Stop bars
 

There is a thread going on the Pacific forum. In Australia, conditional line up clearances are not permitted when using stop bars. Is it the same in other countries? Does the ADC operate the bars or have an assistant?

UK. Where I work we do use conditional runway clearances with H24 stopbars. Stop bar remains lit until the subject aircraft has passed and crossing the hold is safe. There is no assistant, the tower controller works the stop bars. There is also no automatic reset, they have to be lit by the tower controller again when appropriate.

Do I read this right CV; you clear aircraft to cross lit stop bars as SOP?

Ditto to CV. Conditional clearance passed, stop-bar deselected when condition has passed. (We do have a timed reselection of stop-bar but it's a long time so controller normally reselects stop-bar manually.)

Chev - No, he didn't say that!

No chevvron, we never cross lit stop-bars.

Conditional clearance is given, stop bar remains lit.
Aircraft passes, stop bar is deselected, aircrew lines up in accordance with clearance.
ATCO reselects stop bar when aircraft has passed.

In my experience the crews here will question if we forget to drop it and we will then deselect it. I have never had anyone cross a lit stop bar without questioning.

Likewise at LHR. The AGL has no bearing on when one gives a clearance; one just has to remember to drop the bar when it's safe for the aircraft to start moving forwards.

Go to Moscow VNO. SOP to clear aircraft across red stop bars! ATC refuse to deselect when requested. Can make for a long wait.

UK ATC Mats1 does allow for the use of conditionals with stop bars as described by others. At my unit our Mats2 (local instructions) takes this away from us, so no conditionals when stop bars are involved.

Does seem a little pointless issuing a conditional clearance when you have control over when they enter the runway anyway?

But it gives room when to issue the clearance. Meanwhile you can give instructions to the vacating aircraft and have the other one line up already when you drop the stopbar when a push of a button. Workload management thing I assume.

360BakTrak

Obviously you've never been an aerodrome controller.

obwan......er, yes. For 20 years. Maybe I haven't used stop bars for those 20 years. :ugh:

Where I work, there's a high chance that some of the more dubious operators would cross the red stop bar having been issued a conditional, and it's far safer (and licence preserving) not to issue such a clearance. There are stop bars here, but I only work approach radar (for the benefit of Obwan!).

There are different approaches.
In some places they use stopbars for RWY intersection but they deselect the one of the "main" holding point in order to issue conditional clearances.


Another option is to issue conditional clearance and then deactivate the stopbar (which will light up automatically when the aircraft crosses it).


There is also the option suggested by VC - the question of 360BakTrak is legit ("at that point make more sense to just wait and give a line up clearance"). However you can still talk to somebody else while you look for threshold and operate the light, and you benefit of improved awareness and readiness of the flight crew (which efficiency wise it translates in shorter line up time).

Correction

Obviously you've never been an aerodrome controller at a busy unit. (for the benefit of
360BakTrak)