Step climb departure best practices
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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.
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.
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Let's take the case of a radio failure… on the CLN8R, established CLN R268 at D23 and A4000. Thoughts?
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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.
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.
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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.
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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.
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.
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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.
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.
Thread Starter
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.
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.
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Finally, what's the cleared altitude on the departure, not the initial step? You say setting a non-cleared altitude is incorrect
You are from the uk...where were you trained??
Thread Starter
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.
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.
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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.
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.
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.
Even if avoiding nuisance TA's is not in your Company procedures it is in other procedures.
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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.
Thread Starter
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.
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.
Last edited by Journey Man; 6th Jun 2015 at 14:28.
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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
"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
Thread Starter
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...?
If you're on a heading, for whatever reason, are you on the SID anymore...?
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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"
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"
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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.
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.
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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"...
Normally, set all maximum or hard altitude constraints in the MCP altitude window. The next altitude may be set when the restriction has been assured or further clearance has been received. This procedure provides altitude alerting and ensures compliance with altitude clearance limits
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"...
Thread Starter
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.
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.
Last edited by Journey Man; 6th Jun 2015 at 22:15.
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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.
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.