Abstract:

The time delay of the pitot static tube causing high altitude oscillation in an altitude hold system of a fighter has been revealed. The variation of the kinematic viscosity coefficient and the static pressure time delay of the pitot static tube associated with this coefficient has been investigated throughout flight envelope. The characteristic parameters of a phase lead corrective network as well as an engineering design method to compensate the tube delay using this network have been proposed. This method that successfully solved the key technique was demonstrated by flight test.

Key words: altitude hold sy st em, high-alt itude oscillatio n, kinemat ic-v iscosity co efficient, pito t-stat ic t ubedelay, phase-lead compensatio n