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Strange/unexpected IMM EXIT from HOLD


AMJBecker

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I'm flying version 1.2.3 of the Airbus A320 Family Professional and just training myself for flying HOLD patterns. When I try to IMM EXIT a HOLD, I would have expected that the A/C flies the shortest way towards the HOLD FIX an then procede with the flight plan. That's how it is described as well in the Thales Flight Management Pilot Guide from Dec 2004 (quite old but it's the one I have). But the A/C actually flies an extra circle before turning towards the HOLD FIX. See the following screenshots.

 

  • Original Flight Plan (NOLG3A STAR to EDDH ILS 23)
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  • After inserting HAM and defining HAM as HOLD FIX (computed HOLD)
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  • HOLD is shown on ND as expected
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  • A/C enters HOLD (direct entry as expected, no surprise, because it's a computed HOLD) and MCDU shows IMM EXIT prompt
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  • IMM EXIT prompt posted
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  • ND shows extra circle, A/C flies extra circle. This is the issue I'd like to raise. Is this a normal behaviour? I would have expected a behaviour that is described in the Thales document.
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  • What is also remarkable: the recalculated path towards the glidepath became too narrow. But this can be corrected by defining a fly-over at DH658. Following ND Screenshot shows path from HOLD FIX HAM to the glidepath after setting fly-over at DH658
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Just to be sure before we go looking for a bug... are you familiar with the three basic Hold Entry Patterns?

 

If not, then there is a vast amount of information on the web (Google "Hold Entry Patterns").  A very good one is HERE.

 

Best wishes!

 

 

 

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If you mean the direct, parallel and teardrop entry? Yes, I'm familiar with that stuff. 

The issue I have is not about the entry. I have a direct entry, because it is a computed HOLD. My issue is about the extra full circle in case of an immediate exit. I pushed the prompt, when I already was on a straight line to the HOLD FIX. Circling is not necessary, as would be, if I were on the other side of the HOLD loop.

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Okay, now I understand what you meant!

 

I'm sure you're right about the Hold Function in the Airbus Pro, but I have a flight a little later and I'll give it a check and pass this info along. We've been so busy with the Managed Speed and Descent issues that I honestly haven't done a Hold is quite a long time, so it should be looked at.

 

Many thanks!!!

 

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Okay, I found at least 3  problems with the HOLD function... not including the exit issue, so we'll have to take a deep look at the HOLD function.

 

Thanks for letting us know!

 

Best wishes!

 

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  • 3 weeks later...

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