User talk:Janithasuvimal

Aviation and Engineering http://www.aviationandengineering.com

ELECTRONIC INSTRUMENT SYSTEM All instruments essential to the operation of an aircraft are located on panels, the number of which vary in accordance with the number of instruments required for the appropriate type of aircraft and its flight deck layout. The front instrument panel, positioned in the normal line of sight of the pilots, contains all instruments critical for the safe flight of the aircraft. This panel is normally sloped forward 15° from the vertical to minimize parallax errors. Other panels within the flight deck are typically positioned; Overhead, left and right side and centrally between the pilots.http://www.aviationandengineering.com/

TURBOJET ENGINES - Preflight Operations http://www.aviationandengineering.com/2013/09/turbojet-engines-preflight-operations.html Unlike reciprocating  engine  aircraft,  the  turbo jet-powered  aircraft  does  not require a  preflight run up unless  it  is  necessary  to  investigate  a suspected  malfunction. Before starting,  all  protective overs  and air- inlet  duct  covers  should  be  removed. If possible, the  aircraft  should  be  headed  into the wind  to obtain  better  cooling, faster  starting,  and smoother  engine  performance. It is  especially important  that the aircraft  be  headed  into  the  wind if  the  engine  is  to  be  trimmed. The runup  area around  the aircraft  should  be cleared  of  both  personnel  and  loose  equipment. The turbojet engine  intake  and  exhaust  hazard areas  are  illustrated  in Image 01. Care should also be  taken  to  ensure  that  the  runup  area  is  clear of  all  items  such  as nuts,  bolts,  rocks,  rags,  or other  loose  debris. A great  number  of  very  serious accidents  occur involving  personnel  in  the  vicinity  of  turbojet engine  air  inlets. Extreme caution  should  be exercised  when  starting  turbojet  aircraft. The aircraft fuel  sumps  should  be  checked  for water  or  ice,  and  the  engine  air  inlet  should  be inspected  for  general  condition  and  the  presence  of foreign  objects. The forward compressor  blades and  the  compressor  inlet  guide  vanes  should  be visually  inspected for  nicks  and  other  damage. If possible,  the  compressor  should  be  checked for  free rotation  by  turning  the  compressor  blades by  hand. All engine  controls  should  be operated,  and engine  instruments  and  warning  lights  should  be checked  for  proper operation.

Starting a  Turbojet  Engine

The following  procedures  are  typical  of  those used  to  start  many  turbojet  engines. There are, however,  wide  variations  in  the  starting  procedures used  for  turbojet engines,  and  no  attempt  should be  made  to  use  these  procedures  in  the actual starting  of  an  engine. These procedures  are presented  only  as  a  general guide for  familiarization  with  typical  procedures  and  methods. In the starting  of  all turbojet  engines,  refer  to  the detailed  procedures  contained  in  the applicable manufacturer’ s  instructions  or  their  approved equivalent. Most turbojet engines  can be  started  by  either air  turbine  or  combustion-type  starters. Air turbine starters use compressed  air  from  an external  source. This source  may  be  a  ground cart unit  or air  bled  from  another  engine  on  the  aircraft that  is  in  operation. Combustion starters are  small gas  turbine  engines  that  obtain  power  from  expanding gases generated  in  the  starter’ s  combustion chamber. These hot  gases  are  produced by the burning  of  fuel  and  air  or,  in  some  cases,  a slow-burning  solid  or  liquid mono propellant specially  compounded  for  such  starter  units. Fuel is  turned  on  either by moving  the  power lever  to  Idle”  position  or  by  opening  a  fuel shutoff  valve. If an air-turbine starter  is  used,  the engine  should  start  or  “ light  up”  within approximately  20  seconds  after  the  fuel  is  turned  on. This is an  arbitrarily  chosen time  interval  that,  if exceeded,  indicates  a malfunction  has  occurred  and the  start should  be  discontinued. After the  cause of  the  trouble  has  been  removed,  another start  may be  made. If a  combustion  starter  is  used,  the 20.second  interval  need not be  observed,  since starter  operation  will  discontinue  automatically after  a predetermined  time  interval. The following procedures  are  useful  only  as  a  general guide,  and are  included  to  show  the  sequence  of  events  in starting  a  turbojet engine.

CFM56 Engine How To Works CFM56 Engine http://www.aviationandengineering.com/2013/09/how-to-works-cfm56-engine.html The CFM56-7B is the exclusive engine for the Boeing Next-Generation single-aisle airliner (737-600/-700/-800/-900/-900ER/ BBJ). Military customers around the world are taking advantage of the benefits of CFM56-7B-powered 737 military variants: the C-40 Clipper military transport, the P-8 Poseidon anti-submarine aircraft, and the Boeing 737 AEW&C reconnaissance aircraft.

AIRCRAFT GENERATORS AND MOTORS http://www.aviationandengineering.com/2013/09/aircraft-generators-and-motors.html D. C.  GENERATORS

Energy for  the  operation  of  most  electrical equipment  in  an  airplane  depends  upon  the electrical energy  supplied  by  a  generator. A generator  is  any  machine  which  converts  mechanical energy  into electrical  energy  by  electromagnetic induction.

A generator  designed  to  produce  alternating-current energy  is  called  an  a.c. generator, or  alternator; a  generator  which  produces  direct current  energy  is called a d.c.  generator. Both types operate  by inducing  an  a.c.  voltage  in  coils by  varying the amount  and  direction  of  the  magnetic  flux  cutting through  the  coils. For airplanes equipped  with direct-current  electrical  systems,  the  d.c.  generator  is the regular source  of  electrical  energy. One or more  d.c. generators,  driven  by  the engine,  supply electrical energy  for  the  operation  of  all  units  in the  electrical system,  as  well  as  energy  for  charging the battery. The number  of  generators  used is determined  by the  power  requirement  of  a  particular airplane. In most  cases,  only one  generator  is driven  by each  engine,  but  in  some  large  airplanes, two generators are  driven  by  a  single  engine. Aircraft equipped with  alternating-current  systems  use electrical  energy  supplied  by  a-c. generators, also called alternators.

Theory of  Operation

In the  study  of  alternating  current,  basic  generator  principles  were  introduced  to explain  the generation  of  an  a-c. voltage by  a  coil  rotating in  a  magnetic  field. Since this  is  the  basis  for  all generator  operation,  it  is  necessary  to  review  the principles  of  generation  of  electrical  energy. When lines of  magnetic  force  are  cut by  a  conductor  passing  through  them,  voltage  is  induced in  the conductor. The strength of  the  induced voltage  is  dependent  upon  the  ‘ speed  of  the conductor and the  strength  of  the  magnetic  field. If the ends  of  the  conductor  are  connected to form  a complete circuit,  a  current  is  induced  in  the  conductor. The conductor and  the  magnetic  field make  up  an elementary  generator. This simple generator  is illustrated  in  Image l,  together  with the  components of an  external  generator  circuit which  collect  and  use  the  energy  produced  by  the simple  generator. The loop of wire  (A  and  B )  is  arranged  to  rotate  in  a  magnetic field. When the  plane  of  the loop of wire  is  parallel to  the  magnetic  lines  of  force,  the  voltage  induced in  the loop  causes  a  current to flow  in  the  direction indicated  by  the  arrows  in  Image l. The  voltage induced  at  this  position  is maximum,  since  the wires  are  cutting  the lines  of  force  at  right  angles and  are  thus  cutting  more lines of  force  per second than  in  any  other  position  relative  to  the magnetic  field. As the  loop  approaches the  vertical  position shown  in  Image 2,  the  induced  voltage  decreases because  both sides  of  the loop  (A  and  B)  are approximately  parallel  to  the  lines  of  force  and the  rate  of  cutting  is  reduced. When the  loop  is vertical,  no  lines  of  force  are cut since  the  wires are  momentarily  traveling  parallel to  the  magnetic lines  of  force, and  there  is  no  induced  voltage. As the  rotation  of  the  loop continues,  the  number of  lines  of  force  cut  increases  until  the  loop  has rotated  an  additional  90 ”  to a horizontal  plane. As shown in  Image 3,  the  number  of  lines  of  force cut  and  the induced  voltage once  again  are  maxi- mum. The direction  of  cutting,  however,  is in the  opposite  direction  to  that occurring  in  Image l  and  Image 2,  so  the direction (polarity)  of  the induced  voltage  is  reversed. As rotation of  the  loop  continues,  the number  of lines  of  force  having  been  cut  again  decreases, and the induced  voltage becomes  zero  at  the position  shown  in  figure  94,  since  the  wires  A  and B  are again parallel  to  the  magnetic  lines  of  force. If the  voltage  induced  throughout  the entire 360 ”  of  rotation is  plotted,  the  curve  shown  in Image 5  results. This voltage is  called  an  alternating  voltage  because of  its  reversal  from  positive to  negative values-  first  in  one  direction  and  then in  the  other.