Maintenance Manual STEMME S10-VT
Date of Issue: Jan. 01, 1998
Page 3-23
Amendment Nr. 0
Date: --
A4011121_B23.doc
Doc. No. A40-11-121
3.4.7 Engine Controls and Instrumentation
(See also section 3.2.2)
The throttle and choke are operated by bowden-cables, linking the carburetors with the cockpit levers, which
have adjustable friction control. The throttle and choke lever are installed in the centre console between the
pilots. The throttle lever has two stops, one for the 100% (max continuos) power position and one for the
115% (max takeoff) power position.
Engine cooling is controlled by the cowl flaps, opened and closed by a linkage to the propeller-dome handle.
In addition, the cowl flap aperture can be reduced in five steps by the cowl flap operation handle on the
instrument panel (see also section 3.4.3).
Both, engine ignition and engine starter, are controlled by a key switch. A special feature is an ignition
retarder of three seconds after switching the key to position "START", to allow the propeller blades unfold
before engine ignition (see section 3.7.11).
The engine instruments are located on the RH instrument panel.
For positions and function of switches and instruments, refer to section 3.2.2 and 3.7, respectively.
3.4.8 Fire Protection
The engine, including exhaust and induction system are isolated to front, top and rear areas by fire-walls. The
fire-walls consist of stainless steel sheets (thickness 0.38 mm / 0.015 in).
The insides of the engine cowlings on the LH and RH side of the engine and below the engine are coated
with a fire-protective painting (Manufacturer: Courtaulds Aerospace). It consists of three coats of a white fire
resistant paint (type N 56582/T508) and one coat of clear varnish (type 4232-0303, hardener N39-1327 or
N50/2509, thinner N39-3091).
The fuel and oil hoses in the engine compartment are covered by fire-protective sleeves (Aeroquip).
The fire warning system is triggered by two bimetallic temperature sensors above the carburetors. The fire
warning is by means of a red warning light (push-to-test function) on the instrument panel, combined with an
acoustic warning tone via the loudspeaker.
3.4.9 Engine Cowlings
Cowl flaps:
refer to section 3.4.3
The engine cowling consists of three, LH, RH and lower parts. The cowlings are self-supporting and
connected to the fuselage structure forward and aft by means of camlocks.
The LH and RH cowlings are fastened to the structure by 5 Camlocks and include an inlet cowl flap and air
duct assy each.
The cooling air duct of the LH cowling keeps a gap of approx. 5 mm / 0.2 in. to the radiator with the cowling
installed, to allow for relative motion.
The air duct of the RH cowling distributes the ram air from the RH cowl flap to four positions for the cylinder
straight shank ram air cooling, for the intercooler, for the oil cooler and for the induction air of the carburetors.
When installing the RH cowling, the opening for the cylinder cooling is pressed against a rubber sealing on
the coupling sheet of the upper support of the cylinder shank cooling air hose, routed to the distributor on the
cylinders. The induction air duct is prepared with a cut-out for the induction air filter. The filter assy on the
turbocharger inlet, consisting of filter, sealing plate and air hose, remains installed when the cowling is
removed.
The complete lower cowling forms the outlet cowl flap. It is fastened in forward hinges and positioned by a
rear control cable assy, which counteracts two springs acting towards the open position of the flap.
