14 CFR §141.37

1. (a)To be designated as a check instructor for conducting student stage checks, end-of-course tests, and instructor proficiency checks under this part, a person must meet the eligibility requirements of this section:
   1. (1)For checks and tests that relate to either flight or ground training, the person must pass a test, given by the chief instructor, on—
      1. (i)Teaching methods;
      2. (ii)Applicable provisions of the “Aeronautical Information Manual”;
      3. (iii)Applicable provisions of parts 61, 91, and 141 of this chapter; and
      4. (iv)The objectives and course completion standards of the approved training course for the designation sought.
   2. (2)For checks and tests that relate to a flight training course, the person must—
      1. (i)Meet the requirements in paragraph (a)(1) of this section;
      2. (ii)Hold a commercial pilot certificate or an airline transport pilot certificate and, except for a check instructor for a course of training for a lighter-than-air rating, a current flight instructor certificate. The certificates must contain the appropriate aircraft category, class, and instrument ratings for the category and class of aircraft used in the course;
      3. (iii)Meet the pilot-in-command recent flight experience requirements of § 61.57 of this chapter; and
      4. (iv)Pass a proficiency test, given by the chief instructor or assistant chief instructor, on the flight procedures and maneuvers of the approved training course for the designation sought.
   3. (3)For checks and tests that relate to ground training, the person must—
      1. (i)Meet the requirements in paragraph (a)(1) of this section;
      2. (ii)Except for a course of training for a lighter-than-air rating, hold either a current flight instructor certificate with the appropriate category and class of aircraft, or ground instructor certificate with appropriate ratings, to be used in the course of training; and
      3. (iii)For a course of training for a lighter-than-air rating, hold a commercial pilot certificate with a lighter-than-air category rating and the appropriate class rating.
2. (b)A person who meets the eligibility requirements in paragraph (a) of this section must:
   1. (1)Be designated, in writing, by the chief instructor to conduct student stage checks, end-of-course tests, and instructor proficiency checks; and
   2. (2)Be approved by the responsible Flight Standards office for the school.
3. (c)A check instructor may not conduct a stage check or an end-of-course test of any student for whom the check instructor has:
   1. (1)Served as the principal instructor; or
   2. (2)Recommended for a stage check or end-of-course test.