Step climb departure best practices
 

Hi,

I'm looking for some guidance on industry best practices for managing step climb SID profiles with particular reference to vertical mode selection and armed/pre-selected altitude.

As an example of a departure, either the CPT5X or CPT4Y. Here's a link to the UK AIP page on Rocket Route https://fly.rocketroute.com/plates/a...7607&icao=EGWU

CPT5X description:
Would it be acceptable practice to set 5000ft and if managing the vertical profile in VNAV or 3000ft as it's the first step altitude? If using VNAV, In my departure brief I'd discuss TEM points, in particular the potential risk of not capturing the first step and for both crew to be vigilant for this at the key points and to manage tasks appropriately to facilitate this.

Thanks in advance

This post covers a lot of what I'm asking - the interaction with ATC and the selected alt.
http://www.pprune.org/questions/3439...-question.html
http://www.pprune.org/tech-log/26664...ring-sids.html

Just to add, usual caveats about confirming the FMS legs and altitude restrictions apply. If it's relevant, the aircraft is not auto throttle equipped and vertical speed would be careful controlled.

The above thread is quite a few years old, and I'm wondering if the ensuing years experience has formed more concrete practices.

Thanks

My company policy is to set the first level off altitude, as you will usually be cleared higher pretty early on in the departure.

FWIW some Boeing type FCTMs cover this under "Alternate MCP altitude Setting Technique using VNAV"..


If the procedure (SID/STAR) contains closely spaced altitude constraints it's acceptable to enter the terminating level/altitude in the MCP provided you've done a thorough check of the profile contained in the FMC and you ensure the vertical profile is flown in VNAV path.

If "Climb via SID" is the clearance, we set the highest "cleared to" altitude in the MCP, and verify all intermediate altitudes are in the CDU. Climb mode is obviously VNAV (744). Often the restricting altitudes don't really affect us, so dialing in each of them in succession could cause more problems (e.g., ALTitude captured well before level-off).

VNAV
 

Thanks for the feedback.

It seems that procedures are very much operator specific, plus dependent on the aircraft performance and interval between the various crossing altitudes of the step climb.

In the example of CPT5X, I had setup and briefed as described with the final altitude selected in the MCP. On handover from tower to departure we were instructed to "Stop climb A3000" and then reprimanded for having A5000 selected, and advised in future to select the first step altitude.

I think VNAV is a valuable tool in the right circumstances but it caused conflict in terms of the wider system, which was something I hadn't anticipated. At the end of the day, fitting seamlessly into the system is the goal!

The clearance we receive in this particular instance is "Cleared via CPT5X departure, caution step climb…" and part of your read back has to be "caution step climb" otherwise they reiterate - so I understand the clearance limit to be to A5000, as that's indicated on the plate and the clearance cautions us about the step climb. If it was a clearance to A3000 only, no step climb caution would be required. Maybe I've misinterpreted, but under the conditions of the clearance I would think setting the highest cleared altitude, as you state, is correct.

Thanks for the input.

I haven't heard a "caution Step Climb" clearance yet...

WHO reprimanded you for setting A5000? Was the 3000' limit properly set, and were you in VNAV? Had you busted the limit at D18?

The problem is London ATC reads your altitude selection, so the controller cannot confirm you are minding the steps.

Intruder

A common clearance out of Luton on the Compton SID.

Looks like a clear case of ATC getting into the pilots' business... It is NOT his job to question whether you are "minding the steps"! Since he cannot see the entire cockpit setup, he is totally UNQUALIFIED to make such a judgement!

WHERE in UK ATC regulations does it allow for a controller to "reprimand" a PIC for an MCP setting? While I might understand a controller QUESTIONING a setting IF a breach of clearance is imminent, a controller does NOT fly my airplane!

Northolt Departure. I was in VNAV FLC and the A3000 restriction would have been adhered to, but we were reprimanded before we reached A3000 and told to stop climb A3000. At this point, I selected A3000 via the MCP and levelled off at A3000. Once we explained we were in VNAV we were recleared to climb with the SID step climb vertical profile.

As a point to note, VS was restricted to about 2000fpm reducing to 1500fpm. We know we've got traffic above and don't want to be setting off TAs for guys above us.

I was a little confused why we were reprimanded, but my bigger concern is understanding whether this is a one off or whether VNAV managed climb to the final SID altitude is just going to cause conflict in the over all system. I was considering a CHIRP, but turned here first.

Fair enough ATC querying the setting, and warning of a step climb, I have no problem with ATC doing that.

OTOH if UK ATC start issuing reprimands when you're set up to be fully compliant with the SID/STAR restrictions using company/Boeing/Airbus etc approved procedures then that IMHO warrants an MOR to the authority, on the grounds of distraction, unwarranted interference with safe operation, blah, blah...this may well be a case where too much information at the controllers end is actually a dangerous and distracting thing

I don't have access to the jeppy or aerad plate for the Compton 5X but can view the AIP.

In common with the WATFO and HEN altitude restictions, the specific altitude at the D18 boundary is a not-above, not-below restriction. Together with the notes on the plate warning of a step climb, I would certainly set 3000 on the MCP and not climb above unless specifically cleared by ATC. I would also have the 4000 and 5000 restrictons in the FMC to prevent level busts later in the SID.

Compare and contrast with a Clacton 8R from Stansted where the CLN D28 3000 altitude on the AIP is a not-below restriction whereas those at D21,16 & 13 are shown as not-above, not-below. I would therefore set 4000 on the MCP for departure, have it and the subsequent 5000 and 6000 restictions as hard altitudes in the FMC. Doing so, I have never had a word from ATC. It goes without saying that climb performance is not an issue and therefore being above 3000' at D28 is not a problem, but I would stop at 4000' unless cleared above.

It is therefore my understanding that a step-climb with the above type of restrictions does not allow a continuous climb to the highest altitude on the SID. The airspace around London is a bit complicated, with three major airports and plenty of GA traffic, so I can understand ATC's concern.

I must admit I'm not a Stansted regular but I'd say the EGSS CLN 8R, as published by LIDO, with requirements to be:

"D28 CLN mnm 3000
D21 CLN at 4000
D16 CLN at 5000
D13 CLN at 6000"

Would, in my book, be an ideal candidate for the Boeing procedure, with 6000 set as the terminating altitude in the MCP...though maybe a clarification of "cleared climb via the SID" wouldn't be a bad idea (but a waste of R/T??).

Whilst I accept that London ATC seem to be mainly concerned with climbing level busts due to their airspace we all know there are some parts of the world where failing to step up promptly on a departure could potentially be dangerous or even terminal.

‘Do not climb above SID levels until instructed by ATC'
 

Hi Mikehotel152, I agree that climb to the final altitude on the SID is only in compliance with the crossing altitudes. I stated fairly early on that altitude restrictions were confirmed and crosschecked in the FMS - as you'd expect - so with that caveat in place….

I looked at the CLN 8R SID (https://fly.rocketroute.com/plates/a...5913&icao=EGSS), and I came across AAIB Bulletin 2/2012 EW/C2011/03/05 which states:

I would now interpret this to mean that setting the first step altitude in the MCP, i.e. A4000 in the case of CLN8R, is appropriate. It infers ATC clearance is required for further climb. However, there is also a warning to ensure strict compliance with the specified altitudes in the SID. Let's take the case of a radio failure… on the CLN8R, established CLN R268 at D23 and A4000.

Appreciate all input

I think it's been high profile due to number of airprox's in London airspace, the most significant I can think of recent AAIB 9/2010 EW/C2009/07/07; There's many comments regarding the SID and cleared altitudes. In summary the aircraft misheard his altitude clearance and climbed to 4000' instead of 3000'. The controller in your instance clearly had concern maybe a similar thing had happened, you say when you explained you were in VNAV that was enough to re-assure him/ her you knew what you were doing following the SID. From the AAIB report

‘Controllers must remain alert to the potential
for incorrect or unexpected interpretation of ATC
instructions by non-UK aircraft operators and
take appropriate action to ensure any required
separation.’


Personally, I can't see an issue in you being cleared for the SID with the associated altitudes included in that clearence, selecting the highest level associated with the VNAV proceedure which you have to do to follow the profile.

Flying in VS or FLC with ALT cap is higher workload and could result in delayed climbing in the step giving higher rates of climb and distractions which VNAV avoids.

I'm not sure but if you selected the altitidues as you passed them with your VNAV would your AP/FMC recapture or amend the VPATH?

It would be interesting to hear what a controller has to say, maybe post in thier section 'ATC issues' too?

On the E190 which is fully VNAV capable we always and only set the cleared altitude on MCP.

As a regular on LCY (EGLC) and LHR (EGLL) we are familiar with the step restrictions in the London area. Strict adherence to cleared levels and if not clearead otherwise the steps on the SID takes you quickly close to other traffic.

As a general rule:
Set initial "CLEARED" altitude and subsequent "CLEARED" altitudes on MCP. This feeds the mode S repeater and ATC knows that you have set what you are cleared to.
If not cleared otherwise adhere to the intermediate steps.
The clearance: "CLIMB NOW TO FL110" implies cancellation of the steps - maybe someone can add the link to the AIP U.K.

Our policy and also IMHO the best way is to have the aircraft fly in VNAV but only set cleared altitudes on MCP. We (pilots) do not know why ATC restricts us further or clears us beyond SID steps.

Step climb departure best practices
 

The danger with the Boeing procedure (setting the highest SID alt in the MCP) is if you are high perfomance due whatever reason, you might have to revert to VS mode to reduce your climb rate to below 1500ft/min, which might lead to a level bust.

Always set lowest altitude constraint even if flying in VNAV on departure.
To avoid high rate of climb (possible TA)prior to altitude level off ,vnav may have to be exited and level constraint busted.
UK has had mode S 2 for a while and they will interrogate your MCP,your FMS cant be checked by ATC.
I was always taught to set first hard altitude but again i was taught in the UK.
The step climb is 3000 feet, a first step before the final sid altitude of 5000ft.

hypothetical radio failure case
 

Let's take the case of a radio failure… on the CLN8R, established CLN R268 at D23 and A4000. Thoughts?

Not in the 744. VNAV will capture an altitude well below the altitude if the rate of climb warrants it. In general I see capture in a climb approximately equal to the rate of climb -- often 2500-3000' from the MCP set altitude.

AFAIK, there is no reason to limit climb rate to 1500 ft/min on initial departure, unless your company procedures tell you to do it for some reason.

What was your initial (or last) clearance? If A5000, climb via the SID to A5000. Then sort out VMC vs IMC, visual return vs following clearance or published procedure...

For the example I gave of the CPT departure out of EGWU, the departure clearance is "Destination via CPT5X departure; caution step climb; Squawk XXXX"

There's no specific altitude given, other than the caution concerning the step climb.

I'm not sure about the departure clearance given for the CLN8R SID - I haven't flown that.

The last altitude on the Compton SID is the hard A5000 at HEN, so you have to climb to 5000'. Considering note 2 under General Information, stay at 5000' until you have to climb for MEA or for filed altitude per IMC lost comm procedures.

My understanding as well, hence setting A5000 in the MCP and using VNAV in compliance with the step climb altitude restrictions along SID.

Intruder,

In UK airspace,(UK rules and regulations),irrelevant of your aircraft type, a maximum of 1500 ft rate of climb should be used when within 1500 ft of a cleared level.(obviously to avoid nuisance TA or worse).
If your SID first Hard altitude (at or below) is for example 4000 ft,it is prudent to use a mode that will reduce the climb rate in an airspace as congested as London TMA and therefore set 4000 ft in your MCP to avoid busting the SID level,when level at 4000 feet,set 5000 feet and wait for the appropriate waypoint to start the next climb.
The loss of comms scenario in the UK :
If failure occurs when the ACFT is following a notified departure procedure such as an SID and clearance to climb, or re-routing instructions have not been given, the procedure should be flown in accordance with the published lateral track and vertical profile, including any stepped climbs, until the last position, fix, or waypoint, published for the procedure, has been reached. Then, for that part of the period of 7 MIN that may remain, maintain the current speed and last assigned level or MSA, if this is higher.

I personally feel that setting a non cleared altitude of the SID, esp if it's higher set on the MCP than what the initial restrictions say on the chart, we re basically leaving the job of level off to the Fmc VNAV.
Should a FMC fail during climb/ level off , one has to remember to reset back to the clearance altitude to avoid the alt bust, not to mention the additional shock of the fmc failing and possible deviation of the lateral track, airplane accelerating/ cleaning up, high workload after takeoff scenario maybe negotiating little wx. And then going to a territory not allowed which can trigger an RA.
As much I would like to rely on the Fmc to have me level off lower, I may forget/overlook and get busy with something else. Also if there is a level bust for any other reason, ATC is gonna focus on 'what was set on MCP'
So situationally I would decide what altitude to be set, depending on which airspace I am in, wx conditions, traffic density, level off alt.

I have seen many FMC vnav alt bust by about 150' during a low alt level off with A/P which made me think a basic mode could HV been better athan times.

We could certainly play the 'what if...' game all day.

The backstop is proper monitoring and a thorough briefing of threat and error management. If the aircraft enters an undesirable aircraft state, stop looking down at the TV screens wondering what happened and fly the aircraft.

Your comments insinuate that we program the FMS and then sit back and let the plane fly whilst the crew high five and mentally stay on the ground. That's simply not the case. VNAV is a flight management mode, nothing more.

Finally, what's the cleared altitude on the departure, not the initial step? You say setting a non-cleared altitude is incorrect, so define the cleared altitude.

Yes it is the first step!
You are from the uk...where were you trained??

Clearance Limit
 

My clearance limit is the final altitude, in compliance with the published steps. Can you post a specific regulation which states that I would need to await further clearance after passing the fix at the end of the first step altitude?

De Facto, you insinuate that this is a UK specific regulation, whereas others have already mentioned Boeing, for instance, publishes an Alternate MCP altitude Setting Technique using VNAV. Can you publish the regulation that specifically covers this, stating the first step altitude needs to be set.

Finally, if this is covered under UK flight training, I admit I have missed it. Please can you cover the specific training objectives covering this, and provide a reference, link or other published regulation on this.

Thank you.

The danger with the Boeing procedure (setting the highest SID alt in the MCP) is if you are high perfomance due whatever reason, you might have to revert to VS mode to reduce your climb rate to below 1500ft/min, which might lead to a level bust.

But, in order to avoid a nuisance TA, you may go into V/S to reduce vertical speed which then eliminates the VNAV protection from busting a step climb restriction as the MCP is set at the higher altitude.

Even if avoiding nuisance TA's is not in your Company procedures it is in other procedures.

Your clearance limit is the altitude restriction at a particular DME and not the final limit until you have passed all the other alt/DME restrictions.

LSM, what did you understand by "..in compliance with the published steps"? Perhaps I'm not being clear.

Is there any regulatory reference to "final limit"? I couldn't find a definition for that. I'm not trying to be petty, but we appear to be discussing similar points using different terms.

I would call the step climb profile 'altitude restrictions' and the limit of my clearance the final altitude of the SID I've been cleared for. This in no way states that the intermediary altitude restrictions of the step climb are not to be complied with.

Although Airbus is equipped with a wonderful CLIMB mode equivalent to Boeing VNAV , it says From Airbus FCOM PRO-NOR-SRP-01-40 P 5/10: Monitoring the Climb phase:

"Recommendation:To ensure that you will not miss the next constraint, it is recommended to select the FCU altitude to the next constraint as described above"

Also as previously stated in case of reversion to V/S due to TCAS TAs or reversion to Heading to avoid Weather , you would have a level bust. In heading mode the system cannot follow the vertical profile in Airbus

I've no preference either way, as my opening post states, I'm curious and looking for regulatory guidance and industry best practices.

If you're on a heading, for whatever reason, are you on the SID anymore...?

You might be on heading to avoid weather in a busy environment , where you exercised your emergency authority to avoid weather due to a busy frequency , but still ATC expect you to maintain an initial altitude.

Many scenarios are available . Imagine a dual FMS failure as approach your initial altitude ? Bang ! You will be overshooting

Selection of V/S due to TCAS is another example and many more.

Nothing wrong to follow a VNAV profile , automation is nice but it requires a higher level of vigilence and alertness . And you have to be aware of the non standard scenarios and be ready to react promptly.

Aviation is not black or white , there is no wrong or right way to do it. If VNaV is there it means it can be used but not necessarily.

Regulatory guidance ? I dont think there are any , whether you flew the profile in managed or selected climb , both are correct as long as the result is the same.

As for aviation best practice I would say "stay on the safer side"

Journey man, the max rate of climb is UK ,the rest is risk management which does not preclude proper monitoring..
As Lord Spandex wrote,the level limit is by distance....

It is the same scenario,for example you are flying in LNAV and your target speed is just 10 kts above the 1.3 G...do you set bank 10deg or leave it to 25 since LNAV gives bank protection?
I dont know how you would so but i select 10 deg when weather avoidance is possible so in case i need to deviate my bank is already set max 10 deg..in case i forget before going into heading mode...risk management.

Just had a look in the 737 FCTM to provide a reference since requested here so there it goes:Ie:Hard altitude is AT or BELOW .(AT 4000,5000B...)
If you are given vectors,it is airmanship and CRM to confirm with the controller if restriction still applies.
In the UK as you know,when no restriction you will get the "climb NOW FL070"...

de facto, see post 11. Rate of climb already covered. Incidentally, it's a "should" clause applicable to enroute. I agree it's good airmanship, depending on the phase of flight.

Boeing is not applicable regulator. Let's keep on topic. My specific request is for references to industry standard or regulation. What's applicable to Boeing may not be applicable to other types, i.e. non AT equipped aircraft where VS is manually controlled in VFLC. There may be various personal approaches, hence the request for regulatory guidance.

Flying is the responsibility of the pilots. Navigating their magnificent flying machine is nowadays done by gadgets at their disposal. How they manage it is part of their profession, not the regulators, or ATC for that matter.
After all, it is a profession, no? Using V/S, VNAV, LvlChange , HDG Sel, etc are only tools to facilitate us.
Imagine us pilots checking when and how ATC has us on which screen, and in what mode? Are we controlling when we are handed over to the next controller, and how he does it?

Or, are we informed if there is a back up generator ready and available at Brussels Belgo Control?

This robotic manipulation of aircraft is taking over from common sense.

Worries me.