Jep STAR 'speed reduction point'?

[Patches O'Houlihan]

Jepessen indicate the position at which to reduce speed on an arrival with a "X" and an arrow pointing to it stating the speed to be flown.

However, there also seems to be a small 'shaded square' at each of these points, starting from the middle of that "X", in the direction of flight.

Any ideas as to what this square is for....??? (Couldn't find it in the chart legend)

Here's hoping someone knows what I'm talking about...

Patches

[WaterMeths]

I think the "X" depicts the point along the track as you say, but "X"'s appear at other points too, for example where there is a step down on the minimum alt along the track....so perhaps the shaded square actually dictates which of these "X"'s are actually speed limit points. Make sense ?

Or they are airbourne speed camera locations...

[Patches O'Houlihan]

The 'X' is just one of the symbols jep use to indicate various waypoints. The max speed is written with an arrow pointing to the 'X' showing that it is indeed a speed point. This is surely sufficient to show what is required so again, why the extra little shaded square??

At least the airborne traffic officer has some shade to sit under...

[WaterMeths]

You are right in the fact that the X denotes the start of the speed point, but as I said the shaded square differentiates the point from other points along the track. If you look at the legend on the STAR plates themselves they are quite specific. The SLP is the shaded square.........

X is simply a distance along track

Shaded Square is a SLP.

The fact that the speed is written with an arrow is purely because they cant fit a font small enough inside the SLP box to say what the speed is. SLP'scan be 250kts, 220kts 200kts etc.........

Cheers

[Patches O'Houlihan]

does that mean then that the applicable speed must be flown before reaching the 'X' (the arrow would seem to indicate this), or are you allowed to still be reducing while in the 'shaded square' area?

[WaterMeths]

Now there's a question......

I'd say that as it is a speed limit point then that defines the speed you should be aiming for at that point in the arrival. I fly the airbus, and left in managed speed, the magenta circle (deccel point) is a little before the SLP, so the aircraft should be down to that speed by the time it passes the SLP...

Analogy with a speed limit on the road, you shouldn't start to slow down after passing the "30" sign as you are effectively busting the limit. Now I'm starting to sound a little anal !!

As with all things like this, applying common sense usually prevails.

[Dick Deadeye]

Jepessen indicate the position at which to reduce speed on an arrival with a "X" and an arrow pointing to it stating the speed to be flown.

Nope.

Jepessen indicate the position at which you must be at the speed indicated on an arrival with a "X" and an arrow pointing to it stating the speed to be flown.

Where you start to reduce is up to you.

If you want to check it out, just blast through the next 200 kt speed control point you see at 350 kts, and when ATC query it, tell them it's OK, you have started to reduce!

Should impress them no end!