Monday, May 31, 2010
Piaggio Avanti II, The fastest Turboprop
The Unique design, twin turboprop has a 3 Lifting Surface Configuration. The main wing, canard and horizontal stabilizer which all contribute to the total lift produced. The horizontal stabilizer contributes positive lift in flight. In addition the fuselage itself produces lift because of its airfoil shape. The fuselage can produce up to 20 % of the total lift. This combination of 3 lifting surfaces and fuselage allows for a wing that is 34% smaller. This allows for reduced weight and drag. The fuselage and high aspect ratio wings are designed to keep the laminar flow attached as far back as possible which reduces drag, smooth exterior skin with internal riveting also helps to reduce skin friction drag. The result is significantly more aerodynamically efficient than a conventional aircraft design. The wing is rear and mid mounted. The spar passes right behind the cabin. The cabin is circular and pressurized. The anhedralled canards provide stability and balance by providing lift to the front part of the plane. These canards don't have control surfaces. They have flaps which extend when the wing flaps are extended. The rear stabilizer/elevator is used to control pitch. It has a T tail arrangement with swept surfaces for the vertical and horizontal tail. The ventral fins under the aft fuselage enhance stability at lower speed’s, the fins do not add to the drag at cruising speeds. The plane can cruise at over 400 kts at 29000 ft, thats over 450 mph. Not bad for a turboprop, faster than many light jets and almost as fast as some jet powered business aircraft It burns 890 lbs of fuel per hour at this speed, which is much more economical than some jet powered business aircraft. Normally it cruises at 365 knots and at higher altitudes for more efficiency / longer range. This Avanti is the fastest business turboprop and more efficient than most turboprops. The upgraded Pratt and Whitney PT6A-66B engines give a slightly higher top speed than the first Avanti model. It also has a slightly better fuel economy than the first Avanti. Maximum altitude is about 41000 ft. Range is over 1800 nautical miles. The Avanti II also comes with a glass cockpit. Aluminum and composite construction, mostly aluminum. Pilots find this aircraft a bit tricky to fly, It is no doubt a bit tricky to fly and to handle, unlike a conventional aircraft. The cabin is high enough to stand up tall in. The propellers are 5 blade pusher type rear mounted. Since the propellers are behind the cabin they provide a quieter cabin. But the exhaust from the engines blows right into the propellers. Also the airflow coming off the trailing edge of the wings interacts with the propellers. This causes a lot of exterior noise. It has tricycle retractable landing gear configuration with main wheels coming out of the fuselage. Orders for the aircraft were initially very slow which is not surprising because of the hefty price tag of about 6.6 million bucks. Can seat up to 9 people including 2 crew in a spacious and luxurious interior. There’s already about 82 of them registered to owners around the world and more orders are expected. The aircraft has come a long way despite a long history of developmental and company financial difficulties.