Chapter 4- Fuel System Maintenance Flashcards
Fuel Contamination
Fuels must be approved for use and remain free from contaminants and impurities if the aircraft are to remain airworthy and safe. Must only be filled with authorised fuel.
Principle Threats
a. Foreign Particulates
b. Water
c. Microbiological Organisms
d. Cross Contamination
Contamination by water may result in the product being unusable or cause a significant loss of performance. Water in fuel can take up the form of what?
a. Suspended Water
b.Free water
Suspended Water
When the Water is mixed in the fuel solution.
Free water
When sufficient quantities of water particles have joined together and sunk to the bottom of the fuel.
User Responsibilities
To ensure the intergrity and quality of the product from its receipt to the point of issue and use.
Water sediment check procedure
A sample is drained from a valve located at the bottom of a tank into a transparent container.
How to determine free water is present.
A visual check. The lighter fuel floating on the top, however if the sample is jus one liquid with no dividing boundary it can be difficult to distinguish whether it is water or fuel.
How to indicate the evidence of a water/fuel emulsion?
A cloudy sample
How to indicate possible microorganisms?
Slimy deposits
How to detect excessive levels of dissolved water.
Water Detection Capsule
The tablet contains a yellow coloured detection paper,which will turn blue if the sample contains too much water.
Fuel system Testing
Test are perculiar to aircraft type and the details of the work necessary are obtained from the AMM
Fuel system testing work done must cover what points?
a.Leak checks
b.Fuel Flow Test
c. Tested by an authorised person
Fuel Tank Maintenance
*Fuel Tank leaks and repairs
*Rigid Tanks
*Flexible Tanks
Leak rate may be affected by:
a. Cavity drain blockage
b. The tank being plugged by contact with the aircraft structure
c. Self-sealing layer activation
d. Fuel tank level
e. Aircraft attitude
f. Tank Pressurisation
