AvSport of Lock Haven Precession Precision Presentation Copyright © 2015 Taming Turning Tendency Prof. H. Paul Shuch, Ph.D., CFII LSRM-A/GL/WSC/PPC, iRMT

Presentation Copyright © 2015

AvSport of Lock Haven

Precession Precision

Taming Turning Tendency

Prof. H. Paul Shuch, Ph.D., CFII LSRM-A/GL/WSC/PPC, iRMT Heavy

Chief Flight Instructor, Director of MaintenanceAvSport of Lock Haven

FAA Safety Team Lead Representative Piper Memorial Airport, Lock Haven PA




A FAASTeam Wings Safety Seminar




• Sentimental Journey to Cub Haven• Piper Memorial Airport• AvSport of Lock Haven • Your FAA Safety Team

Brought to you by:




RATIONALE:Many pilots report (especially when flying Light

Sport Aircraft) that raising the nose causes the plane to yaw in one direction, and lowering it yaws them in the opposite direction. This gives LSAs a reputation for being instable (or squirrely). In fact, these aircraft are merely obeying natural laws. In this FAA Wings Safety Seminar, a retired physics professor will teach you how to anticipate, detect, and conquer gyroscopic precession.




OBJECTIVES:Upon successful completion of this seminar, you will:

• Visualize Cartesian coordinates• Predict precession effects• Anticipate aircraft yaw response• Respond with decisive rudder• Overcome lateral instability• Avoid hitting the runway lights




Caveat:• The procedures shown here are used successfully by one

particular instructor, in one particular category and class of aircraft. They may not apply in your situation. Your mileage may vary.

Disclaimer:• Nothing in this presentation should be considered a substitute for

adequate dual training, conducted by an appropriately rated flight instructor familiar with your particular aircraft.

Waiver:• By viewing this presentation, you understand and agree that:

– Flying is a sport– There is risk associated with all sports– You accept that risk




Getting to know you…




Which of the following are you?(choose one that best describes you)

• Student Pilot• Sport Pilot• Private Pilot• Commercial Pilot / ATP• Flight Instructor




Introduction:

The Axis of Evil




Pitch, Roll, and Yaw Axes:




Rene Descartes(French mathematician and philosopher,

1596-1650)




CARTESIANCOORDINATES




Mutually Orthogonal








Quiz Time!




For purposes of this course, we will consider the direction in which the aircraft is traveling

to be:

• The X-axis• The Y-axis• The Z-axis• Any axis we choose• None of the above




PRINCIPLES OF THE GYROSCOPE







PRECESSION

(Z) (X)

(Y)




PRECESSION

(Z)

(X) (Y)




PRECESSION




PRECESSION




Another Question!




If the aircraft is traveling down the runway (into the page), and you raise or lower the

nose, the plane will precess in:

• The X-axis• The Y-axis• The Z-axis• All three axes• None of the above








FOUR DEGREES

OF FREEDOM




AILERONS CONTROL ROLL(your bank control)




RUDDER CONTROLS YAW(your directional control)




ELEVATOR CONTROLS PITCH(your airspeed control)




THROTTLE CONTROLS POWER(your altitude control)




Sometimes, you just gotta dance!




Doh!




Gyroscopic precession is best corrected through application of

• elevator• rudder• ailerons• throttle• flaps




IF SOMETHING ROTATES,

IT CAN PRECESS

























I know this one!




Gyroscopic precession is least evident in a(n)

• Airplane• Gyroplane• Powered parachute• Glider• Equally evident in all




TAKEOFFAND LANDINGARE TRICKIEST
















Final Question!




Gyroscopic precession can be observed during:

• Rotation• Flare• Go-around• Power-on stalls• Any of the above




A Final Thought

Which way will you precess? It depends…

Is the engine direct drive, or geared?






















EAA.ORG/WEBINARS

Documents

AvSport of Lock Haven Precession Precision Presentation Copyright © 2015 Taming Turning Tendency Prof. H. Paul Shuch, Ph.D., CFII LSRM-A/GL/WSC/PPC, iRMT