Procedural matters
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Procedural matters
Hi,
Quick question that has come up at work, with no one really being sure what the correct answer is or where to find a reference for it.
You are in the hold which is located at the IAF for an ILS. You are flying at the MHA for that hold as published however the IAF altitude to begin the procedure is one level below your present altitude/level.
When cleared for the approach is it correct....
1. To descend in the hold to the IAF altitude, which is an AT, then go outbound and follow the rest of the procedure descending as required until the platform altitude for the ILS/intercept
2. Maintain the MHA until passing over the IAF and then using flap/speedbrake as required descend rapidly to meet the next AT altitude and then continue the approach.
Option 1 means we have now descended below the MHA in the hold prior to going outbound but we are AT the required altitude for the IAF prior to commencing the procedural approach (no terrain issues below)
Option 2 requires us to begin a procedural approach from an IAF by busting this first AT altitude by more than 1000ft, however, you have not descended below the MHA in the hold.
I have my own opinions on this, and at what point the hold stops being a hold and forms part of the approach as do a number of colleagues so we thought we might put it to the PPrune panel and see what happens!
Look forward to your replies.
Quick question that has come up at work, with no one really being sure what the correct answer is or where to find a reference for it.
You are in the hold which is located at the IAF for an ILS. You are flying at the MHA for that hold as published however the IAF altitude to begin the procedure is one level below your present altitude/level.
When cleared for the approach is it correct....
1. To descend in the hold to the IAF altitude, which is an AT, then go outbound and follow the rest of the procedure descending as required until the platform altitude for the ILS/intercept
2. Maintain the MHA until passing over the IAF and then using flap/speedbrake as required descend rapidly to meet the next AT altitude and then continue the approach.
Option 1 means we have now descended below the MHA in the hold prior to going outbound but we are AT the required altitude for the IAF prior to commencing the procedural approach (no terrain issues below)
Option 2 requires us to begin a procedural approach from an IAF by busting this first AT altitude by more than 1000ft, however, you have not descended below the MHA in the hold.
I have my own opinions on this, and at what point the hold stops being a hold and forms part of the approach as do a number of colleagues so we thought we might put it to the PPrune panel and see what happens!
Look forward to your replies.
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I think it depends on whether the holding is part of the IAP or not. On jeppesen charts, if the holding is in bold lines, it IS part of the procedure, if it's a thin line, the holding is NOT part of the procedure.
I'd say if you are cleared for the approach, then you are cleared to the first point on the approach, which is the Initial Approach Fix. Which has its associated altitude. Simple as that.
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KISS Principle:
Assuming no ATC restriction the minimum holding altitude applies until established on a published segment of the approach other than the holding pattern.
Assuming no ATC restriction the minimum holding altitude applies until established on a published segment of the approach other than the holding pattern.
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Ladies/Gents,
Picture uploaded.
In the hold based on the IAF on the 037/20DME from FQG.
You can see the MHA is 5910 but the procedure begins at an altitude of 4930. If your in the hold and then cleared for the approach do you descend on the outbound leg of the hold to 4930 and leave the IAF at the correct procedural altitude or do you leave the IAF at 5910 and then dive 3200ft within 9.2 miles to arrive at the next AT altitude.
Our discussion is that neither course of action is quite correct.
Your thoughts are once again welcome.
SFFH
Picture uploaded.
In the hold based on the IAF on the 037/20DME from FQG.
You can see the MHA is 5910 but the procedure begins at an altitude of 4930. If your in the hold and then cleared for the approach do you descend on the outbound leg of the hold to 4930 and leave the IAF at the correct procedural altitude or do you leave the IAF at 5910 and then dive 3200ft within 9.2 miles to arrive at the next AT altitude.
Our discussion is that neither course of action is quite correct.
Your thoughts are once again welcome.
SFFH
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In my opinion MHA is based on a speed , radius of turn to ensure obstacle clearance . In that particular case 245 kts as a maximum speed in a hold will involve a larger area therefore MHA of 5910 feet.
Regarding the procedure it says max speed of 205 kts , to reduce the radius of turn and stay in the defined protected area of the procedure . As a general rule , descent is only allowed once inbound within half scale.
So if you were in a hold at 245 kts definitely you cannot descent to 4930. While starting the approach inbound course 037 with a speed of not more than 205 , there is a segment of the procedure that coincides with the hold but you are not in a hold anymore , its just a segment overlaying the hold with a waypoint to fly AT 4930.
Now , Heading or radial when outbound in hold?
Generally the outbound leg of a hold is flown in heading and is not limited or defined by a radial. So I have to assume that the outbound leg depicted here is just the procedure and not the hold . If I had to hold , I will be outbound on heading 037 and not radial 037 from FQG.
This could explain a higher altitude for the hold.
When being cleared for approach I will intercept radial 037 outbound from FQG and descend to 4930 once inbound .
What do you think?
Regarding the procedure it says max speed of 205 kts , to reduce the radius of turn and stay in the defined protected area of the procedure . As a general rule , descent is only allowed once inbound within half scale.
So if you were in a hold at 245 kts definitely you cannot descent to 4930. While starting the approach inbound course 037 with a speed of not more than 205 , there is a segment of the procedure that coincides with the hold but you are not in a hold anymore , its just a segment overlaying the hold with a waypoint to fly AT 4930.
Now , Heading or radial when outbound in hold?
Generally the outbound leg of a hold is flown in heading and is not limited or defined by a radial. So I have to assume that the outbound leg depicted here is just the procedure and not the hold . If I had to hold , I will be outbound on heading 037 and not radial 037 from FQG.
This could explain a higher altitude for the hold.
When being cleared for approach I will intercept radial 037 outbound from FQG and descend to 4930 once inbound .
What do you think?
Last edited by Citation2; 26th Aug 2015 at 21:15.
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I would descend to 4910 (or above) outbound in the hold. After passing 20 DME, descend at your leisure to 2610. I'm assuming that the 2610 is also the platform altitude for the ILS so there is no hurry to get down. No rush to "dive off" the altitude, especially nowadays when CDA's are encouraged.
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I would descend to 4910 (or above) outbound in the hold. After passing 20 DME, descend at your leisure to 2610. I'm assuming that the 2610 is also the platform altitude for the ILS so there is no hurry to get down. No rush to "dive off" the altitude, especially nowadays when CDA's are encouraged.
The lines above and below an altitude with "AT" indicate a mandatory altitude and not an AT OR ABOVE altitude which would be indicated by just a line below the altitude.
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My answer would be to descend in the hold so as to cross the IAF AT 4930'. Because it is a mandatory altitude, if you can't make it, another turn in the hold would be in order.
In my opinion MHA is based on a speed , radius of turn to ensure obstacle clearance . In that particular case 245 kts as a maximum speed in a hold will involve a larger area therefore MHA of 5910 feet.
Regarding the procedure it says max speed of 205 kts , to reduce the radius of turn and stay in the defined protected area of the procedure
Regarding the procedure it says max speed of 205 kts , to reduce the radius of turn and stay in the defined protected area of the procedure
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Be careful about the terms "inbound" and "outbound" here... "Inbound" to the holding fix/IAF is "outbound" on FQG R037.
This is an unusual approach profile. However, once cleared for the approach, I would decelerate to 205 KIAS and configure as necessary in the holding pattern, descending to MHA of 1500M/5910' until inbound to the IAF (outbound, within 1/2 scale deflection of the FQG R037). I would then descend to reach D20 at 1500M/4930' and continue the descent to reach D28 at 800M/2630'.
That way, I would comply with any confusing or possibly conflicting restrictions.
This is an unusual approach profile. However, once cleared for the approach, I would decelerate to 205 KIAS and configure as necessary in the holding pattern, descending to MHA of 1500M/5910' until inbound to the IAF (outbound, within 1/2 scale deflection of the FQG R037). I would then descend to reach D20 at 1500M/4930' and continue the descent to reach D28 at 800M/2630'.
That way, I would comply with any confusing or possibly conflicting restrictions.
