Systems - Fuel Flashcards
General
- Independent Fuel System for Each Engine
- Five Bladder Fuel Cells
- Left Engine – Forward Fuselage and Dorsal Cells
- Right Engine – Center and Aft Fuselage Cells
Total Fuel
3906 lbs
Left Fuel
1916 lbs
Right Fuel
1990 lbs
Refueling (2 methods)
- Single Point Refueling – Refuels Both Systems Simultaneously
- Over-the-Top Refueling – Both Systems Separate
- 60lbs Less of Usable Fuel When Refueled
- Must Fill Left Tank First
How are fuel boost pumps powered?
AC Powered, Supplies Fuel Under Low Pressure to the Engine-Driven Fuel Pump
Gravity Feed Can Maintain Fuel For MAX Power Up to
25,000 ft
Guaranteed Only to 6,000ft (Flameouts Have Occurred at 7,000ft)
Are engine-driven boost pumps necessary for engine operation?
Yes
Boost Pump Switches Only Accessible From the ___ (Lights in ___)
FCP, RCP
Two Fuel Low Pressure Lights in Both Cockpits
- Crossfeed Off – Indicates Boost Pump Failure
- Crossfeed On – Indicates Possible Fuel Leak
- Blinking is Not an Indication of Boost Pump Failure (Occurs When Using AB)
Fuel Pressure Switches
Determine If Engine Driven Boost Pumps are Providing Adequate Pressure
Fuel Shutoff Switches
- DC Operated (Left Essential)
- Fuel Shutoff Valves are Normally Operated by the Throttles (Switches Can Be Used)
- Shuts Off Fuel Flow to the Engine in Approximately 1 Second
- Switches Only Used in Emergency, May Damage Engine-Driven Fuel Pumps and Main Fuel Control
How is fuel crossfeed powered?
DC
Fuel crossfeed corrects imbalances of
200 lbs or more
ON position operates
Both Engines From One Fuel System With the Boost Pump Operating
With Crossfeed ON Ensure
One Boost Pump is Operational and One is Turned Off (Rapid Fuel Imbalance Otherwise)
If Crossfeed Operation is Continued Until the Active System Runs Dry
Dual Engine Flameout Occurs
During Crossfeed, If Using a High Power Setting
Low Pressure Light May Illuminate and Engine RPM Fluctuations May Occur Because of Insufficient Fuel Pressure
Do Not Crossfeed When
- Boost Pump Failure
- Indicator Malfunction (Fuel Quantity)
- Leak
- Low Altitude (2 Engines)
- Low Fuel (2 Engines)
Does fuel flow read for the AB?
No
How many probes for fuel quantity?
7 (AC powered)
Red Bar if Fuel Drops Below
250 ±25lbs in EITHER System >7.5 Seconds
FUEL LOW Light Illuminates When
Red Bar Appears (Not Connected to Fuel System, Only to Gage)
If Indicator (AC) is Lost or EED (DC) is Lost
Warning System is Lost
Fuel Imbalance Indications
10lb Increments Under the Bar With the Greater Fuel (Maximum of 910lbs)
- 0-50lbs – No Display;
- 60-200lbs – White Display; - >200lbs – Red Display
- Maximum Imbalance Indications 910lbs
Fuel Quantity May be Checked with AC Failure b
Engaging Static Inverter
Low Fuel Precautions: When Solo, Ensure
Right Does Not Equal Twice the Left System (CG Out of Limits)
Low Fuel Precautions: Maintain Positive Pitch
With the Fuel Low Caution Light Illuminated (Precludes Uncovering Boost Pump Inlets and Cavitation)
Low Fuel Precautions: Below 650lbs in Either System
Upper Inlet of Boost Pump is Uncovered Causing 40% Reduction in Output
Low Fuel Precautions: During Low Fuel States (250 ±25lbs)
Do Not Use Crossfeed With Both Boost Pumps Operating as Dual Engine Flameout May Occur (There is No Cockpit Indication of Boost Pump Failure in this Situation)
Low Fuel Precautions: During SE and Low Fuel Operation
Leave Both Boost Pumps and Crossfeed On (Prevents Engine Flameout)
Low Fuel Precautions: Avoid MAX Thrust Dives With Less Than
650lbs in Either Fuel Tank
Low Fuel Precautions: Fuel Imbalance Must be Maintained Within
200lbs to Ensure CG Remains Within Limits
Prevention of Fuel Starvation
Avoid MAX Thrust in 0 or – G Flight Exceeding
- 10 Seconds – 10,000ft
- 30 Seconds – 30,000ft
