Recently some data from tests done on a cambered plate have been published. The shape of metal plate aerofoil tested matched that taken up by a flexible two-dimensional sail. The most striking result in the rneasurements was the waviness present near the leading edge in the upper surface pressure distribution. To find the theoretical conditions under which such a waviness would occur a parabolic skeleton aerofoil was investigated, as this shape differed little from the actual aerofoil tested.

The problem considered is that of a circular plate which is supported along an internal concentric circle and subjected to uniform pressure over the area bounded by the support line; the outer edge of the plate is free. This form of loading and support is used in the testing of glass panels, where the rigidity of the panel is determined from a measurement of the central deflexion. However, the formula in current use does not allow for the stiffening effect of the overhanging outer annulus.

When Man first dreamt of flying, he most probably envisaged himself soaring through the air with wings on his arms, and his legs trailing behind him like a bird's. This mental picture quite likely influenced a good deal of his early aeronautical thinking and it is a curious fact that even in comparatively recent years a number of the more bizarre aircraft have incorporated a prone pilot position as if the designers, having abandoned orthodox practice, had also reverted to what perhaps seemed a more natural position.

It is shown that by combining the dependence of boundary layer heating on local flow conditions with the lifting characteristics of hypersonic wings a simple relationship between wing loading and surface temperature can be derived. This replaces the common concept of an altitude/Mach number flight corridor through which hypersonic flight appears possible without exceeding an acceptable surface temperature, and indicates that flight beyond Mach 6 will in fact require considerable material or cooling developments.

Tests at a Mach number of 1·60 show clear evidence of interference on the end tubes of a Pitot rake whose adjacent tubes touch. This effect is increased when the rake is made into a solid rectangular slab by the addition of fillets between the tubes. By making the gap between the tubes equal to one tube diameter the interference is almost eliminated.

The magnitude of the interference on the end tubes is considerably affected by the ratio of the Pitot orifice to the tube diameter; of the three values of this ratio tested the one close to unity (i.e. a sharp-edged Pitot) was found to have the least interference.