You Decide

Horizontal- Flying (Airplane):

Wings:
Wings are made up of airfoils, flaps, ailerons, slats, and spoilers. The entire wing's outer tips are higher than where the wing is attached to the fuselage, creating an angle called the dihedral. This angle helps reduce the likelihood of the plane rolling during flight. Wings often hold fuel, as their thin shape is not large enough for passengers or cargo. Airfoils camber or curve over the tops of them, so air can move more quickly over the top than bottom. According to Bernoulli's principle, air on the top is at a lower pressure than air at the bottom. This difference in pressure leads to lift in subsonic flight. To help you with your research, the following topics are discussed:

• angle of attack
• shape of wing
• area of wing
• density of air
• speed at which wing is travelling or speed of wind

Shape of Wing:

• Straight
  

  * good lift at slow speeds
  * not suited for high speeds
  * creates appreciable drag, being perpendicular to airflow
  * stable flight
  * can be made cheaply and lightly
  

• Sweep (Sweepback or Forwardsweep)
  

  * good at high speeds
  * create less drag than straight wings
  * somewhat unstable at slow speeds
  

• Delta
  

  * good at high speeds, supersonic (for example, Concorde)
  * land and takeoff quickly, so low speed instability not an issue
  

• Swing-Wing
  

  * wing is straight for take-off and landing, thus exploiting straight features of stability at low speeds and maximum lift
  * wing swings to sweepback position during cruising, enabling it to travel at high speeds with little drag.
  * drawback is substantial weight of hinges for transitioning between straight and sweepback wings.
  

Area of wing:

On leading edge of wing -

• Slats
  * slide forwards and backwards
  * slide forwards during takeoff to increase area and camber to allow for high speeds
  * slide backwards during landing to decrease area and allow for slower speeds

On top of wing -

• Spoilers
  * rest "flush" with wing or can extend upwards
  * when extended upwards, reduce lift by disrupting airflow over the top of the wing, increasing drag, and slowing speed

Density of Air:

See the atmosphere section of this You Decide Activity.

As an airplane or the air around it moves more quickly, the forces respective to the airplane may be more dramatic. Some airplanes are best suited for speed -- see wing types above.

Fuselage:
        "Body" of airplane, including cockpit, passenger compartment, and cargo compartment, produces some lift and is streamlined to reduce drag

For more information, visit Parts 3 and 4 of the Aeronautics Tutorial in Virtual Skies.

Vertical-Flying (Rocket):

A nose cone is a tapered, low-friction surface that first comes in contact with air that it passes through. Often cargo and passengers ride in the nose cone. The wings and fins provide directional stability for rocket. The fuselage is the main portion, or body of the rocket. It provides much of the weight for the rocket, so ideally is made from strong, low-weight materials. At its base is the propulsion system. For more information on the propulsion system, see the Propulsion Section of this You Decide Activity. Rockets do not land "whole" like airplanes do. The nose cone is attached to a parachute that will expand upon reentry. All other components of the rocket were discarded earlier in flight.

Rockets often take advantage of launch rods, which provide guidance during take-off until enough force is exerted on the fins/wings for them to provide stability.

Space Shuttle:
Aircraft and rocket come together!
The Space Shuttle takes off like a rocket, but lands like an airplane, allowing it to be reused several times. Newer "Space Shuttles" will be lighter weight and will take off and land like airplanes, now that very high airplane speeds can be achieved consistently. NASA's X-planes are being used for this research.

The shuttle has three major parts:
(1) Fuel Tank - carries fuel; will be discarded after take-off. Most of it burns up upon reentry into Earth's atmosphere the remainder falls into ocean.
(2) Solid Rocket Boosters - used for take-off, provide 71% thrust; will be discarded after take-off, and parachute back to earth to be reused later.
(3) Orbiter - housing for astronauts, cargo; what will complete the entire shuttle journey The orbiter has tail fins and wings like an airplane, as well as landing gear. It uses a parachute to help slow its speed after it has landed.
More information on the Space Shuttle can be found at: http://www.dfrc.nasa.gov/Newsroom/FactSheets/FS-015-DFRC.html Technical drawings and diagrams can be found at: www.hq.nasa.gov/.../History/diagrams/ shuttle/shuttle.htm. Much research is being conducted about merging aircraft and spacecraft designs. Fact Sheets on some of these experimental vehicles can be found at: http://www.dfrc.nasa.gov/Research/index.html

You Decide Intro
You Decide Scenario
You Decide Decision Making Process