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449

Federal Aviation Administration, DOT

Pt. 25, App. K

the applicant identifies compensating fac-
tors that are acceptable to the FAA. The
compensating factors may include experi-
ence on another airplane, but experience on
the candidate airplane must make up a sig-
nificant portion of the total service experi-
ence.

(b)

In-flight shutdown (IFSD) rates.

The

demonstrated 12-month rolling average IFSD
rate for the world fleet of the airplane-en-
gine combination must be commensurate
with the level of ETOPS approval being
sought.

(1) For type design approval up to and in-

cluding 120 minutes: An IFSD rate of 0.05 or
less per 1,000 world-fleet engine-hours, unless
otherwise approved by the FAA. Unless the
IFSD rate is 0.02 or less per 1,000 world-fleet
engine-hours, the applicant must provide a
list of corrective actions in the CMP docu-
ment specified in section K25.1.6 of this ap-
pendix, that, when taken, would result in an
IFSD rate of 0.02 or less per 1,000 fleet en-
gine-hours.

(2) For type design approval up to and in-

cluding 180 minutes: An IFSD rate of 0.02 or
less per 1,000 world-fleet engine-hours, unless
otherwise approved by the FAA. If the air-
plane-engine combination does not meet this
rate by compliance with an existing 120-
minute CMP document, then new or addi-
tional CMP requirements that the applicant
has demonstrated would achieve this IFSD
rate must be added to the CMP document.

(3) For type design approval beyond 180

minutes: An IFSD rate of 0.01 or less per 1,000
fleet engine-hours unless otherwise approved
by the FAA. If the airplane-engine combina-
tion does not meet this rate by compliance
with an existing 120-minute or 180-minute
CMP document, then new or additional CMP
requirements that the applicant has dem-
onstrated would achieve this IFSD rate must
be added to the CMP document.

(c)

Propulsion system assessment.

(1) The ap-

plicant must conduct a propulsion system
assessment based on the following data col-
lected from the world-fleet of the airplane-
engine combination:

(i) A list of all IFSD’s, unplanned ground

engine shutdowns, and occurrences (both
ground and in-flight) when an engine was not
shut down, but engine control or the desired
thrust or power level was not achieved, in-
cluding engine flameouts. Planned IFSD’s
performed during flight training need not be
included. For each item, the applicant must
provide—

(A) Each airplane and engine make, model,

and serial number;

(B) Engine configuration, and major alter-

ation history;

shutdown or occurrence;

(E) Phase of flight or ground operation;

(F) Weather and other environmental con-

ditions; and

(G) Cause of engine shutdown or occur-

rence.

(ii) A history of unscheduled engine re-

moval rates since introduction into service
(using 6- and 12-month rolling averages),
with a summary of the major causes for the
removals.

(iii) A list of all propulsion system events

(whether or not caused by maintenance or
flightcrew error), including dispatch delays,
cancellations, aborted takeoffs, turnbacks,
diversions, and flights that continue to des-
tination after the event.

(iv) The total number of engine hours and

cycles, the number of hours for the engine
with the highest number of hours, the num-
ber of cycles for the engine with the highest
number of cycles, and the distribution of
hours and cycles.

(v) The mean time between failures

(MTBF) of propulsion system components
that affect reliability.

(vi) A history of the IFSD rates since in-

troduction into service using a 12-month
rolling average.

(2) The cause or potential cause of each

item listed in K25.2.1(c)(1)(i) must have a cor-
rective action or actions that are shown to
be effective in preventing future occur-
rences. Each corrective action must be iden-
tified in the CMP document specified in sec-
tion K25.1.6. A corrective action is not re-
quired:

(i) For an item where the manufacturer is

unable to determine a cause or potential
cause.

(ii) For an event where it is technically

unfeasible to develop a corrective action.

(iii) If the world-fleet IFSD rate—
(A) Is at or below 0.02 per 1,000 world-fleet

engine-hours for approval up to and includ-
ing 180-minute ETOPS; or

(B) Is at or below 0.01 per 1,000 world-fleet

engine-hours for approval greater than 180-
minute ETOPS.

(d)

Airplane systems assessment.

The appli-

cant must conduct an airplane systems as-
sessment. The applicant must show that the
airplane systems comply with § 25.1309(b)
using available in-service reliability data for
ETOPS significant systems on the candidate
airplane-engine combination. Each cause or
potential cause of a relevant design, manu-
facturing, operational, and maintenance
problem occurring in service must have a
corrective action or actions that are shown
to be effective in preventing future occur-
rences. Each corrective action must be iden-
tified in the CMP document specified in sec-
tion K25.1.6 of this appendix. A corrective ac-
tion is not required if the problem would not
significantly impact the safety or reliability
of the airplane system involved. A relevant
problem is a problem with an ETOPS group
1 significant system that has or could result

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