 However, with the performance of aircraft increasing considerably during the 1930s, the practice of applying painted markings onto the (then manually powered) control surfaces was discontinued because of the need to rebalance the controls – failure to do this could have adverse effects on the surface's aerodynamic balance, possibly leading to flutter of the control surface at high airspeeds.It was for this same reason that the positioning of the wing roundels was revised so that they no longer overlapped the ailerons.In an attempt to conform to the appearance of French military aircraft, rudder stripes reappeared on aircraft (mainly Fairey Battles and Hawker Hurricanes) of the RAF based in France, starting in early September 1939.