At CDG, on the Southern 2 paralell runways, controllers are allowed to issue early landing clearances, provided that the controller thinks that, should everything go ok, the 2nd, 3rd, 4th... will land safely.... and this whatever the weather, except when low visibility procedures are in force. In taht case, only the 1st one is cleared to land.
Otherwise, if for example the 2nd aircraft is far too close to the preceding one, with a greater speed, if the controller thinks there may be a missed approach, then he tells the second aircraft to continue on the ILS.... but when things are ok, the 6th one can be cleared to land.
(don't know if i'm very clear...... sorry, more difficult in English, and it's quite late by now )
the purpose of all this is to have less messages on the frequency. When there are many aircraft on departure and arrival, the controller does nothing else but talk on the radio... he/she doesn't stop....
It's aimed to be like in Dallas, actually.... don't know if it succeeds.... it's alledgedly the model...
à bientôt
