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-   -   Cancel speed (https://www.pprune.org/fragrant-harbour/511808-cancel-speed.html)

allthecoolnamesarego 4th Apr 2013 20:54

Cancel speed
 
Hi,
This might be in the wrong spot (sorry Mods), but I have a question regarding HK ATC 'Cancel speed'.
When conducting the Ocean 2A departure and on first contact with depature, ATC say ' cancel speed'.
Some of the crew I fly with take this to mean that the 'Max 220 KT until established on track to TD' is cancelled (as well as the 250 below 10000), some take it mean that the 250 below 10 000' but the '220 until TDK' remains in force.

I can't find a reference anywhere to clarify.

Can anyone out there point me in the right direction for a definitive answer?

Thanks

Coolnames

cxorcist 4th Apr 2013 22:24

I'm not an expert when it comes to regs, but I think it cancels both so I crank it up to Econ climb speed once above the MSA (4300').

Tonto Kowalski 4th Apr 2013 23:21

It cancels the 220kt AND 250kt/10000'. There's a note on the port page about it.

The FUB 5th Apr 2013 02:20

250 kts till 4300ft then econ climb. Forget all the cufflink oldies saying not above 300kts till above 10000ft. However, don't select above 250kts till above msa even if the ac won't achieve this speed until above msa.

cxorcist 5th Apr 2013 02:26

The problem with 300kts up to 10K is the level off at 9K'. Crossing traffic over TD at 11K'. Might as well stay "low and fast" until past TD and the traffic overhead there. If you need a max angle type of climb, cash in those knots after TD when you get a higher FL.

allthecoolnamesarego 5th Apr 2013 02:31

Thanks guys,

I appreciate the feedback. I'm actually after the reference that 'cancel soeed' cancels the 220kt until established on track to TD.
On the Jepp plate 10-1P9, the only ref to the 220kts is note 3-2-2-1 which states that "pilots should comply with the published speed restriction...."
The QANTAS Route Manual Sup (I assume the same type of thing as your 'port page' has nothing about the cancel speed situation).

Without sounding ungrateful or disrespectful, I'm not after the way to fly it, but rather the actual ref that states what 'cancel speed' means.

Thanks again

Coolnames

Ex Douglas Driver 5th Apr 2013 02:36

We (CX) have had it confirmed from HKG ATC that when they say cancel speed, they take responsibility for terrain separation in the SID turn (the reason for the 220kt restriction is restrain the turn radius), therefore you are cleared to accelerate to whatever your company allows below/above MSA and below 10000ft.

allthecoolnamesarego 5th Apr 2013 03:12

Thanks EDD,

It would be nice to have that in the Jepp so that all airlines are aware of it.
I was one who believed that the 220kts was/is a SID design contraint, so find it hard to accept that ATC can 'take responsability' for terain sep if one exceeds the design criteria of the SID
Again, the www doesn't allow for 'tone' to be heard, so please don't take my comments as a 'go at you' they certainly are not, I'm grateful for your input.

Do you have a screen shot of your Port Page with this in it?
Might be useful having something similar in ours, as I find it an unnecessary and possibly dangerous distraction, when three piolts all have different views on this during departure.

Thanks again

Ex Douglas Driver 5th Apr 2013 06:25

From the HKG AIP

3.4 TRACK KEEPING ACCURACY
3.4.1 SID procedures are based on aircraft accurately following the published track as defined by the SID navigation aids, reporting points and waypoints. Pilots using FMS/RNAV equipment should note that in order to ensure terrain clearance, Hong Kong SID Significant Points/Waypoints PORPA, PRAWN and ROVER are 'flyover' locations. All other SID Reporting Points/Waypoints are ‘flyby’ locations and turn anticipation by the FMS/RNAV is permitted, however pilots shall comply with the published speed control procedures to limit the radius of turn, unless otherwise advised by ATC.
http://www.hkatc.gov.hk/HK_AIP/AIP/ENR/HK_ENR1.5.pdf
From our HKG Port Page
CANCEL SPEED CONTROL: immediate acceleration is available at any point on the departure (subject to company SOP speed requirements) after ATC cancel speed control. ATC will already have calculated that the aircraft will remain within the departure terrain safety area with allowances for climb performance, wind and higher departure speed.

The AIP quote is pretty clear, but I'd suggest you get your company's flight ops department to formally contact HKG ATC if further clarification is needed. From a driver's point of view, ATC will apply radar terrain separation (rather than the procedural terrain separation provided by the SID) and "cancel speed control" when:
1) prior to the turn when you're already near or above the radar min alt and have a good rate of climb e.g. once you're above 4300ft, the 220kt restriction has no purpose; or
2) they see you're in the turn and nearly established on the outbound track anyway - again with no chance of extending out to the east and infringing on the radar min alt segments while below their height.

bekolblockage 5th Apr 2013 07:23

Ex Douglas Driver has pretty much nailed it.
For the majority of departures, most controllers will use the phrase "after the right turn, cancel speed restrictions" to take the turn radius/terrain bit out of the equation. As said, it cancels everything.

ATC

allthecoolnamesarego 5th Apr 2013 09:41

Thanks EDD,

I could find no reference in the Jepp world wide text. I didn't think to check the HK AIP:ugh:


Cheers

Tonto Kowalski 5th Apr 2013 10:45

As a line driver you should be able to rely on the Jepp and company manuals. We (CX) don't refer to the the Aus AIP when we operate there...

Dan Winterland 5th Apr 2013 11:22

I concur with EDD.

The RNAV SDI initial turns are RTF (Radial To Fix) and require the track to be maintained to acheive the RNP1 constraints. 220/230 must be maintained until on track to the next WP.

treboryelk 5th Apr 2013 11:35

so do you agree with EDD or disagree?

If ATC cancel speed before the turn, 250 below relevant MSA and accelerate after relevant MSA IMHO!

bekolblockage 5th Apr 2013 11:59

Dan, only the 'E' and 'F' SIDs use the RF (radius to fix) path terminator.
(You must be on the 777 or -8?)
If you cancel the speed, the FMS should automatically adjust the bank angle to maintain the radius. Up to a limit of course (23-25 degs from memory).
The other RNAV SIDs do rely on the speed to contain the radius.

Ex Douglas Driver 5th Apr 2013 13:21

Tonto - True. That's the job of Line Ops and their regular close reading of the various AIPs and interpretation for our day-to-day ops for inclusion in port pages (or other companies' equivalent).

At the end of the day, by retaining the 220kt restriction, despite being told to cancel all speed restrictions, they are not doing anything unsafe and are not violating any ATC instructions.

744drv 6th Apr 2013 03:57

I also recall that chart being published. However, I believe it was used to point the finger at a group of individuals who were ignoring the speed limit because 'they had a bigger picture' :ugh:

Lowkoon 7th Apr 2013 11:59

If the performance engineers have worked out that 220kts is the maximum speed you can fly without blowing out the turn and getting too close to the rocks, how can ATC take responsibility for the terrain separation? what criteria do they use and how is it different to what the performance guys calculate? Does ATC do any calculations at all? Genuine questions, I dont know what the answer is.

SloppyJoe 7th Apr 2013 12:16

I expect it is a headwind requirement coupled with your altitude and how close to the start of the turn you are. Possible something along the lines of must be above 3000', within 3 miles of the turn and groundspeed not above 210kts or something similar before they can remove the 220kts restriction. As previously posted some days they say once on track to x no speed restrictions and on other days about 2 miles to the turn the say no speed restrictions.

nitpicker330 7th Apr 2013 13:39

1/ in my experience its very rarely given that early....
2/ if you are not sure then simply hold 220kts until established on the relevant Sid track and then go for it.......
3/ stir in a little HP sauce for flavor....:ok:


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