I agree with someone from before: it's an unrealistic situation, for me personally, I couldn't give less attention to this, since the aircraft is working as it should in all normal and abnormal operations. And what you are calling for, is an unrealistic performance.Why would you want to take off in ATT mode?Oh and btw. I tried it, it performed as usual.

You have not seen the video... I'm pretty sure about this... you have not wasted your time looking at it, so why do you waste your time posting?And continue to follow your checklists without knowing what you're doing... just push buttons in sequence...

Ridiculous comments. Yes, I did watch the video, noting no IRS alignment, no FMC inputs, therefore no V speeds selected. Gear down, locked away about a second later. People who use the software, as intended by the developer are not necessarily robots as you put it.Your problem is clearly not a bug with the IRS in ATT mode.If alignment is lost in flight, the navigation mode is inoperative for the remainder of the flight. Attitude information can be obtained by moving the selector to ATT. The IRU enters the Align mode for 30 seconds during which the airplane should stay in straight and level flight. This re-levels the system and provides attitude displays on the ADI. Some attitude errors may occur during acceleration. After acceleration, errors are slowly removed.With the above in mind, and watching the first half of your video it's apparent there is no straight and level flight to re-level the system.Without an initial alignment the aircraft has no idea where it is, or how far it has gone.....the information hasn't been supplied.Sorry, but I get wearly of people in the forums using the software clearly as not intended, I mean your flying the NGX like little more than a supercharged ultralight trike, then claiming the software has bugs......does not compute.

Unrealistic what?The systems are supposed to work in a way, if they doesn't, checklist or not, there is an error.PMDG in its page product speaks of system simulation, not checklist simulation.I don't know why on your system you cannot replicate it.Just replicate this:Fuel contamination. You have a fuel contamination in all tanks tht shut down the engines, and you are not able to start APU, it is a situation far from unreal. If for you is too muc unreal, just change the example.Ground personnel loaded on plane what you requested, 6000 kgs of fuel. But, ground people loaded 6000 lbs. You will not find the error, and during cruise you will have engine shut down.Land the plane...You will experience an almost complete loss of fligth control movement.Is it a bug? No, as for the checklist all is working, the limitation in flight controls is not in the program.Now, just think on another unrealistic scenarioYou are in an airport, near the sea, somewhere in the ocean, now an heartquake generates a tsunami that will hit you in few minutes, maybe less than 5 minutes. What you do? Follow the entire IRS alignment as per regulations to finish you and 150 passengers under the water, or try to align IRS to ATT?Unreal? Maybe an unrealistic scenario a tsunami? Or an airport near the sea? Or that a pilot will take off in these conditions if he is knowing what it is appening?And If I try to hijack a plane that is parked? If I want to hijack it, I will surely use ATT function, will not wait the police for ten minutes.Unreal? Probably, but the real plane is supposed to do it.Why the simulated one, the one with almost all systems simulated, wont?Again,It is better a plane that simualtes correctly the checklistor a plane that simulates the systems?There is a big difference between them...

Ridiculous comments. Yes, I did watch the video, noting no IRS alignment, no FMC inputs, therefore no V speeds selected. Gear down, locked away about a second later. People who use the software, as intended by the developer are not necessarily robots as you put it.Your problem is clearly not a bug with the IRS in ATT mode.If alignment is lost in flight, the navigation mode is inoperative for the remainder of the flight. Attitude information can be obtained by moving the selector to ATT. The IRU enters the Align mode for 30 seconds during which the airplane should stay in straight and level flight. This re-levels the system and provides attitude displays on the ADI. Some attitude errors may occur during acceleration. After acceleration, errors are slowly removed.With the above in mind, and watching the first half of your video it's apparent there is no straight and level flight to re-level the system.Without an initial alignment the aircraft has no idea where it is, or how far it has gone.....the information hasn't been supplied.Sorry, but I get wearly of people in the forums using the software clearly as not intended, I mean your flying the NGX like little more than a supercharged ultralight trike, then claiming the software has bugs......does not compute.

You reveal that you are only reading the book, but don't understand it.As, if you understand it, you will find that if ATT is selected it needs 30 seconds to align in a level and calm condition (If I take off with them already in ATT mode) I aligned them on ground, meaning that I was leveled for over than 30 secs.You're not understanding that is incorrectly simulated as for the 30 secs of alignment you MUST LOSE the informations, and ten reappears, but in pmdg did not.Try to align in flight with any attitude situation, you will see that it will works normally, it will not correct any error as no error will be shown.Vspeed bugs are necessary for the aircraft? If I know at what speed I must rotate, there is a need of a bug or a voice?Fmc is so important for the flight? MEL says that can be inoperative.About LGs in the second video I can call for another little bug that appeared few times, as I use a button on my controller to rise them. When I pushed the button, the gears went OFF not Up, so I used mouse, left clicked and then right clicked (or viceversa)We can speak also about I've selected LG lever to OFF before full retraction and gears continued to retract...But for checklist are all normal...Please... do the robot and follow this checklist...Browser X button............PUSH

Sorry, but I get wearly of people in the forums using the software clearly as not intended, I mean your flying the NGX like little more than a supercharged ultralight trike, then claiming the software has bugs......does not compute.

This is the point:What is the mean of this software?A simulaton of an aircraft or of a checklist?

The PMDG 737NGX features an unprecedented level of systems fidelity. Developed over three years with technical input from Boeing and a team of real-life 737NG crew and maintenance advisors, we have painstakingly modeled nearly every system on the real aircraft in a fully dynamic and realistic manner.

From Ngx product page...Definetly, The ATT SYSTEM is not correctly simulated. And, if the aircraft responds in this way (as seen in the video) with some users, it is a bug.There is no more to discuss about.

Well, report it as a bug.......Good luck!I stand my usual motto......Never try to match wits with a fool......

Well, report it as a bug.......Good luck!I stand my usual motto......Never try to match wits with a fool......

Quite. I give up this ridiculous discussion.

Hello friends,please, we are plesantly (I hope) discussing of a strange behaviour, just to understand better some things, no need to be angry or being upset.Just for curiosity and with IT troubleshooting spirit, I made few others tests.1) I tried takeoff with autothrottle off, using throttle manually: same behaviour.2) I tried takeoff with IRS in Off mode and finally the plane performed as expected. (This limit the bug on IRS ATT mode).3) I tried repeat all the tests on Prepar3d, and all the results were the same, the good and the bad. (and this indicate me it's not (or not only?) an FSX bug).Anyway, with cooperative and constructive spirit I opened a ticket to PMDG support providing all possible info, and now developers are aware of this and maybe will research the reason.So, why become upset?

I made a clean installation according PMDG instructions, uninstalled by control panel, deleted directories, deleted also any 737 saved flight in Documentsfsx files, reinstalled base package and sp1 running both as administartor.Then I made some tests.1) Started fsx, selected from initial screen pmdg 737 house livery winglets, KTNT, daytime, and started a new free flight. Loaded panel state cold and dark, set fuel 1/3. started battery, apu, electrical, then pumps, engines and all needed to have overhead ok, except for IRS in ATT mode and consequently yaw damper off. Nav1 and adf setted, autopilot off but values setted on speed 240, hdg 096, 2500 feet , FD on, autothrottle armed. I saved at this point the flight. Engated TO/GA, and plane worked well as expected.2) Closed FSX Restarted FSX Loaded from initial screen the saved flight and (after waiting systems initialization) engaged TO/GA. Plane went crazy as other times.3) Closed FSX Restarted FSX Selected plane airport and daytime from initial screen WITHOUT LOADING THE SAVED FLIGHT. Loaded only the saved panel state from FMC and engaged TO/GA Plane taked off regularly and worked well.4) Closed FSX Restarted FSX Loaded from initial screen the saved flight. Reloaded from FMC the saved panel state and engaged TO/GA Plane went crazy. 5) Closed FSX Restarted FSX Loaded from initial screen the saved flight. Loaded from FMC the DEFAULT PANEL STATE Reloaded from FMC the saved panel state and engaged TO/GA Plane worked well So, it seems the problem arise when loading a saved flight without pass through a default panel state.It seems to avoid the "crazy plane bug" one should load the plane starting in a default situation. Maybe searching for IRS bug we found someother. When a flight start from scratch the deafult panel state is loaded, setting all systems running and working.When a flight start from saved situation the saved panel state is loaded without loading the default panel state before.If the results are different maybe something is missing or different or bugged in the procedure of loading (or saving and then reloading wrong?) the panel state.It seems like the load panel state doesn't fill all needed variables (or cannot reload because not all saved); if a default panel state is loaded in advance some variables remain valorized when loading the next state, and all works correctly.If a panel state is loaded without load a default state in advance, some variables have no good values and when the software try to read and use them the plane goes crazy.Or maybe the bug is in the IRS ATT mode; if used without set them before in off or nav mode, some info was never inserted in the system (or wrongly initialized).It would explain why after a regular departure they can be set in ATT mode during flight without make the simplane unstable (no doubt about the real one obviously).Beside the IRS, I think this is a bug worth of some investigation effort.Hope all my troubleshooting can help.Claudio Colangeli

Just received a message from PMDG support.They say were able to reproduce the problem and will investigate to solve it.A BIG Thanks to PMDG for the continuous and professional support offered us.Happy landings to all.

A BIG Thanks to PMDG for the continuous and professional support offered us.Happy landings to all.

+1Strange that other here were unable to replicate the issue, it was so simply and ridicolous to do... Maybe more easy to replicate it than posting the words "ridicolous" some times...