Measurement of the moments and product of inertia of the Fairey Delta 2 aircraft

Abstract

The moments and product of inertia of the Fairey Delta 2 aircraft have been measured using the method of spring restrained oscillations. The moment of inertia results were satisfactory, but difficulty was found in determining the product of inertia due to unsatisfactory design of the single point suspension rig. A dependence of roll period on roll amplitude was discovered and this may be due to some form of ground effect. The damping in roll was found to vary with fuel state. The agreement between the manufacturer's estimates and the measured moments and product of inertia was poor, and there is clearly a continuing need for inertia measurements. Simple estimates of the fuel inertias compared well with the measured values, agreement being within the expected accuracy of the measurements. The fuel load of the Fairey Delta 2 is relatively small, and simple estimates for greater loads might be less satisfactory.