utility of the winds. Whether you use it to prevent brownout or whiteout - by using the wind to keep the cabin clear of dust - or landing to the edge of a ridgeline and knowing that when you pick up you'll be able to pick up a lot more payload than what the power said you could."

All this happens by tying the power back to the torque gauge in the cockpit, he said.

"It's all about knowing when the students used the maximum amount of power and then going back and proving, and more important improving, the next time they shoot the approach," Somogyi said. "It takes out the instructor's subjectivity. It's not what the instructor can do. It's what the student can do. We use the torque meter because the torque meter doesn't lie."


"In a helicopter, torque turns the rotor system," said Chief Warrant Officer 4 Anders Nielsen, an instructor pilot, maintenance test pilot and maintenance examiner at HAATS. "When you run out of torque or engine power it fails to have the capability to maintain that rotor speed. If it cannot maintain that rotor speed, then it slows down - and if it slows down, we fall down."

To simplify, Nielsen said to consider torque in a helicopter like horsepower in your vehicle: The hotter it gets in your car, and the higher you are in altitude, the more horsepower your vehicle loses. Helicopter engines also get weaker the hotter it gets and the higher they go.

"At sea level, we run out of space before we run out of torque or power," Nielsen said. "All the torque you have starts to taper off and disappear rather quickly once you go to altitude.

"All green isn't always all good. That's something we learn wrong from day one," he said. "‘If we pull up on the collective we will always have power to get away from trouble' - that doesn't transfer over to Afghanistan."

Tabular data

Tabular data is based on performance charts and provides rapid and accurate updates for aircraft performance for its maximum gross weight and available power. It provides three numbers for the crew: maximum gross weight, maximum torque, and in-ground effect torque. The pilots use this information to determine the types of maneuvers the helicopter is capable of performing in the given environmental conditions.

"What's nice about tab data is that it lets you know through simple math - we're talking addition subtraction simple multiplication or division," Nielson said. "We can rather quickly figure out what we can and cannot do, which keeps it extremely simple.

"Prior to that, we kind of haphazardly did our performance planning off a computer program and a card we had," he said. "Without tab data, I wasn't able to do these on-the-spot accurate predictions of how much torque I needed."


The environment can also affect the capabilities of the aircraft, increasing or decreasing power requirements.

"I can have plenty of power to land at this one spot, but if I've got a really strong downdraft, low pressure - what I like to call a negative environment - it then takes even more power than what could be predicted in a calm wind environment," Nielsen said.

In the HAATS training area, the winds generally come from the same direction, creating a series of landing zones that can be used to provide specific training objectives while providing a safety margin for inexperienced pilots.

"This consistent air flow allows for accurate wind and terrain analysis - in laymen's terms, how wind flows around an obstacle," Somogyi said. "This wind flow around obstacles is critical for pilots in determining if the winds are going to help them or hurt them on the LZ."

"This training area has really great examples of what the wind does," said Chief Warrant Officer 2 Mary Jo Kraft, a student from the Montana Army National Guard. "The way they explained how wind works … It's like a creek. When the water is moving really fast and it hits a big rock, it's going to come at it with a lot of force, then it goes around and over it. The wind is like that with mountains.

"It was really interesting to take all that into consideration when determining where the winds are coming from," Kraft said. "It's not only the winds that are coming from the south but what they're doing against the slope, against the pinnacle, against these three ridge lines in a row … Wind is really important because it will knock your power down. It will actually take less power during approach when you have a head wind but if you try to do an approach with a tail wind it takes a lot more power."

Training area

HAATS has about a million acres of available training area, with landing zones ranging from 6,500 feet to 12,200 feet, right outside the county airport's traffic pattern.

The unique training area offers a variety of landing areas such as pinnacles, ridgelines, bowls, and confined areas.

"The training area in this course is really phenomenal," Kraft said. "There are so many different varieties of areas you can go and practice your power management techniques."

And according to Somogyi, a number of studies have proven that there's no other place in the entire United States that can replicate HAATS training, in as short of a flight as the school can replicate it in.

"We can get students to 12,200 feet in a very short flight," he said. "We can get them to pretty much any type of LZ that they're going to face anywhere in the world within a matter of minutes. From Fort Carson, it's a good 30-45 minutes, depending on your airframe, to fly out to the training area to train, whereas we have LZs right on the other side of I-70 from here."

A part of one training day is spent flying through the "14ers" (peaks more than 14,000 feet in elevation), on the edge of the training area, to let students experience the extreme turbulence coming off the mountains.

"Our instructor pilots have trained in Honduras, Columbia, Korea, Germany and Hawaii, but those aren't exactly controlled environments," Somogyi said. "Though the process works, it's harder for us to anticipate what the student is going to do when we don't exactly know what the winds are going to do ourselves.

"If the weather comes in here it typically rolls in from the southwest," he added. "We happen to be in a little bit of a bowl, so when the northern part of the training area is closed we use the southern part and vice versa, so it's an ideal location.

There's no mistake why Vail exists where it does, because weather patterns either move around the south or move around the north, and they impact right in Vail."

Because of the controlled environment, HAATS rarely loses more than three days per year due to weather, Somogyi said.