Abstract: An air turbine starter for use aboard aircraft includes a dual range power train and a clutch automatically shifting between the ranges according to the use being experienced by the starter. Main engine starts may be achieved more quickly, while ground check out of aircraft systems using the starter to power main engine accessory devices via the engine gear box may be performed with better power input to the accessories and improved efficiency.

Abstract: An air turbine starter for use in starting a turbine engine includes a pawl and ratchet clutch having a movable member which selectively prevents engagement of the clutch while providing a pawl raceway surface, or allows clutch engagement. No-load acceleration of the air turbine starter is scheduled to ensure that drop-in speed of the centrifugally responsive pawls is not reached by the ratchet member while clutch engagement is being permitted. The movable member is pneumatically controlled in timed coordination with acceleration of the air turbine starter to prevent crash engagement of the clutch. Clutch ratcheting is also substantially prevented.

Abstract: An air turbine starter for use in starting a turbine engine includes a pawl and ratchet clutch having a movable member which selectively prevents engagement of the clutch while providing a pawl raceway surface, or allows clutch engagement. No-load acceleration of the air turbine starter is scheduled to ensure that drop-in speed of the centrifugally responsive pawls is not reached by the ratchet member while clutch engagement is being permitted. The movable member is pneumatically controlled in timed coordination with acceleration of the air turbine starter to prevent crash engagement of the clutch. Clutch ratcheting is also substantially prevented.