How long is a student pilot endorsement valid for that allows solo flight in a specific make and model?

A student pilot endorsement for solo flight in a specific make and model is valid for 90 days. This time frame is set to ensure that the endorsement remains current and that the student pilot maintains proficiency in operating the aircraft.

The requirement for a 90-day endorsement helps promote safety by ensuring that the student pilot has more recent training and experience in the specific aircraft they will be flying solo. After this period, a new endorsement is necessary to confirm the student's capability and readiness for solo flight.

In contrast, the other options do not align with the regulations governing student pilot endorsements. An endorsement valid for 30 days would not provide enough time for students who may need ongoing practice and proficiency. An endorsement until the flight review is completed does not describe the conditions for solo flight endorsements, as the flight review is a separate requirement. An indefinite endorsement until revoked does not ensure regular currency checks and does not reflect the necessary oversight mandated by regulations.