§27.175. Demonstration of static longitudinal stability.
14 C.F.R. § 27.175
Climb. Static longitudinal stability must be shown in the climb condition at speeds from Vy − 10 kt to Vy + 10 kt with—
Critical weight;
Critical center of gravity;
Maximum continuous power;
The landing gear retracted; and
The rotorcraft trimmed at VY.
Cruise. Static longitudinal stability must be shown in the cruise condition at speeds from 0.8 VNE − 10 kt to 0.8 VNE + 10 kt or, if VH is less than 0.8 VNE, from VH −10 kt to VH + 10 kt, with—
Critical weight;
Critical center of gravity;
Power for level flight at 0.8 VNE or VH, whichever is less;
The landing gear retracted; and
The rotorcraft trimmed at 0.8 VNE or VH, whichever is less.
V— NE. Static longitudinal stability must be shown at speeds from VNE − 20 kt to VNE with—
Critical weight;
Critical center of gravity;
Power required for level flight at VNE −10 kt or maximum continuous power, whichever is less;
The landing gear retracted; and
The rotorcraft trimmed at V<I>NE</I> − 10 kt.
Autorotation. Static longitudinal stability must be shown in autorotation at—
Airspeeds from the minimum rate of descent airspeed−10 kt to the minimum rate of descent airspeed + 10 kt, with—
Critical weight;
Critical center of gravity;
The landing gear extended; and
The rotorcraft trimmed at the minimum rate of descent airspeed.
Airspeeds from best angle-of-glide airspeed−10 kt to the best angle-of-glide airspeed + 10 kt, with—
Critical weight;
Critical center of gravity;
The landing gear retracted; and
The rotorcraft trimmed at the best angle-of-glide airspeed.
Notes, amendments, and revision history
Amendments
[Doc. No. 5074, 29 FR 15695, Nov. 24, 1964, as amended by Amdt. 27-2, 33 FR 963, Jan. 26, 1968; Amdt. 27-11, 41 FR 55468, Dec. 20, 1976; Amdt. 27-14, 43 FR 2325, Jan. 16, 1978; Amdt. 27-21, 49 FR 44433, Nov. 6, 1984; Amdt. 27-34, 62 FR 46173, Aug. 29, 1997; Amdt. 27-44, 73 FR 10999, Feb. 29, 2008]
Authority
Authority: 49 U.S.C. 106(f), 106(g), 40113, 44701-44702, 44704.
Source
Source: Docket No. 5074, 29 FR 15695, Nov. 24, 1964, unless otherwise noted.
Amendments
[Doc. No. 5074, 29 FR 15695, Nov. 24, 1964, as amended by Amdt. 27-2, 33 FR 963, Jan. 26, 1968; Amdt. 27-11, 41 FR 55468, Dec. 20, 1976; Amdt. 27-14, 43 FR 2325, Jan. 16, 1978; Amdt. 27-21, 49 FR 44433, Nov. 6, 1984; Amdt. 27-34, 62 FR 46173, Aug. 29, 1997; Amdt. 27-44, 73 FR 10999, Feb. 29, 2008]