Table Of Content032 AEROPLANE PERFORMANCE
© G LONGHURST 1999 All Rights Reserved Worldwide
COPYRIGHT
All rights reserved. No part of this publication may be reproduced, stored in a retrieval system, or
transmitted, in any form or by any means, electronic, mechanical, photocopying, recording or otherwise,
without the prior permission of the author.
This publication shall not, by way of trade or otherwise, be lent, resold, hired out or otherwise circulated
without the author's prior consent.
Produced and Published by the
CLICK2PPSC LTD
EDITION 2.00.00 2001
This is the second edition of this manual, and incorporates all amendments to previous editions, in
whatever form they were issued, prior to July 1999.
EDITION 2.00.00 © 1999,2000,2001 G LONGHURST
The information contained in this publication is for instructional use only. Every effort has been made to ensure
the validity and accuracy of the material contained herein, however no responsibility is accepted for errors or
discrepancies. The texts are subject to frequent changes which are beyond our control.
© G LONGHURST 1999 All Rights Reserved Worldwide
Online Documentation Help Pages
Help
TO NAVIGATE THROUGH THIS MANUAL
When navigating through the manual the default style of cursor will be the hand symbol.
This version of the CD-Online manual also supports a mouse incorporating a wheel/
navigation feature. When the hand tool is moved over a link on the screen it changes to a
hand with a pointing finger. Clicking on this link will perform a pre-defined action such as
jumping to a different position within the file or to a different document.
Navigation through a manual can be done in the following ways:
© G LONGHURST 1999 All Rights Reserved Worldwide
Online Documentation Help Pages
Help
The INDEX The EMAIL button The PAGE The SEARCH button allows
button takes you to enables you to send button takes you you to search for specific
the Index of the us your comments to the previous words within the manual
manual you are in, regarding this and next pages (More information can be
if it is available. product, provided in the book. found in the ‘Searching’
you have an internet section). The arrows are used
connection. to display the previous and
next words whilst using the
search tool.
The CONTENTS The WEB The BACK button The HELP The EXIT
button takes you to button takes returns you to your button button exits
the first page of the you to the previous position in takes you from the
main Table Of Click2PPSC the document. to the help application.
Contents. web site. pages.
© G LONGHURST 1999 All Rights Reserved Worldwide
TABLE OF CONTENTS
Basic Aerodynamics
Engine Performance
Surface Load Bearing Strength
Contaminated Surfaces
Aerodrome Surface Dimensions
Miscellaneous Definitions
Speeds
The Effect of Variables
Legislation Background
Take-off Class ‘B’ Aeroplanes
© G LONGHURST 1999 All Rights Reserved Worldwide
TABLE OF CONTENTS
The Take-off Climb – Class B Aeroplanes
En-Route - Class ‘B’ Aeroplanes
Landing - Class ‘B’ Aeroplanes
Performance Class ‘A’ Aeroplane Take-Off
The Take-off Climb - Class ‘A’ Aeroplanes
En-Route - Class ‘A’ Aeroplanes
Landing - Class ‘A’ Aeroplanes
Reduced Thrust Take-off - Class ‘A’ Aeroplanes
Increased V2 Procedure - Class ‘A’ Aeroplanes
© G LONGHURST 1999 All Rights Reserved Worldwide
032 Aeroplane Performance
Basic Aerodynamics
Level Flight
Climbing Flight
The Effect of Altitude on Climb Performance
The Buffet Onset Boundary Chart
Descending Flight
© G LONGHURST 1999 All Rights Reserved Worldwide
Basic Aerodynamics
Basic Aerodynamics
1
Level Flight
1. In level, unaccelerated flight there are four main forces acting on an aeroplane. They are lift,
weight, thrust and drag. To maintain level flight these forces must remain in equilibrium. Lift must
be equal and opposite to weight and thrust must balance drag.
FIGURE 1-1
The Forces in
Level Flight
Chapter 1 Page 1 © G LONGHURST 1999 All Rights Reserved Worldwide
Basic Aerodynamics
2. To graphically depict the variations in strength of any force against speed then IAS, or more
correctly EAS should be used because compressibility must be accounted. However, to show the
variation of power, the rate of doing work, against speed then TAS must be used.
Lift
3. Lift may be defined as that force acting on an aeroplane which is at right angles to the
direction of the airflow. It can be calculated for level flight at any specified weight and altitude by
the formula:
Lift = C ½φV2S.
L
Where C = the coefficient of lift; φ = air density; V = free air velocity; S = wing area.
L
4. The coefficient of lift is a mathematical factor that varies with the angle of attack (up to the
stalling speed). To maintain level, unaccelerated flight the formula must remain in balance. If the
weight and altitude are fixed then the only remaining variables in the formula are the coefficient of
lift and the free air velocity. The coefficient of lift is dependent on the angle of attack for its
magnitude. Thus if the speed is increased the angle of attack must be reduced to maintain level
flight, otherwise the aeroplane will climb. Similarly if the speed is reduced then the angle of attack
must be increased or else the aircraft will descend. All angles of attack have a corresponding IAS.
Level flight can only be maintained if the formula remains in balance.
Chapter 1 Page 2 © G LONGHURST 1999 All Rights Reserved Worldwide
Basic Aerodynamics
5. Lift is generated by an aerofoil and is that force which acts upward at right angles to the
direction of movement of the aerofoil. It acts through a point on the aerofoil referred to as the centre
of pressure (CP). This point moves forward with increasing angle of attack up to the stalling angle
where it moves abruptly backward. The normal movement is between 30% and 20% of the chord
line from the leading edge. A point, approximately 25% along the chord line from the leading edge,
known as the aerodynamic centre is where, no matter what the angle of attack, the pitching
movement remains constant at its zero lift value. Lift depends on the following factors:
(a) Forward speed
(b) Air density
(c) Viscosity of the air
(d) Wing shape
(e) Wing area
(f) Angle of attack
(g) Condition of the wing surface
(h) The speed of sound
The value of lift can be calculated from the formula:
2
Lift= C .1/2ρV .S
L
Chapter 1 Page 3 © G LONGHURST 1999 All Rights Reserved Worldwide
Description:Engine Performance must be increased or else the aircraft will descend. Thus the thrust remains at a constant value; this is referred to as a flat rated
