A person who holds a flight instructor certificate that has not expired may renew that flight instructor certificate by—

Passing a practical test for—

One of the ratings listed on the current flight instructor certificate; or

An additional flight instructor rating; or

Submitting a completed and signed application with the FAA and satisfactorily completing one of the following renewal requirements—

A record of training students showing that, during the preceding 24 calendar months, the flight instructor has endorsed at least 5 students for a practical test for a certificate or rating and at least 80 percent of those students passed that test on the first attempt.

A record showing that, within the preceding 24 calendar months, the flight instructor has served as a company check pilot, chief flight instructor, company check airman, or flight instructor in a part 121 or part 135 operation, or in a position involving the regular evaluation of pilots.

A graduation certificate showing that, within the preceding 3 calendar months, the person has successfully completed an approved flight instructor refresher course consisting of ground training or flight training, or a combination of both.

A record showing that, within the preceding 24 months from the month of application, the flight instructor passed an official U.S. Armed Forces military instructor pilot or pilot examiner proficiency check in an aircraft for which the military instructor already holds a rating or in an aircraft for an additional rating.

The expiration month of a renewed flight instructor certificate shall be 24 calendar months from—

The month the renewal requirements of paragraph (a) of this section are accomplished; or

The month of expiration of the current flight instructor certificate provided—

The renewal requirements of paragraph (a) of this section are accomplished within the 3 calendar months preceding the expiration month of the current flight instructor certificate, and

If the renewal is accomplished under paragraph (a)(2)(iii) of this section, the approved flight instructor refresher course must be completed within the 3 calendar months preceding the expiration month of the current flight instructor certificate.

The practical test required by paragraph (a)(1) of this section may be accomplished in a full flight simulator or flight training device if the test is accomplished pursuant to an approved course conducted by a training center certificated under part 142 of this chapter.