If we are talking about roll input:
then during the descent along the glide slope beam, as the ILS transmitter is neared, since the beam-error radio signal is a function of angular beam errors, a significant increase results in the sensitivity of the input beam-error radio signal to movement of the airplane relative to the beam centre.
That is, because the radio measures angular beam errors rather than actual linear distances, as the transmitter is neared, a small airplane movement off the beam centre results in a proportionately large angular beam error.
A correspondingly large radio beam-error signal would result, causing overcontrol. To correct for this condition, a desensitiser network is included.
This network receives an input from the radio altimeter which is applied to a function generator. When the altitude of the airplane drops below 1000 feet, the output of the function generator changes the gain of the desensitiser circuit, which provides initial amplification of the beam-error signal for initial very tight control.
The descent of the airplane down the glide slope beam towards the transmitter is directly proportional to the radio altitude as the airplane approaches the localizer transmitter. Therefore, the function generator controls the desensitiser circuit to reduce the gain of the beam-error signal in proportion to the increase in sensitivity of this signal, thus preventing overcontrol to small linear beam displacements.
Another function generator is included in the final bank-angle limiter. This function generator goes into operation at an altitude of approximately 1000 feet and reduces the bank-angle limit as the airplane approaches touchdown. The bank-angle limit is reduced to a maximum of 5 degrees, as touchdown is neared. This prevents excessive bank angles as touchdown is approached.