Power Selection

The method in which to select an appropriate power setting has already been discussed so let’s go ahead and just select a cruise power setting of 55 percent power. Now, the Cruise Performance table can be a little tricky to interpret. From this table, we can derive the cruise speed and fuel burn. This data is displayed based on standard temperature deviation and cruise pressure altitude. Remember we are cruising at 5,500 feet pressure altitude and the forecast temperature is -1°C. The standard temperature at 5,500 feet is 4°C which is 5°C colder than standard. As you can see this can lead to a lot of interpolation. On the written exam, you will never be asked to perform this many interpolations on a single question. That being said, while you could interpolate to find the accurate values it is much easier to simply use the 6,000 feet values and round the values conservatively. Again, do not take this approach for your written exam. That being said, in order to achieve 55% power at 5,5000 feet, we will plan to use a power setting of approximately 2,300 RPM. The resulting KTAS and GPH are 103 knots and 7.8 GPH. Round these to 100 knots and 8 GPH respectively and complete the navigation log as shown below.