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PhilH

Quick RNAV / LNAV question before I buy

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Hi guys,

 

I'm seriously considering buying the Q400 from Majestic, it looks fantastic! However, I plan on using mostly to fly in remote areas that have no ILS - but only have GPS (RNAV) approaches.

 

It seems like there are many problems with the plane turning too early on final, skipping the IF of the approach, especially with RNAV approaches featuring 90 degree turns. I have searched and searched and found no video of a complete RNAV approach. The descent (VNAV) part isn't confusing to me, it's mostly the LNAV part that confuses me.

 

A friend of mine has the Q400, and I kindly asked him to try and fly an approach for me, (on the latest patch), and he was unable to do it.

 

Could someone PLEASE do a video of this approach (or an approach of this kind, RNAV with 90 degree turns) and post it here? This is the only thing that's making me wait to get the Dash. Thank you very much!

 

 

 

 

Here is the approach he tested:

 

No matter where he came from, "ODGUS" was always skipped. If flying from the southwest direct to ENARA for example, the Dash turns direct to DERGO after ENARA! Making it way to high (and unrealistic). Perhaps he's doing something wrong? I have read through the documentation and can't figure it out.

 

 

IMG_20140926_015313.jpg

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Page 113 of the manual:

 

"* Please note, there are waypoints where procedure requires that the aircraft overlies the waypoint before proceeding to the next. In such cases the FMS will position the terminator right over the waypoint, and not ahead of it. Such condition is marked as “*” behind the waypoint name, and can also be set manually by selecting the leg in the flight plan, and the “OVFLY->” prompt on the right side.

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It appears that the OVFLY can't be done manually on approach segments. I had suggested that method, but it wouldn't do anything unless the waypoint had been manually entered, in which case the star (*) appeared.

 

But I don't think that would help, as you can see on the chart above, the only overfly waypoint is the FAF anyway (DERGO). Also, I think the airplane is completely skipping the segment (not turning too early). It goes ENARA => DERGO, completely forgetting ODGUS.

 

Thanks for the tip though!

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Could someone PLEASE do a video of this approach (or an approach of this kind, RNAV with 90 degree turns) and post it here? This is the only thing that's making me wait to get the Dash. Thank you very much!

 

for me it turned slightly inside OGDUS when i tried it, but was fairly well lined up by DERGO and was well stabilized by the time i was near decision height. i flew it with vnav also which probably isn't correct according to the plate lol.. one thing to notice, it is slightly off centerline, but i think that is a scenery issue and i couldn't find an updated afcad for cymx... (saw the exact same issue when trying CYUL last week and the ILS would line you up slightly off center, but was fixed with an AFCAD from the avsim files)..

 

anyway the video link will be here, it's got 45minutes of uploading time left so check back later 

http://youtu.be/35XQvOIPemQ

 

cheers,

-andy crosby

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Hi Andy,

 

Thank you very very much for your time and effort!

Your video is the proof I was looking for. The approach worked perfectly compared to what my friend is getting... Which means it's most likely something he`s doing wrong. At least I know the aircraft seems very capable of doing those RNAV approaches properly.

 

Anything special in the setup? You just program the approach using the FMC, delete the -NO LINK- before ODGUS and that`s all, right?

 

 

Thanks again for your help!

 

Phil

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Anything special in the setup? You just program the approach using the FMC, delete the -NO LINK- before ODGUS and that`s all, right?

 

yep... don't think i did anything special... the nolink removed was before OLAKI which i selected as the transition when entering it from the approach page. i think i had programmed YMX as the waypoint before that so somewhere along the YMX->OLAKI leg is where the vid starts. 

 

one thought is that maybe your friend doesn't have the current version? they did tweak the behavior of the lnav on one of the patches, maybe 1.007 or 1.008 or something, it's up to 1.011 now

 

cheers

-andy crosby

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Perhaps the patch is the problem, I think he said he was on 1.009.

 

In any case, I don't really care if he's doing something wrong. I just wanted to make sure the Q400 was able to fly these approaches properly and you showed me it can. I'll get it and learn to fly it properly, now I know it's not a bug!

 

Thank you very much again!

 

Phil

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for me it turned slightly inside OGDUS when i tried it, but was fairly well lined up by DERGO and was well stabilized by the time i was near decision height. i flew it with vnav also which probably isn't correct according to the plate lol.. one thing to notice, it is slightly off centerline, but i think that is a scenery issue and i couldn't find an updated afcad for cymx... (saw the exact same issue when trying CYUL last week and the ILS would line you up slightly off center, but was fixed with an AFCAD from the avsim files)..

 

anyway the video link will be here, it's got 45minutes of uploading time left so check back later 

http://youtu.be/35XQvOIPemQ

 

cheers,

-andy crosby

 

Hi Andy,

 

Just wanted to thank you once again. It must have been a mistake or patch problem on my friend's side.

 

I just purchased the Majestic Q400 and tried simply departing YUL, climbing to 5000 and proceeding direct to ENARA for the RNAV approach. It worked perfectly. Turned on final at the right time, descending properly with VNAV, everything is flawless.

 

Once again, thank you very much for your time! I will not regret buying the Dash.

 

 

Phil

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