SLF query

[Kulu]

Hi all

A friend of my parents was flying yesterday from Nice to Tel Aviv (the flight was the 12.40 ISR) and it was delayed on the ground for a couple of hours - the cabin announcement was that the delay was due to over crowded skies around part of the route (I think it was Cyprus).

I'm interested to know what could have caused that, (eg was it bad weather elsewhere that made re-routing necessary) and how common it is. I'm also interested to know (this because I've been asked by folks) why if the air conditioning on the aircraft was not being run, the cabin doors could not be opened to let some air in.

I'm assuming that the doors stay closed simply to stop people wandering around and falling out, but would be glad to know if there's any technical reason! (The more serious question is the overcrowding one).

All help gratefully received.

[NudgingSteel]

I've got absolutely no idea about the open doors part of the question so I'll leave that to any aircrew passing through this forum!

However, the 'overcrowding' in the skies presumably refers to air traffic flow restrictions due to overdemand in one or more sectors ('chunks' of airspace, if you like). This could have been due to many things, I don't know what was the cause today but examples include: bad weather (thunderstorms) requiring lots of avoidance; high demand (summer holidays, lots of flights wanting to route the same way at the same time); temporary airspace closures (possibly due to military exercises, rocket firings etc); ATC staffing problems (controllers sick, therefore one or more sectors may need to close or be combined with another sector which requires a reduction in traffic levels to allow the existing sector controllers to cope), and so on. In one form or another these restrictions exist daily throughout Europe. I should say the CFMU (central flow management unit) do a damn good job at keeping it flowing impressively well, without much praise generally, and no I don't work for them!!!
Hope some of this is of use.

[BOAC]

Kulu - not sure of airline or their operating procedures, but a lot of airlines PROHIBIT open doors with no external equipment present,eg stairs/catering truck/jetty etc due to c/crews' unfortunate ability to hurl themselves out of same. The equipment has to be clear in case the start-up restriction is advanced, and often it is not possible to get ground staff to the a/c to remove such.

The Captain MAY elect to contravene company orders in such a case, and I have found that an 'opposite corners open' policy produces a reasonable draft, but you can see the possible hole he/she digs? The only consolation is that all the crew are experiencing the same!

NS has covered the ATC question, and I would add that there may have been Israeli entry restrictions (which are quite controlled) and the entry 'procedure' takes place in the Nicosia ATC area.

[Kulu]

Guys, just a short note to thank both of you for your replies; you've been very helpful! :)

[perkin]

My understanding (as a lowly SLF) is that in order to just request a slot during busy periods the aircraft must be ready to depart, that is, all ground equipment removed, doors closed, cabin secure (this was the story told by a Captain one time during such a delay). This could be the reason for the delay this time?

Surely if the APU was running some air would be circulating at least?

[Kulu]

Hi Perkin

It's a good point about the APU; I think the cabin announcement was that the engines were off to conserve fuel, hence no air conditioning. I don't know how long the APU can run for under those conditions, but I think they were on the ground for two hours total.

[BOAC]

Indefinitely, but it has to be
a) fitted
b) serviceable
c) Company policy (vis Jet2:uhoh:) to use it

[A Very Civil Pilot]

Even with the APU running, it may be hard pushed to adequetly cool a full aircraft (I guess that Nice in June is warm!). With doors closed and no APU, the temperature will soon rise to unacceptable levels. (At least on the 737 classic).

Assuming there was a slot delay, the crew can ask ATC to put in a 'ready message', meaning that they are ready to go. In that case the slot could be cancelled if the flow controllers see that letting the aircraft depart now will not cause congestion downroute. Accordingly, doors have to be closed and steps removed to allow for an immediate pushback and start.

This is often the same reason we see passengers on 'Airline' and similar TV shows, having missed the checkin complaining, saying 'I can see the aircraft on the ground and it hasn't left yet, so let me on.' It is probably ready, waiting for a slot improvement, and won't risk losing that to allow late pax on board!