spaschal on DSK3GDR082PROD with CFR

Federal Aviation Administration, DOT

Section 29.927

minute OEI torque and the maximum
speed for use with 30-minute OEI
torque must be conducted as follows:
For each engine, in sequence, that engine must be inoperative and the remaining engines must be run for a 30minute period.
(2) Continuous OEI power run. For
rotorcraft for which the use of continuous OEI power is requested, a run at
continuous OEI torque and the maximum speed for use with continuous
OEI torque must be conducted as follows: For each engine, in sequence,
that engine must be inoperative and
the remaining engines must be run for
1 hour.
(3) The number of periods prescribed
in paragraph (k)(1) or (k)(2) of this section may not be less than the number
of engines, nor may it be less than two.
(l) [Reserved]
(m) Any components that are affected by maneuvering and gust loads
must be investigated for the same
flight conditions as are the main rotors, and their service lives must be determined by fatigue tests or by other
acceptable methods. In addition, a
level of safety equal to that of the
main rotors must be provided for - 
(1) Each component in the rotor drive
system whose failure would cause an
uncontrolled landing;
(2) Each component essential to the
phasing of rotors on multirotor rotorcraft, or that furnishes a driving link
for the essential control of rotors in
autorotation; and
(3) Each component common to two
or more engines on multiengine rotorcraft.
(n) Special tests. Each rotor drive system designed to operate at two or more
gear ratios must be subjected to special
testing for durations necessary to substantiate the safety of the rotor drive
system.
(o) Each part tested as prescribed in
this section must be in a serviceable
condition at the end of the tests. No intervening disassembly which might affect test results may be conducted.
(p) Endurance tests; operating lubricants. To be approved for use in rotor
drive and control systems, lubricants
must meet the specifications of lubricants used during the tests prescribed
by this section. Additional or alternate

lubricants may be qualified by equivalent testing or by comparative analysis
of lubricant specifications and rotor
drive and control system characteristics. In addition - 
(1) At least three 10-hour cycles required by this section must be conducted with transmission and gearbox
lubricant temperatures, at the location
prescribed for measurement, not lower
than the maximum operating temperature for which approval is requested;
(2) For pressure lubricated systems,
at least three 10-hour cycles required
by this section must be conducted with
the lubricant pressure, at the location
prescribed for measurement, not higher
than the minimum operating pressure
for which approval is requested; and
(3) The test conditions of paragraphs
(p)(1) and (p)(2) of this section must be
applied simultaneously and must be extended to include operation at any oneengine-inoperative rating for which approval is requested.
(Secs. 313(a), 601, 603, 604, Federal Aviation
Act of 1958 (49 U.S.C. 1354(a), 1421, 1423, 1424),
sec. 6(c), Dept. of Transportation Act (49
U.S.C. 1655(c)))
[Doc. No. 5084, 29 FR 16150, Dec. 3, 1964, as
amended by Amdt. 29-1, 30 FR 8778, July 13,
1965; Amdt. 29-17, 43 FR 50600, Oct. 30, 1978;
Amdt. 29-26, 53 FR 34215, Sept. 2, 1988; Amdt.
29-31, 55 FR 38967, Sept. 21, 1990; Amdt. 29-34,
59 FR 47768, Sept. 16, 1994; Amdt. 29-40, 61 FR
21908, May 10, 1996; Amdt. 29-42, 63 FR 43285,
Aug. 12, 1998]

Section 29.927

Additional tests.

(a) Any additional dynamic, endurance, and operational tests, and vibratory investigations necessary to determine that the rotor drive mechanism is
safe, must be performed.
(b) If turbine engine torque output to
the transmission can exceed the highest engine or transmission torque
limit, and that output is not directly
controlled by the pilot under normal
operating conditions (such as where
the primary engine power control is accomplished through the flight control),
the following test must be made:
(1) Under conditions associated with
all engines operating, make 200 applications, for 10 seconds each, of torque
that is at least equal to the lesser of - 
(i) The maximum torque used in
meeting Section 29.923 plus 10 percent; or

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