---
kind: "range"
citation: "14 C.F.R. §§ 27.337–27.341"
title: "14"
from: "27.337"
to: "27.341"
count: 3
url: "https://uscodex.org/cfr/14/27.337..27.341"
---

# §27.337. Limit maneuvering load factor.


The rotorcraft must be designed for—

- (a) A limit maneuvering load factor ranging from a positive limit of 3.5 to a negative limit of −1.0; or
- (b) Any positive limit maneuvering load factor not less than 2.0 and any negative limit maneuvering load factor of not less than −0.5 for which—
  - (1) The probability of being exceeded is shown by analysis and flight tests to be extremely remote; and
  - (2) The selected values are appropriate to each weight condition between the design maximum and design minimum weights.

# §27.339. Resultant limit maneuvering loads.


The loads resulting from the application of limit maneuvering load factors are assumed to act at the center of each rotor hub and at each auxiliary lifting surface, and to act in directions, and with distributions of load among the rotors and auxiliary lifting surfaces, so as to represent each critical maneuvering condition, including power-on and power-off flight with the maximum design rotor tip speed ratio. The rotor tip speed ratio is the ratio of the rotorcraft flight velocity component in the plane of the rotor disc to the rotational tip speed of the rotor blades, and is expressed as follows:


# §27.341. Gust loads.


The rotorcraft must be designed to withstand, at each critical airspeed including hovering, the loads resulting from a vertical gust of 30 feet per second.