Follow the SID

[terrahead]

Heard on 28/8 at LGW and interested in comment/ thought a subject worth airing:

Twr to Ac about to depart and previously cleared on the DVR SID from 26L: "After departure maintain 4000ft."

Ac (pilot) replies: "I always do."

Now, the SID has a step climb doesn't it, from 4000ft to 5000ft, and if cleared on the SID an ac is expected to follow the vertical profile, isn't it? I know this almost never happens, as the tactical situation permits the Controller to give an earlier climb, and on this particular occasion the Twr controller had explained to curious pilots the reason [survey ac at 5000ft - perfect gin clear day].

BUT, wasn't that pilot incorrect to say he always maintains the initial restricted altitude until positively cleared to climb further?

OR, when you think about it, a clearance on a SID without any further clearance is such a rarity and the airspace is so crowded many of us might be nervous about following the full vertical profile without positive clearance.

Or would you behave in just the same way as if cleared for an approach procedure where you would happily follow the vertical profile to the runway.

[DFC]

BUT, wasn't that pilot incorrect to say he always maintains the initial restricted altitude

If I was intending to level at 4000 for whatever reason and ATC came back with a "maintain 4000", I would think the exact same. Perhaps I may not make such an RT transmission but never the less I would be thinking the same thing i.e. why is this guy telling me to do something I am already doing - did I make a mistake or did ATC?

If it is true and an aircraft was cleared on a SID that involved a climb through an aircraft at a level that was not separated from the SID then that by definition is a reportable incident because after all if the R/T had failed, that departingaircraft could ahve collided with the survey aircraft wile on the SID.

The answer would be for the aircraft not to have been cleared for the SID in the first place.

Regards,

DFC

[Turn It Off]

Seperation was ensured because the restriction was issued before takeoff, After departure maintain 4000ft..

There is step climb in the SID of 4000A, the cleared level is 5000A, as that is the end level on the SID. Therefore, the clearance issued was absolutely correct and absolutely necesary to ENSURE separation.

Unless otherwise cleared, a pilot should follow the vertical profile of the SID, regardless of whether or not it is NORMALLY ammended (subject to the safe control of the a/c which the Pilot is responsible for.....). Only if a positive ammendment is received should the SID be disregarded.

[ukatco_535]

The answer would be for the aircraft not to have been cleared for the SID in the first place.

if thats the case, there are gonna be a hell of a lot of delays in the TMA, as we constantly have a/c on cat B flights operating below sid altitudes, often for several hours on end.

The clearance was safe and the SID should have been issued, with the level amendment, as per turn it offs post.

what is not known, is how it was phrased. Yes, it is a step climb, so the pilot should be left in absolutely no doubt that he has to stop totally at a given altitude and the reason ahould be given, to amplify.

I don't work in a tower but something along the lines of "C/S maintain 4000' on departure there will be traffic above" wait for acknowledgement, then "C/S cleared for take off....."

[Muppetfly!]

I'm just wondering if its another trial of R/T phraseology. For example when approving start delivery now say 'hold position' and do not mention the word push - this is due to several a/c pushing without clearance.

Pointing no fingers, I just wonder if this iniative comes from confusion I have heard about the initial stop or blocked altitiude on the SID.

Over the last couple of months I have heard a number of carriers when either checking in with London after departure say 'xxxx ft climbing 6000' - because ultimately the SID finishes there. As we all know however the first block is 4000 on a LAM/CLN/DVR. A couple of crews I have heard too querying with delivery about where they should stop climbing (and good on them too!)

All this makes me think things could be getting lost in translation (not literally!). We use Aerad charts which are very clear - are Jeppesons also??

[ukatco_535]

I'm just wondering if its another trial of R/T phraseology.

Nope: there is no new phraseology. the guys and gals at the airports do not get that much feedback from us on which carriers call the wrong level.

We have to query every time it happens and although it is a pain, it is a combination of some poor SID plate layouts and (some)foreign pilots (not being xenophobic it's just a fact of life).

it would get into dangerous territory if the tower were to start introducing the step altitudes as 'hard stop' levels, as the SIDs are designed to keep A/C within controlled airspace by virtue of headings and altitudes until at least such time as the A/C reaches the fix at the end of the SID.