14 CFR §194.203

1. (a)Instructor pilots at a manufacturer. In addition to the provisions specified in § 61.3(d)(3) of this chapter, a flight instructor certificate issued under part 61 of this chapter is not necessary to conduct flight training if the training is given by an instructor pilot in a powered-lift at the manufacturer, provided the training is conducted in accordance with the manufacturer's training curriculum and is given to either—
   1. (1)A test pilot;
   2. (2)A person authorized by the Administrator to serve as an initial check pilot, chief instructor, assistant chief instructor, or training center evaluator for the purpose of initiating training in a powered-lift under an approved training program under part 135, 141, or 142 of this chapter, as appropriate; or
   3. (3)An FAA test pilot or aviation safety inspector.
2. (b)Flight instructors under part 135 of this chapter. Notwithstanding the requirement in § 61.3(d)(3)(ii) of this chapter, a person must hold a flight instructor certificate with the appropriate powered-lift ratings to conduct training in accordance with a training curriculum approved to meet the requirements of § 194.243(a)(1).