14 CFR · Part 25

14 CFR § 25.521

General.

(a)

Seaplanes must be designed for the water loads developed during takeoff and landing, with the seaplane in any attitude likely to occur in normal operation, and at the appropriate forward and sinking velocities under the most severe sea conditions likely to be encountered.

(b)

Unless a more rational analysis of the water loads is made, or the standards in ANC-3 are used, §§ 25.523 through 25.537 apply.

(c)

The requirements of this section and §§ 25.523 through 25.537 apply also to amphibians.

Regulations Referenced

14 CFR 25.523 14 CFR 25.537

Reflects the eCFR edition current as of September 29, 2026. Retrieved from ecfr.gov on October 16, 2026.

Primary Source

Official Source (14 CFR · Part 25)