There is a lot of pressure these days to squeeze every movement that is possible out of a runway. Even at airports that sometimes are not considered to be busy the peak periods now see delays caused by limited runway capacity. In some cirumstances one way to increase runway capacity - if the runway and taxiways are suitably configured - is to line up more than one aircraft on the runway.
The UK Manual of Air Traffic Services permits this - the relevant text is below:
Line-up instructions may be issued to more than one aircraft at different points on the same or crossing runways provided that:
a) it is during daylight hours;
b) all aircraft are continuously visible to the aerodrome controller;
c) all aircraft are on the same RTF frequency;
d) pilots are advised of the number of aircraft ahead in the departure sequence, and the position/runway from which these aircraft will depart;
e) the physical characteristics of the runway do not render preceding aircraft in the departure sequence invisible to succeeding aircraft on the same runway.
There is no guidance about how far apart the aircraft have to be when a preceeding aircraft in the sequence rolls. The rolling aircraft will generate propwash or jet eflux straight at an aircraft lined up behind. There is the risk also that debris etc. will be picked up and blown toward the aircraft behind.
Pilots I have spoken to do not have a consistent view on whether they are happy with such a line-up clearance. Some have said that there is no way that they would accept the line-up regardless of the distances involved whilst others don't see a problem and there are views in-between depending on the exact circumstances.
Just wondered whether anyone has additional guidance or experience that might help to clear up whatever safety issues there are in the procedure?
What is interesting is that it is difficult to question the wisdom of doing this without additional guidance or safety assessment - to use the current buzzwords - when
Eurocontrol appears to be advocating doing it without any apparent limitations - take a look at the videos on the page. One view I've heard after viewing the videos is that if Eurocontrol says it's OK, then it must be safe.
Any other views?