Lift Off

The world’s first civilian tiltrotor aircraft, the Bell/Agusta 609 has just entered its second test stage. Dubai-based Captain Robert Denehy is one of the leading players in the process.

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By  Neil Denslow Published  December 5, 2004

|~||~||~|The Bell/Agusta 609, the world’s first civilian tiltrotor aircraft, is set to enter its second major testing phase this month, when it will fly in its aeroplane set-up for the first time. Capt. Robert Denehy, assistant general manager of Dubai’s Aerogulf Services, is playing a leading role in the program. He is chairing the BA609 Industry Steering Committee, and will also fly test flights as part of the aircraft’s maturation program. Aerogulf Services will also be one of the first operators of the aircraft. The company has ordered two BA609s and it is also working with Sheikh Sultan bin Mohammed Al Mejren, who has placed orders for three others. Denehy’s involvement in the BA609 program springs from a long-standing interest in tiltrotor aircraft, which was first sparked by seeing an early NASA prototype over 20 years ago. “I’ve been interested since 1981, when I saw the first Bell XV-15 fly at the Paris air show,” he explains. “I was just finishing my degree in aeronautical science, and I looked at this thing on TV, and said ‘here I am with this degree and I have never even heard of anything like this.’ I just thought: ‘what the heck is it?’” he remembers. Tiltrotors as a concept have been around for a long time, and they have found use in the military sector, although the American V-22 Osprey was grounded in December 2000 after two crashes killed 23 marines. The BA609 is a different design and specification to the V-22, but the grounding was one of a number of factors to have delayed developments of the civilian aircraft. Despite the development problems, there is strong commercial interest in the BA609, with the first two years’ worth of production having already been sold. Operators are interested as tiltrotors offer the best attributes of helicopters and fixed wing aircraft. They are capable of taking off and landing vertically, but once the nacelles are swung down into the horizontal position the aircraft can fly twice the range of conventional helicopters, at twice the speed, giving it the same capabilities — if not better — as a small aeroplane. These attributes make the aircraft ideally suited for a variety of roles, including search & rescue, the offshore market and corporate travel. Aerogulf Services, for instance, first ordered its BA609s, which hold six to nine passengers, to ferry oilrig workers from Dubai to offshore Iranian oilfields, when it looked like Western firms would be able to operate there. “Initially, all of the Iranian oilfields were being opened up to the West, and Western companies love to operate out of Dubai,” says Denehy. “We were looking to operate out of here [with BA609s], as we could reach any of the Iranian fields, which no other aircraft could do... However, with the way things developed — because of the delays in the program and the deteriorating relations between the US and Iran — we have redirected over to the VVIP and military support market,” he adds. The BA609 should appeal to the VVIP market, as passengers will be able to make long-haul trips without having to go to an airport. Instead, they can fly from a helipad on the roof of the building or in the garden, and then go directly to a similar location up to 1000 nm away, if using the long-range version. This should especially appeal in the local market, where a large number of individuals have both the means and space needed for such a flight. “It is absolutely ideal for what we call palace-to-palace transport,” comments Denehy. “The way things stand right now, VVIPs have to fly to and from airports, going through varying degrees of security exposure and standard customs procedures. Having an aircraft like the BA609, they will no longer have to do that. They can take off from their palace and go directly to another palace in another country.”||**|||~||~||~|Aside from its range, tiltrotors also offer a more comfortable ride than helicopters, as the nacelles can move forward to accelerate independently, which allows the body of the aircraft to remain level. “This winds up as a real benefit for passengers, who while flying in fixed wing aircraft or helicopters are usually subject to having the fuselage inclined quite steeply at times,” explains Denehy. The ability to move the engines on the nacelles also means that the aircraft can land on a steep landing area. “Even if you have a slope over 20o, you can take the aircraft, move the nacelles and change the angle of the fuselage, so it matches the slope and land right on it. This is a much better capability than you would have with a helicopter,” adds Denehy. The first BA609 delivery will take place towards the end of 2007, with Aerogulf expected to get at least one of the first off the production line. Before the aircraft gets to this point, however, it needs to go through a host of certification and testing programs. This process began in line with the drawing up of the first designs for the aircraft, as the FAA needed to establish a new certification category for civilian tiltrotor planes. To do this, Bell and the FAA combined elements of FAR Part 29 and Part 25 to form the new Part 21 category. Denehy’s role in the development process is to chair the BA609 Industry Steering Committee, which is feeding information from operators to the manufacturer. A number of major operators are represented — including Bristow, CHC International and CHC Scotia, PHI, Shell Oil Company — and they are helping put together maintenance plans for the aircraft, drawing on their experience of operating helicopters and aeroplanes. “We are going through every system and every component onboard the aircraft and are establishing the scheduled maintenance requirements,” explains Denehy. “It is a good situation, as we can say ‘we have this component and we use an identical one on our helicopters, and you have us going in there repeatedly for checks when in fact after thousands of hours we have never found a problem.’ We can then look to make adjustments to the tasks that are accomplished and the intervals between them.” The FAA and Transport Canada are also sitting in on the committee meetings, although they are not members of it, and giving their input. This allows them to have their say early on in the process, and to see how the final maintenance rules were reached, which should help with the eventual certification process. “At the end of the process, we are going to come up with a document that goes to the maintenance review board, which is the FAA. By having them there with us, they can see how we derive these numbers and where they came from. They also have the opportunity to contribute themselves,” adds Denehy. “Sometimes, we have as many as 14 regulatories sitting in on a meeting and contributing to it.” Denehy will also play a key role in the later stages of the flight test process. Four prototype BA609s will be built for the test flights; two in Italy and two in Texas. The first American one was used for the helicopter mode test flights in March, when it performed hovering, pedal turns, rearward and forward flights up to altitudes of 5000 feet and 100 knots. It is now being used for test flights in the aeroplane set-up. Later in the maturation process — an extended testing period that is needed because of the aircraft’s revolutionary design — Denehy and another civilian pilot will fly a prototype, testing its capabilities on standard missions. “We will fly the aircraft during the development process, not pushing it to the ends of the envelope, but doing normal day-to-day flying to show that all of the wear rates are correct and that the aircraft is doing what it is supposed to do,” he explains. Piloting the aircraft will be a unique challenge, as it combines facets of both helicopter and fixed wing flying. The basic controls are similar to a helicopter’s, as the pilot has both a cyclic stick and a collective; however, in the aeroplane mode it flies and moves like a fixed wing aircraft. As such, pilots should ideally be both helicopter and fixed wing rated, as well as instrument rated, which only 10% of pilots are. “If you are used to having been in both of these types then you are comfortable in both situations,” says Denehy. “However, the emphasis is for current experience in helicopters, because [flying a tiltrotor] you require developed skills for hovering, performing auto-rotations, and you need an awareness of unique aerodynamic characteristics in the helicopter mode. Fixed wing pilots do not have these things at the forefront of their minds and they need a thorough understanding to keep themselves out of trouble,” he adds. “It is good though, to have experience on the fixed wing side, as when you are flying in the aeroplane mode, you could encounter things like a low speed accelerated stall that a helicopter pilot might not be used to.” Yet, while flying a tiltrotor is similar to a helicopter or aeroplane, it also offers its own challenges. “A tiltrotor takes a little bit of getting used to,” says Denehy. “During the transition you have to use a thumbwheel to move the nacelles, so there is an extra dimension on top of what a helicopter pilot is used to doing.” A number of pilots around the world are gearing up for the challenge and Bell is building a training centre to support them. Theses pilots, including Denehy, are clearly excited about the prospect of flying the BA069, as it promises to be totally new experience for them and for the aerospace industry as a whole. “We are definitely looking forward to them,” says Denehy. “It is going to be a quantum leap in aviation.”||**||

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