I’ve noticed a trend on several check rides recently. Applicants are planning a flight at a certain power setting, TAS and Fuel Burn, but flying something totally different in the air.
Two private and one instrument applicant each planned a cross-country using 75% power, which equals about 2550 RPM. However, in cruise flight they set 2100 to 2200 RPM which will through off all the ground speeds, enroute times and fuel burns At some point in the check ride the I will ask how fast we’re going, when are we going to get to our destination and how much fuel will it take. In one case we where 30 knots slower than planned. Each applicant was asked why the big difference, none had indicated that the low power setting was a big part of the problem. When the power setting was pointed out each applicant said they always used that lower power setting.
Some flight schools advocate flying slow on the check ride. That’s fine, I get that but for the cross-country part of the ride, fly what you planned. If you plan the cross country at 75% power at 2550 RPM and 115 knots at 10 gph, fly it that way. When the cross-country part of the ride is over, slow the plane down to a slow cruise (I like around 23-2400 RPM).