Lec 8.4.13 Aerodynamic Forces

7/28/2019 Lec 8.4.13 Aerodynamic Forces

1/45

AERODYNAMIC FORCES IN FLIGHT

MANEUVERS

Turns

Climbs

Descents


2/45

Still remember the Traffic Pattern?

Upwind Crosswind Downwind (1000ft)

Base - Final


3/45

VFR flying

Where we are and our DESINATION


4/45

Visual Flying Rules- Clear of cloud

- In sight of the ground and sea

- Have other aeroplane in sight

- Avoid collision with other planes or terrain- Not at night

SummaryYOU TAKE CARE OF YOUR SEPARATION


5/45

Clear of Cloud


6/45

VFR Weather Minima

1. General

Visibility 5 km and cloud ceiling of not less

than 1500ft.

In Uncontrolled airspace remain clear of cloud

and in sight of surface under 3000ft.

Not at night!


7/45

Weather Minima


8/45

How can I not

collide with others?


9/45

General Flight Rules

A/C CONVERGING FROM THE RIGHT

TRAFFIC AT THE RIGHT

HAS THE RIGHT OF WAY


10/45

CONVERGING

TRAFFIC AT THE RIGHT

HAS THE RIGHT OF WAY


11/45


A/C APPROACH HEAD-ON

EVERYONE TURNS RIGHT!


12/45


A/C OVERTAKING

RIGHT OF WAY

OVERTAKE FROM THE RIGHT


13/45

Our AirspaceZones and UCARAs

Controlled and Uncontrolled airspace


14/45

Our Airspace


15/45


16/45

Zone Under control (conc. )

Lei Yue MunWaglan Zone

Tuen Mun Zone

Pak MongShum Shek

Place to Note


17/45

Place to Note

UCARA Not Under control

Port Shelter Tolo

New Town

SKARA Border


18/45

Route 1Straight Out departure SSKFANCCC

GRIHBRJoin KaitakCircuit : Downwind runway 13


19/45

Right Crosswind departureHBRGRI

Ma Wan Corridor 1000ft maxTPZ

PAK () - Join CLK Circuit : Final Runway 25L

Route 2


20/45

Sek Kong Airfield

Ex- RAF Sek Kong Camp

HKAC can fly during weekend


21/45

Entry Points

Gaps ()

-: Kadoorie Gap (,)-: Fire Station Gap (,)


22/45

Entry Points

Gaps ()

-: Kam Tin Gap

-: Pagoda

-: Mai Po

(, GFS Only)


23/45


24/45


25/45

Straight Out departureLYMWAG

PSH TOL

NEW TOWNKDGKadoorie Gap

SKARA

Route 3


26/45

Still have any questions?


27/45

Aerodynamic Forces: Turns


28/45

Aerodynamic Forces: Turns In turns, two forces (lift and weight) would be apparent

In a bank it would be apparent that lift is not act directly oppositeto the weightit now acts in the direction of the bank.

When the airplane banks, lift acts inward toward the center of theturn, as well as upward, meaning the force of lift is divided into twocomponents.

Why? An airplane, like any moving object, requires a sideward forceto make it turn. In a normal turn, this force is supplied by bankingthe airplane so that lift is exerted inward as well as upward.

The force of lift during a turn is separated into two components atright angles to each other.

One component, which acts vertically and opposite to the weight(gravity), is called the vertical component of lift.

The other, which acts horizontally toward the center of the turn, is

called the horizontal component of lift, or centripetal force.


29/45


30/45

Aerodynamic Forces: Turns


31/45

Aerodynamic Forces: Turns To provide a vertical component of lift sufficient to hold

altitude in a level turn, an increase in the angle of attack isrequired.

Since the drag of the airfoil is directly proportional to itsangle of attack, induced drag will increase as the lift isincreased. This, in turn, causes a loss of airspeed inproportion to the angle of bank; a small angle of bankresults in a small reduction in airspeed and a large angle of

bank results in a large reduction in airspeed. Additional thrust (power) must be applied to pre-vent a

reduction in airspeed in level turns; the required amount ofadditional thrust is proportional to the angle of bank.

To compensate for added lift, the angle of attack must be

decreased, or the angle of bank increased, if a constantaltitude is to be maintained.

An increase in airspeed results in an increase of the turnradius

Standard Rate Turn


32/45

Aerodynamic Forces: Climbs


33/45




34/45

Aerodynamic Forces: Climbs If the climb is entered with no change in power setting,

the airspeed gradually diminishes because the thrust

required to maintain a given airspeed in level flight is

insufficient to maintain the same airspeed in a climb.

When the flightpath is inclined upward, a component

of the airplanes weight acts in the same direction as

the total drag of the airplane, thereby increasing thetotal effective drag.

Consequently, the total drag is greater than the power,

and the airspeed decreases.

The reduction in airspeed gradually results in a

corresponding decrease in drag until the total drag

(including the component of weight acting in the same

direction) equals the thrust.



35/45




36/45

Aerodynamic Forces: Climbs Since in a climb the airplanes weight is not only

acting downward but rearward along with drag,additional power is required to maintain thesame airspeed as in level flight.

The amount of power depends on the angle ofclimb.

When the climb is established so steep that thereis insufficient power available, a slower speedresults.

It will be then the amount of reserve power or

excess power determines the climb performanceof the airplane.

Aerodynamic Forces: Descents


37/45

Aerodynamic Forces: Descents When forward pressure is applied to the elevator control to start

descending, or the airplanes nose is allowed to pitch down, theangle of attack is decreased and, as a result, the lift of the airfoil

is reduced. This reduction in total lift and angle of attack is momentary and

occurs during the time the flightpath changes downward.

The change to a downward flightpath is due to the liftmomentarily becoming less than the weight of the airplane as

the angle of attack is reduced. This imbalance between lift and weight causes the airplane to

follow a descending flightpath.

From the time the descent is started until it is stabilized, theairspeed will gradually increase.

This is due to a component of weight now acting forward alongthe flightpath, similar to the manner it acted rearward in aclimb.

The overall effect is that of increased power or thrust, which inturn causes the increase in airspeed associated with descendingat the same power as used in level flight.


38/45

Four Fundamentals of Flight


39/45

Four Fundamentals of Flight The four fundamentals of flight are

"Straight and Level",

"Level Turns",

"Straight Climbs and Climbing Turns", and

"Straight Descents and Descending Descents"

The four fundamentals of flight are required

to maneuver the aircraft in all phases of

normal and emergency flight.


40/45

Straight and Level


41/45

Straight and Level References: Both flight instruments and Outside visual

Use Pitch, Bank and Power

Primary and Secondary Instruments

If heading deviates, set Bank with Horizon and AI Verify coordination with TC

Bank angle no greater than standard rate: 3 degrees/second

If Altitude deviates:

Set pitch with Horizon and AI Small changes (100') Pitch ONLY

Large changes (>100') Pitch AND Power

Coordination of Controls:

Always keep ball of TC centered

Trim Technique

Trim to relieve control pressure already held. NOT to control yokemovement.

Turns


42/45

Turns Purpose: Change A/C direction

References: Both flight instruments and Outside visual

Banking

Types:

a) Shallow: Stability acts to level wings

b) Medium: A/C tends to hold bank angle

c) Steep: Overbanking tendency

Purpose of bank: Change vertical lift to horizontal lift during which:

(1) Vertical lift opposite gravity

(2) Horizontal lift parallel to earth surface

(3) Resultant vector perpendicular to wings Requires greater AOA to counter loss of lift

Adverse Yaw

1. Caused by lowered aileron on raised wing (more drag)

2. Use of rudder to control

Straight Climbs


43/45

Straight Climbs References: Both flight instruments and Outside visual

Controls used: Elevator, Rudder, and Power

Considerations:

a) As airspeed reduces power must be increased.

b) Climbs require excess thrust (AOA requires excesspower)

Left Turning tendencies:

a) Torque

b) Asymmetrical thrust (P-Factor)

c) Spiral slip stream (slow airspeed) d) Gyroscopic precession (right tendency)

e) Counter Left turning tendencies with rudder

f) Keep Ball Centered on inclinometer

Trim: After established, set trim.


44/45


45/45

Lec 8.4.13 Aerodynamic Forces

Documents

Transcript of Lec 8.4.13 Aerodynamic Forces