"I was told, a long time ago at CATC methinks, that there had been a few incidents involving pilots given "cleared ILS approach" and then immediately descending to MDH/MDA regardless of step-down fixes or traffic beneath the glide....."
ICAO is quite clear about this: If you are cleared for a radar vectored ILS approach, you have to maintain the last assigned altitude and then, after being established on the localizer, descent on the glidepath. So "diving" immediately to the MDH/MDA is obviously NOT the correct thing to do.
In case you can't descend with the ILS, due to airspace for example, the procedure 'to get you on the localiser first, and then clear you to "descend with the ILS" when other airspace / procedures allow you to' does absolutely make sense. (Thanks Chilli Monster). Also in case of parallel runways, it does make sense to first get a clearance to establish the A/C on the localizer only.
However, on many other occassions, there are no such restrictions and in the UK still you will always hear "descent with the ILS". Actually, I can't recall that I ever received a "cleared ILS approach" in the UK.
I'm operating through whole Europe, and everywhere else outside the UK, I do receive the instruction "cleared ILS approach". Never heared of any problems though of pilots descending below the glide slope due to this instruction.
As I was just curious about the background of the instruction "descend with the ILS", I posted this topic. Am I right stating (WITHOUT ANY OFFENCE!!) that (except in case where you can not directly follw the glide due to airspace/procedures) the instruction "descend with the ILS" is a "practice" of UK controllers? Or does the UK law prohibit the instruction "cleared ILS approach"?
Thanks for the replies so far. Could anybody give me more information on this?
Regards,
RB.