Broadening The Subject
I wanted to develop this thread because our (London) procedures cause some (understandable) confusion amongst some airlines.
I thought I could reduce the confusion by explaining the reasons for the procedures.
On transfer from London en-route to an approach frequency a pilot is requested to report cleared level, aircraft type and information received.
Cleared level becomes particularly significant when approaching areas of dense traffic and especially a hold where a level bust can very quickly become critical. In the LTMA many outbound routes pass under or near the holds thus increasing the number of potential conflicts in the event of a level bust.
Aircraft type is checked to ensure correct vortex turbulence separation in the intermediate approach and in particular on final approach. It is also checked on behalf of the tower who may be issuing conditional clearances to other aircraft or vehicles based on correct visual identifiction of an aircraft type. For this reason also variant changes are noted - e.g A319 v A320.
'Infomation received' enables us at a glance to check for any significant weather or pressure changes.
Several airlines omit some or all of this information on first contact with approach possibly because they are mindful of the "callsign only" request which does take place on transfer from Intermediate Director to Final.
The reason that happens legitimately at that stage is because the precision of the Final Approach task (particularly but not exclusively at LHR) requires exact timing of heading and level instructions. Whilst this is by no means always safety related an overlong initial call can impinge on our attempts to optimise spacing for the benefit of all inbound AND oubound aircraft.
So, DLH in particular please note, callsign, cleared level, aircraft type, information received on first contact (with for example LL Approach). Callsign only, ONLY on transfer to Final Director.
Thank you