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Deleting hard heights

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Old 26th April 2018 | 09:37
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From: England
Deleting hard heights

Hi

Can anyone tell me if there is any regulatory information that demands that information on the CDU must reflect the SID?

ie Your first stop altitude is 4,000 feet hard altitude, and ATC clear you to 4,000 feet. Why not then delete the 4,000 feet hard altitude? Not an SOP or flying manual question, but a regulatory question. Is it written down somewhere by EASA CAA FAA etc

Thanks in advance
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Old 26th April 2018 | 10:32
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Question. Why would you? How does it improve the situation? It will reduce situational awareness in a critical phase. Regulatory? I doubt it.
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Old 26th April 2018 | 11:04
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From: 60 north
Delete away.

We almost never fly the Stars and Sid as published. A lot of direct to....
Why would Naa mikromanage such a thing??
Read what ICAO recommends , if anything.
As your question is SID specific I would only be concerned about MSA , airspace restricted altitudes etc.
On Stars I personalty delete altitude restrictions I know are not used to do CDA.
Plenty of places , RAT this gives you a higher and safer situational awareness. ( on Stars, Approaches)
PO
Your SOP should cover this. ?
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Old 26th April 2018 | 11:13
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From: Having a margarita on the beach
Originally Posted by tonker
Hi

Can anyone tell me if there is any regulatory information that demands that information on the CDU must reflect the SID?


Yes it does, You can find more info Here
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Old 26th April 2018 | 11:14
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From: Hundred Acre Wood
If you fly an Airbus, leaving things as they are will give you a magenta reminder on the ND (if you have constraints selected).
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Old 26th April 2018 | 11:18
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RAT this gives you a higher and safer situational awareness.

If you mean deleting an FMC hard altitude "gives you............." you'll have to explain that. Or am I misunderstanding what you've written?
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Old 26th April 2018 | 11:18
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From: IRS NAV ONLY
The coded hard altitude in the FMC database is one of the safety layers keeping you away from a level bust on departure. Can't think of any good reason why you would want it gone.
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Old 26th April 2018 | 11:25
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From: Having a margarita on the beach
Guys in PBN OPS You are not allowed to start changing and modifying stuff at your own convenience, there's loads of literature regarding that. Your FMC database is checked and approved by your operator following a specific protocol and it is not supposed to be modified every single sector.

edit* : unless you are specifically instructed to cancel speed and altitude restrictions from ATC.
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Old 26th April 2018 | 11:35
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From: 60 north
RAT 5
Thanks, I made no sense there,
Example , ILSz rwy 13 AGP the box has 5000 twice within a short distance. If deleting the first this will give ca 5800 and you are then on a higher profile. Safer!?

Not relevant I suppose as we are talking SID.
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Old 26th April 2018 | 11:42
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Originally Posted by BluSdUp
Example , ILSz rwy 13 AGP the box has 5000 twice within a short distance. If deleting the first this will give ca 5800 and you are then on a higher profile. Safer!?
What if there is a crossing track with minimum altitude of 6000' ?
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Old 26th April 2018 | 11:55
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There is not. You are cleared for the ILS at that point. The GS is at 5800 but has small ups and downs as there is hills reflecting the GS slightly.
But, Yes do not apply this anywhere!
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Old 26th April 2018 | 13:08
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Thanks Blu.
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Old 26th April 2018 | 13:18
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From: Check with Ops
edit* : unless you are specifically instructed to cancel speed and altitude restrictions from ATC.
Edited again: Or flying in somewhere like the UK or Japan when ATC clearance to higher automatically cancels the restriction.....unless re-stated.

Yes, I too wish they could come up with one version auto cancel or not auto cancel, I really don't care which one but just pick one and stop the individual differences
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Old 26th April 2018 | 20:39
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Originally Posted by tonker
Can anyone tell me if there is any regulatory information that demands that information on the CDU must reflect the SID?

ie Your first stop altitude is 4,000 feet hard altitude, and ATC clear you to 4,000 feet. Why not then delete the 4,000 feet hard altitude? Not an SOP or flying manual question, but a regulatory question. Is it written down somewhere by EASA CAA FAA etc
First, there is no regulation requiring a CDU. you can fly a VOR/DME-based SID using raw VOR and DME data if you like.

HOWEVER, if you are flying an RNAV SID, with authorization to do so in an OpSpec or LoA, you must follow the applicable regulations for the level of RNAV you are using. For example, if flying an RNAV1 or RNAV2 SID, you must use an autopilot or flight director. Either of those would be difficult to use without the correct information in the CDU. OTOH, you MIGHT be able to use the MCP in place of CDU altitude constraints, but why would you?
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Old 27th April 2018 | 02:17
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From: Kopavogur
ATC clearance cancels out SID altitude restrictions in most countries .
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Old 27th April 2018 | 02:59
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From: Somewhere over the rainbow
If you fly a RNAV SID/STAR. You can clear the altitude constraints or speed restrictions if ATC tells you no altitude/speed restrictions. The only thing you are not allowed to do in the FMS is to add manually a waypoint.

“Manual entry of SID/STAR waypoints is not permitted.”
From our SOPM.
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Old 27th April 2018 | 13:18
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From: Having a margarita on the beach
Originally Posted by TPE Flyer
FCOM is very clear, that clearing the SPD CST from the MCDU in NOT the recommneded procedure.
Are You aware of the fact that there are other aircrafts around the world other than Airbus and different company SOPs ?
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Old 27th April 2018 | 19:41
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Originally Posted by TPE Flyer
FCOM is very clear, that clearing the SPD CST from the MCDU in NOT the recommneded procedure. Selecting the desired speed on the FCU is.
Where does it state this? Please provide a reference.
All my FCOM mentions is that if a specific speed is required, use selected. Nothing against clearing unused speed constraints, i.e. 250 below 100 if you have already accelerated. Why fly around with incorrect predictions?

Either way I would not get too worked up about it. Surely you make many more alterations to the MCDU during climb and descent, like sequencing the flight plan when on vectors. That's much trickier than a simple deletion of a speed constraint. If you can't manage that..
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Old 28th April 2018 | 13:08
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Originally Posted by RAT 5
Question. Why would you? How does it improve the situation? It will reduce situational awareness in a critical phase. Regulatory? I doubt it.
Unless it is specified in an aviation authority approved operations document.
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Old 28th April 2018 | 14:48
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From: Between a rock and a hard place
This thread is about to turn into another SOP fist fight.

Delete them as you please, just don't bust the level off. Valid for any departure, whether out of LHR or anywhere else.

We've got no SOP in place that requires the hard altitudes in the FMC.
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