Minimum climb gradient on Dublin SID's

Real World Aviation
#1

There is something that doesn’t make sense with the minimum climb gradient on the Dublin SID’s:

Capture%20chart
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If you look at the box in the bottom left corner, you will see that there is a table where it shows the minimum climb gradient for the SID. I tried applying this yesterday on a flight and I ended up at 30000ft with a VS of 3000fpm. My throttle was at 91%. What doesn’t make sense to me is that it doesn’t seem right to be climbing at 30000ft with a VS of 3000fpm. So my question is, until what point do I have to respect this table? When can I reduce my VS even if I have a GS of over 300kts? This table is on all the SID’s at Dublin and does not apply to this SID exclusively.

4 Likes
#2

Until you have left DUB VOR - the red circle.

#3

Where does it say that in the chart?

#4

Someone help me please!

#5

What do you mean? Your question was already answered.

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#6

How do I know that what he said is correct?

#7

A few things.

  • you can always say unable SID. ATC won’t really like it per say beacuse now they will have to baby you with alt segments and possible directional vectors for other ACs that can meet the SID.

But to answer your question…

Once past the DUB VOR you can decrease your VS but you can’t go more than 290kts or unless directed by ATC (by them saying resume normal speed)

#8

Does this apply for all airports when I don’t have a specific altitude which tells me when the minimum climb gradient doesn’t apply anymore?

#9

The red circle just depicts where that MSA is. As soon as you are above OR outside the MSA, you can theoretically disregard that climb gradient.

#10

I don’t know international (Europe or Asia) airpace speed regs, but in the US in class B airpace it’s 200kts. Below 10,000 250kts. Above that… fell free to turn on your after burners.

#11

lol no it’s not. Class B airspace doesn’t have a speed limit, just the standard 250/mach 1.

As for the question, the minimum climb gradient is to avoid clonking an obstacle. Every SID will have a specific altitude given as part of the IFR clearance prior to departure.

#12

Whoops. I meant to say below class B 200kts.

The only alt restriction is above 3000 at OE and same at DW551 in conjunction with your speed restrictions.

#13

So in this situation I would use the minimum climb gradient box until I pass the red line, after which I can reduce my VS?

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#14

You’d likely climb above 2200 first.

#15

I don’t understand. At which point do I not have to use the minimum climb gradient table? What does the red circle represent?

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#16

As stated earlier:

#17

What is an MSA?

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#18

Minimum safe altitude. If you fly at that altitude, you won’t hit anything. It’s the red number corresponding to the red circle.

#19

Capture%20chart%202
@Ryan_E, if we take this chart, would I use the minimum climb gradient table until I reach 2500ft or until I pass the MSA?

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#20

You’d have to maintain it until above any MSA sector you’re in or will come across. You’d likely maintain a pretty consistent vertical speed until you’re well clear of this SID.

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