Bill Crawford’s Flightlab Blog

Holding top rudder in a steep turn, to keep the nose up, is usually a no-no. But it’s one of flying’s great temptations, and has a time-honored history of abuse. Top rudder means that the pilot is trying to use the side of the fuselage to generate lift. Most fuselages are not particularly efficient that way, and produce lots of drag in the process. But top rudder can be warranted. In aerobatic competition, pilots are supposed to make their turns at no less than 60-degrees of bank. Usually you rack it over a little more to make sure the judges believe you. A 70-degree-bank turn requires a 2.9-g pull if done at constant altitude and with coordinated rudder. That’s not really a problem in an aerobatic aircraft if you’re going fast enough, but at low speed you may not have the energy necessary to pull the required g. And the induced drag from that g is going to slow you down even more. In this situation, the wing needs help from the fuselage. So you add some top rudder.
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