How gyroscopic couple work in a aroplanes and ship?

Effect of the Gyroscopic Couple on an ship and Aeroplane :-

Ships and aeroplanes consist of large moment of inertia propeller and fly wheels. When aeroplane or ship takes right or left turn there occurs a rate of change of angular momentum because of change of direction of angular momentum vector. Thus a counter couple is produced when they terns.

1. When the engine or propeller of aeroplane or fly wheel of ship rotate such that the spin angular momentum vector is along the sailing direction and when the aeroplane or ship takes a left turn, then the effect of reactive gyroscopic couple will be to dip the nose (stem: for ship) and raise the tail of the aeroplane or ship.
2. When the aeroplane or ship takes a right turn under similar conditions above, the effect of reactive gyroscopic couple will be to raise the nose and dip the tail of the aeroplane or ship.

In the case of ships the fly wheel must be mounded such that the spin axis is along the length so as to maintain dynamic stability.