FUEL – GENERAL
The fuel system consists of the following sub-systems:
• fuel storage
• fuel distribution
• fuel indicating
FUEL STORAGE – GENERAL DESCRIPTION
The storage system is composed by two tanks connected together through a
flange located on the lower side of the tanks. Both tanks are gravity refilled
through a filler cap located on top of the tank 2 (optional left hand gravity
filler cap and optional pressure (closed circuit) refuelling are also available).
At the bottom of each tank is located a sump plate where a fuel drain valve
and a water drain valve are installed.
To ensure an equal level of pressure between the tanks and the existing
ambient pressure, each tank is provided at the top with a venting pipeline
routed to the opposite side.
A flame arrestor in each venting pipeline prevents a flashback to the tanks in
the event of fire hazards, such as lightning strikes.
The total fuel tank capacity is 1588 litres (1270 kg).
FUEL STORAGE – MAIN COMPONENTS
TANKS
The two tanks (tank 1 and tank 2) are located on the rear side of the cabin
between the engine compartment floor and the cabin floor.
The fuel tanks are bladder-type and are attached to the airframe by two
types of restraints: velcro pads and nylon chord.
The two tanks are interconnected by an open flange that permits free flow:
this ensures automatic fuel balancing between LH and RH tanks, when the
fuel level is above the flange (about 228 kg per tank).
Consequently, each tank retains a maximum of about 228 kg that cannot be
transferred to the other tank: this permits a suitable amount of fuel to be
saved in case of rupture of one of the tanks.
In case of crash, the main landing gear collapses upward, away from the fuel
tank: in this case, foams in the lower side of each tank help to maintain the
tank in the right position.
SUMP PLATES
The sump plates are located at the bottom of each tank and are provided
with:
• a fuel booster pump
• a secondary fuel quantity probe with a low level sensor
• a fuel drain valve
• a water drain valve
FUEL DRAIN VALVES AND WATER DRAIN VALVES
The water drain valves can be operated electrically with a switch located in
the main landing gear sponson; it permits to sump fuel for normal check
operations.
The fuel drain valve is used to drain the fuel for maintenance purposes only.