BMS F-16C/D 4.34, Руководство по эксплуатации самолета

Страница: 128 / 234

T.O. BMS1F-16CM-1 BMS 4.34 Change 2.00
BMS 4.34 Dash 1
© Red Dog 2012-2019
Page: 128
A trapped fuel condition may happen in abnormal situations such as:
•
Imbalance situation. For instance if the A/L system feeds the engine alone (ENG FEED to
AFT) and the aircraft carries two external wing tanks, the left wing tank will empty in the left
internal wing tank but the right external wing tank will remain full. When the left external wing
tank is empty and the left internal wing tank starts to empty into the aft fuselage tank a trapped
fuel message will be displayed on the HUD notifying the pilot that some fuel is trapped in
external tanks. In this case in the right external wing tank.
You will get a TRP FUEL warning when fuel remains in the external tanks and the amount of
fuel in any internal tank is decreasing.
•
AR door open for too long. When the AR door is opened the external tanks depressurise a
bit to allow the fuel coming from the AR door to actually be transferred to the external tanks (if
carried). In this case the external tanks are not transferring fuel to the internal tanks anymore,
because of the drop in pressure.
If the external tanks are kept depressurised for too long it may be possible that the fuel left
inside cannot reach the internal wing tank. In that case a TRP FUEL condition may develop.
•
AIR SOURCE to OFF or RAM . The same is true if the AIR SOURCE knob is placed in any
other position than NORM or DUMP. Both these positions, besides activating the ECS,
pressurise the fuel tanks. If they are not pressurised the fuel may not transfer correctly. That
being said, if you leave the AIR SOURCE knob set incorrectly the problems induced on the
ECS system will happen much quicker than any fuel pressurisation problems. So chances are
that you will notice these first and fix the problem before fuel pressurisation problems occur.
Five conditions must be met for a TRP FUEL warning to occur:
•
FUEL QTY SEL knob is in NORM
•
Aerial refuelling has not occurred within the previous 30 - 90 seconds
•
Fuselage fuel has been at least 500 pounds less than fuselage capacity for 30 seconds
•
Total fuel has been at least 500 pounds greater than fuselage fuel for 30 seconds
•
Fuel flow has been less than 18000 pph for 30 seconds
A TRP FUEL warning may also occur with prolonged AB use if fuel flow to the engine exceeds the
maximum transfer rate from the external tanks. This is not really a true TRP fuel and will clear as soon
as AB is disengaged or when the fuel transfer rate decreases back to within the maximum possible
transfer rate of the external tanks.