(a) The powerplant and auxiliary power unit cooling provisions must be
able to maintain the temperatures of powerplant components, engine fluids,
and auxiliary power unit components and fluids within the temperature
limits established for these components and fluids, under ground, water,
and flight operating conditions for which certification is requested, and
after normal engine or auxiliary power unit shutdown, or both.
(b) There must be cooling provisions to maintain the fluid temperatures
in any power transmission within safe values under any critical surface
(ground or water) and flight operating conditions.
(c) Except for ground-use-only auxiliary power units, compliance with
paragraphs (a) and (b) of this section must be shown by flight tests in
which the temperatures of selected powerplant component and auxiliary
power unit component, engine, and transmission fluids are obtained under
the conditions prescribed in those paragraphs.