In these modes of control, the pilot enters into the MCDU a sequence of targets that defines an intended flight path.
This coordination step is called activating the approach and is achieved by pushing a key on one of the MCDU pages.
This required the pilot to program these constraints into the flight computer through the MCDU keyboard.
The MCDU display indicated this change (the loss of the altitude constraints) through the disappearance of two normally present indications.
In the latter three cases, however, in which the pilots had to realize the problem based on a review of the data on the MCDU HOLD page, they needed help from the instructor to realize that a problem existed and to modify their input to resolve the problem.