Aircraft brake system

A method for operating an emergency brake system for an aircraft, wherein the brake system includes a modulating emergency/parking brake valve in fluid communication with a pressure source and a wheel brake, the brake valve being disposed between the pressure source and the wheel brake, the method comprising:

• operating the emergency brake system in a first stage by moving a handle of a lever assembly from a non-actuated position where the wheel brake is disengaged to an intermediate position where the handle is precluded from further movement toward a fully-actuated position until a lock mechanism, which is operatively connected with the handle, is unlocked;
• unlocking the lock mechanism;
• and
• operating the emergency brake system in a second stage by moving the brake handle from the intermediate position toward the fully-actuated position after unlocking the lock mechanism.

A lever assembly for an aircraft emergency/parking brake, comprising:

• a handle movable between a non-actuated position wherein the brake is disengaged and a fully-actuated position wherein the brake is fully engaged, the handle being freely movable from the non-actuated position to an intermediate position wherein during movement therebetween the brake applies a braking force based upon a position of the handle;
• and
• a lock mechanism operatively connected with the handle, movement of the handle from the intermediate position to the fully-actuated position being obstructed by the lock mechanism to prevent inadvertent operating of the brake in the fully-actuated position unless the lock mechanism is unlocked;
• and
• an unlocking mechanism operatively connected with the handle for unlocking the lock mechanism.