MULTI-MODAL GAS-TURBINE STARTER AVAILABILITY

An example system includes a first gas-turbine engine configured to propel an aircraft, the first gas-turbine engine comprising: a first air-turbine starter, the first air-turbine starter configured to rotate a spool of the first gas-turbine engine; and a first electric starter, the first electric starter configured to rotate the spool of the first gas-turbine engine; and one or more controllers collectively configured to: cause, during a time period, the first-air turbine starter and the first electric starter to start the first gas-turbine engine while the aircraft is on the ground; measure, during the time period, values of one or more parameters of the first gas-turbine engine; and determine, based on the values of the one or more parameters, whether the first electric starter is available for use in performing mid-air restart of the first gas-turbine engine.