Lanchester was undoubtedly a great British engineer. He died just 47 years ago, at which time the name Lanchester could be seen on the front of some motor cars, but many knew little about the great contributions that Frederick William Lanchester had made to both mechanical and aeronautical engineering.

Whether Lanchester was interested in automobile aerodynamics or not, the subject combines two of his great loves. He designed and built petrol-engined cars, and his 1898 machine won the RAC’s Gold Medal (Fig. 1). As might have been expected, the drag coefficient of this vehicle is not recorded.

The planar vortex lattice method is extended to the case of wings in small-amplitude oscillations in ideal flow. Vortex rings are used to represent the bound vorticity on the wing and the trailing vorticity in the wake. A modified procedure for solving the unknown vortex strengths gives greater computing efficiency. Comparisons with results reported in the literature show good agreement for the various test cases considered. Convergence with increasing lattice density is uniform.

A simplified trailing vortex concept has been used to model unsteady aerodynamic effects onto the mathematical model for an augmented unstable aircraft. An output error method with, and without, an equation decoupling technique in the frequency domain has been used for the estimation of parameters. The two approaches of estimation are compared for the cases where unsteady effects are included or excluded from the estimation model. It is shown that the incorporation of the equation decoupling technique makes the estimation algorithm robust with respect to initial guess values of the parameters. Finally, the inclusion of unsteady aerodynamics is shown to reduce the variation in the parameter estimates due to different control input forms.

The theory behind Foa’s rotary jet-thrust augmentor dates back to 1955, but there is a fundamental fallacy in it, which is proved by this note. When corrected, the augmentation value equals that of the static-jet augmentor.

The principles and theory of the jet-fan thrust augmentor are outlined. Thrust augmentation ratios of these will be around three times those of static-jet augmentors.