CDA into Gatwick

[flatfour]

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 ?

[GBALU53]

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Bigger being Boeing 767 or even 777 or even the odd 747 aircraft, i could be wrong but do not quote :ok: :ok: ?

I hope this might be if assitance.

[flatfour]

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.

[Hotel Mode]

Americans dont generally do CDA's they just dive and fly level because thats the rules in the states.

[captjns]

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?

[ukatco_535]

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.

[Say again s l o w l y]

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........:*

[Cuillin]

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.

[Bokkenrijder]

Hmmm...:hmm:

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...

[captjns]

Hmmm...:hmm:

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.

[Major Cleve Saville]

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.

[captjns]

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.

[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.

[Cuillin]

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.

[Major Cleve Saville]

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 .

[Flightman]

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! :ok:

[FlapsOne]

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!

[foghorn]

The definition of CDAs allows for one short level segment to allow g/s intercept from beneath. From memory a couple of miles.

[Flightman]

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