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zazaboeing

Parallel Hold Entry --> Error

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Hi guys!I was really anxious expecting the update, having installed it, i went for a "test" flight yesterday ... :)When on the approach procedure, I had a parallel entry and the airplane totally lost itself (like older versions).I started only testing holding procedures then, and realized the plane does very well on Offsets and Direct, but on the Parallel entries, sometimes it keeps on the outbound heading forever, without turning back to the fix (most common problem) and sometimes it just turns to the right when its supposed to turn to the left and join the hold.Any comments? Randazo?Thanks!!

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Hi RafaelI've had the same problem a while ago! And I was told that they are going to look at it. It seems like they did not do anything!I asked for an answer from PMDG and never got one. Only one of the beta testers said that he would address this but I never heard anything else.I would be surprised if you get an answer from PMDG...CheersMartin

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Rafael,Just a few comments from me:To pin-point the problem we really need some more information from you. About the parallell entry; could you elaborate on the "airplane totally lost itself". It really doesn't tell us anything worth knowing. ;-) AFDS modes, SID/STAR in effect, model, ZFW, fuel load, load distribution, well just about any fact you can think of. And would be great with a screen shot or two of the panels. And we'll start from there ok?Can you describe the initial settings for us to test the hold entries you say are not working? And maybe give us a screenshot or two?Cheers,

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Hi there Mats.I always had these problems before, and I was expecting the updates about the holding matters, the update was correctly installed, but the problems remains. Just like before."Lost" in this example:I was flying a Gol 37-700, light loaded, (don't remember exactly) and about to enter the D3 VOR/DME procedure to SBVT. LNAV and ALT HOLD (4000')and SPD 230 Kts engaged.The inbound leg of the holding is 081

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Sounds like the autopilot on this a/c hates the parallel entries to holds about as much as GA instrument fliers do :). If I can ever make a parallel entry into a teardrop without tranversing to the unprotected side if the fix, I always do (sometimes in a missed approach segment, entry at the MAHF is technically a "parallel", but a teardrop will do as well).Sorry for the off-topic! Bruce.

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Hummmmmmm looks like a ADD TO LIST ITEM ;DBest Wishes,[h4]Randy J. Smith[/h4][h3]P M D G's 747-400[/h3][h4]coming to a runway near you[/h4][/font color]Caution! Not a real pilot, but do play one on TV ;-)AMD 64 3200+ | ASUS KV8 DELUXE | GFORCE 5700 ULTRA @535/1000 | Maxtor 6Y080M0 SATA 80 GIG | 512 DDR 400 | Windows Xp Pro | Windows Xp Pro 64 |

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Hello Randy, are you a developer?So if you need to add it to the patch list, do it please!Hey Mats, did you get the info you needed?Looking foward to hear from you !Thanks!

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No I am not BUT was really involved in this aspect helping the FMC programmer on holds. You notice best speed now ;-)? So it's almost perfect but this stuff is complex lol and I am glad I do not do the programming, only the whining pleading and praising.Best Wishes,[h4]Randy J. Smith[/h4][h3]P M D G's 747-400[/h3][h4]coming to a runway near you[/h4][/font color]Caution! Not a real pilot, but do play one on TV ;-)AMD 64 3200+ | ASUS KV8 DELUXE | GFORCE 5700 ULTRA @535/1000 | Maxtor 6Y080M0 SATA 80 GIG | 512 DDR 400 | Windows Xp Pro | Windows Xp Pro 64 |

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I posted some tests a while ago about the enhanced behavior for holding pattern entry after the service update, and for me this works very well. However I have tried Rafael's scenario at SBVT, 351 deg inbound to hlg 81 deg, R turn, the ac turned left(as supposed) but didn't revert to the hld entry at all. I tried it several times with the same result. The only way to get it to the hld, was to reselect the hld at LSK1L and exec it.But I have also tried this at several different airports, and then it works ok. At first I thought that this must have something to do with the initial inbound to the hld point, so I tried also to set up the "same" scenario at a different airport, but again it works OK for me. Take a look at the pics. the first with the same "angle of attack" as at SBVT, worked great for me here:http://forums.avsim.net/user_files/88153.jpgThe next one with a different angle, but again it works fine:http://forums.avsim.net/user_files/88157.jpg.Due to update of a whole bunch of sid/star files after the service update I have flown dozens of these holdings as test flights, and they all worked fine, so this one at SBVT was strange. Maybe something trigger this instance at certain circumstances, while it works well at others airports? I don't know.If needed I can give further info on the setup for these tests.

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Very nice post...Best Wishes,[h4]Randy J. Smith[/h4][h3]P M D G's 747-400[/h3][h4]coming to a runway near you[/h4][/font color]Caution! Not a real pilot, but do play one on TV ;-)AMD 64 3200+ | ASUS KV8 DELUXE | GFORCE 5700 ULTRA @535/1000 | Maxtor 6Y080M0 SATA 80 GIG | 512 DDR 400 | Windows Xp Pro | Windows Xp Pro 64 |

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Well, don't know, but I wanted to show that this function actually is improved and works well at different headings into the hld. But that SBVT thing, odd...

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I got the exact same problem. When coming from INKET (Netherlands) flying to ROT (Hold over ROT inbound course 029, right turns) the plane should do a direct entry, but instead it does a nonstandard parrallel entry (makes some kind of teardrop outside of the hold).I tried this several times, but the problem remains.I think the problem is that somehow the airplane doesn't overflies the holding fix, which it should acccording to the procedures.I have added a picture showing this error.I hope this clearifies it a bit.Paul

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Another example:http://forums.avsim.net/user_files/89829.jpgThis could have been a perfect parallel entry if only the A/C had overflown the RICCE fix...edit:A/C enters picture from the lower right and exits towards the top.As it is, it starts the turn early, causing it to fly along the racetrack in the opposite! direction, then after the first turn starts to cross the racetrack correctly towards RICCE, but again turns away early, but settles onto the correct track eventually.FL270, IAS 230 kts, no winds; hold programmed during flight, not part of preprogrammed SID/STAR.Best,Martijn

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You apparently are way over my head in this discussion, but out of curiosity, what is a "Parallel Entry" in simple terms?

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>You apparently are way over my head in this discussion, but>out of curiosity, what is a "Parallel Entry" in simple terms?>> Hello Bob:Start FS-Flying Lessons-Instrument Pilot - Lesson 3: Holding PatternsIt's all in there!Regards, Murray

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"Center: Delta 1234 cross 10 west of ABC at and maintain 11,000Delta: We are kinda close and probably won't make thatCenter: Well don't you have spoilers?Delta: Yes, but those are for my mistakes, not yours"LOL, was that an actual transmission? Sorry to get off topic, but that made me giggle.

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That's actually quite good, Martijn. All that is required is to keep on the protected side of the fix, which you did. It doesn't matter how elegant or not the hold looks. This would be typical of a cross-wind from the top (north?), and recovering in up to 2 turns (which you did) meets the PTS. Bruce.

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Thanks, Bruce,but actually all credit should go to the PMDG AP!I tried several holds on FMS/AP, and most were entered correctly (teardrop, parallel, direct entry, as called for by the angles) except that the initial turn was always commenced too early-and in this case, that does make it look like there was a stiff breeze from the North, but there was no wind. I posted this hoping it might contribute to finding out why things go wrong. I think it's the fact that the initial fix is being missed.Most of the time, I'm getting fairly good holds like this from the PMDG FMS/AP...if only they could erm...fix it so that the AC would pass directly over the initial fix and THEN start the turn...: sometimes the early turn results in the FMC not progressing to the hold-at line because it doesn't seem to sequence the missed wpt. (usually, that same fix) as reported by Per in another post earlier in this thread-in that case you have to 'bump up' the hold-at line manually.I think many of the failed holds in the other posts might have turned out OK if only the aircraft had crossed the fix before entering the hold proper. It's only a small flaw in otherwise excellent FMC/AP behavior.BTW I'm going on pg.175 in Bulfer's FMC user's guide. I don't know if the real NG does overfly the fixes automatically, altough I suspect that it does...but please correct me if I'm wrong...or perhaps in the RW the pilots do not leave it to the autopilot at all and fly the holds themselves? Best,Martijn

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Hi Martijn,In fact holds are very rare (at least in the US) these days, as seperation is achieved more through flow control (speed direction by ATC). And I'm sure that those airline captains that are in holds would rather the AP fly the hold :)I'm just doing my instrument rating, so the AP in my plane is always "inoperative" :) One must first learn how to fly using those steam gauges!Bruce.

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Thanks Bruce,>In fact holds are very rare (at least in the US) these days, as seperation is achieved more through flow control (speed direction by ATC). Yeah, that's much more efficient I guess...knowing FS flow control though, ought to be plenty of holds there! :-hah >And I'm sure that those airline captains that are in holds would rather the AP fly the hold I guess so, except the ones who were oval racers in their younger days maybe...>I'm just doing my instrument rating, so the AP in my plane is always "inoperative" One must first learn how to fly using those steam gauges!Hey, good luck with your IR!Best,Martijn

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Thanks. I'm really enjoying the preciseness of instrument flying.Bruce.

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I know this is an old topic but since there is still no reply from PMDG in this I'm kicking it up.I am very curious if PMDG is adressing this problem in a future update on the 737NG. Furthermore I'd like to know if PMDG is already working on an update. (since they've been working on the 1900C aswell)Regards,Paul

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