14 CFR § 137.1

This part prescribes rules governing—

Agricultural aircraft operations within the United States; and

The issue of commercial and private agricultural aircraft operator certificates for those operations.

In a public emergency, a person conducting agricultural aircraft operations under this part may, to the extent necessary, deviate from the operating rules of this part for relief and welfare activities approved by an agency of the United States or of a State or local government.

Each person who, under the authority of this section, deviates from a rule of this part shall, within 10 days after the deviation send to the responsible Flight Standards office a complete report of the aircraft operation involved, including a description of the operation and the reasons for it.