Landing 323 Flashcards
What are the two parts of landing?
Descending Approach
Ground Roll
Descending Approach:
• L/D is an angle attack remember
• Minimum Safe Approach Speed
o 1.3 X Vso
o Transition to Vso at touchdown (NOT BEFORE)
• Steepest approach angle for your approach as possible.
o Reduce flare distance, minimize horizontal component of inertia
- Large increase in drag as aircraft pitches up
- As wing tip stalls on a swept wing, burbling flow misses the tail surfaces. There is no buffet.
- Airfoil center of lift moves inward and forward.
Newton’s Second Law:
• Newton’s Second Law : The direction of the force is the same as that of the acceleration.
After Touchdown:
Thrust
Drag
o Thrust = 0
♣ Throttle at idle after touchown
♣ Reverser makes thrust value = negative thrust
o Drag
♣ Induced and parasite at touchdown
♣ Parasite at end of roll
F =
F = MA
Aerodynamic drag decreases as _______ decreases.
Friction _______ as _____ decreases.
Aerodynamic drag decreases as velocity decreases.
Friction increases as velocity decreases.
• Acceleration and Deceleration
Proportional to
Inversely proportional to
o Proportional to the sum of all forces
o Inversely proportional to Mass of object
Friction
Depends on:
Characteristics of :
_________ ability
Product of _____ - _____
Friction: • Depends on forces acting normal to runway • Characteristics of landing surface • Braking ability • Product of Weight - Lift
How can you minimize landing distance:
Minimize stall speed
Maximize deceleration
How can you minimize Vso (4)
Minimize Weight
Maximize Air Density
Maximize surface Area & Cl
Flaps
Minimizing Vso in depth.
• Minimize weight –
o gives you a slower landing speed
o shorter distance to decelerate
• Maximize air density (not very easy to control)
o Low altitude
o Low temperature
♣ Slower airspeed.
• Maximize surface area & CL
o Maximize surface area (really only way is fowler flaps)
o Maximize Clmax
♣ Flaps
♣ Maximize flaps regardless of wind conditions
• Flaps
o High Lift Device
o Same amount of lift at slower speed
o Reduces horizontal component of inertia
o Increases angle of descent without increasing airspeed
How can you Maximize Deceleration?
Negative THRUST: WHAT DOES IT DO
o Provides approx. 40% of forward thrust
o Thrust reversers
o Reversible pitch props
Increases drag
♣ Aerodynamic Drag
Increases friction
♣ Max Wheel Braking
♣ Decrease Lift – spoilers, flaps up, etc.
♣ Anti-skid brakes
Other factors with Maximum Deceleration?
Wind
Runway Slope
Pilot Technique
o Wind
♣ Headwind component reduces groundspeed
o Runway slope
♣ Weight component
o Pilot Technique
♣ Approach Speed
♣ Use of flaps
♣ Use of Brakes
Landing Errors (4)
What happens and whY?
• Wheel Barrowing
o Excessive speed, full flaps. Touchdown too fast hold the airplane down with forward pressure.
• Balloons
o Thinks ground coming up too fast, pulls back
• Bounces
o Too fast, or too great descent rate. Gains altitude as airspeed slows
• Porpoise
o Touch nose gear, then mains, then nose gear.
Wind Shear:
Define it
How can you tell on final if there’s a shear layer?
Describe Horizontal Gusts
Describe Vertical Gusts
Falling air ______ angle of attack
Decrease in lift causes _______ to increase
- Any sudden change in the direction or speed of wind
- Watch wind sock and winds aloft if it’s drastic there’ll be shear
o Horizontal gusts (side to side gusts not crosswinds)
♣ Change in airspeed
♣ Induces a pitching moment to return to the airplane to trimmed speed
♣ Induces new drag and lift values for new airspeed
o Vertical Gusts ♣ Change Angle of attack ♣ May introduce damaging flight loads ♣ Rising gust increases angle of attack • Too many G’s • Stall ♣ Falling air decreases angle of attack • Decrease in lift - recovery altitude increases.
