Learning Center Library Contents

Down Arrow
Welcome Guest
Aviation Learning Center Document Time in Your Tanks - P-8740-03
Author: Federal Aviation Administration Date: 1995
used for alignment
used for alignment
Viewing Options: View Document as Chapters Chaptersused for alignment View Full Document Full Documentused for alignment View Print-Friendly Document Printer Friendlyused for alignment Search Inside this Document Search Insideused for alignment

< Previous Chapter used for alignment Next Chapter > used for alignment

Fuel Management Tips
used for alignment

Flight Planning

As described in the previous chapter, you should compute a reasonable time limit for your aircraft. Factors to be considered in planning each flight include:

  • Trip length.

  • Cruise altitude.

  • Wind. (Caution: Don't count on forecast tailwinds; they can change!)

  • Number of passengers (weights plus baggage).

  • Inflight endurance of persons on board.

Resolve not to exceed the time limit you establish, and estimate your ETA for each checkpoint. Be aware of your actual progress, and think about landing at an alternate if you are running behind your estimated ETA.

Fuel Quantity and Quality

Fuel gauges are subject to malfunctions and errors. Therefore, unless restricted by the gross weight or center of gravity limits, it is considered good judgment to "top off" the tanks at fuel stops. If the fuel load must be limited, you should endeavor to get an accurate measurement of fuel quantity by using a dipstick calibrated for the aircraft.

Condensation can occur in partially filled tanks. Filling the tanks at the completion of the trip will reduce the probability of fuel contamination by condensation.

Use the grade of aviation gasoline specified by the manufacturer for your aircraft. Use the next higher grade when the specified grade is not available. Never use automotive gasoline or aviation gasoline of a lesser grade than that specified by the engine manufacturer.

Visually check the color and cleanliness of the fuel in your aircraft by draining the fuel sumps and strainers after each fueling and during preflight inspection. Never assume your fuel quantity and quality to be correct. Check it! In addition, you should know the fuel system of your aircraft, and never operate a fuel selector without visually checking its position. Do not reposition the fuel selector just before takeoff or landing.

Leaning the Mixture

Proper leaning of the fuel mixture will provide a number of benefits:

  • Improve engine efficiency and increase airspeed.
  • Provide smoother engine operation.
  • Provide greater fuel economy and longer range of operation.
  • Provide longer spark plug life with less fouling.
  • Reduce maintenance costs.

You should also know when to lean the mixture:

  • Normally aspirated engines: Lean any time the setting is 75 percent or less. Use full rich for full throttle operation at 5,000 feet density altitude and below.
  • Turbocharged engines: Always use full rich for takeoff, regardless of altitude. Lean at cruise as recommended by the manufacturer.

Finally, you should also know how to adjust the mixture for high altitude takeoff and landing:

  • Lean to maximum RPM for carburetor engines.
  • Lean to proper fuel flow and fuel pressure settings for injected engines.
  • Lean before entering the traffic pattern to ensure maximum power for go around.
  • Enrich the mixture for descent only as required. Enrich enough to keep the engine running smoothly.
  • Go to full rich when in the traffic pattern, or as required when landing at high elevations.

Remember - A tank full of fuel is a tank full of time! Don't let either run out.

used for alignment