Note on the application of the linearised theory for compressible flow to transonic speeds

It is shown that for finite aspect ratio the linearised theory of compressible flow remains theoretically consistent in the region of transonic speeds, although tis predictions may deviate appreciably from experimental results in that region. The variation of the theoretical lift curve slope of an aerofoil of finite span is considered as the mach number increases from below unity to above unity, and it is shown that the lift curve slope remains finite and continuous.