Wikiposts
Search
ATC Issues A place where pilots may enter the 'lions den' that is Air Traffic Control in complete safety and find out the answers to all those obscure topics which you always wanted to know the answer to but were afraid to ask.

SLOT Vs CTOT

Thread Tools
 
Search this Thread
 
Old 5th Jan 2008, 09:40
  #1 (permalink)  
Thread Starter
 
Join Date: Jun 2002
Location: London
Posts: 4
Likes: 0
Received 0 Likes on 0 Posts
SLOT Vs CTOT

Happy New Year to you all
Could somebody please clarify if a CTOT has the same tolerances as a slot (-5 +10) and if possible where this information is printed.
Thanks in advance. D
DEED is offline  
Old 5th Jan 2008, 09:43
  #2 (permalink)  
 
Join Date: Apr 2007
Location: Seaworld
Posts: 63
Likes: 0
Received 0 Likes on 0 Posts
CTOT is the same as the slot. CTOT is just the official term for it.
Traffic is... is offline  
Old 5th Jan 2008, 15:41
  #3 (permalink)  
StandupfortheUlstermen
 
Join Date: Dec 2001
Location: Peoples' Democratic Republic of Wurzelsetshire
Age: 53
Posts: 1,182
Likes: 0
Received 0 Likes on 0 Posts
Is it deja vu or have we done this one recently?

(The clue is at the bottom of the page)
Standard Noise is offline  
Old 6th Jan 2008, 18:10
  #4 (permalink)  
 
Join Date: Oct 2006
Location: Somewhere on a RWY
Posts: 26
Likes: 0
Received 0 Likes on 0 Posts
Hi there...

There is a slight difference between CTOT and SLOT.

The CTOT is a time (eg.: 0745 UTC)
DAT123 has a CTOT of 0745 UTC

The slot is a time window of 15 minutes calculated on the CTOT
DAT 123 has a slot from 0740 till 0755 UTC

Greetings
B.
BravoMike is offline  
Old 6th Jan 2008, 18:41
  #5 (permalink)  
 
Join Date: Dec 2002
Location: flightdeck/earlyhours commute
Posts: 199
Received 0 Likes on 0 Posts
Controlled? or calculated? Take Off Time.
CTOT=slot time. The slot being 15minutes wide, (-5/+10) around the time.

So be ready to push allowing taxi to, and be ready for departure at the hold
-5/+10mins on the CTOT.
As I understood it.

Why it is -5/+10 would be interesting to know, in the 'headful of useless factoids'
Shiny side down is offline  
Old 6th Jan 2008, 20:21
  #6 (permalink)  
 
Join Date: Jan 2000
Location: ireland
Posts: 109
Likes: 0
Received 0 Likes on 0 Posts
ctot tolerance

to be pedantic, and yet correct.... there is no tolerance of -5+10 on a slot. this is a common misconception.

the bible on slots is the eurocontrol basic cfmu handbook. section 4 page 4-7 refers

it states quite clearly that for airline operators, they need to coordinate the departure time to comply with the slot i.e. slot time/ctot minus taxitime equals pushback time.fullstop.

the 15 minute window is designed for atc, and atc alone to " optimise the departure sequence "

pilots seem to think that this is their bit of leeway, and can get quite possesive of something that is patantly not theirs!

a little education can go a long way!
beamwidth is offline  
Old 6th Jan 2008, 20:27
  #7 (permalink)  
 
Join Date: Sep 1999
Location: Scotland
Posts: 417
Likes: 0
Received 0 Likes on 0 Posts
beamwidth is correct. At many places I've been to pilots call ATC and advise them they will "make the +10 on that slot" (or words to that effect) without having the courtesy to ask if they can be co-ordinated late in the first place!
Kiltie is offline  
Old 7th Jan 2008, 09:03
  #8 (permalink)  
 
Join Date: Oct 2005
Location: NEW FOREST
Posts: 102
Likes: 0
Received 0 Likes on 0 Posts
CTOT = Calculated Take Off Time
QWERTY9 is offline  
Old 10th Jan 2008, 10:50
  #9 (permalink)  
 
Join Date: Aug 2001
Location: UK
Posts: 102
Likes: 0
Received 0 Likes on 0 Posts
So with a CTOT one would request taxi to make good that CTOT. In the common scenario of 4 or 5 aircraft at the holding point, would the crew then be expected to adjust their off-blocks time to make good the CTOT? If so, how do they get the time factor required for the adjustment?
refplus20 is offline  
Old 10th Jan 2008, 13:29
  #10 (permalink)  
Moderator
 
PPRuNe Radar's Avatar
 
Join Date: Jul 1997
Location: Europe
Posts: 3,228
Likes: 0
Received 0 Likes on 0 Posts
The pilot should ask for taxy at an appropriate time to make good their CTOT regardless of the traffic on the airfield. That's not really the pilot's problem.

ATC will then take the responsibility for massaging the system around the planned CTOT, be that using the 15 minute window period, or arranging for an extension if the aircraft can't get airborne within the CTOT window due to congestion
PPRuNe Radar is offline  
Old 11th Jan 2008, 18:31
  #11 (permalink)  
 
Join Date: Feb 2001
Location: Hants, UK
Posts: 1,064
Likes: 0
Received 0 Likes on 0 Posts
Each airfield has an assumed taxi time from the gate to the runway. This can be increased in times of high congestion. Any delay calculation is based upon the difference between the EOBT and the Taxi time.

So at Heathrow, where assumed taxi time might be 20 mins, an EOBT of 0900 with a CTOT of 0920 will be attributed as no delay. EOBT 0900, CTOT 0930 is a 10 minute delay.

So in this case you should be ready to leave blocks no later than 20 mins before your CTOT.
eyeinthesky is offline  
Old 19th Jan 2008, 04:32
  #12 (permalink)  
 
Join Date: Jan 2008
Location: uk
Posts: 29
Likes: 0
Received 0 Likes on 0 Posts
"""to be pedantic, and yet correct.... there is no tolerance of -5+10 on a slot. this is a common misconception.

the bible on slots is the eurocontrol basic cfmu handbook. section 4 page 4-7 refers

it states quite clearly that for airline operators, they need to coordinate the departure time to comply with the slot i.e. slot time/ctot minus taxitime equals pushback time.fullstop.

the 15 minute window is designed for atc, and atc alone to " optimise the departure sequence "

pilots seem to think that this is their bit of leeway, and can get quite possesive of something that is patantly not theirs!

a little education can go a long way!""""
Well put, and informed. the use of the extra time by pilots, instead of atc doesnt help the system function at all,along with not bothering to apply early enough for a new slot or put in a delay in order to free up that "slot" for another (in fact company) aircraft. More education on this i really do think is needed
WhatUMean is offline  
Old 20th Jan 2008, 14:33
  #13 (permalink)  
Registered User
 
Join Date: Jul 2004
Location: uk
Posts: 35
Likes: 0
Received 0 Likes on 0 Posts
Couldnt agree more, there still seems to be a lot of confusion about slots, and how and why and by who they are issued. and doesnt seem to be a good enough education of handling companies and also pilots of exaclty the improtance of upto date flightplans.
RadarRambler is offline  

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off



Contact Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service

Copyright © 2024 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.