spaschal on DSK3GDR082PROD with CFR

Federal Aviation Administration, DOT

Section 33.79

hail, as defined in appendix B to this
part. Acceptable engine operation precludes flameout, run down, continued
or non-recoverable surge or stall, or
loss of acceleration and deceleration
capability, during any three minute
continuous period in rain and during
any 30 second continuous period in
hail. It must also be shown after the
ingestion that there is no unacceptable
mechanical
damage,
unacceptable
power or thrust loss, or other adverse
engine anomalies.
(b) Engines for rotorcraft. As an alternative to the requirements specified in
paragraph (a)(2) of this section, for
rotorcraft turbine engines only, it
must be shown that each engine is capable of acceptable operation during
and after the ingestion of rain with an
overall ratio of water droplet flow to
airflow, by weight, with a uniform distribution at the inlet plane, of at least
four percent. Acceptable engine operation precludes flameout, run down,
continued or non-recoverable surge or
stall, or loss of acceleration and deceleration capability. It must also be
shown after the ingestion that there is
no unacceptable mechanical damage,
unacceptable power loss, or other adverse engine anomalies. The rain ingestion must occur under the following
static ground level conditions:
(1) A normal stabilization period at
take-off power without rain ingestion,
followed immediately by the suddenly
commencing ingestion of rain for three
minutes at takeoff power, then
(2) Continuation of the rain ingestion
during subsequent rapid deceleration
to minimum idle, then
(3) Continuation of the rain ingestion
during three minutes at minimum idle
power to be certified for flight operation, then
(4) Continuation of the rain ingestion
during subsequent rapid acceleration
to takeoff power.
(c) Engines for supersonic airplanes. In
addition to complying with paragraphs
(a)(1) and (a)(2) of this section, a separate test for supersonic airplane engines only, shall be conducted with
three hailstones ingested at supersonic
cruise velocity. These hailstones shall
be aimed at the engine-s critical face
area, and their ingestion must not
cause unacceptable mechanical damage

or unacceptable power or thrust loss
after the ingestion or require the engine to be shut down. The size of these
hailstones shall be determined from
the linear variation in diameter from 1inch (25 millimeters) at 35,000 feet
(10,500 meters) to 1-4-inch (6 millimeters) at 60,000 feet (18,000 meters) using
the diameter corresponding to the lowest expected supersonic cruise altitude.
Alternatively, three larger hailstones
may be ingested at subsonic velocities
such that the kinetic energy of these
larger hailstones is equivalent to the
applicable supersonic ingestion conditions.
(d) For an engine that incorporates
or requires the use of a protection device, demonstration of the rain and
hail ingestion capabilities of the engine, as required in paragraphs (a), (b),
and (c) of this section, may be waived
wholly or in part by the Administrator
if the applicant shows that:
(1) The subject rain and hail constituents are of a size that will not
pass through the protection device;
(2) The protection device will withstand the impact of the subject rain
and hail constituents; and
(3) The subject of rain and hail constituents, stopped by the protection device, will not obstruct the flow of induction air into the engine, resulting
in damage, power or thrust loss, or
other adverse engine anomalies in excess of what would be accepted in paragraphs (a), (b), and (c) of this section.
[Doc. No. 28652, 63 FR 14799, Mar. 26, 1998]

Section 33.79

Fuel burning thrust augmentor.

Each fuel burning thrust augmentor,
including the nozzle, must - 
(a) Provide cutoff of the fuel burning
thrust augmentor;
(b) Permit on-off cycling;
(c) Be controllable within the intended range of operation;
(d) Upon a failure or malfunction of
augmentor combustion, not cause the
engine to lose thrust other than that
provided by the augmentor; and
(e) Have controls that function compatibly with the other engine controls
and automatically shut off augmentor
fuel flow if the engine rotor speed drops
below the minimum rotational speed at

725

VerDate Sep<11>2014

12:50 Apr 30, 2019

Jkt 247046

PO 00000

Frm 00735

Fmt 8010

Sfmt 8010

Y:\SGML\247046.XXX

247046