Bankstown RNP RWY 11 approach on Garmin G1000
"... and the airspace boundary are unknown to the system"
Wow. As usual, I've learned something new from you, Alpha. It's counterintuitive, as I've seen airspace boundaries on (TSO'd) GPS displays.
Thanks.
Wow. As usual, I've learned something new from you, Alpha. It's counterintuitive, as I've seen airspace boundaries on (TSO'd) GPS displays.
Thanks.
Tossbag, yes pretty much.
From my own experience it seems that Boeing aircraft systems seem to favour a 2.5-3 degree profile, whereas the Airbus logic is not quite as straight forward and in some cases goes towards a more dive and drive profile. This can vary based on weight, wind, and temperature. Its just the different logic used in the navigation systems.
Garmin systems being more GA focused seem to also favour a 3 degree profile. The key thing to remember here is that the system is only as smart as the information it hold. In the Bankstown case for the RAKSO-SBKWI leg there are only 2 known points that being RAKSO or SBKWI (the 6.5nm fix and the airspace boundary are unknown to the system). So starting at 3700ft at RAKSO and wanting to be 2500ft at SBKWI presents some options..
a) I can give you a 3 degree descent from 3700ft @ RAKSO to 2500ft, or
b) I can give you a 3 degree descent to 2500ft @ SBKWI from 3700ft, or
c) I can plot a constant descent from 3700ft @ RAKSO to 2500ft SBKWI which would be 1.5deg (approx)
These are pretty much the only coding options available......each nav system manufacturer may choose a different option....and each of them are valid for a specific system/aircraft. For example option a) may be suited Cessna 400 series piston aircraft allowing for deceleration. Option b) may be more suited to turboprop aircraft and option c) may be suited to jet aircraft. In all cases the start, end and minimum altitudes are honoured. I hope this helps explain it.
From my own experience it seems that Boeing aircraft systems seem to favour a 2.5-3 degree profile, whereas the Airbus logic is not quite as straight forward and in some cases goes towards a more dive and drive profile. This can vary based on weight, wind, and temperature. Its just the different logic used in the navigation systems.
Garmin systems being more GA focused seem to also favour a 3 degree profile. The key thing to remember here is that the system is only as smart as the information it hold. In the Bankstown case for the RAKSO-SBKWI leg there are only 2 known points that being RAKSO or SBKWI (the 6.5nm fix and the airspace boundary are unknown to the system). So starting at 3700ft at RAKSO and wanting to be 2500ft at SBKWI presents some options..
a) I can give you a 3 degree descent from 3700ft @ RAKSO to 2500ft, or
b) I can give you a 3 degree descent to 2500ft @ SBKWI from 3700ft, or
c) I can plot a constant descent from 3700ft @ RAKSO to 2500ft SBKWI which would be 1.5deg (approx)
These are pretty much the only coding options available......each nav system manufacturer may choose a different option....and each of them are valid for a specific system/aircraft. For example option a) may be suited Cessna 400 series piston aircraft allowing for deceleration. Option b) may be more suited to turboprop aircraft and option c) may be suited to jet aircraft. In all cases the start, end and minimum altitudes are honoured. I hope this helps explain it.
Thread Starter
So if you are given the BK 11 LNAV approach by Sydney Terminal when you are OCTA approaching RAKSO does that allow you to enter and leave the class C airspace on descent to WI?
SWH, that screenshot is from the Jeppesen database, granted its an older cycle so unless it have been taken off, which I am not aware it has been, then it is accurate. How are you viewing the coded data? The procedure doesn't have to be a VNAV procedure to have the vertical path angle in the coding, hence the lack of temperature limitations.
When you live....
I’m a little confused by this thread - I would never expect a G1000 or other system to keep me clear of controlled airspace - only to fly the approach appropriately (I.e to the manufacturers specs as alfacentauri explained). How can your FMC know what clearances you have or don’t have?
UTR
Thread Starter
Only in Australia from my experience would an IFR aircraft on an IFR approach go in and out then in again of controlled airspace.
Once I flew the approach with a US trained pilot coming in from overhead Richmond. It was beyond comprehension to him that he was not cleared for the approach. I explained that we would actually be in uncontrolled airspace when the approach started and he was on his own. No descent clearance would be given.
Once I flew the approach with a US trained pilot coming in from overhead Richmond. It was beyond comprehension to him that he was not cleared for the approach. I explained that we would actually be in uncontrolled airspace when the approach started and he was on his own. No descent clearance would be given.
Only in Australia from my experience would an IFR aircraft on an IFR approach go in and out then in again to controlled airspace.
So if you are given the BK 11 LNAV approach by Sydney Terminal when you are OCTA approaching RAKSO does that allow you to enter and leave the class C airspace on descent to WI?
You can only ever have one IFR aircraft ( that hasnt reported visual) in the BK CTR at one time. My understanding is the APPCH permission from SY CEN is for sequencing into BK even though you are OCTA from SY airspace for the majority apart from the aformentioned segment of the IAF-IF leg, which without a clearance to enter ( different to approach permission), you must avoid.
Lead Balloon,
To clarify, the airspace data and approach data are in separate parts of the database. They are unknown to each other, and so there are no smarts to compare approach path and airspace data…..
Thats kind of the point of the prediction arc in large fms systems. It allows the pilot to know if an altitude is going to be reached by a certain point and adjust if required.
To clarify, the airspace data and approach data are in separate parts of the database. They are unknown to each other, and so there are no smarts to compare approach path and airspace data…..
Thats kind of the point of the prediction arc in large fms systems. It allows the pilot to know if an altitude is going to be reached by a certain point and adjust if required.
You can only ever have one IFR aircraft ( that hasnt reported visual) in the BK CTR at one time. My understanding is the APPCH permission from SY CEN is for sequencing into BK even though you are OCTA from SY airspace for the majority apart from the aformentioned segment of the IAF-IF leg, which without a clearance to enter ( different to approach permission), you must avoid.
I believe it is to do with ATC are required to seperate IFR from IFR in Class D. Under normal circumstances, most IFR aircraft when VMC prevails operate inbound via the VFR reporting points, and report visual with their inbound call, which enables ATC to employ visual separation to IFR aircraft as they are visual, which obviously cant be done in conditions less than VMC with aircraft on IAP's. Radar/ ADSB is only available for situational awareness to controllers in BK tower to my knowledge.
The only quote that somewhat references it is in the ERSA " IFR Operations in VMC", " Pilots electing to terminate an IFR flight under the VFR should communicate itention to ensure their arrival is processed efficently "
So what it looks like is a 'local procedure.' Unpublished, but IFR pilots are expected to understand and comply. Contributing to confusion and misunderstanding (as in Dick's question).
Great airspace system (sarcasm).
Great airspace system (sarcasm).
tossbag, it's pretty simple really. You're IFR operating in Class D airspace so subject to a clearance to conduct the approach in D, and as you're required to be separated from other IFR aircraft in D you have exclusive use of the airspace until you've either landed or conducted a missed approach.
Tossbag, Dick's question had nothing to do with your "local procedure". He asked about why his FMS didn't stop him clipping a CTA step in when in full auto. He was given the answer.
I see nothing "local" about being cleared for an approach. The fact that you start out OCTA and, because of the way you operate your aeroplane/FMS, you then clip a CTA step, sound like a personal problem.
There is much nashing of teeth about hypotheses here. To go anywhere with this, we need to know exactly what ATC says. Obviously they won't "give" you the approach (your post #27).
As for
Read note 4. And observe the 20nm range ring from SY.
Perhaps a more-specific caution on the chart re the Sydney step might be in order. AVSEF it.
I see nothing "local" about being cleared for an approach. The fact that you start out OCTA and, because of the way you operate your aeroplane/FMS, you then clip a CTA step, sound like a personal problem.
There is much nashing of teeth about hypotheses here. To go anywhere with this, we need to know exactly what ATC says. Obviously they won't "give" you the approach (your post #27).
As for
Just out of interest, is this 'procedure' published anywhere? ERSA, DAP's/Jepps?
Perhaps a more-specific caution on the chart re the Sydney step might be in order. AVSEF it.
I'm just wondering if a note is missing from the RNP chart, there is a star next to the @2500 limit at WI, which resembles the same star on the NDB RWY 11C chart which states you have to be 2500 by 17 DME SY. Although this procedure is horribly non aligned with rules concerning CTA as some of them seem to pass in and out of CTA steps. The marked descent line seems to infer all is ok as long as you are 2500 at WI. It would be interesting what a controller familiar with the area would expect an aircraft to do, ie remain clear of the 20 DME step or as long as you are 2500 by 17 DME SY no probs...
tossbag, it's pretty simple really. You're IFR operating in Class D airspace so subject to a clearance to conduct the approach in D, and as you're required to be separated from other IFR aircraft in D you have exclusive use of the airspace until you've either landed or conducted a missed approach.
Captain Bloggs, you'll note in my previous posts I was asking questions to understand what is being said by ATC. You obviously have someone sitting beside you to help clear up any confusion, sit in the cockpit by yourself in IMC and manage the workload of this procedure and see how you go. Personal problem? No, Dick is confused by whether he has a clearance to clip, the last thing you need when SP-IFRing in IMC is to be chipped by ATC for busting CTA.
I think you need to calm down a little, look at the broader implications of what is being discussed.
I think you need to calm down a little, look at the broader implications of what is being discussed.
Garmin navigators will provide vertical guidance on almost every approach in the database. On LNAV approaches it will give you LNAV+V where the the +V refers to a pseudo glide path that is a mathematically derived 3 deg slope. This is very handy but care must be taken because it will not account for any mandatory crossing altitudes.
One gotcha with GARMIN systems is that the system switches from terminal mode to approach mode (ie LPV, LNAV/VNAV or LNAV) when the active leg is the leg to the FAF. If there is a fix between the IAF and the FAF it will not sequence to approach mode until after that waypoint which means there will be no glide path until after you pass the waypoint at which point you will be above the glide path.
The work around is to activate vectors to final after you pass the IAF which will cause the FAF to be the active to waypoint.
One gotcha with GARMIN systems is that the system switches from terminal mode to approach mode (ie LPV, LNAV/VNAV or LNAV) when the active leg is the leg to the FAF. If there is a fix between the IAF and the FAF it will not sequence to approach mode until after that waypoint which means there will be no glide path until after you pass the waypoint at which point you will be above the glide path.
The work around is to activate vectors to final after you pass the IAF which will cause the FAF to be the active to waypoint.
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The work around is to activate vectors to final after you pass the IAF which will cause the FAF to be the active to waypoint.