Previously, I discussed the fact that all aspects of a circuit rely upon the accuracy of the section before. If you fly your base turn different each time then, not only will you not learn from circuit to circuit, but your flying will appear (and be!) haphazard and reactionary.
Tied in with this phenomenon, is a fundamental aspect to flying that many students seem unwilling to accept and take into consideration – wind. Its effects are felt in every area of aviation and a little bit of planning and preparation with regards to wind will make your flying all the more accurate and therefore enjoyable.
Consider the following events. On the way to your circuit lesson the radio tells of an early sea breeze and you notice the smoke from the local cement factory blowing nearly horizontal. Take note! File this information away and compare it to the TAF or METAR received during your flight preparation before you walk out the aircraft. In early training days, take the time to look at the wind direction and strength and picture it in relation to the runway. Even better, get a pencil and paper and draw the wind vector on a runway diagram. Now you have drawn it on paper, think about what it means to you and your aeroplane for the flight.
For example: a wind of 15 knots may not seem like much on the ground but in the circuit it will change many aspects to how you fly the aircraft. So what do I think about if faced with this scenario? I remember the radio telling me about the sea breeze. I note that it has already begun: the wind is not the gusty, bumpy morning easterly off the hills but the steady sea breeze, likely to stay around for the afternoon. I look at the runway direction and compare it to the wind. In a very basic way, will I be blown into or out of the circuit while on downwind? From this, I can determine the initial angles of bank I will set on crosswind and on base, and the drift correction I will apply on downwind in order to fly the correct ground track throughout the circuit.
Each aircraft type has basic rules of thumb that guide the young pilot for angles of bank and drift. For example, your aircraft may need an extra five degrees of bank on base for each 10 kts of crosswind. Apply these to the wind of the day, and write them down so you won’t forget once in the aircraft. What else is affected by wind? Power to set on the base turn. If a crosswind is blowing you into the circuit, angle of bank required on base will be higher, track miles flown around the corner will be less and, consequently, less power is required. Again, apply the rules of thumb and write it down. This way, a picture is built in your mind (and on your self-briefing sheet) of what the first circuit is going to look like.
By doing this simple exercise you are not only mentally preparing yourself for the flight, but are also giving yourself the best chance at learning from the moment you get airborne. If you had simple ignored all the clues about the wind and had not thought about its effects, the first circuit is a circuit of discovery. Discovering the crosswind angle of bank is not working, the uncorrected downwind heading does not hold the circuit spacing, and the base turn simply drives you through the centerline. Instead, make the first circuit a circuit of confirmation – confirming that your preparation was spot on. So, love it or hate, wind can help or hinder your flying. Get my drift?