A guidance apparatus mounted on the belly of a tanker aircraft for providing visual indications to the pilot of the receptor aircraft with respect to the approaching operation to carry out the refueling by means of a refueling boom. The guidance apparatus includes light emitting devices including modules of light emitting diodes and control devices for supplying current to the light emitting diodes that include dimming control units for controlling the intensity of the light emitted by the light emitting devices via a dimming signal depending on a dimming voltage. The dimming control units are adapted to provide to the light emitting devices a pulse-exponential amplitude modulated dimming signal so that the light intensity can be properly controlled in all visibility conditions.