323 - Thrust, Climb Performance, Takeoff Performance Flashcards
What is thrust?
Thrust overcomes it’s opposing force _______.
Mechanical force generated by engines:
Examples of thrust producing things. (4)
Thrust is the force that moves the airplane forward through the air.
Overcomes - Drag
Mechanical force generated by engines:
- Winglets
- Forward acting component of lift
- Forward acting component of weight
- Expanding air - Concorde intake = 15%
As a mechanical force, what does propulsion need to have physical contact with to create thrust?
To produce thrust it must ___________.
Newton’s Third Law/ Beronoulli?
A Fluid
It must accelerate a mass of particles to produce thrust.
Newton’s Third Law - Equal and opposite reaction.
A propeller is an __________.
It is/is not 100% efficient. (because it’s an airfoil)
Each blade produces what kind of drag?
____ from the other blade also effects it’s efficiency.
_____ also reduce efficiency.
A propeller is an airfoil.
It is not 100% efficient.
Why?
It produces both induced and parasite drag.
Disturbed airflow from the other blade reduces efficiency. (prop slippage)
Wingtip vortices created also reduce efficiency.
As speed increases, relative wind moves _____ and _____ to the chord line. (release the breaks)
Forward and closer to the chord line.
Airflow in front and airflow from the bottom add up and new relative wind changes.
If aircraft velocity = 0 . then the relative wind is ______ prop rotation.
Can you stall a propeller because of this?
Opposite prop rotation.
Definitely can stall a prop.
Two methods of climbing?
Trade Kinetic for Potential Energy
Use Excess Thrust
Trading kinetic energy for potential energy is known as ?
Zoom Climb
Using excess thrust is used for a _________.
Sustained Climb
TAKEOFFS:
Runway Slope:
Upslope
Downslope
Most paved runways have less than ______° slope, but still has ________.
Upslope - weight component becomes the retarding force
Downslope - weight becomes the accelerating force
Most paved runways have less than a 2° slope but still has a significant force.
Two forces in climb are
_______ and ______ to flight path
Perpendicular forces to the flight path.
Parallel to the flight path.
What forces are perpendicular to your flight path in climb?
Drag
Thrust
Lift
Best Rate of Climb Speed is? (vy)
Airspeed that provides the greatest gain of altitude inthe shortest time.
Fixed pitch prop has tip efficiency only at one airspeed whereas a constant speed can be fully efficient in other speeds.
Yep.
High Thrust to Weight ratio = ______- acceleration _______ climb rate
Big acceleration - High climb rate.
1 hp = ___ ft lbs
33,000
