Vacuum System - Robin DR400/140B Supplementary Information

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c) Assuming that the coolant's temperature is more than 94°C, the short circuit is completely
bypassed and all of the fluid is directed through the large circuit, thus ensuring a maximum coolant
temperature of 105°C.
Cabin heating and defrosting system
Except for the fact that when the cabin heating is operative, windshield defrosting operates as well.
Outside air is still used, but it is now heated by contact with the hot coolant fluid exiting the engine
through the third non-regulated thermostat's outlet in a second heat exchanger. The air inlet for this
heat exchanger is located in the lower part of the front engine cowling.
This heat exchanger is fitted with a valve which is controlled by a knob on the instrument panel: the
so-called cabin heat shutoff (unfortunately simply labelled "CABIN HEAT") which can be selected in
open or closed position:
a) In the open position (knob pulled out), the valve in the heat exchanger directs the heated outside
air to a second valve located in the engine firewall. This latter valve is controlled by a second knob on
the instrument panel (also labelled "CABIN HEAT"!!! find it on the right hand side of the first one,
immediately above the "CABIN AIR" control) and admits or prevents the heated outside air to enter in
the cabin (exactly as was the case in the original system). When this second knob is pushed in, the
outside heated air is dispersed in the engine compartment.
b) In the closed position (knob pushed in), the valve in the heat exchanger pre- vents the outside air
to flow to the firewall, also dispersing it in the engine compartment. In other words, when the cabin
heat shutoff knob is closed, the usual cabin heat knob has no effect. The open position (knob pulled
out) is the normal position during flight.

VACUUM SYSTEM

Only one vacuum pump remains available since the installation of the TAE 125-1 engine.
EMERGENCIES
Section 3 of the "Supplement" covers the TAE 125-1 related emergencies.
In addition to Section 3 please find below some helpful hints:
01.- Assuming an engine failure in flight, selecting the thrust lever in middle position and cycling the
engine master switch "OFF" then "ON" may help to restart the engine. In addition, no restart should
be attempted above 13000 ft.
02.- Considering the propeller stopped case, the best is to consider that, if the propeller stops at more
than 70 KIAS, the engine or propeller is blocked and refrain from using the starter.
03.- Considering the FADEC malfunctions in flight (pages 3-6 and 3-7 of the "Supplement") three
cases are considered: (a) one FADEC light is flashing, (b) both FADEC lights are flashing and (c)
abnormal engine behaviour. Regarding this latter item, the text says (page 3-5): "If the engine acts
abnormally during flight and the system does not automatically switch to the B-FADEC, it is possible to
switch the B-FADEC manually". The question is: how can the pilot know that B FADEC has not
automatically replaced A FADEC? Probably by the fact that, following the illumination of A FADEC
warning light, the engine shows "abnormal behaviour".
If we consider the "BOTH FADEC WARNING LIGHTS ARE FLASHING" case, if this happens with
satisfactory fuel contents, one may believe that it may be due to the fact that B FADEC has not
automatically taken over, and that switching manually to B FADEC might restore normal engine
operation.
Versie oktober 07