Soon after, Johanna Weber and Dietrich Küchemann at the RAE published a series of reports on a new wing planform, known in the UK as the "slender delta" concept.[8][9] The team, including Eric Maskell whose report "Flow Separation in Three Dimensions" contributed to an understanding of the physical nature of separated flow,[10] worked with the fact that delta wings can produce strong vortices on their upper surfaces at high angles of attack.[6] The vortex will lower the air pressure and cause lift to be greatly increased. This effect had been noticed earlier, notably by Chuck Yeager in the Convair XF-92, but its qualities had not been fully appreciated. Weber suggested that this was no mere curiosity, and the effect could be used deliberately to improve low speed performance.[9][6]