spaschal on DSK3GDR082PROD with CFR

Section 33.29

14 CFR Ch. I (1-1-19 Edition)

demonstrate by test or other acceptable means that the overspeed function
remains available between inspection
and maintenance periods.
(g) Software. The applicant must design, implement, and verify all associated software to minimize the existence of errors by using a method, approved by the FAA, consistent with the
criticality of the performed functions.
(h) Aircraft-supplied data. Single failures leading to loss, interruption or
corruption of aircraft-supplied data
(other than thrust or power command
signals from the aircraft), or data
shared between engines must:
(1) Not result in a hazardous engine
effect for any engine; and
(2) Be detected and accommodated.
The accommodation strategy must not
result in an unacceptable change in
thrust or power or an unacceptable
change in engine operating and starting characteristics. The applicant must
evaluate and document in the engine
installation instructions the effects of
these failures on engine power or
thrust, engine operability, and starting
characteristics throughout the flight
envelope.
(i) Aircraft-supplied electrical power. (1)
The applicant must design the engine
control system so that the loss, malfunction, or interruption of electrical
power supplied from the aircraft to the
engine control system will not result
in any of the following:
(i) A hazardous engine effect, or
(ii) The unacceptable transmission of
erroneous data.
(2) When an engine dedicated power
source is required for compliance with
paragraph (i)(1) of this section, its capacity should provide sufficient margin
to account for engine operation below
idle where the engine control system is
designed and expected to recover engine operation automatically.
(3) The applicant must identify and
declare the need for, and the characteristics of, any electrical power supplied
from the aircraft to the engine control
system for starting and operating the
engine, including transient and steady
state voltage limits, in the engine instructions for installation.
(4) Low voltage transients outside
the power supply voltage limitations
declared in paragraph (i)(3) of this sec-

tion must meet the requirements of
paragraph (i)(1) of this section. The engine control system must be capable of
resuming normal operation when aircraft-supplied power returns to within
the declared limits.
(j) Air pressure signal. The applicant
must consider the effects of blockage
or leakage of the signal lines on the engine control system as part of the System Safety Assessment of paragraph
(e) of this section and must adopt the
appropriate design precautions.
(k) Automatic availability and control
of engine power for 30-second OEI rating.
Rotorcraft engines having a 30-second
OEI rating must incorporate a means,
or a provision for a means, for automatic availability and automatic control of the 30-second OEI power within
its operating limitations.
(l) Engine shut down means. Means
must be provided for shutting down the
engine rapidly.
(m) Programmable logic devices. The
development of programmable logic devices using digital logic or other complex design technologies must provide
a level of assurance for the encoded
logic commensurate with the hazard
associated with the failure or malfunction of the systems in which the devices are located. The applicant must
provide evidence that the development
of these devices has been done by using
a method, approved by the FAA, that is
consistent with the criticality of the
performed function.
[Amdt. 33-26, 73 FR 48284, Aug. 19, 2008]

Section 33.29

Instrument connection.

(a) Unless it is constructed to prevent its connection to an incorrect instrument, each connection provided for
powerplant instruments required by
aircraft airworthiness regulations or
necessary to insure operation of the engine in compliance with any engine
limitation must be marked to identify
it with its corresponding instrument.
(b) A connection must be provided on
each turbojet engine for an indicator
system to indicate rotor system unbalance.
(c) Each rotorcraft turbine engine
having a 30-second OEI rating and a 2minute OEI rating must have a means
or a provision for a means to:

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