The document summarizes the key functions and components of an aircraft fuel system. The fuel system provides an uninterrupted fuel supply to the engine at all operating conditions. Fuel tanks are pressurized by compressed air from the engine compressor casing. The compressed air passes through a filter and pressure reducing valve to reduce the pressure to around 6 PSI before entering the fuel tanks. This air pressure is enough to feed fuel into collector or fuselage tanks where boost pumps supply fuel to the engine-driven pump. External drop tanks and rear tanks empty first before fuel transfers to fuselage and wing tanks.

1. Aircraft Fuel System by A ALANKAR

2. INTRODUCTION

3. FUNCTION: TO PROVIDE AN UN-INTERRUPTED SUPPLY OF FUEL TO THE ENGINE DRIVEN PUMP AT ALL OPERATING CONDITIONS OF THE AERO-ENGINE AIRCRAFT FUEL SYSTEM

4. EXCESSIVE VAPOUR FORMATION IN AN OPEN VENTED TANK AT HIGH ALTITUDE. COMMON PROBLEMS

5. FREEZING OF FUEL / ICE FORMATION AT LOW TEMPERATURE. COMMON PROBLEMS

6. MAINTAINING SHAPE AND POSITION OF TANKS SO THAT THEY DO NOT COLLAPSE. COMMON PROBLEMS

7. MAINTENANCE OF PRE-DETERMINED ORDER OF EMPTYING TANKS. COMMON PROBLEMS

8. SUPPLY OF FUEL TO THE ENGINE IN INVERTED FLIGHT CONDITION BECOMES INTERRUPTED. COMMON PROBLEMS

9. FIRE HAZARDS. COMMON PROBLEMS

10. FUEL TANKS ARE PRESSURIZED BY COMPRESSED AIR TAPPED FROM THE ENGINE COMPRESSOR CASING. HOW IS PRESSURIZATION OF AIRCRAFT FUEL TANKS ACHIEVED?

11. BEFORE THE COMPRESSED IS PIPED INTO THE AIR SPACE INSIDE AIRCRAFT FUEL TANKS, IT PASSES THROUGH AN AIR-FILTER AND SUBSEQUENTLY THROUGH A PRESSURE REDUCING VALVE (P.R.V.) AND ITS PRESSURE IS REDUCED TO ABOUT 6 P.S.I. (i.e.0.4 BAR). HOW IS PRESSURIZATION OF AIRCRAFT FUEL TANKS ACHIEVED?

12. THIS AIR-PRESSURE IS SUFFICIENT TO FEED THE FUEL INTO EITHER THE COLLECTOR TANKS OR FUSELAGE TANKS WHERE FUEL BOOSTER PUMPS ARE FITTED TO SUPPLY THE FUEL TO THE ENGINE DRIVEN PUMP (E.D.P.). HOW IS PRESSURIZATION OF AIRCRAFT FUEL TANKS ACHIEVED?

13. EXTERNAL TANKS (i.e. DROP TANKS AND REAR TANKS) ARE EMPTIED FIRST. FUEL IS TRANSFERRED FROM THERE TO THE FUSELAGE TANKS AND TO THE WING TANKS. HOW IS PRESSURIZATION OF AIRCRAFT FUEL TANKS ACHIEVED?

14. REMEMBER, FUEL IS NOT FED TO THE ENGINE DRIVEN PUMP BY AIR PRESSURE. HOW IS PRESSURIZATION OF AIRCRAFT FUEL TANKS ACHIEVED?

15. TO RECUPERATOR TO REAR IN FRONT TANK TANK TO DROP TANK P.R.V. AIR-FILTER SCHEMATIC DIAGRAM: COMPRESSED AIR

16. POSITION OF AIRCRAFT FUEL TANKS