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Tuesday 21 February 2012

TILTROTOR


" TILTROTOR" this is the new terminology we hearing now a days. All the aviation people use to think about such a design which uses VTOL and Fixed wing aircraft. We think this design is not implemented yet, but this is.
Yes what you heard is right. it is implemented and waiting for FAA certification.

        AGUSTAWESTLAND is one of the aviation firms made this dream come true. The shown pictures are the AW609 aircraft.

        
 The unique characteristics of the AW609 Tiltrotor combine the benefits of a helicopter and a fixed wing aircraft into one aircraft. Taking off and landing vertically, flying above adverse weather conditions with up to nine people in comfort in a pressurised cabin at twice the speed and range typical of helicopters, the AW609 represents the next generation of aircraft transport for civil (both private and commercial operators), government and para-public roles. This multi-role aircraft can be configured for passenger transport, search and rescue, law enforcement, maritime surveillance, training and government applications. The AW609 will be certified for instrument flying in known icing conditions and features a composite fuselage and wings, an advanced glass cockpit and full fly-by-wire digital controls. These advanced technologies will provide new levels of performance, reliability and affordability for future operators.

Its Applications:

» COAST GUARD 
The performance characteristics of the AW609 offer coast guards capabilities and cost-effectiveness simply not available in any other single aircraft. The AW609 offers coast guard operators highly cost-effective and time efficient point-to-point transportation at speeds up to 275 knots and ranges up to 700 nm. 
 
 » EMS/SAR 
The AW609 is a multi-mission tiltrotor aircraft designed to employ the speed of a turboprop airplane with the vertical takeoff and landing capability of a helicopter offering unique capabilities to EMS/SAR operators. For EMS and SAR operations, the AW609 offers basket, litter and a 600 lb capacity exterior hoist option. 
 
 » OFFSHORE 
The AW609 offers speed, range, all weather capability and comfort making it an ideal aircraft to transport crew offshore. Designed from the outset for low maintenance and maximum operational flexibility, the AW609 will offer operators cost-effective, point-to-point transportation at cruise speeds up to 275 knots and at ranges up to 700 nautical miles. This long range capability makes the AW609 particularly suited to “deepwater” operations in the Oil & Gas industry.
 
 » GOVERNMENT VVIP 
The AW609 offers new flexibility in transport for VVIPs and Heads of State. The combination of vertical takeoff and landing together with range capability and speed enable the VVIP to reach distant congested urban areas directly, quickly and with high levels of security. The pressurised spacious cabin provides a comfortable and productive working environment and the aircraft has ample space to carry any necessary luggage.
 
AW609 Demonstration

 
 TECHNICAL DATA:


Weights
Max take off 7620 kg 16800 lb
Max useful load 2495 kg 5500 lb

Engine Rating (2 x Pratt & Whitney PT6C-67A)
Take off power 1447 kW 1940 shp
Maximum continuous power 1249 kW 1675 shp

Fuel Capacity
Standard* 2470 lb 369 USgal

           * Unusable Fuel 50 l (13 USgal)

Crew
Pilots / Passengers 2 / 9

External Dimensions
Length (overall) 14.04 m 46 ft
Overall height 5.10 m 16.70 ft
Prop rotor diameter 7.92 m 26 ft

Performance (ISA - MTOW - pending certification)
Max demonstrated speed 616 km/h 333 kts
Max cruise speed 509 km/h 275 kts
Rate of climb n.a. m/s n.a. ft/min
Operational ceiling 7620 m 25000 ft
Max range (standard tanks) 1296 km 700 nm
Cabin pressure altitude 8000 ft 2438 m
 
EQUPMENT 
  • Pressurised  cabin
  • Fly by wire flight control system
  • Heated composite rotor blades
  • Nine seat interior with soundproofing
AVIONICS SYSTEMS

  • 3 multi-function active matrix Liquid Crystal Displays (LCDs)
  • Full IFR package
  • Dual-channel Nacelle Interface Unit (NIU) (each nacelle)
  • Dual-channel data concentrator unit
  • System maintenance diagnostics computer
  • Integrated Avionics Processor Unit (IAPS)
  • Flight guidance system
  • Flight management system
  • Global positioning system
  • Weather radar
  • ELT







Saturday 11 February 2012

Satellite orbit information


Geostationary Orbit


 
The most common orbit used for satellite communications is the geostationary orbit (GEO). This is the orbit described above – the rotational period is equal to that of the Earth. The orbit has zero inclination so is an equatorial orbit (located directly above the equator). The satellite and the Earth move together so a GEO satellite 
appears as a fixed point in the sky from the Earth.

The advantages of such an orbit are that no tracking is required from the ground station since the satellite appears at a fixed position in the sky. The satellite can also provide continuous operation in the area of visibility of the satellite. Many communications satellites travel in geostationary orbits, including those that relay TV signals into our homes.


However, due to their distance from Earth GEO satellites have a signal delay of around 0.24 seconds for the complete send and receive path. This can be a problem with telephony or data transmission. Also, since they are in an equatorial orbit, the angle of elevation decreases as the latitude or longitude difference increases between the satellite and earth station. Low elevation angles can be a particular problem to mobile communications.




Low Earth Orbit/Medium Earth Orbit


        
        A low earth orbit (LEO), or medium earth orbit (MEO) describes a satellite which circles close to the Earth. Generally, LEOs have altitudes of around 300 – 1000 km with low inclination angles, and MEOs have altitudes of around 10,000 km. 

A special type of LEO is the Polar Orbit. This is a LEO with a high inclination angle (close to 90degrees). This means the satellite travels over the poles.





            Satellites  that  observe our planet  such as  remote  sensing  and  weather  satellites often  travel  in a  highly  inclined LEO  so  they  can  capture  detailed  images  of  the  Earth’s surface  due  to  their  closeness  to  Earth.  A satellite  in  a  Polar orbit  will  pass  over  every  region  of  Earth  so  can  provide global  coverage.  Also  a  satellite  in  such  an  orbit  will sometimes  appear  overhead  (unlike  a  GEO  which  is  only overhead  to  ground  stations  on  the  equator ).  This  can  enable communication  in  urban  areas  where  obstacles  such  as  tall buildings  can  block  the  path  to  a  satellite.  Lastly,  the transmission  delay  is  very  small.

       Any  LEO  or  MEO  system  however ,  for  continuous  operation,  requires  a   constellation  of  satellites.  The  satellites  also move  relative  to  the  Earth  so  wide  beam  or  tracking  narrow  beam  antennas  are  needed.

            






Elliptical Orbit


                A  satellite  in  elliptical  orbit  follows  an  oval - shaped  path.  One  part  of  the  orbit  is  closest  to  the  center  of  Earth  (perigee)  and   another  part  is  farthest  away  ( apogee ).  A  satellite  in  this  type  of  orbit  generally  has  an  inclination  angle  of  64  degrees  and  takes  about  12  hours  to circle  the  planet.  This  type  of  orbit  covers  regions  of  high  latitude  for  a  large  fraction  of  its  orbital  period.