CRITICAL ITEMS Flashcards
T TANK MODE - AUTO
FCMC controls CG.
T TANK MODE - FWD
(What do you need for a forward transfer??? Open 2, close 2, 1 x pump, no overflow protection to CTR.)
(TATA-PN)
Initiates a manual forward transfer to the centre tank.
By opening 2 valves:
‐ TT ISOL valve, (TTI)
‐ AUX FWD XFR valve. (AFT)
By closing two valves:
‐ TP ISOL valve, (TPI)
‐ AFT XFR valves. (AT)
AND…..
- TT FWD XFR pump operates.
- No overflow protection to centre tank overflow
T TANK MODE - FAULT
(FAULT, it’s EFF’d)
‐ Excess AFT CG (based on the THS position (independent of fuel quantity)
‐ FCMC is unable to carry out the forward transfer
- The FUEL LO TEMP warning
‐ Inner tank < -37 °C, or
‐ Outer tank < -40 °C, or
‐ Trim tank < -40 °C.
T TANK FEED selector - AUTO
STOPS FWD XFR when the trim tank is at low level, to maintain the trim tank transfer line full.
Why??? APU is supplied with fuel through the trim tank transfer line.
T TANK FEED selector - ISOL
(1 x line, 4 x valves + pump)
TT Transfer Line isolated
+
4 valves close:
(2 AFT, 2 FWD)
1. TT isolation valve (TTI)
2. TT Inlet valve (TTI)
3. AUX FWD transfer valve (AFT)
4. Trim pipe isolation valve (TPI)
————————————————
The trim tank forward transfer pump stops.
T TANK FEED selector - OPEN
(x3)
3rd option, 3 valves, 3 mins
Opens 3 valves for a FWD TXFR
TAT3
2 x Manual forward transfer valves
‐ TRIM TK ISOL valve (TTI)
‐ AUX FWD XFR valve (AFT)
AND
- TRIM TK inlet valve (TTI)
The valves remain open, until 3 min after trim tank is low, to allow drainage of the transfer pipe.
OUTR TK XFR pb-sw - ON
(Inlet > transfer > inlet)
Initiates the outer to inner tank transfer by opening: :
‐ The outer inlet valves,
‐ The outer transfer valves,
‐ The inner inlet valves.
OUTR TK XFR pb-sw - AUTO
The FCMC controls the outer to inner tank transfer. 3 500 kg to 4 000 kg inners.
OUTR TK XFR pb-sw - FAULT
IFF
‐ Inner tank low level is reached and the outer tanks not empty, or
‐ FCMC is unable to carry out transfer to the inner tanks, or
‐ The FUEL LO TEMP warning is triggered.
CTR TANK XFR - AUTO
The FCMC controls the centre to inner tank transfer. Between full and 2 000 kg below full.
CTR TANK XFR - MAN
- Initiates CTR to INR transfer by opening the inner tank inlet valves.
- No overflow protection.
CTR TANK XFR - FAULT
‐ Inner tank low level is reached and the center tank not empty, or
‐ FCMC is unable to carry out the transfer to the inner tanks.
L(R) STBY - OFF
Pump is OFF
L(R) STBY - ON
Standby always linked to main pump…
Runs when main pump is:
failed or off.
L(R) STBY - FAULT
- Pressure drops
- Inhibited when:
1. Pump selected OFF, or
2. Main pump is running.
MEMO - TRIM TK XFR
GREEN - appears during trim tank transfer.
MEMO - T TK XFRD
GREEN - trim tank has been emptied following a forward transfer.
Forward fuel transfer stops, when:
- The computed CG = Target CG -0.5 %.
- Inner reaches 5 000 kg
MEMO - OUTR TK XFRD
OUTR tank has been emptied following a transfer into the inner tank.
- Inner tanks contents cycled between 3 500 kg and 4 000 kg
- When tank empy for 5 mins, OUTR TK XFR valve closes
MEMO - OUTR TK XFR
OUTR TK XFR controls the transfer by cycling the associated inner tanks contents between 3 500 kg and 4 000 kg.
Explain the fuel feed system:
- CTR to INNERS
- INNERS empty down to 4 000 kg
- TRIM TANK to INNERS
- INNERS empty down to 3 500 kg
- OUTERS to INNERS
If required for CG control, the trim tank may be emptied earlier
AFT transfer STOPS when:
AFT - A Fast Train STOPS in:
Chang Mai (CHIT-MAI)
- CG = Target -0.5 % , or
- Trim tank high level sensor wet, or
- Inners 6 250 kg, or
- T TANK MODE pb FWD, or
- Manual transfer from the centre or outers to inners, or
- Automatic transfer from centre to inners.
- If inner tanks unbalanced by > 500 kg, the transfer will stop on the lightest side, and related AFT transfer valve will automatically close until fuel balance is restored.
AFT fuel transfer STARTS when ALL of the following conditions are met:
(x6)
What would be the very first transfer during a flight??? FL 255 - then work out the rest.
- FL 255
- Gear retracted
- Slats retracted
- Trim tank not full
- Inners > 6 250 kg
- CG not on target.
FWD Transfer STARTS, if ONE of the following conditions are met:
Start CITEing
- CG = Target CG.
- Inner tank decreases to 4 000 kg.
- Time to dest is 35 mins or below FL 245 (or 75 mins with TT FWD transfer pump failure)
- Electrical emergency configuration.
FWD Transfer STOPS, if ONE of the following conditions are met:
5 & 5
- Computed CG = Target CG -0.5 %.
- One inner tank reaches 5 000 kg.