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Ecostar

Story and Photos by Ned Dawson

Page: 1/2

Being the launch operator for any new aircraft is a massive step forward. It takes lots and lots of intestinal fortitude, guts for short. Is the new machine going to work? Will it live up to expectations? Dave and Patti Chevalier, owners and operators of Blue Hawaiian Helicopters in Hawaii, have every right to be nervous about laying out more than US$17 million for ten brand new Eurocopter EC-130-B4s. That's a lot of cash and a lot of helicopters.

For the Chevaliers and others, operating a helicopter business in Hawaii has become more difficult over the past few years because of the inevitable noise issues, complicated by the FAA's dogged attempts to nail any operator who slightly steps outside some very unrealistic guidelines. "Over 80 percent of our tours are over national parks on Maui and the Big Island, so it was of crucial importance that we look at ways to decrease noise exposure in these areas," Dave explained. Having a helicopter designed the way the operator wants it in the past has been a pipe dream. Well, not this time. Back in 1995 Dave was the chairman of the Helicopter Tour Operators Committee (HTOC) within Helicopter Association International. "As a committee we decided we should approach the manufacturers to see if we could encourage them to seriously look at quiet technology, " he recalled. The public acceptance of the helicopter and its associated noise is one of the biggest obstacles facing not just helicopter tourism operators, but helicopter operators in general. "I suppose you could say that operators such as ourselves are the public ambassadors for the industry, since the majority of people who fly with us have never been on a helicopter before. This gives us a perfect opportunity to show them just how incredible the helicopter can be, as it gets them in to see things they couldn't see any other way," he added. The feedback to the committee from the various manufacturers was mixed, with most thinking they had already turned the corner on the noise problem. Bell already had its 407 and was sure that it would be sufficient. MD Helicopters was already using the NOTAR technology. Although these two products provided some alternatives, their technologies weren't what the committee was after. One manufacturer was, however, willing to listen and that company was Eurocopter. It was receptive to the proposals and indicated that it would be willing to work with the committee, but this in turn created a problem as the committee was made up of operators with various makes and models of helicopters. The solution was to form a users group that included Bob Engelbrecht of North Star Trekking in Alaska, and Ron Williams of Air Star Helicopters in Arizona.

Having the designers who worked for one of the world's leading helicopter manufacturers listening to what the tour operators wanted in a helicopter and then incorporating it into a brand new product is an amazing feeling. "We all decided that what we needed was a helicopter that was primarily a lot quieter than the AS-350. Many passengers also complained that it was a tight fit, so the new design needed more room built into it. Better visibility was a must also. From here it was now up to the Eurocopter design team," explained Chevalier. When the design team in France had finished their task, the result was the EC-130-B4. A first look at the EC-130 tells you it's obvious that it was based on the AS-350 family. But from there, things have changed. . . considerably! Gone is the tail rotor and in its place is the EC-135 Fenestron. It had to be reverse engineered because the original on the 135 accounted for the main rotor blades going in the other direction. The 135 was German built, thus the blades rotated one way. The 130 on the other hand is French built so the blades go the opposite way. Simple logic, simple solution. The asymmetrical array of the ten blades spaced at different intervals reduced the noise signature substantially, because the majority of helicopter noise comes from the tail rotor blades. On the EC-130 it's the exhaust and blade tip noise, which you normally don't hear on an AS-350 that is the problem.

A closer look at the tail boom shows that Eurocopter has given the aircraft a smooth, clean look. All the rivets that are common on the boom of the 350 have disappeared. "We still have the large amount of bolts holding the tailboom to the fuselage, but now we have a true honest-to-goodness frame there and this ensures added strength," explained Eurocopter Technical Representative Tom Brown. "One thing I like about this aircraft is that it is designed using technology that already exists," explained Chevalier. "The doors are from the EC-120, as are the main windows and controls, with the VEMDs from the AS-350-B3 and 120, so it is already field proven," he added. The new tailboom has an extended blast shield to protect the tail rotor driveshaft bearings. Between the blast shield and the drive shaft cover there is also a layer of protective covering, providing yet further protection. "The way you get horsepower out of these engines is you have to get the air super-hot to go across a set of wheels and keep them spinning, but you have to keep them just hot enough so that the blades don't start stretching on their own. This requires some very exotic metals, which they call Unatanium and it is manufactured in very exotic ways so that you can spin it at high RPM against high temperatures and still get the horsepower," added Brown.

Also noticeable on the new helicopter are the larger landing gear fairings. These were designed to prevent "Dutch roll." If it wasn't there, the back end of the aircraft would have a tendency to wiggle around. If you look at helicopters with vertical fins on their horizontal stabilizers, they are working on a stability issue. Eurocopter could have put fins on the stabilizer, but the design group decided they could achieve this with fairings on the aft landing gear instead. They stretched the fairings out and this in turn eliminated the Dutch roll tendency. It also helps create lift under the aircraft, adding to its stability. Eurocopter did, however, extend the length of the horizontal stabilizer, and rumour has it, that the way they found out how far to extend the stab was to keep adding to it until bugs started appearing on the leading edge. The landing gear is much like the EC-120. The gear is, in a sense, it is articulated like the Gazelle. It is mounted in three positions, two in the front and one at the back, so the aircraft has a bit of a wobble to it. Ground resonance has always been a problem in helicopters, but with the EC-130 this is virtually eliminated. The natural harmonic of the landing gear is so far away from the harmonic of the aircraft that it prevents ground resonance. A feature with the Astar is that the landing gear is very stiff and rigid, so it has a frequency at which it shakes, in sympathy with the main rotor. This had to be dampened, but if the devices aren't really right and the rotor rpm drifts downward, when the two drift together you get ground resonance. At the top of the Fenestron fin the kink is also very noticeable. This was designed to help reduce the forces and unload the tail rotor during flight, requiring less control input. The top of the tail is actually a wing, and starts to fly in its own right at a certain airspeed, creating lift along the leading edge and pulling the tail into proper position. The EC-130 lands flat instead of right rear first, like the AS-350. This is due mainly to do with the controls on the aircraft and how they are rigged. Mostly it was necessary to counter the right drift of the aircraft because of the rotor turning. Eurocopter tilts the disk slightly to stop it from drifting to one side. The flight controls are slightly tilted, but not very noticeably. When the cyclic is centered, it actually has a very slight tilt built in. Neutral, you would think, would mean a flat disk, but it, too, has a slight tilt built into it. "You can actually land this more like an MD500," explained Blue Hawaiian's Chief Pilot, Dave McGuff.

All the cowlings on the EC-130 are carbon fibre, which has reduced the aircraft's weight substantially. Operators are hard to please. They always want an aircraft that can pick up a large amount of weight, but weighs next to nothing itself. Unfortunately, there are not many aircraft like the Lama anymore. The lifting capability of the EC-130 is about the same as the B3. The top cowlings are also a little taller, and cover up more of the swash plate than the regular Astar. Normally about an inch below the stationary star is exposed, but on the EC-130 it comes right up to the split line between the stationary and rotating star. This helps protect it a little more, plus keeping it out of the environment. The airframe itself is beefed up all the way around. The keels that run through the belly of the aircraft, which is what the aircraft is sitting on, are chemically milled beams instead of stamped metal as on the Astar. The front of the EC-130 is certainly distinctive. Since one of the user group requests was to give their passengers more room, the Eurocopter designers did just that, plus more. It's nearly a foot wider from inside door to inside door which allows seating for four across, not your normal bench seats as in the BA or B2. The new EC-130 also has energy attenuating seats as used in the 120 and 135. This means that nothing can be put under them, as they have to be able to crush and absorb the energy. This required Blue Hawaiian to relocate their video recorders into the rear baggage compartment. The width of the cabin is also maintained all the way to the front, and doesn't taper in from the back as in previous models. To do this, an EC-120 cabin was cut in half and an additional center section added. This is what gives the cabin its unique look.




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