Levelling off above ATC cleared altitude on approach
Thread Starter
Levelling off above ATC cleared altitude on approach
There has been some discussion at my place of work about the legality of levelling off for deceleration and configuring above your ATC cleared altitude. Eg you are cleared to 2500’/ cleared for the approach, but the FMS has a level decel at 3000’.
Can you fly the descent managed, levelling at 3000’ until approach slope intercept (normally 3 deg)!or must you force the aircraft down to the cleared altitude and intercept approach slope from there?
It is a bit pedantic in my opinion, but if anyone has any references it would be greatly appreciated.
Can you fly the descent managed, levelling at 3000’ until approach slope intercept (normally 3 deg)!or must you force the aircraft down to the cleared altitude and intercept approach slope from there?
It is a bit pedantic in my opinion, but if anyone has any references it would be greatly appreciated.
Surely unless the approach procedure is prescriptive or when a CDA is required, I would say you can fly it how you like. ATC will always tell you if they want you to reach the platform by a certain point/distance etc. Plus some RNAV procedures are designed and coded as you describe...
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I'll probably be shot down for being too simple....but isn't it as simple as the minimum rate of climb or descent in controlled airspace is 500fpm except for the purpose of acceleration or deceleration?
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Why do your colleagues need to decelerate so aggressively? If it is required, unless issued a minimum RoD then I can't see any issue. On our A320s, when selecting Flaps 2 you might get upto 800fpm climb as the flap comes out (poor FMGC logic), nobody ever seems to complain.
Thread Starter
Thanks, it’s not necessarily about aggressive decel, more the legality of flying the final descent into the approach as coded, which has the aircraft fly a level decel at an altitude above the ATC cleared altitude, which is also the commencement altitude of the approach. The proposed alternative is to either harden altitudes in the FMC to make the decel at 2500’, or fly a selected mode down to 2500’ prior to arming the approach. (A330 if it makes any difference)
Personally I can’t see a problem unless, as mentioned, you are given STANDARD RATE or some similar clearance, but I can’t find any reference to confirm either way.
Personally I can’t see a problem unless, as mentioned, you are given STANDARD RATE or some similar clearance, but I can’t find any reference to confirm either way.
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Common sense?
Levelling off at 5450ft in the vicinity of the airport to comply with a speed request is unlikely to make you friends with ATC. On the approach? Independent parallel approaches use different platform heights for obvious reasons so I'd be inclined to stick to it like glue to ensure separation.
On the other hand, if I'm already level at 3000ft on the localiser, decelerating nicely, and ATC offer a further descent to 2500ft and further with the ILS my inclination would be to remain level and intercept the glideslope from 3000ft in the spirit of our CDFA policy. Others might pay lip service and start a 200fpm descent towards 2500ft.
Levelling off at 5450ft in the vicinity of the airport to comply with a speed request is unlikely to make you friends with ATC. On the approach? Independent parallel approaches use different platform heights for obvious reasons so I'd be inclined to stick to it like glue to ensure separation.
On the other hand, if I'm already level at 3000ft on the localiser, decelerating nicely, and ATC offer a further descent to 2500ft and further with the ILS my inclination would be to remain level and intercept the glideslope from 3000ft in the spirit of our CDFA policy. Others might pay lip service and start a 200fpm descent towards 2500ft.
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There has been some discussion at my place of work about the legality of levelling off for deceleration and configuring above your ATC cleared altitude. Eg you are cleared to 2500’/ cleared for the approach, but the FMS has a level decel at 3000’.
Can you fly the descent managed, levelling at 3000’ until approach slope intercept (normally 3 deg)!or must you force the aircraft down to the cleared altitude and intercept approach slope from there?
It is a bit pedantic in my opinion, but if anyone has any references it would be greatly appreciated.
Can you fly the descent managed, levelling at 3000’ until approach slope intercept (normally 3 deg)!or must you force the aircraft down to the cleared altitude and intercept approach slope from there?
It is a bit pedantic in my opinion, but if anyone has any references it would be greatly appreciated.
3.2.2.4.1 In order to ensure that controllers can accurately predict flight profiles to maintain standard vertical separation between aircraft,
pilots of aircraft commencing a climb or descent in accordance with an ATC Clearance should inform the controller if they anticipate that their rate of climb or descent during the level change will be less than 500 ft per minute, or if at any time during such a climb or descent their vertical speed is, in fact, less than 500 ft per minute.
The above is complemented by the rules of CDO below 6000 ft where applicable.
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There has been some discussion at my place of work about the legality of levelling off for deceleration and configuring above your ATC cleared altitude. Eg you are cleared to 2500’/ cleared for the approach, but the FMS has a level decel at 3000’.
Can you fly the descent managed, levelling at 3000’ until approach slope intercept (normally 3 deg)!or must you force the aircraft down to the cleared altitude and intercept approach slope from there?
Can you fly the descent managed, levelling at 3000’ until approach slope intercept (normally 3 deg)!or must you force the aircraft down to the cleared altitude and intercept approach slope from there?
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It is a bit pedantic in my opinion, but if anyone has any references it would be greatly appreciated.
I know you're just looking for answers, but to me we are trying to solve a problem that doesn't exist. Typical pilot stuff to do.
AUStronauts at work again ggrowler, a firm grasp of the non essential.
For a laid back country, we sure are uptight, too many bush lawyers.
I'm pretty relaxed about all things, and at this phase of flight i believe it's more important to fly the profile that will get you where you want to be, company speed restrictions, configuration recommendations etc, than worry about these little issues. You're 10 miles from touchdown, it's going to make tenth fifths of f*@# all difference to the traffic pattern.
For a laid back country, we sure are uptight, too many bush lawyers.
I'm pretty relaxed about all things, and at this phase of flight i believe it's more important to fly the profile that will get you where you want to be, company speed restrictions, configuration recommendations etc, than worry about these little issues. You're 10 miles from touchdown, it's going to make tenth fifths of f*@# all difference to the traffic pattern.
Last edited by Roj approved; 26th Aug 2019 at 08:57. Reason: corrected the grammar, for all that care
Gender Faculty Specialist
Depends where You are, and often the answer will be found in the AIP Enroute section 1. As an example, for the UK :
3.2.2.4.1 In order to ensure that controllers can accurately predict flight profiles to maintain standard vertical separation between aircraft,
pilots of aircraft commencing a climb or descent in accordance with an ATC Clearance should inform the controller if they anticipate that their rate of climb or descent during the level change will be less than 500 ft per minute, or if at any time during such a climb or descent their vertical speed is, in fact, less than 500 ft per minute.
The above is complemented by the rules of CDO below 6000 ft where applicable.
3.2.2.4.1 In order to ensure that controllers can accurately predict flight profiles to maintain standard vertical separation between aircraft,
pilots of aircraft commencing a climb or descent in accordance with an ATC Clearance should inform the controller if they anticipate that their rate of climb or descent during the level change will be less than 500 ft per minute, or if at any time during such a climb or descent their vertical speed is, in fact, less than 500 ft per minute.
The above is complemented by the rules of CDO below 6000 ft where applicable.
The 500fpm minimum (in the UK) is only a requirement above the transition altitude and in a hold.
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. Eg you are cleared to 2500’/ cleared for the approach, but the FMS has a level decel at 3000’.
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Thread Starter
Vilas,
The clearance will normally be given through 5-6000’ - “Descend 2500’, cleared XX Approach”. I have always believed that from this point I could descend in whatever manner I sort fit (within all limits of course) to decelerate and configure, not below 2500 until established.
There is no problem with maintaining a continual descent to 2500 if I choose, but my question is whether I must.
The clearance will normally be given through 5-6000’ - “Descend 2500’, cleared XX Approach”. I have always believed that from this point I could descend in whatever manner I sort fit (within all limits of course) to decelerate and configure, not below 2500 until established.
There is no problem with maintaining a continual descent to 2500 if I choose, but my question is whether I must.
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Vilas,
The clearance will normally be given through 5-6000’ - “Descend 2500’, cleared XX Approach”. I have always believed that from this point I could descend in whatever manner I sort fit (within all limits of course) to decelerate and configure, not below 2500 until established.
There is no problem with maintaining a continual descent to 2500 if I choose, but my question is whether I must.
The clearance will normally be given through 5-6000’ - “Descend 2500’, cleared XX Approach”. I have always believed that from this point I could descend in whatever manner I sort fit (within all limits of course) to decelerate and configure, not below 2500 until established.
There is no problem with maintaining a continual descent to 2500 if I choose, but my question is whether I must.
Let's look at it from another angle. When a climb or descent clearance is given you may very ROC or ROD but a clearence to descend or climb doesn't include a level segment. For whatever reason you wish to leave off at another altitude in climb or descent should require ATC approval.
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And yes, you can configure, slow down, whatever. BUT - you need to descent to 2500ft eventually EXCEPT they tell you it is "pilots discretion", then it is, quiet logic, up to you. Not really rocket science....