Airframe Mechanic Certification Aircraft Fuel Systems 2

Question 1

What material is commonly used for flexible fuel hose connections in certified aircraft fuel systems?

Accepted Answer

Teflon-lined synthetic rubber hose

Answer

Teflon-lined synthetic rubber hoses are used for flexible fuel connections because Teflon resists aviation fuel degradation and the rubber provides flexibility to absorb vibration.

Question 2

Where should a fuel tank sump drain be located to be most effective?

Accepted Answer

At the lowest point where water and sediment accumulate

Answer

Sump drains are at the lowest point so water, which is denser than fuel, and sediment collect there and can be drained during preflight inspection.

Question 3

What is the purpose of a fuel cross-feed system on a multi-engine aircraft?

Accepted Answer

To allow fuel flow from one wing tank to the other or to feed any engine from any tank

Answer

A cross-feed system allows fuel to be transferred between tanks for lateral balance or to supply any engine from the opposite wing tank in the event of a fuel pump failure.

Question 4

Under what conditions may automotive gasoline (mogas) be used in a certificated aircraft?

Accepted Answer

Only when the aircraft has an STC specifically approving its use

Answer

Automotive gasoline may only be used in certificated aircraft when a Supplemental Type Certificate (STC) has been issued specifically approving mogas for that aircraft and engine combination.

Question 5

What is the maximum allowable fuel tank leakage per FAA standards?

Accepted Answer

Seepage (wetness without drops forming) is acceptable; dripping is not

Answer

FAA standards distinguish between 'seepage' (fuel wetness with no drops) which is acceptable, and 'leakage' where drops form, which is not airworthy.

Airframe Mechanic Certification Practice Test

Airframe Mechanic Certification Practice Test

Airframe Mechanic Certification Aircraft Fuel Systems 2