Aircraft Fuel Systems Presentation PDF

Here is the converted markdown format of the provided text. # Aircraft Fuel Systems ## Learning Objectives At the end of this lesson, you will be able to: * Analyze accidents involving fuel systems and assess possible causes. * Explain the difference between fuels and identify categories of ai...

Here is the converted markdown format of the provided text. # Aircraft Fuel Systems ## Learning Objectives At the end of this lesson, you will be able to: * Analyze accidents involving fuel systems and assess possible causes. * Explain the difference between fuels and identify categories of aircraft in which they are commonly used. * Apprise other students of critical components of an aircraft fuel system. * Describe guidelines for how to fuel an airplane safely. ## Warm-Up Watch this humorous general aviation pilot safety announcement about fuel management. Be prepared to discuss the questions below. **Video** * How is fuel management in an airplane different from fuel management in a car? * Why is it important to know how your airplane fuel system works? ## Aircraft Fuel Systems * Must function under all operating conditions * Functioning may be affected by fuel grade, contamination, unusual attitudes. * **Two main types** * Gravity feed * Fuel pump driven ## Gravity Feed Fuel Systems * Depend on gravity to deliver fuel to the engine * Simplest type of fuel system * Common in high-wing aircraft * Fuel is stored in the wings, above the carburetor. * Gravity draws fuel from the tanks into the engine. ## Fuel Pump Systems * Two pumps * Main pump is located near and driven by the engine * Auxiliary pump or boost pump is electrically driven * Provides added reliability * Provides fuel pressure for engine start * Controlled by a switch in the cockpit * May need to be on for takeoff, landing, priming, or high-altitude flight ## Inverted Fuel Systems * Aircraft that fly upside down have special inverted fuel systems with a "flop tube" or a "header tank.” * A flop tube is a flexible tube with a weight on one end. * Located in the fuel tank * The weighted end of the tube always falls to the lower side of the tank, drawing fuel from there * A header tank is a small tank located low in the cockpit or fuselage. * When the aircraft is upside down, the header tank is above the engine, allowing gravity to pull fuel into the engine ## Class Discussion Based on your knowledge of automobile fuel systems and what you've learned so far in this class, name as many components of an aircraft fuel system as you can. ## Fuel System Components * Includes all components needed to store fuel and deliver it to the engine * Common components include * Tanks * Pumps * Gauges * Strainers * Drains * Filler Systems * Primers * Selectors * Sumps ## Primer * Used in both gravity fed and pump systems * Vaporizes fuel and pushes it directly into the cylinders * Helpful in starting, especially in cold weather when there's not enough heat to vaporize the fuel in the carburetor * Overpriming may flood the engine, making it harder to start * Primer should be kept locked during flight to prevent inadvertently creating an overly rich fuel-air mixture ## Finding the Fuel Tanks * Usually located inside the wings * Some aircraft also have supplemental tanks to extend range * Tip tanks: permanent tanks located at the end of each wing * External tanks: temporary tanks fitted to the outside of the aircraft for certain operations * Ferry tanks: temporary tanks, sometimes located inside the passenger compartment for long flights ## Fillers * Fuel filler openings are typically located on top of each wing * Used to fill the tanks * On high wing and larger aircraft, a ladder may be needed to reach the filler * Covered by a cap, sometimes locking * May have a vent, which must be kept clear ## Vents and Overflows * Aircraft fuel tanks are vented to the outside * Maintains atmospheric pressure inside the tanks * Important as pressure changes significantly with altitude * Vents may be part of the filler cap or a small tube below the wing * Overflow drains allow fuel to expand at high temperatures * Excess fuel can flow out to prevent damage to the tank * May use the same tube as the vent ## Types of fuel tanks * Bladder tanks * Look like large bags * Made with heavy rubberized material * Can be removed for replacement * Rigid tanks * Look like boxes * Made of metal, plastic, or composite * Can be removed for replacement * Wet wings * Sections within the wings that are sealed to hold fuel * Common on larger aircraft ## Quantity and Pressure Gauges * Fuel quantity gauges are typically supplied for each tank. * Fuel may be measured in pounds (especially in larger aircraft) or gallons. * FAA regulations only require the gauge to read accurately when the tank is EMPTY. * Pilots must visually check tanks. * Good fuel planning is critical. * Fuel pump systems may also have a pressure gauge. * Some fuel systems have a fuel flow gauge to help the pilot determine how quickly fuel is being used. ## Selectors * Choose the fuel source among multiple tanks. * Many have four settings: Left, Right, Off, Both * When set to Both, fuel from both tanks is used. * Does not guarantee fuel will be used equally * Often mandatory for takeoff and landing (placards show requirements) * When set to Left or Right, only fuel from that tank is supplied to the engine. * Useful for balancing the fuel load in flight * When no Both setting is available, pilots must switch tanks often to maintain balance. * Many set a timer as a reminder to switch ## Running on Empty * Remember, the only time an aircraft fuel gauge must provide an accurate reading is when the tank is empty. * Never run a fuel tank dry. * Could allow air to enter the tank * Can lead to vapor lock * Engine may stop and be difficult or impossible to restart * Restart is especially hard in fuel-injected engines because fuel can become so hot it vaporizes in the fuel line and never reaches the engine ## Fuel Strainers * Contain screens or filters * Help remove contaminants from the fuel before they reach the engine - Dirt - Debris - Moisture * The strainer is located between the fuel tank and the carburetor * The strainer typically has a drain located on the belly of the aircraft ## Sumps and Drains * A fuel sump is a low point in the fuel tank * Located under each wing * Located under the belly * Allows contaminants to collect in one location * Water, dirt, and most other contaminants are heavier than fuel and sink to the sump *Sumps are equipped with drains * Drain a small amount of fuel from each sump and the fuel strainer drain before every flight - Allows the pilot to ensure the correct grade of fuel is each tank * Keep draining until there are no signs of contamination ## Contamination Hazards *Contaminants can be pumped into the tanks from fueling source or they from the tanks themsleves. * Water is the most common contaminant. - May leak into the tank through the filler cap - May be the result of condensation in partically filled tanks * Water can freeze, causing fuel system icing. - May block fuel lines or ingested by engine - Fuel additives can reduce icing risk * Water can displace fuel in the carburetor, leaving the engine with nothing to burn. ## Be The CFI Pretend you're a flight instructor teaching a student about a specific component of the fuel system. Working with a small group, come up with a short lesson about your assigned fuel system component. Be creative! Your group will teach the lesson to the class. ## Fuel Grades * Using the right type of fuel for the aircraft's engine is critical. * Turbine engines use jet fuel. * Reciprocating engines use aviation gasoline or avgas. * Some may also use diesel or automobile gasoline * Aviation fuels are color-coded with dye. * Reduces the likelihood of misfueling * Placards near the fuel filler show the type of fuel required. ## Jet Fuel * Kerosene based * Classified as Jet A or Jet B * Clear or straw colored * Has a higher flash point than gasoline-based fuels * Requires higher temperatures to ignite ## AVGAS * Gasoline based * Most common is 100LL * LL stands for "low lead" * Pale blue in color (see image) * Other variants are less common * 80 octane avgas is red * 100 octane avgas is green * If the recommended fuel is not available, the next higher octane can besubstituted (e.g. 100 octane can be substituted for recommended 80 octanefuel) * A small number of aircraft can run on automobile gasoline * Industry is moving to find an unleaded replacement for 100LL avgas ## Fueling Safety * Improper fueling can lead to major consequences. * Misfueling may require something as benign as draining the fuel system, or it may lead to something as serious as an engine failure during flight. * If someone else is fueling your aircraft, always remain present and observe the process. * If you are fueling your aircraft, double-check that you are pumping the proper grade and quantity. ## Fueling Guidelines **Fuel Grade and Quantity** Always ask the employee to read back your fuel order. Match the fuel truck with your fuel order. If self-fueling, verify the fuel pump in use is the correct grade. **Fuel Nozzel** Verify the fuel nozzle is compatible with the aircraft fuel filler. Avgas nozzles are small and round. Jet fuel nozzles are larger with a flat end. ## Fueling Guidelines **Aircraft Grounding** * Always ground the aircraft to the fueling source * Prevents static discharge that can cause explosions * Fuel trucks and fuel pumps have a special wire on a reel that is connected to the aircraft to ground it **Payment** *When paying, verify the fuel grade and quantity on invoice matches what was ordered and intended ## Fueling Guidelines **Preflight** * Visually check the tanks for quantity and fuel color. * Drain a sample from each tank sump. Check for water and contaminants and note the fuel smell and color. * If there is any doubt about the type of fuel in the tanks, DO NOT DEPART! **Fuel Caps** *Ensure that fuel caps are secure. *If the cap comes off in flight, fuel can siphon out of the tanks at a very fast rate. **Can you recall the color of 100LL and jet fuel?** ## Investigation Nation Each group of students will be assigned a different type of fuel-related accident (fuel starvation, fuel exhaustion, fuel contamination, or misfueling). Each group should select one accident related to their type of fuel-related accident. Develop a poster, slide presentation, or storyboard to present your findings to the class. Presentations shouldinclude information about circumstances surrounding the accident, the role of fuel in the accident, additional causes of/contributors to the accident, and ideas for how the accident might have been prevented. Use the following webpage to research accidents: https://www.ntsb.gov/\_layouts/ntsb.aviation/index.aspx Shows a screenshot of the Event Details page. *Airport Name, Airport Code, Weather Condition, Broad Phase of Flight* *None, All* *Location information available for most cases in the United States since2002* *Latitude, Longitude* *Submit Query, Download XML, Downloaded Text, Reset* ## Private Pilot Knowledge Test Question What type of fuel can be substituted for an aircraft if the recommended octane is not available? A. The next higher octane aviation gas. B. The next lower octane aviation gas. C. Unleaded automotive gas of the same octane rating. ## Private Pilot Knowledge Test Answer What type of fuel can be substituted for an aircraft if the recommended octane is not available? A. The next higher octane aviation gas. B. The next lower octane aviation gas. C. Unleaded automotive gas of the same octane rating. ## Private Pilot Knowledge Test Question Filling the fuel tanks after the last flight of the day is considered a good operating procedure because this will A. Force any existing water to the top of the tank, away from the fuel lines to the engine. B. Prevent expansion of the fuel by eliminating air space in the tanks. C. Prevent moisture condensation by eliminating air space in the tanks. ## Private Pilot Knowledge Test Answer Filling the fuel tanks after the last flight of the day is considered a good operating procedure because this will A. Force any existing water to the top of the tank, away from the fuel lines to the engine. B. Prevent expansion of the fuel by eliminating air space in the tanks. C. Prevent moisture condensation by eliminating air space in the tanks. ## Private Pilot Knowledge Test Question To properly purge water from the fuel system of aircraft equipped with fuel tank sumps and a fuel strainer quick drain, it is necessary to drain fuel from the A. Fuel strainer drain. B. Lowest point in the fuel system. C. Fuel strainer drain and fuel tank sumps. ## Private Pilot Knowledge Test Answer To properly purge water from the fuel system of aircraft equipped with fuel tank sumps and a fuel strainer quick drain, it is necessary to drain fuel from the A. Fuel strainer drain. B. Lowest point in the fuel system. C. Fuel strainer drain and fuel tank sumps. ## Fueling Up! In the summative assessment,you will review a preflight checklist for a Cessna 172 and identify the items related to fuel and fuel-systems. For each check-list item,you will describe why a pilot should perform this check. In addition, you will describe the differences between avgas and jet fuel and also describe three guidlines that pilots should follow in order to safely fuel an airplane.