PLT125: Climb Performance
What code PLT125 covers, why the FAA tests it, and how to study Climb Performance before your checkride.
Recall aircraft performance - climb / descent
What this means for your checkride
Climb performance comes from excess power and thrust. Best angle of climb speed gives the most altitude gained per unit of horizontal distance, for clearing an obstacle; best rate of climb speed gives the most altitude gained per unit of time. Both change with altitude and converge at the absolute ceiling.
Choosing the right climb speed affects obstacle clearance and time to altitude, so the FAA tests the difference between best angle and best rate of climb and how climb rate falls with density altitude.
Best angle and best rate of climb are not interchangeable. Using best rate off a short, obstructed runway can trade away the obstacle-clearance angle you needed.
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.