VT-10 Primary INAV Ground School Instrument 3 Practice Test

Reserve fuel endurance is the amount of time you can stay aloft using only the reserve fuel, providing a safety margin beyond your planned flight. In many training contexts for light aircraft, this standard reserve is about 20 minutes of flight at typical cruise consumption. So, after accounting for planned fuel, you should be able to continue flying for roughly 20 more minutes if you need to. Ten minutes would give too small a cushion, thirty minutes is more than the typical training standard, and sixty minutes is unnecessarily large for everyday planning.