Title 14 - Aeronautics and Space
Volume: 1Date: 2023-01-01Original Date: 2023-01-01Title: Section 25.1517 - Rough air speed, VRA.Context:
Title 14 - Aeronautics and Space. CHAPTER I - FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION. SUBCHAPTER C - AIRCRAFT. PART 25 - AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY AIRPLANES. Subpart G - Operating Limitations and Information. - Operating Limitations.
§ 25.1517
Rough air speed, V
RA.
(a) A rough air speed, V
RA,
for use as the recommended turbulence penetration airspeed, and a rough air Mach number, M
RA
, for use as the recommended turbulence penetration Mach number, must be established. V
RA
/M
RA
must be sufficiently less than V
MO
/M
MO
to ensure that likely speed variation during rough air encounters will not cause the overspeed warning to operate too frequently.
(b) At altitudes where V
MO
is not limited by Mach number, in the absence of a rational investigation substantiating the use of other values, V
RA
must be less than V
MO
minus 35 KTAS.
(c) At altitudes where V
MO
is limited by Mach number, M
RA
may be chosen to provide an optimum margin between low and high speed buffet boundaries.
[Amdt. 25–141, 79 FR 73469, Dec. 11, 2014, as amended by FAA–2022–1355; Amdt. No. 25–146, 87 FR 75710, Dec. 9, 2022]