30/10/09 1738.3 FLT by pilot Fuel leaking into pitot/static system (leaking out of pitot probe)
Pitot static system drained
Also
P37
1.16.10 The aircraft manufacturer also commented on the deferred defects related to the
fuel leak:
(i) Fuel leaking into pitot/static system (leaking out of pitot probe): Fuel leaking
into pitot/static system - the most serious problem. This is indicative of a fault
in a fuel valve; however, fuel in the pitot static system will also prevent correct
operation of the aircraft instruments and flying control feel system. Although
not a common occurrence, it can occur by internal failures in components in
the fuel venting system, either an Inward-Vent Valve Diaphragm, a Float
Control Valve Diaphragm, an Outward Vent Valve Diaphragm accompanied
with fuel in the vent pipe or by a leak in an Inward Vent Valve NRV. All of
these components are connected to the pitot/static system and are installed in
each integral wing tank. Extract from the Aircraft Maintenance Manual Sect 7
Chap 5 that states:
Note: "The main system provides the pitot and static pressures required to
operate the pressure switches, transducers, feel simulator and altitude and air
speed unit. The pressures are taken from a pressure head, extended on a
probe located under the nose air intake. In addition, the head provides two
sources of static pressure, one of which supplies the instruments and the other
which serves the fuel venting system."
