PILOT’S OPERATING HANDBOOK
SECTION 7
DESCRIPTION
Edition 0 -- October 31, 2013
Rev. 1
Page 7.7.4
AUTOMATIC TANK SELECTOR
(Figures 7.7.2 and 7.7.3)
Automatic tank selection allows, without pilot's intervention, feeding the engine from one tank or the other in
predetermined sequences. These sequences depend on airplane configuration (ground, in-flight, fuel low level
CAS messages appearance).
Automatic tank selection system comprises an electronic sequencer, an actuator attached on the fuel unit, ”FUEL
SEL” two-position selector (AUTO, MAN) and ”SHIFT” push-knob located on ”FUEL” panel.
To operate the automatic selector, set ”FUEL SEL” switch to AUTO position and manual selector to R or L.
Selector operation
When the system is operated,
”AUTO SEL”
CAS message disappears ; the sequencer chooses a tank (R or L)
and through the actuator, positions the fuel unit selector on the selected tank. The sequencer controls the time
during which the selected tank will operate. This time varies, depending on airplane conditions.
Airplane on ground : tank is changed every minute and 15 seconds.
Pre--MOD70--0402--28
Airplane in flight : tank is changed every ten minutes, as long as a fuel low level
”FUEL LOW L”
or
”FUEL LOW R”
CAS message does not appear. When the first low level CAS message lights on, the
sequencer immediately selects the other tank. The selected tank will operate until the second low level CAS
message lights on. When both low level
”FUEL LOW L-R”
CAS messages are visible, the sequencer
changes tanks every minute and 15 seconds.
Post--MOD70--0402--28
Airplane in flight : tank is changed every five minutes, as long as a fuel low level
”FUEL LOW L”
or
”FUEL LOW R”
CAS message does not appear. When the first low level CAS message lights on, the
sequencer immediately selects the other tank. The selected tank will operate until the second low level CAS
message lights on. When both low level
”FUEL LOW L-R”
CAS messages are visible, the sequencer
changes tanks every minute and 15 seconds.
NOTE
The manual selector is driven by the fuel unit and is positioned on R or L mark
corresponding to the tank selected by the sequencer. Therefore, the pilot continuously
knows the tank which is operating.
Test for system proper operation
”SHIFT” push-knob allows the pilot to test system proper operation anytime.
When the system operates, the fuel tank is changed when ”SHIFT” push-knob is pressed once.
If airplane is on ground or in flight, low level CAS messages not visible, the new selected tank remains operating
and a new sequence is initiated.
NOTE
This procedure allows the pilot to preferably choose the tank from which he wants to
take fuel.
In all cases, proper system operation is indicated by rotation of the manual selector.
Setting ”FUEL SEL” switch to MAN position or setting manual selector to OFF position leads to system
de-activating and appearance of
”AUTO SEL”
CAS message.
”AUTO SEL”
CAS message also lights on
when order given by the sequencer has not been executed after 12 seconds.