{"id":18806,"date":"2022-06-27T08:05:48","date_gmt":"2022-06-27T12:05:48","guid":{"rendered":"https:\/\/ops.group\/blog\/?p=18806"},"modified":"2022-06-29T08:08:57","modified_gmt":"2022-06-29T12:08:57","slug":"shush-keep-the-sound-down","status":"publish","type":"post","link":"https:\/\/ops.group\/blog\/shush-keep-the-sound-down\/","title":{"rendered":"Shush! Keep the Sound Down!"},"content":{"rendered":"

Sometimes, folk who live in and around airport areas get cranky because, well, airplanes are quite noisy.\u00a0So airports have some methods in place to help reduce complaints – noise sensitive areas, decibel monitoring, night flight restrictions, noise level regulations, and the thing we’re going to look at in this post – noise abatement procedures.<\/strong><\/p>\n

Where do we use noise abatement procedures?<\/h4>\n

Contrary to popular belief these aren’t just for departure.<\/strong> You get noise abatement routings, and noise abatement approaches.<\/p>\n

These are fairly boring though, and by boring I really mean fairly obvious. A noise abatement routing just doesn’t fly you low over sensitive areas.\u00a0Noise abatement approaches generally say stuff like \u201ctry and do a CDA\u201d<\/em> or \u201cdon\u2019t fly level for more than 2 nm\u201d<\/em> or \u201cdon\u2019t fly in with all your flaps dangling out from 10,000\u201d<\/em>.<\/p>\n

EGLL\/London Heathrow<\/strong> has a particularly exciting bunch of rules for the arrivals and approaches (probably because English people really like to complain a lot) if you do want to check these out.<\/p>\n

The Takeoff ones<\/h4>\n

For folk who\u2019ve been around a while, you might remember TKOF Proc A and B.<\/strong> Well, forget \u2018em. They don\u2019t exist anymore.<\/p>\n

Actually, just checked and some random airports do still use these, but most use NADP I or NADP II\u00a0<\/strong>so that’s what we’re going to talk about.<\/p>\n

NADP I<\/h4>\n

Also known as the \u201cclose in\u201d procedure<\/strong>, this keeps folk living directly next to the airport, and birds and things happy.<\/p>\n

You take-off, reduce your thrust at 800 feet<\/strong> (that\u2019s above ground level!) then climb at a speed somewhere between V2+10 and V2+20 to 3000 feet,<\/strong> at which point you accelerate to your en-route climb speed.\u00a0<\/span><\/p>\n

Accelerate smoothly<\/em> is what it actually says, and as you do it, retract them flaps and slats and any other dangling bits you have hanging out.<\/p>\n

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NADP I.<\/p><\/div>\n

NADP 2<\/h4>\n

The \u201cdistant\u201d procedure<\/strong>. Although not that distant.<\/p>\n

This one has you take-off and at 800 feet you clean up<\/strong> all the sticky-outy stuff, and then you reduce your thrust<\/strong> and fly at your Vzf speed<\/strong>. Which is probably something near to your minimum clean speed. So climb away at something safe and sensible, until you get to 3000 feet, then accelerate.<\/p>\n

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NADP II.<\/p><\/div>\n

Right. You knew that already. So why are we talking about them?<\/h4>\n

Well, you’d be surprised how many people don’t entirely ‘get’\u00a0<\/em>NABTs. There are a few pointers to consider to as well…<\/p>\n