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.

CDA into Gatwick

Thread Tools
 
Search this Thread
 
Old 23rd Feb 2006, 21:16
  #1 (permalink)  
Thread Starter
 
Join Date: Feb 2006
Location: UK
Age: 86
Posts: 15
Likes: 0
Received 0 Likes on 0 Posts
CDA into Gatwick

I live very near Gatwick and a large number of aircraft , usually USA airlines, seem to approach Gatwick much lower than UK airlines. Is this a procedure of these USA aircraft or just bad flying ?
flatfour is offline  
Old 23rd Feb 2006, 21:38
  #2 (permalink)  
 
Join Date: Nov 2005
Location: Isle Du Cyber
Posts: 933
Likes: 0
Received 0 Likes on 0 Posts
Bigger Aircraft

Do you think they could be bigger aircraft than normal??

Normal aircraft being Boeing 737 aircraft.

Bigger being Boeing 767 or even 777 or even the odd 747 aircraft, i could be wrong but do not quote ?

I hope this might be if assitance.
GBALU53 is offline  
Old 23rd Feb 2006, 22:03
  #3 (permalink)  
Thread Starter
 
Join Date: Feb 2006
Location: UK
Age: 86
Posts: 15
Likes: 0
Received 0 Likes on 0 Posts
Sorry. My fault. There is a rumour that they are permitted approach at lower heights from other airlines and this has caused a rumpus among residents. BAA refuse to identify the offending airlines publicly. Seems preposterous to me but I don't know the facts - as a layman.
flatfour is offline  
Old 23rd Feb 2006, 22:15
  #4 (permalink)  
Junior trash
 
Join Date: Nov 1999
Location: UK
Posts: 1,025
Likes: 0
Received 0 Likes on 0 Posts
Americans dont generally do CDA's they just dive and fly level because thats the rules in the states.
Hotel Mode is offline  
Old 23rd Feb 2006, 22:47
  #5 (permalink)  
 
Join Date: Jan 2006
Location: In a far better place
Posts: 2,480
Likes: 0
Received 0 Likes on 0 Posts
Originally Posted by Hotel Mode
Americans dont generally do CDA's they just dive and fly level because thats the rules in the states.
Not true Einstein... Like pilots in Europe we are trained to conserve fuel as best as possible which means essentially the same profiles are followed when ever possible. What does it mean when STN director tells us to descend from 6000 to 3000 in 9 miles. Does that mean that he can dilly dally down to 3000 at his own convenience. Does that mean that he can descend below 3000 before the director clears him otherwise?
captjns is offline  
Old 24th Feb 2006, 09:06
  #6 (permalink)  
 
Join Date: Oct 2004
Location: surrey
Posts: 239
Likes: 0
Received 0 Likes on 0 Posts
Our American cousins fly exactly the same procedures in the London TMA as everyone else - ATC do not have one set of rules for them and one for others.

As for how the pilot flies the approach - well that is another matter but believe me there are enough monitoring devices around that what you are saying is not a common occurence - we would see it on radar, HMUs etc.

Maybe the odd aircraft doe s a dodgy approach, but I'll wager it's not soleley and American problem.
ukatco_535 is offline  
Old 24th Feb 2006, 09:36
  #7 (permalink)  
 
Join Date: Mar 2000
Location: U.K.
Age: 46
Posts: 3,112
Likes: 0
Received 0 Likes on 0 Posts
What a load of old rot.

As ukatco states, it makes no difference where a company is based, we all fly the same approaches as told to us by ATC.

The American a/c may well be larger and so look as if they are lower/closer, but that's it.

Uniformed residents associations........
Say again s l o w l y is offline  
Old 24th Feb 2006, 10:26
  #8 (permalink)  
 
Join Date: Jan 2004
Location: UK
Posts: 96
Likes: 0
Received 0 Likes on 0 Posts
There is a big difference in how various airlines fly approaches.

I stayed at a relative's home in Battersea last summer for several days. I guess this is about a 10 mile final for the westerlies at LHR.

We slept with the windows open and could not believe the noise from the early morning long-haul arrivals.

After several mornings of been woken up by this racket I got out of bed to investigate.

The noise was being created by 767s/777s/744s/330s of various foreign airlines who were flying straight and level with gear and flap down and an associated increase in power to compensate.

The biggest culprits belonged to US companies. From the other side of the house I could see BA and Virgin aircraft lowering their gear at a more sensible range - established on the glidepath and, I guess, about 7 miles from the airfield.

Hell of a difference to the local noise imprint.
Cuillin is offline  
Old 24th Feb 2006, 12:42
  #9 (permalink)  
 
Join Date: Apr 2005
Location: "this is where the magic happens"
Posts: 260
Likes: 0
Received 0 Likes on 0 Posts
Hmmm...

As a foreigner now flying for an orange UK low cost airline, I don´t really agree with the foreing v.s. UK argument about CDA´s.

Except for the LGW and most foreign crew, very few pilots in my current outfit know how to fly a good CDA approach (engines @ flight idle and without speedbrakes! ) and from a training perspective there is a strong emphasis on level segments in the aproach.

From my experience, you will not score ´browny points´ on your line check by making a smooth continuous descent from TOD.

Just my 2 cents...
Bokkenrijder is offline  
Old 24th Feb 2006, 13:16
  #10 (permalink)  
 
Join Date: Jan 2006
Location: In a far better place
Posts: 2,480
Likes: 0
Received 0 Likes on 0 Posts
Originally Posted by Bokkenrijder
Hmmm...

As a foreigner now flying for an orange UK low cost airline, I don´t really agree with the foreing v.s. UK argument about CDA´s.

Except for the LGW and most foreign crew, very few pilots in my current outfit know how to fly a good CDA approach (engines @ flight idle and without speedbrakes! ) and from a training perspective there is a strong emphasis on level segments in the aproach.

From my experience, you will not score ´browny points´ on your line check by making a smooth continuous descent from TOD.

Just my 2 cents...
Very simple and no rocket sceintry required. Descend at a lesser rate than required that of a normal 3 degree path until G/S intercept. Minimum thrust is better than trust required to maintain level altitude.
captjns is offline  
Old 24th Feb 2006, 14:32
  #11 (permalink)  
 
Join Date: Mar 2005
Location: U K
Posts: 89
Likes: 0
Received 0 Likes on 0 Posts
Originally Posted by captjns
Very simple and no rocket sceintry required. Descend at a lesser rate than required that of a normal 3 degree path until G/S intercept. Minimum thrust is better than trust required to maintain level altitude.
A CDA is designed to'minimise' noise not merely reduce it. The idea is thrust idle from TOD and on (or above) a 3 degree G/S until stable @ e.g 1000' aal on finals.
If you are using a low v/s to stay below the G/S and merely avoiding a 'level segment' (how ATC assess a CDA) this will look good on the statistics but is not what is intended by a CDA.
Major Cleve Saville is offline  
Old 24th Feb 2006, 14:43
  #12 (permalink)  
 
Join Date: Jan 2006
Location: In a far better place
Posts: 2,480
Likes: 0
Received 0 Likes on 0 Posts
True statement Major Cleve. But in the real world when there are numerous arrivals at once we don't always have the luxury to fly that perfect profile from top of descent to 1000 AGL of with certain restrictions imposed by ATC. At destination airports, where traffic is not a factor, self created CDAs are rather easy to fly from TOD to 1000 AGL.
captjns is offline  
Old 24th Feb 2006, 15:18
  #13 (permalink)  
 
Join Date: Oct 2000
Location: Berkshire, UK
Age: 79
Posts: 8,268
Likes: 0
Received 0 Likes on 0 Posts
Cuillin.. No one airline is a "culprit". Flying into Heathrow early in the morning is a very busy task and CDAs are almost impossible. Both runways are usually in use for landing and there is a major problem separating traffic which may be crossing over other traffic for the different runways. For this reason some aircraft may have to expedite their descent whilst others may be held high while someone goes underneath. There are no set procedures for all this - it's all straight out of the radar controllers heads.
HEATHROW DIRECTOR is offline  
Old 24th Feb 2006, 20:40
  #14 (permalink)  
 
Join Date: Jan 2004
Location: UK
Posts: 96
Likes: 0
Received 0 Likes on 0 Posts
LHR Director

I believe you have missed my point.

Some airlines configure for min power approaches (nominal flap for the stage of approach/gear up) and others fly 'draggy' approaches with the gear down at an early stage. All airlines are subject to the variations on the day and understandable demands of ATC. The 'non-draggy' airlines are as likely to be subject to a straight and level portion of the approach as the 'draggy' airlines. Do they really need to have the gear down at 12 miles while below the glideslope? Are their SOP's that inflexible?

If you don't believe me then stand on Wandsworth Bridge at 0530z on a clear day.

There is absolutely no criticism of ATC in respect of the procedures.

Incidentally, I am an airline ATPL who was formerly a fully validated CAA ATCO.
Cuillin is offline  
Old 24th Feb 2006, 22:09
  #15 (permalink)  
 
Join Date: Mar 2005
Location: U K
Posts: 89
Likes: 0
Received 0 Likes on 0 Posts
If the objective is idle power; left to its own device the FMGC on my current type is designed for a descent at idle say at 250kts and a level deceleration at idle power.
This probably produces less noise than the orange version: below the G/S using V/S with the power above idle, but will not count as a CDA (whilst meeting the objective of minimum noise).
I suspect the USA carriers are just as quiet but using a different profile.

Bokkenrijder: I find a lot of statements in pprune including yours: "Except for the LGW and most foreign crew, very few pilots in my current outfit know how to fly a good CDA approach (engines @ flight idle and without speedbrakes!) and from a training perspective there is a strong emphasis on level segments in the aproach" extremely arrogant: a capable pilot is a capable pilot no matter where he comes from and I am guessing you are from the NL from your title. I am sure a lot of people would love to comment on the CRM and interpersonal skills your compatriots exhibit on and off the flight deck. I suspect humility would not be a feature of the comments!

Level segments are taught in training because most training is concerned with abnormal and emergencies where a 'stabilised approach' is often safest. No doubt you will at some point dazzle us with your single engine (and non-precision?) CDAs .

Last edited by Major Cleve Saville; 24th Feb 2006 at 22:24.
Major Cleve Saville is offline  
Old 25th Feb 2006, 18:35
  #16 (permalink)  
 
Join Date: Oct 2004
Location: UK
Age: 51
Posts: 171
Likes: 0
Received 0 Likes on 0 Posts
Thumbs up Early morning arrivals at LHR

Originally Posted by HEATHROW DIRECTOR
Cuillin.. No one airline is a "culprit". Flying into Heathrow early in the morning is a very busy task and CDAs are almost impossible. Both runways are usually in use for landing and there is a major problem separating traffic which may be crossing over other traffic for the different runways. For this reason some aircraft may have to expedite their descent whilst others may be held high while someone goes underneath. There are no set procedures for all this - it's all straight out of the radar controllers heads.
What do you mean by early mornings HD? 0600-0700 CDA compliance is currently at 85% ( without having to get my laptop out to check ) with TEAM ops on the increase as well. All down to excellent work by ATC (using stats provided by me) over the last 18months!
Flightman is offline  
Old 25th Feb 2006, 23:37
  #17 (permalink)  
 
Join Date: Jun 2001
Location: UK
Posts: 1,178
Likes: 0
Received 0 Likes on 0 Posts
From my experience, you will not score ´browny points´ on your line check by making a smooth continuous descent from TOD
Oh yes you will!
FlapsOne is offline  
Old 26th Feb 2006, 09:10
  #18 (permalink)  
I say there boy
 
Join Date: Mar 2000
Location: Somewhere
Posts: 1,065
Likes: 0
Received 0 Likes on 0 Posts
The definition of CDAs allows for one short level segment to allow g/s intercept from beneath. From memory a couple of miles.
foghorn is offline  
Old 26th Feb 2006, 10:40
  #19 (permalink)  
 
Join Date: Oct 2004
Location: UK
Age: 51
Posts: 171
Likes: 0
Received 0 Likes on 0 Posts
Originally Posted by foghorn
The definition of CDAs allows for one short level segment to allow g/s intercept from beneath. From memory a couple of miles.
"1 segment of level flight, not greater than 2.5nm" Level is defined as a height change of not more than 50ft over a track distance of 2nm., as measured by the BAA NTK system
Flightman 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.