Why do turboprops have two control levers

Will there soon be a vertical take-off passenger jet?

Boeing has received patent protection for the concept of a vertical take-off and landing commercial aircraft. The American company is still silent as to whether this aircraft should really be built. At the same time, however, Boeing refers to its extensive experience with VTOL military aircraft.

Boeing's flagship for its experience in building vertical take-off and landing aircraft: the V-22 Osprey tilt-rotor convertible aircraft. It has been used by the US Air Force and the US Marine Corps since 2005. Apparently Boeing is considering building a civilian VTOL passenger aircraft. VTOL stands for.

Photo: Bell Boeing

Since 2007 Bell and Boeing have been building the so-called tilt-wing V22 Osprey in series - mainly for the US Navy. In the meantime there are also foreign military buyers interested in this machine. The V22 can carry 24 fully equipped soldiers and is therefore considerably larger in terms of capacity than most helicopters. The V22 also flies faster than almost all helicopters. It is powered by two Rolls Royce turboprop engines, one of which is attached to the end of each of the two wings.

Overcoming teething troubles

During take-off and landing, the engine is directed vertically upwards and so the aircraft can take off like a helicopter and then land later. After take-off, the engines swivel around and now pull the aircraft forward, as is the case with any normal propeller plane. The technical challenge of the V22 Osprey lay mainly in the slewing maneuver, in which the machine had to be kept stable in the air.

Drawing Boeing Patent.

Source: USPTO

This is particularly difficult at the moment when level flight begins, because the aircraft is initially too slow to develop enough lift. By the time this difficulty was overcome, several V22s crashed - so many that the entire program was about to be discontinued. Today, however, there are orders for several hundred V22s.

Place fΓΌr 100 passengers

The civil aircraft targeted by Boeing is to offer space for 100 passengers and their luggage and be used in short-haul travel up to a distance of almost 2,000 kilometers. In contrast to the Osprey, two engines are to be integrated into each wing. In addition, Boeing's patent protection stipulates that the aircraft can also be equipped with two or four smaller jet engines. With that it would reach a significantly higher cruising speed than the 446 km / h of the V22 Osprey.

No information can be obtained from Boeing as to how likely the civil tilt-wing aircraft will be equipped with small jet engines. The four large turboprop engines are required for vertical take-off and vertical landing in any case.

Modern design

While the V22 Osprey is built in the classic high-wing type, the wings of the civil aircraft should be much lower and thus resemble modern jet airliners. The tail unit of the passenger plane is designed as a simple T, while the V22 has a V-shaped tail unit.

The AgustaWestland AW609 is a vertical takeoff, tilt rotor convertible aircraft similar to the Bell Boeing V-22.

Source: Dmitry Mottl

In Europe there is a competing product - but it is much smaller: the Italian-British AW-BA609. This tilt-wing aircraft is already being tested in flight, but offers no more than nine passengers and is therefore only suitable for commercial air traffic in exceptional cases.

The BA609 goes back to an early American development whose technical rights of use had been acquired by Augusta-Westland. The BA609 seems to have the same panning problems as the V22 Osprey initially. There have been accidents here too.

A two-seater that takes off and lands vertically is the Lilium jet that is currently being built. The aircraft is powered by twelve electric turbines on each wing.

Source: Lilium Aviation

Engineers in Bavaria have developed a promising innovation in terms of extravagant aircraft. The electric jet from Lilium Aviation takes off and lands vertically, is operated with a joystick and has a top speed of 400 km / h. In January 2018, the personal plane is due to hit the market.

 

A contribution by:

  • Peter Odrich

    Peter Odrich studied business administration with a focus on transport companies. After 28 years as a business editor for a German national daily newspaper with long activities in East Asia, he returned to his native Great Britain. Since then he has reported freelance for newspapers and technical information services in various countries. Transport issues, metals and East Asian issues are in the foreground.