PLT088: Airspeed Indicator Markings
What code PLT088 covers, why the FAA tests it, and how to study Airspeed Indicator Markings before your checkride.
Interpret speed indicator readings
What this means for your checkride
The airspeed indicator's color arcs mark the airplane's operating speed ranges: the white arc is the flap operating range, the green arc the normal operating range, the yellow arc a caution range flown only in smooth air, and the red line the never-exceed speed. Each boundary is a specific V-speed drawn from the airplane's limits.
These markings turn the airplane's structural and aerodynamic limits into speeds you can read at a glance, so the FAA tests what each arc and line means and when a range may be used.
The yellow arc is not simply a faster-is-fine band. It is a caution range permitted only in smooth air; in turbulence you stay at or below the top of the green arc.
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.