Section 137.11 - Certificate required(a) Except as provided in paragraphs (c) and (d) of this section, no person may conduct agricultural aircraft operations without, or in violation of, an agricultural aircraft operator certificate issued under this part.(b) Notwithstanding part 133 of this chapter, an operator may, if he complies with this part, conduct agricultural aircraft operations with a rotorcraft with external dispensing equipment in place without a rotorcraft external-load operator certificate.(c) A Federal, State, or local government conducting agricultural aircraft operations with public aircraft need not comply with this subpart.(d) The holder of a rotorcraft external-load operator certificate under part 133 of this chapter conducting an agricultural aircraft operation, involving only the dispensing of water on forest fires by rotorcraft external-load means, need not comply with this subpart.Doc. No. 1464, 30 FR 8106, June 24, 1965, as amended by Amdt. 137-3, 33 FR 9601, July 2, 1968; Amdt. 137-6, 41 FR 35060, Aug. 19, 1976