Airspeed Limitations

This is the one chapter of the manual whose contents are approved, and it opens with the speeds. Everything here is a limit rather than a recommendation — the chapter states that operating the aeroplane outside its approved limitations is not permissible, and the airspeeds are where that bites first.

At a glance

• v_O (up to 1080 kg / 2381 lb)101 KIAS
• v_O (above 1080 kg to 1180 kg / 2601 lb)108 KIAS
• v_O (above 1180 kg)113 KIAS
• v_FE (flaps LDG)98 KIAS
• v_FE (flaps T/O)110 KIAS
• v_NO130 KIAS
• v_NE172 KIAS

WARNING — Operating the airplane outside the approved operating limitations is not permissible.

What this chapter covers

Chapter 2 holds the operating limitations, instrument markings and placards needed for safe operation of the aeroplane, its powerplant, its standard systems and its standard equipment — and the limitations it contains are approved.

Manoeuvring speed rises with mass

There is no single v_O. Three mass bands each carry their own figure: at or below 1080 kg (2381 lb) it is 101 KIAS; from there up to 1180 kg (2601 lb) it is 108 KIAS; heavier than that it is 113 KIAS. Past v_O, no control surface may be moved fully or abruptly.

The direction of that relationship is worth fixing: the heavier the aeroplane, the higher the manoeuvring speed. A pilot who remembers a single v_O will be using the light-aeroplane figure at heavy mass, which is conservative, or the heavy figure when light, which is not.

Flap speeds

v_FE is scoped to the flap setting. With flaps at LDG the limit is 98 KIAS; with flaps at T/O it is 110 KIAS. The take-off setting carries the higher limit by 12 knots.

The two top-end speeds

At 130 KIAS sits v_NO, the maximum structural cruising speed — a figure the airspeed table sets equal to the design cruising speed v_C. Smooth air is the only condition under which it may be passed, and even then only with caution. v_NE is 172 KIAS, the never-exceed speed in smooth air, and it must not be exceeded in any operation.

Forty-two knots separate the two, and they behave differently: one has a conditional door in it, the other has none.

Check yourself

• What is v_O at 1000 kg, at 1150 kg and at 1250 kg?

• Which flap setting has the higher v_FE, and what are the two figures?

• What is v_NO, and under what condition may it be exceeded?

• What is v_NE, and under what condition may it be exceeded?

• What does the manual say about operating outside the approved limitations?

Study aid — always fly your aircraft's current AFM/POH.