The following is excerpted from the book

EMERGENCY MANEUVER TRAINING

CONTROLLING YOUR AIRPLANE DURING A CRISIS

by Rich Stowell

Use of this excerpt is restricted to personal reference only and is not for

commercial use or public dissemination.

Copies of EMERGENCY MANEUVER TRAINING are available from the

author's website: http://www.richstowell.com

Emergency Maneuver Training

Controlling Your Airplane During A Crisis

Rich Stowell Consulting P.O. Box 1026

McCall, Idaho 83638

http://www.RichStowell.com

Copyright © 1996 by Rich Stowell

All Rights Reserved. No part of this book may be reproduced or transmitted in any form or by any means, electronic or mechanical, including photocopying, recording, or by any information storage and retrieval system, without permission in writing from the author, except for brief passages quoted in a book review.

Fifth printing, Fall 2011

Library of Congress Catalog Card Number: 92-70243

ISBN 1-879425-92-0

EMT is a registered trademark of Rich Stowell and CP Aviation, Inc.

PARE is a registered trademark of Rich Stowell.

The “Power-Push-Roll”, “Separation + Elevation”, and “Speed-Spot-Set-up” strategies are trademarks of Rich Stowell.

Printed in the United States of America!

Disclaimer

This book is intended to be a teaching tool for emergency maneuver and other unusual attitude training programs. The information presented herein is as accurate, complete, and authoritative as possible. However, there may be errors and omissions, both typographical and in content.

This book should be used as a general guide only and not as the ultimate source of aeronautical principles or procedures. It is designed to complement and supplement other aviation texts and formal flight instruction. For additional reference materials and recommended reading, refer to the Bibliography.

Stalls, spins, invertedflight, and other unusual attitudes, whether intentional or unintentional, may be life threatening. The information presented herein is not a substitute for actual flight training or for proficiency in the maneuvers and techniques described. The author and publisher strongly recommend that you receive hands-on flight training only from qualified flight instructors experienced in the procedures outlined herein, using only approved, well maintained, and properly loaded airplanes with appropriate safety equipment- including parachutes-before attempting any of the maneuvers described in this text.

The author and the publisher shall not be liable or responsible to any person or entity with respect to any loss or damage caused or alleged to be caused directly or indirectly by the information contained in this book. This text is not a substitute for common sense or the exercise of good judgment.

As stated in the Federal Aviation Regulations, Part 91, Section 91.3, Paragraph (a):

The pilot in command of an aircraft is directly responsible for, and is the final authority as to, the operation of that aircraft.

Curved Flight

Airplanes carve just two shapes in the sky: straight lines and curves. The turn certainly is the most common form of curved flight. Although all pilots can perform this versatile maneuver, few can properly describe its mechanics. Unfortunately, an incomplete understanding of turning flight can lead to inappropriate control inputs during critical flight operations. Losing control of the airplane while turning is cited in many accident reports. Therefore, understanding turn dynamics is essential to control the airplane.

This chapter focuses primarily on the aerodynamics of turning flight. Different types of turns are discussed as well. Since improperly executed turns often precede fatal accidents, the need for proper coordination and proper turn technique cannot be overemphasized.

Current flight training typically focuses on only two elements pertaining to turns: First, the rudder doesn't turn the airplane. Second, the horizontal component of Lift is the force that turns the airplane. Many training handbooks and flight instructors, however, fail to continue beyond this to identify the true turn control. Consequently, many pilots know which control surface doesn't turn the airplane, but aren't sure which of the remaining two really does. When pressed to name it, many respond that ailerons turn the airplane. In actuality, the ELEVATOR~S our primary turn control. Another look at our controls verifies this:

The rudder's primary function is to cancel the many yaw effects associated with flying: adverse yaw arising from aileron inputs; gyroscopic effects arising from elevator inputs; torque, P-factor, and slipstream arising from the use of power; yaw arising from airplane rigging. The rudder permits coordinated, ball-centered flight. Used correctly, it improves the quality and the efficiency of our flying. If all secondary yaw effects could be designed out entirely, airplanes wouldn't need this control surface (unless, of course, we

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wanted to perform slips and spins). The rudder was never intended to be a turn control.

Ailerons are our roll, or bank control. To illustrate their function, recall an airshow performance you may have seen. When the airshow pilot performs a full roll, does the airplane turn? No! When the airshow pilot performs an eight-point hesitation roll, stopping every 45 degrees, does the airplane turn? No! Even when the airshow pilot rolls to 90 degrees of bank and flies down the length of the runway in knife-edge flight, the airplane still doesn't turn.

Figure 5-1: Knife-Edge Pass

Aileron inputs merely characterize our turns. They cannot, and do not curve our flight path. They do, however, permit a wide range of possible curves, facilitated by pointing Lift in different directions. With ailerons deflected, the airplane rolls; with ailerons neutralized, rolling ceases instantly and a bank is established. Unfortunately, banking tends to be the most dramatic and least natural part of a turn. It's this action, and not the often subtle, but necessary elevator input that erroneously leads pilots to perceive ailerons as the turn control. Later in this chapter, we'll see some turns that require aileron inputs OPPOSITE to the direction of flight.

Unconvinced, some pilots rationalize the apparent knife-edge flight anomaly by postulating that opposite rudder cancels the airplane's turning tendency. Opposite rudder doesn't have anything to do with preventing turns in knife-edge. Rudder deflection allows the fuselage to generate Lift like a wing, balancing the airplane's Weight. The airplane wouldn't stay airborne otherwise. Furthermore, since rudder controls the angle of attack of the FUSELAGE, and elevator controls the angle of attack of the WING, how can the rudder cancel the wing's Lift? It can't. Lift is a function of the wing's angle of attack. It's controlled with the elevator. The only way to neutralize Lift, which points straight at the horizon in knife-edge, is to reduce the angle of attack-with the elevator-until zero Lift is produced.

Curved Fliaht - 51

The elevator truly is our turn control. Roll, yaw, and power are the spices we mix with pitch to flavor our turns. Combining different proportions of these ingredients gives each turn a distinct character. Visualize the airplane moving from your head to your feet as you make pitch inputs. Regardless of your attitude, the flight path always curves. We alter our flight path by pushing and pulling on the elevator control. How we manipulate it ultimately determines the turn's shape and quality.

Think about the curved flight we experience on a single trip around the traffic pattern: We rotate to a climb attitude on takeoff with back elevator pressure. We level off at pattern altitude using forward elevator pressure. We perform level crosswind and downwind turns, then descending base and final turns. These are done by banking with ailerons and pulling the nose around to a new heading with elevator. Lastly, back elevator pressure allows us to flare for landing.

We can demonstrate the validity of elevator as the turn control with more dramatic examples. How about a 360 degree turn starting with zero bank? The resulting maneuver is a vertical turn, also known as a Loop. Looping maneuvers are better left to skilled aerobatic pilots flying aerobatic airplanes.

/--- 1 ¥S

/' 360" VERTICAL TURN 0' ANGLE OF BANK AT START & FINISH

Figure 5-2: A Loop is a Vertical Turn

Thinking in terms of three dimensional space, many kinds of turns become possible. Each one is linked to movements relative to the pilot. Imagine some of the possibilities with just 30 degrees of bank to the left: We can fly a level turn by applying the correct amount of back elevator pressure. Too much back pressure initiates a climbing turn. Way too much pull starts

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a loop tilted 30 degrees from vertical. Insufficient back pressure yields a descending turn. A hefty amount of forward elevator carves an outside loop.

Figure 5-3: Various Turns Starting with 30 Degrees of Bank

None of these turns are freaks of nature. Each one is consistent with the laws of aerodynamics. We simply make use of the fact that elevator inputs curve our flight path. Some of these maneuvers may be limited by one or any combination of aircraft design, energy, andpilot skillfactors. What's available to us in a practical sense, however, should not obscure our understanding of what's theoretically possible in three dimensions: We can climb, descend, or even remain level; we can maintain a constant bank angle, or allow our bank to vary during climbs and descents-various forms of curved flight, all controlled through elevator inputs.

Forces in Turns

Forces develop any time mass is accelerated (see Chapter 2-Basic Aerodynamics). Acceleration occurs any time our airspeed OR our direction of flight changes. Since pushing and pulling on the elevator alters our flight path, and thus subjects us to acceleration (even though airspeed may be constant), it changes the forces acting on the airplane. We perceive these changes as g-load-total Lift divided by gross Weight-whenever the flight path curves.