CrabwiseMatch distance and speed before calculating time
A knot is one nautical mile per hour. Thus 90 NM at a constant 120 knots takes 0.75 hours, or 45 minutes. Dividing 90 kilometres by 120 knots without conversion mixes units, even though the arithmetic still produces a number.
One nautical mile is 1,852 metres. If a question uses statute miles or kilometres, convert the distance or speed consistently. Treat US and imperial gallons as different units; a value labelled only 'gallons' needs clarification.
Label what every direction represents
Write TRUE or MAG beside course, runway direction and wind direction. For a wind triangle, also write FROM beside wind. A direction representing the movement of an air mass points opposite the reported wind-from direction.
Heading and track are different fields. A problem that gives track made good and heading may be asking you to find wind, rather than to calculate the heading needed for an intended course.
Keep fuel volume, mass and flow separate
Eight US gallons per hour for a hypothetical 45-minute exercise means 6 US gallons for that time interval. Taxi, reserve and other specified allowances are separate quantities; this arithmetic does not decide which allowances are required.
Converting fuel volume to mass requires a density assumption. A training value is not a measurement of the fuel in a particular aircraft. Do not combine a pounds-per-hour rate with a gallon quantity without accounting for that difference.
- Record whether speed is IAS, CAS, TAS or ground speed.
- Convert minutes to hours before multiplying an hourly flow.
- Retain unrounded intermediate results.
- Use approved aircraft information for actual flight tasks.