Airframes, Aerodynamics, and Theory of Flight Flashcards
Stresses - Compression
Crushing or squeezing parts together
Stresses - Tension
Stretching or pulling apart objects
Stresses - Shearing
Cutting or sliding an object apart
Stresses - Bending
Pulls one side of an object apart while squeezing the other side
Stresses - Torsion
Twisting Motion
Fuselage Type - Truss Type
- Frame of wood beams or metal tubes (bolted or welded)
- Frame carries load and fuselage stresses
- Two types, Warren and “N” Girder
Fuselage Type - Monocoque
- “Stressed Skin”
- Skin carries some of the load
- Perfect Stressed Skin: Skin carries ALL of the load
- Formers maintain shape
- Bulkheads carry load
- Stringers run lengthwise and hold bulkheads together
Fuselage Type - Semi-Monocoque
- Combination of stressed skin and formers or frame system
- Includes a firewall, separates the engine compartment from the rest of the fuselage
- Cessna 172
Chord
Straight line joining the leading and trailing edges of wing
Camber
Upper curvature of the wing
Span
Distance from wingtip to wingtip
Wing root
- Inboard section of wing closest to fuselage
Load Factor
Actual load being imposed on the wings vs the weight of the aircraft
Spars
Run from wing root to tip and carry most of the load in flight
Ribs
- Give shape to the wing and prevent twisting
False Ribs
- Smaller ribs placed between leading edge and front spar
Compression Struts
Steel tubes placed between the spars to prevent compression/distortion of the wing
Drag/Anti-Drag Wire
Provide additional support to the wing
Wing Tip Bow
Curved metal tube giving the wingtip its shape
Semi-Cantilever Wing
Supported by external struts
Full Cantilever Wing
No external bracing
Stabilator
No fixed horizontal stabilizer
Canard
Horizontal stabilizer at front of aircraft
Control Systems
Ailerons - Torque Tube
Elevators - Push/Pull Rod
Rudder - Cable and Pulley
Nose Wheel Advantages
- Greater visibility over the nose
- Nose over tendencies eliminated
- Greater maneuverability on ground
Tail Wheel Advantages
- Less Drag
- Cheaper and easier to build and maintain
- Will sustain less prop damage
- More suitable for ski operations
Brakes - What to look for
- Hydraulic leak around main gear (red puddle)
- Cracks in the pucks
- Rusting over long periods due to lack of use
4 Forces
- Lift acts 90º to wing span
- Weight acts at C of G
Factors Affecting Lift
- Angle of Attack
- Velocity of the Airfoil
- Density of the Air
- Wing Area
- Shape of the Aerofoil
Coefficient of Lift
- Relative measure of aerofoil’s lifting capabilities
- Varies with angle of attack and aerofoil type
- Higher camber and flaps will yield greater CL
- Increases up to critical angle of attack, the decreases rapidly (stall)
Total Drag
Induced Drag + Parasite Drag
Parasite Drag
- Drag produced by any surface that doesn’t contribute to lift
- Interference Drag (Joining of two or more parts)
- Profile Drag (Form Drag + Skin Friction)