Abnormal Engine Behavior - Cessna 172 R Pilot Operating Handbook

Supplement POH
Cessna 172 R&S
(FAA-Version)

ABNORMAL ENGINE BEHAVIOR

If the engine acts abnormal during flight and the system does
not automatically switch to the B-FADEC, it is possible switch to
the B-FADEC manually.

WARNING:
(1) Select an appropriate airspeed to avoid engine overspeed.

WARNING:
(2) "Force-B" switch to B-FADEC
(3) Flight may be continued, but the pilot should:
i) Select an airspeed to avoid engine overspeed
ii) Land as soon as possible
iii) Be prepared for an emergency landing
It is only possible to switch from the
automatic position to B-FADEC (A-FADEC
is active in normal operation, B-FADEC is
active in case of malfunction). This only
becomes necessary when no automatic
switching occurred in case of abnormal
engine behavior.
When operating on FADEC backup battery
only, the "Force B" switch MUST NOT BE
activated. This will shut down the engine.
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Issue 3
Revision 2, Mar. 2022