The dynamic analysis of the journal bearing which supports the planets of an epicyclic gear stage is described. The analysis includes an assessment of the damping characteristics of the bearing, the stability, and the response of the planet to gear mesh interactions between the sun, the planet, and the ring gear. A digital program was developed which provides the numerical solution of the equations of motion by forward integration in time. The full nonlinear expressions have been used for both the hydrodynamic bearing forces and the gear mesh interaction forces. Centrifugal and Coriolis effects due to the planetary motion are taken into account. Numerical results for a PT6 reduction gearbox indicate that the bearing is highly stable and not adversely affected by gear mesh excitations.