Any news on HOLD mode bug at takeoff?

[jgoggi 65]

Hi, just out of curiosity, how is the fixing of the increasing thrust during HOLD mode at takeoff going? Did you manage to find out what it is caused by? I suppose you have been working on it for more than 4 months, now, it must really be a tough issue.

Thanks.

 

[PMDG777 231]

7 minutes ago, jgoggi said:

Hi, just out of curiosity, how is the fixing of the increasing thrust during HOLD mode at takeoff going? Did you manage to find out what it is caused by? I suppose you have been working on it for more than 4 months, now, it must really be a tough issue.

Thanks.

 

Since the NGX had just released and the recent 744 update was just a minor fix, it probably wasn't included since attention was all on the NGX. I reckon the next big updates for the 744 (possibly in line for the 748 release) might include it. 

[77west 139]

Oh not again.... come on James, they are working on it and it is not a high-priority fix. Hell, it is probably within the allowable margin of sensor error on the real aircraft.

[Captain Kevin 586]

Oh, great. Here we go again. I don't know how many times everyone has to tell you, PMDG included, that if it was an easy fix, it would have already been fixed. The fact that it still hasn't been fixed yet is likely because it isn't an easy fix. Pestering them again and again isn't going to make it get solved any faster, and I think Kyle asked you to knock it off. Really, the only person who is fixated on the EICAS screen on take-off for whatever reason is you. Like I've said before, although it has been acknowledged that the issue is there, I have never personally noticed it unless I was going back through my videos actively looking for it. On take-off, I have more pressing matters to worry about than a minor thrust increase.

[anden145 2,285]

11 minutes ago, jgoggi said:

Hi, just out of curiosity, how is the fixing of the increasing thrust during HOLD mode at takeoff going? Did you manage to find out what it is caused by? I suppose you have been working on it for more than 4 months, now, it must really be a tough issue.

Thanks.

 

James, please enlighten me...

I assume you've already submitted a ticket to the PMDG Support Staff regarding this, correct? If that is the case, why do you keep making new topics regarding this, when the PMDG team is already aware of this issue and are working on it. 

I'm terribly sorry, but quite frankly I fail to understand your logic behind these posts? You have (of course) every right to do so - I simply don't understand what you hope to accomplish...

[jgoggi 65]

Please, could the question be directed only to PMDG? Thanks. Since the only known fact is that they are working on it, I was just curious if they are still facing problems with the issue and trying to fix it or if it has already been solved and will be included in a next update. Once again, please, refrain from replying unless you are from PMDG and know what is being done with it. I will skip reading any reply that is not from PMDG. If they reply, I will say thank you, if they don't, ok, it was just a curiosity, since I did not think it was such a hard issue that after almost 5 months a solution was not found yet. Thank you!

[77west 139]

Just now, jgoggi said:

Please, could the question be directed only to PMDG? Thanks. Since the only known fact is that they are working on it, I was just curious if they are still facing problems with the issue and trying to fix it or if it has already been solved and will be included in a next update. 

1. If you only want PMDG to respond, reply to your support ticket in their system. Not on the forum...

2. If they have not yet fixed it, then, ergo, they must still be working on it, ergo, they have nothing to report.... but perhaps Kyle will be along shortly to indulge you.

[PMDG777 231]

2 minutes ago, jgoggi said:

Please, could the question be directed only to PMDG? Thanks. Since the only known fact is that they are working on it, I was just curious if they are still facing problems with the issue and trying to fix it or if it has already been solved and will be included in a next update. Once again, please, refrain from replying unless you are from PMDG and know what is being done with it. Thank you!

James we are not going through this every time there is an update. PMDG are not going to come on these forums after every update and give you specifically an update on when it will be done. I thought we were being reasonable about this, I thought you had accepted the fact that it was getting worked on. It doesn't take a genius to realise that if it wasn't included in the latest fix, it isn't ready yet. And please, stop shutting everyone down who replies and demanding only a response from PMDG. You've been given a response countless times and it's still the same, just because you're a customer doesn't mean you have the right to demand a response from PMDG. If you want an official response, submit another support ticket.

[anden145 2,285]

+1

[Piotr007 164]

Quite strange though...

Mighty PMDG and some pesky bug during hold mode on TOGA, when O see those numbers N1 exceed the set max I get agitated.

Aarghh not again... come onnnnnm

[Captain Kevin 586]

42 minutes ago, jgoggi said:

Please, could the question be directed only to PMDG? Thanks.

No. As has been stated the last time you said this, you're posting this in a public forum, where anybody can respond. If you only want PMDG to respond, you need to submit a support ticket. Ignore everyone else if you wish, but you still have to follow the rules here.

[DEHowie 269]

The thrust increasing is a natural effect seen on every jet aircraft i have flown.

The throttle hold mode(note its NOT thrust hold) is a mode whereby the autothrottle sets the limit thrust(Thrust ref)...on reaching HOLD(65-80 kts airframe dependent) speed the autothrust no longer can modify engine thrust. Ie it sets the thrust then depowers the servos to the thrust levers to ensure an autothrottle issue cannot reduce thrust.

It isnt an active system ie continually keeping the thrust the same like the Airbus system which continually maintains the desired EPR or N1.

As the aircraft with thrust set accelerates and the autothrottle in hold and no ability to adjust thrust accelerates ram effect will increase engine rpm ie N1 and can change EPR.

Here is an extract from our 787 manual...the 747/777/767/757 are all identical in application of Throttle Hold mode.

Quote...

The PM should verify that takeoff thrust has been set and the throttle hold mode (HOLD) is engaged. Once HOLD annunciates, the autothrottle cannot change thrust lever position, but thrust levers can be positioned manually. The HOLD mode remains engaged until VNAV engagement or another thrust mode is selected. 
Note: Takeoff into headwind of 20 knots or greater may result in HOLD before the autothrottle can make final thrust adjustments. 

The HOLD mode protects against thrust lever movement if a system fault occurs. Lack of the HOLD annunciation means the protective feature may not be active. If HOLD annunciation does not appear, no crew action is required unless a subsequent system fault causes unwanted thrust lever movement. As with any autothrottle malfunction, the autothrottle should then be disconnected and desired thrust set manually.

 

The engines spinning up due to Ram effect occurs on EVERY engine on every jet out there. As you can see its not a THRUST HOLD function but THROTTLE HOLD designed to not hold a set thrust setting but depower the autothrottle servos and stop a malfunction reducing thrust catastrophically.

 

[DEHowie 269]

PS and a video in HD of the 747 which clearlybshows the drift away from the Thr Ref setting during the take off roll. Its in HD and if you screenshot the Vid yiu can zoom in and see thst after Thr Hold engages the EPR and rpm change.

Enjoy...

 

[Dez 7]

4 hours ago, Captain Kevin said:

Oh, great. Here we go again. I don't know how many times everyone has to tell you, PMDG included, that if it was an easy fix, it would have already been fixed. The fact that it still hasn't been fixed yet is likely because it isn't an easy fix. Pestering them again and again isn't going to make it get solved any faster, and I think Kyle asked you to knock it off. Really, the only person who is fixated on the EICAS screen on take-off for whatever reason is you. Like I've said before, although it has been acknowledged that the issue is there, I have never personally noticed it unless I was going back through my videos actively looking for it. On take-off, I have more pressing matters to worry about than a minor thrust increase.

You have made your point in several topics, no need to go all over it again it seems to me you like your own sound in this forum. Give it a break please.

Mo Dez

[jgoggi 65]

54 minutes ago, DEHowie said:

PS and a video in HD of the 747 which clearly shows the drift away from the Thr Ref setting during the take off roll.

Doesn't seem to me like you say. Look at min. 3:00: N1 after HOLD engagement is about 90.1 and at lift off it even decreases to 89.9, anyway remains we can say constant between 89.9 and 90.1. You can see many real life videos on Youtube and you can realize that after HOLD engagement N1 remains more or less constant. Now go and see what our 747 does....