A sampling rate of at least 10 data samples every second is necessary to accurately record the maneuver, and each data sample must be accurately time correlated with the data samples of the other parameters. The starting point for a check climb is usually brake release at the start of the takeoff roll. Although the airplane is not really checking the best-climb schedule until after the pilot has completed the takeoff, acceleration and transition, the check climb maneuver usually includes the total time and fuel used from brake release. In order to accurately establish the weight at the start of the maneuver, a special fueling and weight measurement may precede the engine start, and the airplane might be positioned closer to the runway to avoid a long taxi time. The test begins on the runway by establishing Military Power with the brakes on.
Time starts when the brakes are released.
If the check climb is to be in afterburner, the afterburner is ignited simultaneously with brake release. The pilot completes a normal takeoff with rapid gear and flap retraction. The airplane is allowed to accelerate at low altitude to a speed somewhat below the speed for best climb. The pilot then performs a fairly abrupt pullup and attempts to stabilize on the best climb speed schedule at the lowest practical altitude. Once stabilized on the climb schedule the pilot will adjust speed as the airplane climbs so that the schedule of best-climb speed is maintained as the altitude increases.