Week 7 Period: The circuit

A rectangle flown at a fixed angle of attack, and why the airspeed indicator is the wrong instrument to fly an approach on

5 April 2027

Before you arrive#

Your specific energy figures from week 4, for each corner of the circuit. You will fly against your own arithmetic today.

In this period#

The circuit is a rectangle: upwind, crosswind, downwind, base, final. It lets an approach be flown from a known geometry rather than improvised, and it is the most repetitive part of the course — flown until it is boring, then past that.

The substantive content is on final, and concerns which instrument you are looking at:

• the speed that keeps a wing flying changes with weight, fuel burned and turn rate
• the angle at which the wing stops flying does not change

For that reason final is flown on angle of attack — on an indexer showing three lights, of which you want the middle one — and the resulting airspeed is a consequence you do not have to compute.

Students find this uncomfortable, because the airspeed indicator reads a number that feels like information. By week 8 it is not looked at on final at all.

Afterwards#

Fly six circuits in a booked slot with the airspeed indicator covered. Note what your airspeed turned out to be on each one, and how little it varied.