PLT314: The Longitudinal Axis and Roll
What code PLT314 covers, why the FAA tests it, and how to study The Longitudinal Axis and Roll before your checkride.
Recall longitudinal axis - aerodynamics / center of gravity / direction of motion
What this means for your checkride
The longitudinal axis runs nose to tail. The airplane rolls about it, controlled by the ailerons, and its stability about this axis is called lateral, or roll, stability. Dihedral and wing placement are the main design features that provide it.
Knowing the three axes and which control and stability go with each is foundational, so the FAA tests the longitudinal axis, its control (ailerons), and its stability (lateral).
Motion about the longitudinal axis is roll, controlled by the ailerons. Do not confuse it with the lateral axis (pitch) or the vertical axis (yaw).
Where to study it
A code on your test report is an area of deficiency. An authorized instructor must review it with you and endorse that review before you take the practical test, and the examiner may revisit it during the oral. Study it until you can explain it out loud, not just recognize the answer.