(a) The oil system for components of the rotor drive system that
require continuous lubrication must be sufficiently independent of the
lubrication systems of the engine(s) to ensure --
(1) Operation with any engine inoperative; and
(2) Safe autorotation.
(b) Pressure lubrication systems for transmissions and gearboxes must
comply with the requirements of §§29.1013, paragraphs (c), (d), and (f)
only, 29.1015, 29.1017, 29.1021, 29.1023, and 29.1337(d). In addition, the
system must have --
(1) An oil strainer or filter through which all the lubricant flows,
and must --
(i) Be designed to remove from the lubricant any contaminant which may
damage transmission and drive system components or impede the flow of
lubricant to a hazardous degree; and
(ii) Be equipped with a bypass constructed and installed so that --
(A) The lubricant will flow at the normal rate through the rest of the
system with the strainer or filter completely blocked; and
(B) The release of collected contaminants is minimized by appropriate
location of the bypass to ensure that collected contaminants are not in
the bypass flowpath;
(iii) Be equipped with a means to indicate collection of contaminants
on the filter or strainer at or before opening of the bypass;
(2) For each lubricant tank or sump outlet supplying lubrication to
rotor drive systems and rotor drive system components, a screen to prevent
entrance into the lubrication system of any object that might obstruct the
flow of lubricant from the outlet to the filter required by paragraph
(b)(1) of this section. The requirements of paragraph (b)(1) of this
section do not apply to screens installed at lubricant tank or sump
outlets.
(c) Splash type lubrication systems for rotor drive system gearboxes
must comply with §§29.1021 and 29.1337(d).