STEMME S12, Maintenance Manual

Page: 45 / 290

DOCUMENT NUMBER:
L500-912.820 ISSUE JUL 20, 2016
AMENDMENT: 00
DATE: --
CHAPTER- PAGE 3-11
MAINTENANCE MANUAL STEMME S12
3.4 POWER-PLANT
3.4.1 ENGINE
Engine description See »Maintenance Manual (Heavy Maintenance)
for ROTAX Engine Types ROTAX 912 and 914
Series«, section 71.
Upper (rear) Engine Attachment A tubular steel frame at the upper engine flanges,
mounted in two vibration absorbing elements
in the upper lateral tube of the fuselage frame.
Lower (front) Engine Attachment A separate tubular steel frame at the lower
engine flanges in two vibration absorbing
elements in the forward lateral framework
junctions.
Type ROTAX 914 F2/S1 (modified ROTAX 914 F Aircraft
engine, propeller shaft design with flange for
fixed pitch propellers).
The ROTAX 914 F2/S1 is modified by STEMME and based on the type ROTAX 914 F2. The modification
was completed as a co-operation with ROTAX and with approval by ROTAX.
The base engine ROTAX 914 F2/01 is certified according to JAR-E / FAR 33. It is turbocharged and
has an electronic dual ignition system.
The modified version ROTAX 914 F2/S1 was specially developed for the model S12, a derivative of
the motorglider STEMME S10.
The engine modifications are certified together with the S12 according to JAR 22. The modified
version ROTAX 914 F2/S1 has the STEMME (internal) production No. 11AM-M.
Due to special requirements for installation in the center fuselage, the following modifications
were made:
• Relocation of the turbocharger unit to the aft of the engine to stay within the outlines
of the S12 fuselage. The turbocharger unit is supported by five struts aft of the engine.
A supercharger inter-cooler is installed. Relocation of the turbocharger unit required
modifications of the exhaust system. The exhaust headers are attached to the turbocharger
by springs, positioning them in spite of the high thermal stress.
• The layout of the oil pipes for the turbocharger are modified.
• The exhaust headers and the muffler are shrouded by temperature-resistant material, thus
thermally isolating the system from the engine bay. The turbocharger unit and the air box
are isolated by radiation protective shields.
• The original ROTAX engine mounting is not used. STEMME specially developed an engine
mounting for a center installation, consisting of two upper and one lower supporting
element.