Tilt rotor- The sublime

TILT-ROTOR THE SUBLIME

(S. Kishore, M. Arun Krithick, Praise Thomas Cherian, M. Praveen Anns, N. Tamil Selvan, G. Raghul

Bsc.Aviation II YEAR

REMO INTERNATIONALCOLLEGE)

INTRODUCTION

AEROPLANE (Aircraft): A powered flying vehicle with fixed wings and a weight greater than that of the air it displaces.

HELICOPTER (Rotorcraft): Helicopter is type of rotorcraft which lift and thrust are supplied by rotors .This act as the helicopter to take off and land vertically, to hover, and to fly forward, backward, and laterally.

HYBRID: Tilt-Rotor is the hybrid of rotorcraft and aeroplane. Tilt-Rotor is an aircraft which produces lift and propulsion by way of one or more powered rotors mounted on rotating engine pods or nacelles. Usually at the end of the fixed wings or an engine   mounted in the fuselage with drive shafts transferring power to rotor assemblies mounted on the wingtips. Osprey v-22 is the main type of Tilt-Rotor aircraft.     

PATENTED BY WHOM AND ITS ORIGIN
The first design resembling modern tilt- rotors was patented by George Lehberger in May 1930, but he did not further develop the concept. The idea of constructing vertical tack-off and landing (VTOL) aircraft using helicopter-like rotors at the wingtips originated in the 1930s. World War II, a German prototype FA269, was developed starting in 1942, but never flew.

PERFORMANCE OF TILT-ROTOR

Heavy Lift Rotorcraft System investigation studied several candidate configuration of very large Rotorcraft designed for the civil mission, with gross weight in excess of 150,000 lb or 45,359 kg and spend of 300 knots or greater such aircraft will face severe design challenges to meet acceptable performance and safety . This had been designed to face wind shear and jet streams, thunderstorms weather etc. Civil Tilt-Rotor (LCTR) was designed to carry 120 passengers capacity 1200 nm at 350 knots. The engine of the aircraft is Turbo shaft and it gives comparatively very lower noise than other Rotorcraft and propeller aircrafts. It also provides greater cruise altitude than helicopters. Tilt-rotor can easily reach 6000 m/20000 ft or more whereas helicopters typically do not exceed 3000 m/10000 ft altitude performance are good comparatively others. This engine acts rotor while hovering mode, it acts propeller while cruising mode so it is called Proprotor.


USES AND ITS ROLES

CIVILIAN ROLES: 

Now for the first time a production model is on track to be approved for civilian roles such as emergency medivac flights, search-and-rescue operations and executive travel. It will be launch on coming next year. It had officially announced on April 15, 2019. New York Mayor Michael Bloomberg who wants to board a Tilt-Rotor near his home and fly at speeds higher than 300 mph to a meeting a thousand miles away. About three hours later, it land on a helipad at the meeting location( AgustaWestland AW609 -mode at Paris Air Show 2007) .

MILITARY ROLES:

“This will carry a squad of Army soldiers, or a squad of Marines, to an assault area faster and increase the lethality compared to the V-22 [Osprey], which is a larger platform and more of a utility aircraft,” said by Jeff Schloesser, a retired Army major general and executive vice president of strategic pursuits for Bell’s Washington operations. Bell’s V-280 Valor and V-22 [Osprey] are all the extreme level aircrafts.

DEMERITS OF TILT-ROTOR

In starboard weapons less carrying capacity compared to helicopters more moving parts will hurt maintenance cycle.
When hovering the performance of the aircraft would be less compare to the helicopters. In Tilt-Rotor most of the accidents and incident caused by hovering because due to harsh landing approach.
 Sometimes accidents may occur due to pilot's errors because the controls are typically hard and difficulty to face the challenges, while having critical situations like Gusty winds while hovering (Not in military tilt-rotor).

CONTROLS OF TILT-ROTOR

Tilt able rotors are great technical challenges and key issues for high-powered flight controls, which have attracted the attention of many researchers. Hovering is similar to rotor-craft like Vertical takeoff or landing. Yaw is controlled by tilting its rotors in opposite directions, Roll is provided differential thrust, Pitch is provided through rotor cyclic and Vertical motion is controlled with conventional rotor blade pitch.
A unique control similar to a fixed-wing engine control called a Thrust Control Lever (TCL).

ACCIDENTS AND INCIDENTS OF TILT ROTOR

Unfortunately Tilt-rotor facing accidents frequently maximum twice accidents per year, so the manufacturers trying to mitigate the accidents and incidents.
V-22 Osprey had 12 hull loss accidents that resulted in a total of 42 fatalities. During testing from 1991 to 2006 there were four crashes resulting in 30 fatalities.
July 2006: V-22 experienced compressor stalls in its right engine in the middle of its first transatlantic flight to the United Kingdom.

December 2006: It was reported that a serious nacelle fire occurred.

March 2007:  V-22 experienced a hydraulic leak that led to an engine-compartment fire before takeoff on 29 March.

November 2007;An MV-22 Osprey of VMMT-204 caught on fire during a training mission and was forced to make an emergency landing.

December 2016:On 13 December 2016 when a MV-22 crash-landed, a second MV-22.

January 2017: On 29 January 2017, an MV-22 experienced a hard landing during Yemen against Al-Qaeda, causing two injuries to U.S. troops. The aircraft could not fly afterward and was destroyed by U.S. airstrikes.

FAMILY OF TILT-ROTOR

In other crafts of its family, which had been designed only for the purpose of experiments and further small purposes. There are two types,

TILT-JET (Tilting of Jet) which had almost failed and very low efficiency to hovering but after the cruising performance would be good and it has provided Great thrust. In future, manufacturers may modify and use it for many roles because this concept creates interest among all Manufacturers.

TILT-WING (Tilting of Wing) which was the first concept and it had helped to develop, the concept of Tilt-Rotor which is in servicing yet. A Tilt Wing aircraft features a wing that is horizontal for conventional forward flight and rotates up for vertical takeoff and landing. It is similar to the Tilt Rotor design where only the propeller and engine rotate. Tilt Wing aircraft are typically fully capable of VTOL operations.

THE TILT-ROTOR STILL IN SERVICE

 It is still in servicing for many roles. Recently US involved it. (Bell Boeing V-22 Osprey)
Primary users:    United States Marine Corps United States Air Force, US Navy coast guard.                         
Number built- 200+ as of 2014
Program cost- US$35.6 B after planned procurement of 408 aircrafts.

CONCLUSION

There are more aircrafts like Tilt-Rotor. Zunum's Aero planned for 2022 Hybrid Jet. The airplane will use a 1 megawatt battery and the company is currently testing batteries used in hybrid trucks and ships, but is not wedded to a specific battery technology. They are trying the battery to be independent and are designing the airplane to accept the most efficient, safest, and lightest battery available in 2022.

                              (Tilt rotor)

                   

                              (Tilt wing)
                         
                       

                               (Tilt Jet)     

                           

                 ( Bell Boeing V22 osprey) 


                     

                 (Augusta Westland AW609)


                        

   (Zunnum's future hybrid electric A/C)





 REFERENCE:
“Augusta Westland plans to fly 2021” Official website - Aviation international news
“NASA’s heavy lift aircraft” Official website - NASA.
“Warwick & Graham pge-44 flight international”
“Tilt Rotor” Official website - Helis.com
“Zunnum’s Aero planning hybrid Aircraft” Official website - Zunnum.aero.com
“Rotor and structural dynamic of turbo machinery” author –Subbiah, littleton