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Tilt Forward

Tilt Forward

I watched a small Cessna dawdled its way down finals, towards its inevitable flare and landing. As I kept my eyes on the small fixed wing it seemed like any other training field on a quiet weekday. Then suddenly, mid-flight, the small plane lurched and faltered in the sky, the pilot had obviously had his attention captured by the very unusual activity on the parallel runway and I think he’d had the living daylights scared out of him!

I was in Amarillo, Texas in the year 2000 and lumbering its way into a powerful hover, not far from me, was a threatening but very impressive V22 Tiltrotor. I was in the USA on a Churchill Fellowship to look at the future civil applications of TiltRotor technology. Bell Helicopter Textron were my hosts and I was being given the full tour on all aspects of this fascinating new aspect of aviation. Tiltrotor promised to be able to go further, faster and hover when you get there. It seemed like aviation was evolving to the next level and I wanted to have a closer look.

Nine years later here in Australia, noises are finally being made about the possible introduction of the first TiltRotor aircraft into our skies. Back then I thought that the successful evolution of this concept was about to become the new face of aviation. After all, it is probably no understatement to say that this is the most significant development in aviation since the advent of the helicopter. V22s now fill our screens in some top-budget Hollywood blockbusters lending credibility to the commercial arrival of the product. However, internet chat rooms and technical publications still run hot with conflicting stories of the Tiltrotor’s real success or otherwise. Comment will always vary between the forward thinkers who embrace the concept and those who are cynical.

In my observations, as I criss-crossed the USA, I was very mindful of one huge underlying fact. This is not, by any means, a new concept. The concept has been proven since the first flights of the US Military XV-3 Research Aircraft way back in 1955. Its successor, the XV-15, took to the skies in 1977. That very same airframe was still flying test bed evaluation flights and demonstrations when I was in Texas, some 23 years later. It is no surprise, therefore, that the civil version (the BA609) is visually and proportionally very similar. Concepts are easy enough to come by but taking a concept through to a production aircraft is a whole different world. A quick viewing of a Discovery Channel documentary or thumbing through a Complete Illustrated History of Aircraft will tell you that a great many things have taken to the skies without every reaching a commercial production line. I was soon to learn that it was only the development of composite fibre technology which allowed the commercial realization of the TiltRotor concept. Through the extensive use of these weight saving, super strength materials, the manufacturing process has allowed for practical aircraft of suitable strength and operational weight. And with this groundbreaking development came the very real interest of the US Military. It must, however, be understood that this is not just one company putting together a new aircraft. Generally speaking Bell Helicopter Textron wear the public face of TiltRotor. What may be overlooked by the cynics or general public though is that there is a massive collaboration of minds which have come together here. The very best people from N.A.S.A, Bell, Boeing, Augusta and many sections of the US Military have all had a very significant input, as too have countless volumes of feedback and wish-lists from all types of possible end users. As well as the many years of flight trials and evaluations on the existing airframes, technology has grown and expanded to allow thousands of hours of wind-tunnel testing and extensive computer simulations of virtually every conceivable operational detail and requirement.

With workable aircraft now available on the drawing board, the US Military through to Congress got behind the concept and placed firm orders for a large new aircraft to fit the very selective doctrine of the Marine Corps. The V22 was hatched and with the huge orders which come with customers like these, Bell could then allow the natural flow-on of a suitable, smaller civil aircraft. The idea itself is relatively simple, wingtip nacelles can be tilted from the upright hover position, forward once in flight to the horizontal position. Accelerating the aircraft as they rotate forwards from the hover soon gives you the speed and appearance of a turbo-prop airplane. The speed of a turbo-prop with the hover ability of a helicopter! This ingenious combination then allows much greater speed en route, which gives a much extended range and better loiter time once on scene. The applications, it would seem, are endless.

I visited and spoke with a vast range of people, both as developers and possible end users. Design, research, manufacture and marketing, piloting and maintenance were all on my list. So too were operators in the fields of oil and gas providers, emergency medical services and search and rescue. I wanted to get the full picture of just where the manufacturer was pointing this aircraft and where the users wanted it to sit.

Within the military world there are slight variants to the V22 frame. What started out primarily as a utility vehicle for the Marines has also been modified for a role with the Air Force. One of the main differences here is losing the blade-fold capability, which the Marines required for shipboard operations. Climbing over a V22 in the hangar, the gear mechanism which allows the folding is in itself a massive piece of engineering when viewed at close range. Shedding this weight alone would free up considerable payload for the Air Force to play with. Primarily the V22 is an aircraft very similar in size and appearance to the C130 Hercules. Picture the lovechild of the C130 and a CH-46 Chinook helicopter and you have just about got the V22 in both appearance and capability. Its basic mission is to carry up to 24 troops and 9000kg of payload.

In the civil field, the end product has the unenviable role of trying to be all things to all people. With great interest shown by oil and gas, EMS, SAR and the corporate world, the marketing people would be working overtime trying to fill everyone’s needs. What is on offer with the BA609 is a very sleek looking aircraft capable of vertical take-off and landing, a cruise speed of around 275 kts and a useful range of around 750nm. It is a two pilot, nine passenger aircraft with a ceiling of 25,000 ft and fully certified for IFR flight in known icing conditions. Extended range tanks can also be fitted to stretch its legs out to around 1000nm. The aircraft will sit in roughly the same footprint as a B412 or S76 but be able to go more than twice the distance at more than twice the speed. Add to that scenario the fact that the user no longer has to drive to and from the airport for their private fixed-wing aircraft and the 609 becomes every bit as time efficient as a business jet over 600nm.

For the tech-hungry folk, the facts are also impressive. The power plant is two digitally controlled Pratt and Whitney PT6 engines. They are rated at 1675 shp each for continuous use and can be bumped to 2445 shp for 30 seconds contingency power. Triplex digital fly-by-wire control systems provides excellent redundancy and an EFIS adaptive cockpit flight display keeps the pilot in the loop. Flying the simulator was an impressive and unique experience. Controls and cockpit are simple and provide no great surprises for the rotary-wing pilot. Only the forth dimension of the Nacelle wheel on the collective introduces the really unique excitement. The Nacelle tilts forwards in increments of one degree from the 95 to 85, and in single steps from 85 to75, 75 to 60 and 60 to zero. Only when you push the wheel forward and hold it down for a rapid transit do you really get to feel the power and the significant conversion from a docile hovering machine to a high performance fixed-wing.

There is a plethora of safety features and unique attributes in both of these Tiltrotor aircraft, which are just too numerous to go into here. Needless to say, more than 50 years of developments and technology have resulted in two extraordinary aircraft. Yes there have been problems and delays and questions but what completely new direction in flight has not suffered just such teething woes? It is fantastic to finally see the V22’s in flight regularly on our televisions, movie screens and air shows. I trust they are doing the job well for which they were developed. And now to hear talk of a 609 being considered for an EMS role in our country is excellent news for our industry. With Australia’s massive coastline, huge distances and sparse population, surely TiltRotor can be the perfect answer to some of our most important questions. I think tilting is the way forward.

WORDS: Brenton Davies

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