SY1112 Fuel System Flashcards
Do the engines share the fuel system
No. independent for each side
Left Engine Fuel Cells
Forward Fuselage and Dorsal Cells
Right Engine Fuel Cells
Center and Aft Fuselage Cells
Total Fuel and per respective side
- 3906 lbs total w/ single point
- Left = 1916 lbs
- Right = 1990 lbs
- Manual fueling is 60 lbs less
Which tank must be filled 1st
Left Engine tanks
Fuel Boost Pumps
AC Powered, Supplies Fuel Under Low Pressure to the Engine-Driven Fuel Pump
Max Altitude with gravity feed
- 25000’
- Guaranteed only to 6000’, flameouts @ 7,000’ have occurred
Are Engine-Driven Boost Pumps Necessary for Engine Operation
Yes
Normal Fuel Px, when does WCA light illuminate
- 10 Psi norm
- 6 Psi light on
Left Boost Pump is in the
Forward Fuselage Cell
Right Boost Pump is in the
Aft Fuselage Cell
Two Fuel Low Pressure Lights in Both Cockpits with Crossfeed off or ON
- Crossfeed Off – Indicates Boost Pump Failure
- Crossfeed On – Indicates Possible Fuel Leak
Is Blinking low fuel Px during AB an indication of boost failure?
-No during AB
Fuel Shutoff Switches are ___ Powered, normally operated by. how long does it take to shutoff fuel w/ switch?
- DC powered on Left Essential
- Normally controlled via throttle
- 1 sec to shutoff fuel, can cause damage to engine driven fuel pump and MFC
Fuel Crossfeed is powered by?
Does what when switched on?
- DC power
- Electrically opens/closes valve in crossfeed manifold
When to use crossfeed function?
W/ fuel imbalance over 200 lbs, less than that use differential throttles
When you turn on crossfeed, what else should you do?
-Crossfeed on, light tank boost pump OFF!
Don’t Crossfeed when?
- Boost Pump fail
- Fuel indicator failure
- Leak
- Low Alt w/ 2 engines
- Low fuel w/ 2 engine
Does fuel flow read during AB?
NOPE burn those dinos
Fuel quantity powered by?
AC powered
Fuel imbalance
- 10 lbs increments under heavy tank
- white # : 60-200lbs
- Red # : 200lbs or more
Fuel Low light comes on at?
250 lbs and below with 7.5 sec delay
Can you check fuel quantity with AC failure? How?
Yes, by Engaging Static Inverter
Fuel imbalance will solo should never exceed
Ensure Right Does Not Equal Twice the Left System, CG out of limits
At what weight in fuel does fuel output go down?
-below 650 lbs output is reduced 40%
Situation to use Crossfeed and leave boost pumps on?
Single engine/ low fuel
Avoid max thrust dives with _____lbs or less
650 lbs
Fuel Imbalance Must be Maintained Within for CG
200 lbs
Prevention of Fuel Starvation
Avoid MAX Thrust in 0 or – G Flight Exceeding
- 10 sec - sea lvl to 10k’
- 30 sec - 10k’ to 30k’
With FUEL PRESS light on, crossfeed OFF, fuel shutoff in norm and throttle is out of off, is it boost pump fail or leak?
boost pump fail
With FUEL PRESS light on, crossfeed ON, fuel shutoff in norm and throttle out of off, is it boost pump or leak
leak
Easy way to differentiate between boost pump fail and fuel leak with FUEL PRESS light?
crossfeed OFF is boost pump fail, crossfeed ON is fuel leak
When is a normal momentary illumination of the FUEL PRESS light
AB ignition
How much of an imbalance before using crossfeed
200lbs
Can you transfer fuel from one tank system to another using crossfeed
no
If operating single engine, how do you use all the available fuel in both sides
crossfeed
What is the rule for turning switches ON/OFF when using crossfeed
Turn one ON to turn on OFF
When crossfeeding with only one engine (using fuel from both sides), the engine is fuel by which tank group
the one with the stronger boost pump
When less than 250 lbs in either system managing balance is less important than what
preventing a flameout
When less than 250 lbs in either system, what should be done to prevent flameout.
Both boost pumps on, crossfeed on
With both boost pumps on, crossfeed on and one tank empties, what happens
the other tank takes full over fuel feeding
The RCP boostpump and crossfeed lights indicate what
switch position and not actual operation
What 5 times do you not cross feed
"Boost pump fail Fuel leak Fuel quantity malfunction Two engines and low altitude Two engines and low fuel"
When should you use split throttles to balance fuel
traffic pattern, low-altitude
How is the engine fuel if the boost pump is inop
gravity feed
With one to two engines and one to two fuel systems (left/right) when will gravity feed provide sufficient fuel
gravity feed should be sufficient for 2 engine and 2 fuel systems, 1 engine and 2 fuel systems, but may NOT be sufficient for 2 engines and 1 system
Main fuel pumps supply fuel under _________ pressure
high
Main fuel control is a _______________ unit
hydromechanical
Main fuel control has two major systems, the _____________ and ________________ system
computer, metering
Main fuel control computer section…
senses engine inlet temp, compressor discharge pressure, engine speed and throttle position
Fuel metering section…
delivers computed fuel flow to the engine
Auxiliary function of the main fuel control is…
schedule the Variable Geometry System (VGS)
The overspeed governor (OSG)…
mechanically monitors the maximum speed of the engine
Fuel flow transmitter…
measures main engine fuel flow only, not AB
Afterburner fuel pump is mounted…
on the engine accessory section
Afterburner fuel control has three major sections…
- computer section 2. fuel metering section 3. nozzle control
AB computer section senses…
compressor discharge pressure and throttle setting
AB fuel metering section…
supplies correct fuel flow to pilot burner and main AB spraybar manifolds
T5 system (turbine discharge temp) engages at ___
97%
AB nozzle control section…
schedules the exhaust nozzle opening when directed by the T5 system
of sets of spraybars in the AB section
2
___________ bus is used for a ground start
Battery
_________ engine should be started first
Right
Static inverter converts __ power to __ for the ______ engine instruments
DC, AC, right AC
Battery switch should be ___ before connecting the APU
On
After checking everything’s clear, the first step to starting the engine
Signal crew chief to connect the air supply
Second step
Signal starting #2
Start right engine at __% RPM minimum
12
Third step
Signal crew chief to divert air to left engine
Fourth step
Signal starting #1 and start same as right
With one engine operating you can attempt _______________ airstarts
unlimited
With a dual engine flameout, attempt to start the ___________ engine first
right
Leave the throttle at IDLE for __ seconds before aborting a start
30
Airstart envelope
Compressor stall is a…
disruption of smooth airflow over the compressor blades
Low altitude, high airspeed compressor stall indications
loud noise, rapid RPM decrease, rapid EGT increase
High altitude, low airspeed compressor stall indications
rapid RPM decrease, rapid EGT decrease
Sheared oil pump shaft fail indications
oil pressure and RPM decrease to Zero, T5 system fails
Correct course of action for Sheared oil pump shaft
Shut down the affected engine
T5 system failure indications
AB will probably not ignite, high EGT, closed nozzle at or above ~97% RPM
