Depending on your specific operation, flying may have slowed without any obvious sign of when things will get back to normal. However, it is critically important that we continue to maintain the quality of our fuel supplies.
Often, I am asked, “How long is fuel good for?”
A widely accepted answer to that question, assuming stagnant storage, without any new fuel being added or without the fuel being recirculated and filtered, is:
- One year for aviation turbine jet fuel
- Only 6 months for aviation gasoline AKA avgas 100 LL.
Once the time periods listed above have passed for the respective fuel type, you must send a properly obtained fuel sample, in the correct sample container, to a lab to have a few ASTM tests performed to verify the fuel is still on-specification.
Even when we are not flying, we must continue to perform the industry standard tests to protect the quality of our fuel. We must continue to sump fuel tanks to remove water and particulate, as well as recirculate the fuel in order to sump filter vessels under pressure. Simply recirculating the fuel and performing the industry standard tests will go a long way toward avoiding problems associated with stagnation.
When performing fuel storage tank sumps, remember to displace an adequate volume to evacuate the entire sample line and access fuel from the tank bottom. Filter sumps must be performed under pressure to ensure proper evacuation of low points.
Remember, filter differential pressure, which should not exceed 15 psi at the rated flow of the filter vessel, tells us the condition of the filter. It should only be read when fuel is flowing through the filter vessel.
For more information or to answer any specific questions, please contact me
at Aviation Training Academy, 281-386-8512, firstname.lastname@example.org
— Walter P. Chartrand