DOCUMENT NUMBER:
L500-912.820 ISSUE JUL 20, 2016
AMENDMENT: 00
DATE:
CHAPTERPAGE 730
MAINTENANCE MANUAL STEMME S12
COWL FLAPS
• Check condition and t of inlet and outlet cowl aps. Grease hinge bolts of outlet cowl
ap (observe section 6.5).
• Check cable lines and connections to aps.
• Check function of inlet and outlet cowl aps when operating nose-cone handle and cowl
ap reduction handle. Specially observe if aps are fully opened by springs.
•
Check fairing section aft of outlet cowl ap for condition, attachment and sealing to
re-wall.
• Check if aps close properly if nose-cone is closed.
• Check apertures of inlet cowl aps corresponding to cowl ap handle positions “Open”
and “Closed” (5th notch) with nose-cone open and locked.
INLET COWL FLAP OPENINGS, MEASURED FROM LEADING EDGE OF FLAP TO COWLING:
Fully opened 120 ± 5 mm / 4.7 ± 0.2 in
Fully reduced opening (fth notch) 30 ± 5 mm / 1.2 ± 0.2 in
7.4.10 PROPELLER
System description: See section 3.4.10
The numerical positions in the following text refer to the propeller diagram (see gure 3.4.10.a).
7.4.10.1 GENERAL
The complete propeller pitch control mechanism (including all mechanical and electrical compo-
nents) is redundant and is able to operate each propeller blade separately. Both systems are coupled
to each other through a mechanical coupling ring and an electrical backup system. Hence, the
mechanism is fully redundant. In order to prevent incorrect assembly, all paired parts belonging
to the pitch change of the one propeller blade are marked with a red dot; those belonging to the
other blade remain unmarked.
Propeller pitch can be changed manually for inspection and maintenance purposes by swinging
the blades approx. 90 degrees outward, gripping the blades in the outer third of their length and
pushing them in the direction of ight (ne pitch) or against direction of ight (coarse pitch).
See also details in the S12 Aircraft Flight Manual, section 4 Daily Checks.
Adjustment of the propeller or its electric system may only be performed by the manufacturer or
by qualied and authorized personnel. All results of an inspection of the adjustment or changes
in setting must be entered in a report according to Form Propeller Adjustment Report (Annex
D). The last valid report must be led together with the Operational Documentation (Annex C).
Repair, overhaul and inspection of structural damage to the variable pitch propeller or to its
subsidiary assemblies after an operational interruption may only be performed by qualied and
authorized personnel.