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Nightstop
26th Apr 2002, 07:47
We were recently cleared immediate take-off, jet aircraft at 3.4nm final. The taxyway from the holding point onto the runway is uphill so getting the aicraft to move from stationary takes some thrust/time, indeed we have a company SOP not to apply an excessive amount of thrust when taxying. Unfortunately the ATCO hadn't taken this into account and the aircraft on final was required to go-around. Later, the reason stated by ATC was that we were slow to line up. Well, if you're reading this (Miss) we did our best, honest :rolleyes:

1261
26th Apr 2002, 09:21
You can always refuse an immediate, remember! :)

Dan Dare
26th Apr 2002, 09:24
It wasn't me this time:D

First off, with a gap that size she'd have been wrong not to try to get you off (much tighter could be a struggle, but not impossible).

The decission would have been made from experience in similar circumstances (what we're paid our peanuts for judging), and an assessment of the conditions and the operators and aircraft types involved.

Things that can go wrong:

1) Departing aircraft PAINFULLY slow to roll. If you can't accept an immediate (ie ROLLING!!!!!!!!!) departure, then don't accept such a clearance, wait for a better chance.

2) Controller misjudged the gap. If the inbound is a little faster than normal, she should have been able to tell (depends on her equipment), but sometimes it can catch you out. Also if its heavy then it wont slow down so much from four miles, which is difficult to know. If there is little or no headwind component on final, then things obviously happen a little quicker, but she should take all of these things in to account.

3) Controller or arriving pilot bottled out too soon, where it would have worked nicely given a bit of balls and an over the threshold clearance (or for lucky NATS controllers a conditional "after the departing ... cleared to land")

Of course, if she did get it wrong then it is logged as "pilot error" because it looks better on the records (much like your "ATC delays") ;).

I don't think its signifficant that there is an uphill slope to the runway. Each pilot she squeezed off in a tight gap would have to go up the same hill, so if 99% of the time it works, **** sometimes it doesn't and someone has to go arround.

Ramble over. Visit your local tower for a fuller picture!

Standard Noise
26th Apr 2002, 16:57
3.4NM - plenty of space. We do quick backtracks (our taxiway is approx. 600 metres from the threshold) on a regular basis, with a/c at 7NM.
99% of the time it works and everyone's happy (a/c launch 3 to 4 mins earlier, pax get home quicker, less fuel used etc.)

Must admit, I agree with 1261 and Dan Dare completely.

Oh, to be paid peanuts, that'd be a step up!

Pointer
30th Apr 2002, 14:46
well if you count LCY as an airport and not to the nautical version ..eg. carrier then we probbably do some quick backtracks.

meaning almost full length of rwy backtrack with traffic 4 miles has occured :D but then again we don't land but fall from the sky!

Pointer

MANAGP
30th Apr 2002, 16:21
Many airlines (mine included) have Quick Access Recorders fitted to aircraft which monitor amongst other things Thrust applied and Taxi speed. We are not permitted to taxi above 20 kts g/s, Thus if you are having to start moving from a standstill uphill with limited thrust it takes a while. This is most annoying when invariably you get your crossing clearance just after stopping!!

Nightstop
30th Apr 2002, 22:20
Thank you MANAGP , as you say the spy in the cab has to be taken into consideration at all times :eek: I've no problems with Cleared Immediate Take - Off from a rolling start but this clearance was......

MrWalker
1st May 2002, 05:11
Always remember that you are born with a finite but unkown number of immediates, don't waste them because when you really need it the cupboard may be bare.:D