aircraft design + flight instruments

• fuselage is where the aircraft's main component. People and baggage are found here. Wings, Empennage, and Undercarriage are attached to it
• fuselage designs: truss, monocoque, Semi-monocoque
• Truss: steel tubes attaches to a form frame
• Semi-monocoque: round formers held together using stringers (long strips) to make longitudinal shape. Formers and skin take the load
• Monocoque: round formers held together using stringers (long strips) to make longitudinal shape. skin takes all of the load
• control surfaces: Rudder, ELevator, Ailerons
• Rudder: found on empennage, controls yaw
• Elevator: found on empennage, controls pitch
• ailerons: found on wings, controls roll
• Trim tabs: hold control surfaces in place to allow pilot to fly on a desired condition/attitude under a certain load airspeeds. goes in opposite direction of the control surface.
• Flaps: increase lift and drag
• Spoilers: decrease lift, found on wing
• Divebreaks: increase drag
• spars: run from wingtip to root. can be externally braced using struts. transmit load into fuselage
• skin: covers wings/fuselage.

  GOAL: to be smooth to promote aerodynamic flow
• Ribs: help form aerofoil shape. increase strength and structure. Types: Web and Truss
• Planform: wing shape that is the same on both sides of the aircraft, with the same angle of incidence and chord length. Varies depending on use of a/c.
• Central single main gear: main wheel id ahead of c of g. rests on mainwheel and one wing.
• Tailwheel: main wheels ahead of c of g. decrease in parasitic drag, is cheaper
• tandem: wheels on wingtip. Main gear in line w/ fuselage. low weight and drag. uncommon
• Fixed landing gear: can have wheel fairings to decrease drag
• retractable: gear is retracted into fuselage after takeoff. found on high-perf gliders.
• types of breaking systems:

  1. elec
  2. mech
  3. hydr
• pitot static system: has 1 pitot tube and 2 static ports

  has ASI, VSI, Variometer, Altimeter

  measures pressure differential
• pitot tube: measures ram air, is most accurate when a/c is at cruise speed and in cruise flight, and has a drain hole at the rear to eliminate excess moisture
• static ports: measures static pressure outside of a/c, placed perpendicular to airflow so that ram air is not measured
• Altimeter: measures pressure of atmosphere

  meant to indicate a/c height above sea level in standard temps

  functions on principle of pressure:

  1. a/c climbs -> pressure enters, expands, needle turns
  2. a/c descends -> higher pressure allows capsule to compress while turning needle

  number shown is indicated altitude

  3 needles
• standard atmospheric conditions:

  29.92" Hg above sea level

  15 C

  air is dry
• pressure altitude: indicated altitude corrected for non-standard temperature

  • Indicated altitude when tool set to 29.92" Hg used
  • PA = IA + (1000 x (29.92" Hg - Altimeter settings))
• indicated altitude: read from altimeter when normal setting used
• density altitude: pressure altitude corrected for non standard temps

  • final determinant when considerins a/c performance
  • calculated using whiz wheel
  • DA = PA + (100 x (outside air temp - international standard temp))
• Absolute altitude: actual height above ground level

  • AA = TA - surface elevation
• True altitude: exact height above sea level

  • IA x (1 + 4/1000 x (outside air temp - international standard temp))
• decrease in temp causes altimeter misreads:

  • decrease in temp = increase in reading
• VSI: tells if pilot is climbing or descending in ft per min

  • measures change in baromic pressure which occurs alongside change in height (outside air pressure deceases and increases)
  • its movement indicates up or downward trend
  • once it stops, it indicates exact rate
• Variometer: indicates variations in altitude (ft / min or miles / sec)

  green ball indicates climb

  red ball indicated decsent
• Air Speed Indicator: indicated speed in relation to airflow outside in Knots

  • connected to both pitot and static source
  • RAM - static = dynamic (airspeed)
  • increase in alt = decrease in pressure
  • must read 0 on ground
• static pressure: pressure exerted in air molecules in a still air mass

  • acts in all direc
  • equally exerted on surroundings
  • also exerted when air in motion
• dynamic pressure: pressure exerted by air molecules in motion

  • strength increases if speed of body relative to air increases
  • strength decreases if altitude increases
• total pressure/RAM air: static pressure + dynamic pressure

  • dynamic pressure due to a forward motion