Hi PMDG,I just bought your 737 and it seems to have some major problems with it's vertical guidance. I took a short flight from KCLT to KATL at FL240 to give the plane a try. I put in the crossing restriction of 13,000 and 250 kts at WOMAC as published on the MACEY 2 arrival. About 5 minutes out of top of descent I reset the MCP altitude for 13,000.The plane continued along to the FMC computed T/D as normal, and upon reaching it, started descent as normal. Unfortunately it nosed over (waaaaay over) and entered a vertical dive peaking at roughly 20,000 feet per minute. I let it go for a moment to see what would happen and it just kept on going, with airspeed peaking at about 480 knts indicated before I had enough and put on some speed brakes. Eventually after speed brake application the descent came back to something resembling normal, but it still didn't rejoin the VNAV path and ended up getting me to 13,000 feet about 19 nautical miles short of WOMAC.I was a bit nervous about the possibility of having another 20,000 foot per minute dive when only 11,000 to 12,000 AGL, so leaving WOMAC I elected to give level change a try instead of VNAV. The descent in level change seemed much more sane, but unfortunately busted the 5,000 foot altitude constraint I gave it by roughly 800 feet.So, all in all this is pretty disapointing. I hate having to ask this on the day of release, but, when will the patch be available? :) I feel kind of like I've paid $40.00 to beta test your airplane.I don't want to leave on such a negative note, so let me also say that most of this plane is pretty impressive. It's pretty smooth to hand fly, definately one of the best flight models I've seen for MSFS. Same for the lateral autoflight guidance. Very smooth and barely any altitude deviation in turns. VERY nice job on that, PMDG 737 and PIC 767 are the only planes I've seen that are so precise in this regard. I just hope these VNAV and LVL CHG problems can be fixed as 20,000 foot per minute dives from the computed top of descent point really tend to overshadow all of the good things. :-(-Shaun

PMDG,I forgot to mention something. Also, with all 4 wing tank pumps on (no fuel in center tank) I ended up with a fuel imbalance of roughly 1000 lbs at the end of my short flight, with the right tank being the light one. Not sure if this is a bug or if I need to have crossfeed open even with all 4 pumps running. Please let me know.-Shaun

HiThe same Problems here, looks not very goodregardsMarcus

Shaun,I will fly your FP tonight and check it out.Questions :- Can you confirm you were in PTH descent (have not switched to SPD DES?)- when you say LVL CHG busted your next constraint, you mean your MCP set alt, i.e. you ended up being 800 ft below your MCP alt ?thanksanthonyAnthony MertonPrecision Manuals Developmenthttp://www.precisionmanuals.com

HiAny idea because the fuel imbalance ?regardsMarcus

Marcus, was the APU running during the flight?

Anthony,Thanks for the help. Yes it was in PTH, but even if it had switched to SPD it is pretty crazy to have it fly a speed that's like 100 knots over the red line. And with LVL CHG yes I was refering to the MCP altitude. It went 800 feet below and then climbed back up.-Shaun

OK, thnaks for this info.Do you remember your flight plan ? If yes, it could be useful to know what wpts were there.thanksanthonyAnthony MertonPrecision Manuals Developmenthttp://www.precisionmanuals.com

Hi Anthony,even I had the same problem with VNAV descending at almost 10.000 fpm rate after I had previously set an altitude costraint in the FMC. I used "path" descent. I was coming in to EDDF and had set a 250/FL110 costraint at Epino intersection.Regards,Bjorn Ghezzi

Anthony,Thanks for looking into this and for the fast replies. My flight plan was as follows:KCLT HOR1.HARAY SPA.MACEY2 KATL (FL240)KCLT HARAY SPA ODF MACEY WOMAC/13000ft/250kts LOGEN ATL KATLIncidentally, I've just taken another hop from ATL to MCO and I'm sad to say that I got the same nose dive at top of descent. Another problem came up also. This time I didn't want to see what would happen, since I already knew... so I shut off the autopilot and quickly recovered. Then I shut off VNAV, re-engaged a/p and engaged LVL CHG. For some reason though this time LVL CHG was giving a large descent rate of 4700 feet per minute, so I attempted to use VSPD.Is the vertical speed mode just eye candy? When I engaged it the button lit up, (don't recall if it showed on the PFD.. shame on me for not x-checking a mode change with the PFD :-) ) but it did not command a change in vertical speed. It stayed at -4700 dispite my dialing in -1500. I then disengaged the A/P, manually trimmed the plane out for -1500, re-engaged, then dialed a change to -2500 into the VSPD window.. yet it still maintained -1500.On this flight my flight plan was as follows:KATL ATL5.SOONE.J89.OTK.LEESE9 KMCO (FL330)KATL ATL SOONE ICBOD OTK CLAWZ UGENE COAXE ALADN LEESE/13000ft/250kt ORLAt the risk of upsetting someone, I'm going to pose a few questions anyhows. I don't understand how something like VNAV initiating nose dives rather than descents at T/D could be missed during beta testing or even alpha testing. A lot of people are reporting this so obviously it's not something I've messed up. I mean overall this is a great plane but why release it in a state where it can't be flown reliably on autoflight? I do enjoy hand flying but only below FL180 or so. :)I don't really know how to feel about paying $40 for a plane that's incomplete. I mean, on one hand, I should be praising your work on this incredible plane. Minus these problems it really IS the best add-on FS has seen to date. On the other hand though, I feel that by releasing with such serious problems as these you've really made us pay to be beta testers. I don't mind being a beta tester but I wish I would have gotten the plane at the same time the rest of the testers did if I'm going to test. :)In closing, I just wish you'd waited until the plane was finished to put it out. It would have also given you time to finish the documentation. It is pretty shocking that a company called Precision MANUALS would release such a complex add-on without a MANUAL! :) Maybe it's just been a long time and I've forgotten, but I don't remember your Fly 757 being this way.-Shaun

Agreed 100% with your comments about the too early release. This product did NOT undergo enough testing. I have many commercial beta test products both in the past and currently on the go and I would be very uspset if any of the commercial releases I was involved with were released in this state.I have no idea why this was done especially in view of the fact that the manuals are not even ready yet. Incredible!Tim WestnuttBeta TesterDreamfleet Boeing 737-400 (and forthcoming C-310 - Still undergoing rigorous testing)MAAM-SIM R4D and B-25FFS Cirrus SR22 (forthcoming)And plenty more!http://forums.avsim.com/user_files/20387.gif

I have to agree, Tim. When I origionally posted this reply I focused on being nice just on the off chance that this VNAV thing really WAS missed during beta testing. Having read the pinned topic at the top of the forum revealing what the underlying problem is though, there's just no way. I can't believe it's even *REMOTELY* possible that in a month of beta testing, NOBODY flew a STAR with a crossing restriction above 10,000 feet.There's no way that this "slipped by", I just wonder now WHY they rushed it out the door with that problem in it. This kind of rush job is very disapointing, especially so late in the game and ESPECIALLY from PMDG.There are some developers (I won't start calling out names though) that I'd expect this kind of thing from and not even bother to voice a complaint, it's just to be expected. PMDG has a much better reputation than this though. Usually they are very good about releasing non-broken products.Maybe the cash drawer is running a little too thin. Maybe they just read too many posts on the forum from people salivating for the product, and decided to get *something* in our hands that we could enjoy some aspects of even if it wasn't totally done. :) I don't know though and I guess I really shouldn't speculate on why. Hopefully PMDG will tell us in time.It's a shame to see such a good company put out an unfinished product and not even include the documentation. I hope that PMDG will compensate those of us who bought the product in good faith that major things like this wouldn't be broken. Not a refund obviously, but.. some way.. somehow. :)-Shaun

Shaun,You were descedning at xxxx ft/min at xxx IAS and set the MCP alt xx secs before actual altitude has been reached ?Thanks,VangelisE. M. VaosPrecision Manuals Development Groupwww.precisionmanuals.com

I don't know all that anymore, the flight was several hours ago. The vertical speeds are in a previous post.. and the altitude was many thousands of feet above the target altitude.-Shaun

Have to agree with you guys...probably released two or three weeks early. The registration thing is not intuitively obvious and is creating a lot of confusion...the vertical dive thing is a hard to believe artifact that should have been caught in beta testing...several have posted major frame rate decay with the VC...not even a basic manual...and I'm sure there will be some other things.I was VERY surprised to see the release announcement last night, but also am VERY impressed with this plane, or at least what I'm sure it will be in a short period after some of the things that should have been fixed get fixed. But hey, PMDG is a great company and I'm sure they'll continue to provide top notch support...this is a top drawer add-on and I remain very optimistic!