Sometimes the concepts of “uncoordinated flight” and “cross-controlled flight” can be very confusing to students. The normal first response of a student when asked to explain the concept of “cross-controlled” is negative. The student tends to think of “cross-controlled” as a bad thing to do. So let’s first define each term. “Uncoordinated flight” is defined as flight where the yaw string is not straight. Anytime the yaw string is not straight induced drag increases. “Cross-controlled flight” is defined as flight where the stick has been moved to one side and the opposite rudder is being used. As instructors we need to get across to students that these two terms are NOT synonymous. That is, uncoordinated flight may or may not be cross-controlled flight and cross-controlled flight may or may not be uncoordinated flight. Also, uncoordinated flight might be a good technique to be used in certain situations or it might be a very bad maneuver in another. And believe it or not the same can be said concerning cross-controlled flight. Now I bet I’ve really confused some of you. Let’s look at some examples to try to understand.
1. Uncoordinated and cross-controlled
A slip is an uncoordinated maneuver that is also a cross-controlled. If the maneuver is deliberate such as when trying to lose altitude without gaining airspeed it would be a good maneuver and certainly the “right” thing to do. Or one might be doing a sideslip to offset a crosswind. Again this would be the correct thing to do under those circumstances.
2. Uncoordinated and not cross-controlled
As we all learned very quickly when we first started flying, uncoordinated flight can occur without being cross-controlled. It can occur when both the stick and rudder are being applied in the same direction but the amount of rudder is not the right amount for the amount of bank. This type of non-intentional uncoordinated flight is certainly not good and with practice can be avoided. A skid is uncoordinated but not cross-controlled and as we discussed in the last article it is one of the worst and most dangerous things a pilot can do.
3. Not uncoordinated (Hey that’s coordinated) and cross-controlled
Now let’s look at a steep turn. To initiate the turn one would use both stick and rudder in the direction of the turn. But then to establish the turn one would move the stick back to the opposite side (top side or high side) and yet still have some rudder in the direction of the turn (bottom foot or low wing). In this case one is indeed coordinated and yet cross-controlled and it is the correct thing to be doing. Hence, cross-controlled can be the appropriate maneuver to stay coordinated.
4. Not uncoordinated (once again coordinated) and not cross-controlled
This sound like normal flight and indeed it is. For the vast majority of our flying this is how we want to fly.
In summary, neither “uncoordinated” nor “cross-controlled” flight is in and of itself wrong. There are situations where each is indeed the correct thing to do. The student simply must be taught when each or both are appropriate.
Fly Safely and HAVE FUN!