View Full Version : Noise abatement termination alt
SE7EN
11th Dec 2005, 03:28
If a specific noise abatement procedure (eg MAN) specifies a termination altitude of 4000 ft, can one accelerate prior to this altitude, or must we wait til 4000 ft?
I have come across differing opinions on this one and it would be helpful to hear what ATC has to say.
ukatco_535
11th Dec 2005, 19:06
the noise abatement procedures are usually to do with A/C track. In the London TMA we will usually inform A/C that there are no ATC speed restrictions on first contact.
The noise abatement means (in the case of Heathrow for example), that we cannot vector you before that altitude.
If you have to turn early off the SID for weather, before the abatement altitude, we have to record it - just in case anyone who was silly enough to buy a house near a major airport in the first place makes a complaint.
For the speed/climb profile, you need to know what noise procedure is required - NDAP 1 or NDAP 2 (Procedure A or Procedure B in old money).
As far as I am aware, when NDAP 1 is specified (which requires speed to be limited to V2+10 to 20Kt until 3000ft AAL), an ATC statement of "no speed restriction" does not lift this speed limitation for noise control.
Similary, NDAP 2 limits the speed to Vzf +10 to 20Kt until 3000ft AAL...........which can be more than 250Kt in some aircraft so in that case, ATC saying "no speed" is good news provided your company/national authority permits more than 250Kt when below 10,000.
Manchester does not specify which procedure to use, it simply gives an instruction to cross the noise monitoring area at or above 1000ft AAL and operate so as to reduce noise during the climb........Oh, and there is a Pay per decibel fine system. Thus I expect that your company will specify one of the above procedures in the ops manual.
Having said that, it appears that provided you either don't set off the noise monitor or are willing to pay, the height limitations specified only apply to tracks and not to speeds.
Regards,
DFC
SE7EN
12th Dec 2005, 08:35
Many thanks for the replies chaps. Much appreciated.