Unit 3-1 Flashcards
Who completed the very first air to air refueling?*
Describe what happened
When?*
Wing-walker Wesley May
Climbed from a Lincoln Standard to a Curtiss JN-4 airplane with a can of fuel strapped to his back
November 12, 1921
Who completed the first actual mid-air refueling?*
When?*
Capt. Lowell Smith and Lt. John P. Richter
June 27, 1923
What is the purpose of aircraft fuel systems?*
Deliver fuel to the engines safely under a wide range of operational conditions (uniform flow, clean fuel, constant pressure)
Monitor the quantity of fuel, check fuel pressures, temperatures, and flow rates (only has to be accurate when empty)
Why is reliability of the aircraft fuel system important for piston engines?*
Turbine engines?*
Will not result in power interruption for more than 20 seconds for piston engine
Will not cause flame out for turbine engine
Why is fuel system independence important for multi-engine aircraft?*
Fuel system for one engine is not affected by fuel system for another engine
One engine failure will not cause failure from other engine
What are the two types of fuel systems?*
Gravity-feed
Pressure-feed
Describe a gravity-feed fuel system
What aircraft is it in and where?*
Use force of gravity to cause fuel to flow
Bottom of the fuel tank must be high enough to provide enough pressure
High wing light aircraft – placed inside the wing
It’s all “downhill”
What is the priming system?
What does the primer do?
What aircraft have this system?
A subsystem used to prevent damage to the fuel system
Separate system to charge or prime the cylinders with fuel for starting
Draw fuel from carburetor inlet bowl or fuel strainer
Non-fuel-injected, reciprocating aircraft engines must often be primed before starting
What do fuel selector valves do?*
Shutoff the fuel flow manually
Select which tank (left, right, both) to feed the engine
Transfer fuel from one tank to another
Direct fuel to one or multiple engines
Each engine has at least one
Describe a pressure-feed fuel system*
What aircraft is it in and where?*
More common
Uses boost pump to move fuel
Fuel tanks are located too low to provide enough fuel pressure
Wing tanks – same level with carburetor
Fuel pumps
Fuel boost pump – start the engine
Engine-driven pump – normal operation
Inside the wing of low wing aircraft
Large aircraft, jets
What do fuel pumps do?*
Where are they located?
Starts the engine
Move fuel through the fuel system when gravity flow is insufficient
Move fuel from tank to engine, tank to tank, engine back to tank
Provide a positive pressure and eliminate air that could cause “vapor lock”
Usually mounted inside the tank (submersible)
What do electric driven fuel pumps do?*
Provide a positive feed to the fuel metering device (carburetor or fuel injection)
Receive fuel from the fuel boost pump
What are the types of materials used for fuel tanks?*
Aluminum alloy (best)
Light, strength, easily shaped and welded
Fuel-resistant synthetic rubber
Rubber bag (bladder) – conform to a space provided in the wing or fuselage
Light in weight
Can eventually fail, make sure they are always full
Composite materials
Stainless steel
What are the two major types of fuel tanks?
Integral
Bladder
When are integral fuel tanks manufactured?
How is fuel kept in the tank?
Manufactured when the aircraft is built
Sealed seams, spars, and ribs with fuel-proof sealing compounds
Internal baffles to prevent fuel sloshing
