How long does a pilot have to wait for a letter of revocation before their temporary certificate expires?

The correct understanding is that a pilot must wait for the arrival of the letter of revocation to understand the status of their temporary certificate. When the FAA issues a temporary certificate, it is typically valid until a permanent certificate is issued or until a letter of denial or revocation is sent. If a pilot has been issued a temporary certificate, the effective status is contingent upon receiving communication from the FAA regarding any issues that could revoke or deny the certificate. Therefore, the pilot does not have a fixed time limit to wait, but rather it is essential for them to remain vigilant until they receive the official correspondence regarding their certificate's status. This approach ensures that the pilot is aware of any potential actions that may necessitate their compliance with regulatory procedures.