jgoggi

So, as I feared, HOLD thrust bug not fixed...

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So many cosmetic correctiions in this first update, but what I think it's the real annoying bug is not fixed, as I feared: the self increasing thrust during HOLD mode at takeoff (that's why I insisted on it, I felt it was not being given the right priority). Look at the screenshot in the attached link: green takeoff reference N1=98.7, real N1 at lift off:100.3 (and still increasing until 400 ft). If it was the real plane, it would be AOG with that issue!

N1.jpg

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I'm fairly certain, that they're aware of this 'bug', since you so insistently have been adament about it. It could be, that the solution is a bit more complicated and that they are still working on a solution for it.

Who told you, it would be fixed in the update which was just released?

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They told me "hopefully", but it's a bug of the system logic, it should have maximum priority... (and I didn't want to add that it should have already been detected during beta testing of the release version...).

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When i read the changelog i knew that this thread will appear soon ;)

RSR quote from the update thread:

Quote

 we anticipate pushing a number of updates for this product line in very rapid succession

This is the first update since the new dynamic update system went live. It absolutely makes sense to issue a smaller update with mainly cosmetic changes to "test" the system before they throw any major releases at it. According to RSR's statement above, we can expect further updates soon. Just be a bit patient ;)

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10 minutes ago, woozie said:

It absolutely makes sense to issue a smaller update with mainly cosmetic changes to "test" the system before they throw any major releases at it. According to RSR's statement above, we can expect further updates soon. Just be a bit patient ;)

Yes, seen this way, it makes sense... 

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Because OH, MY GOD, THE PLANE'S GOING TO CRASH BECAUSE WE TOOK OFF AT 1.6% N1 OVER WHAT WE WANT!!!! We should just drop everything and not update anything until this gets fixed, right? Because, you know, trying to adjust the payload for one plane and getting a completely different value shouldn't be fixed, right (last time I checked, entering 24 in the payload should NOT give you 10, it should give you 24)?

2 hours ago, jgoggi said:

They told me "hopefully",

Key word being hopefully. Hopefully does not mean actually.

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Captain Kevin, I suppose you are in the real world aviation, aren't you? Then you should know that even an 1.6% is often outside the accepted limits...

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1.6, 0.0000001, 1 billion... The point is not the number, is that the logic is wrong... You get it?

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I look at this first update as a test and the real meat will come later when all the update bugs are worked out. 

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6 hours ago, jgoggi said:

If it was the real plane, it would be AOG with that issue!

Firstly, no. At worst, you're looking at an AT INOP sticker. At best, you just fly because the automation isn't causing any actual limitation exceedances. I recall mentioning this in other threads, this is still flyable. Yes, it's wrong, but your reaction to it is quite a bit hyperbolic, and overly-fixated.

James - seriously. We've told you that we're looking into it. Constantly bringing it up isn't going to get it fixed faster. It's not going to make us more aware of it than we already are. The fact that the issue isn't fixed shouldn't be seen as some personal thing that we're holding out on you. Seriously - go enjoy the plane and quick hyperfixating on something so minor. You're really missing out here.

 

 

Thing that sucks about this whole situation is that it really makes you wish there were some, you know...micro-updater function where we could update the product when the issue is fixed. I mean, right now, all the little cosmetic things that were a little easier to fix are just getting held up at the cost of  trying to chase this world-ending, plane-is-unflyable bug down...

Oh, wait...

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1 hour ago, scandinavian13 said:

Firstly, no. At worst, you're looking at an AT INOP sticker. At best, you just fly because the automation isn't causing any actual limitation exceedances.

Anyway this is an A/T issue, but a PMDG 747 software issue, because it occurs just when the A/T is NOT connected...  I haven't tried, but what if you takeoff at almost max thrust? Will the EEC control that thrust increase during the HOLD period? If not, the thrust increase may well lead to an exceedance...

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I'm looking forward to the update that will fix this, but how could this go unnoticed in tech beta and even in the larger beta?

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14 minutes ago, fabristunt said:

but how could this go unnoticed in tech beta and even in the larger beta?

Easy. In the grand scheme of things it is insignificant.

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2 hours ago, jgoggi said:

Anyway this is an A/T issue, but a PMDG 747 software issue, because it occurs just when the A/T is NOT connected...  I haven't tried, but what if you takeoff at almost max thrust? Will the EEC control that thrust increase during the HOLD period? If not, the thrust increase may well lead to an exceedance...

You're flying a computer mate. What part of "we're looking into it" don't you understand? They'll fix it, give them time.

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3 hours ago, pcubine said:

Easy. In the grand scheme of things it is insignificant.

I'd agree with you for things like the wonky animation of the heading reference switch or any cosmetic details, but this is a big one, and on systems, a thing that PMDG takes pride in modelling accurately.

I hope they'll fix it soon :)

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10 hours ago, jgoggi said:

Captain Kevin, I suppose you are in the real world aviation, aren't you? Then you should know that even an 1.6% is often outside the accepted limits...

As a matter of interest, I am not. I only fly in the simulator. In any event, if you had LOST thrust, that'd be one thing since a loss of thrust would result in possibly more runway being used, but since the thrust went up, in theory, you'd actually get off the ground quicker. As far as I'm concerned, plane still flies. For the record, I never said this wasn't an issue. I understand that this is an issue. I'm just saying that they shouldn't be expected to drop every single issue just to fix this one, which may or may not be easy to fix. I don't know what is involved in fixing this, but I'm sure they would rather get the easy stuff done and out of the way. By the way, watching my own video, starting at 10:30, the N1 slowly increased, the EPR stayed mostly the same up until the point of rotation. This is with the Boeing 747-400ERF with PW4062s.

 

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James,

I think you need to take a step back and read your posts.  You really are coming across a bit stridently, rather pedantic, exceedingly histrionic and it is making you look a rather foolish.

From the perspective of those of us type rated to command the airplane- your observation makes it pretty clear that you don't have any experience with the way these things are operated in the real world. 

Yes, as you have pointed out, we do see a small climb in rotation, but this isn't catastrophic to the operation of the airplane, and in the real world would go largely un-noticed or excused as ram rise by just about all the flight crew flying the thing without the benefit of the auto-throttle.  (Your assertion that this is some kind of gross inaccuracy tells me that you have absolutely no experience flying behind actual engines, fwiw.)

I told you previously we would look at it.  That stands.  It is in our tracking system and will get addressed at some point.  Given that it is not a catastrophic fault- we might look at it tomorrow... it might be next year.  I do not know- but no amount of screeching at the top of your lungs and blasting us with breathy, emphatic presumptions about "as i feared" is going to change that.

(Your title sounds ridiculous by the way... Really? As you feared? If this is the largest thing you fear right now- you must be leading a charmed life...)

Now:  Calling this update "largely cosmetic" is just flat out offensive to the thousands of developer hours that have gone into shaping and improving the 747 since it's release.  It shows that you are grossly out of touch as to the amount of work that takes place behind the scenes, know virtually nothing about how the software operates or how the airplane is simulated and are instead singularly focused on a personal agenda that you have inflated to such grand levels self importance that you sound ridiculous here in your posts.

So as I suggested- take a step back... take a deep breath...

 

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The way I look at this is, yes, this is a FADEC system, but in terms of AOG - back on the classic 747 fleet, I highly doubt that all four engines were exactly on point during the takeoff, I would think a ~2-3 % tolerance either way would be acceptable, if not slightly more. By the time the flight engineer has stopped fiddling with them, you may well have been over 80 or 90kt. Same for takeoff weight - you never really know exactly how much you weigh; plane may say 395,000kg, I promise you you will be either side of that. Sometimes by a couple of tonnes. Real airplanes have flown for years with known software bugs that were not deemed that important to fix. That is the real world. Not everything is black and white, and to be honest; I would much rather my engines increase a percent or two than decrease. That said, even a 1 or 2 percent decrease will NOT mean the difference between taking off or going for a swim in the sea; it may mean a difference of a few hundred feet on the roll, if that.

Heck, the margin of error on the engine sensors is probably around a percent or so...

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Wes,

The classic 747 point is very valid.

I am routinely flying a non-EEC DC-3 and a non-EEC Citation S/II.  The goal on both is to get the power set at or above the target figure by 70knots.  Relatively easy to do in the DC-3, not so easy to do in the S/II.

We have left the pavement with anywhere from 5-7% over the target/one over target with one under target/etc... As long as both aren't grossly under- you call it good and go.  Any pilot who is going to fiddle with throttles and abort or refuse to fly because he can't get the power set to perfection prior to takeoff isn't going to make it in real world aviation.

Running up on redline is a different deal, obviously- and in that arena the EEC on the 400 should prevent it.  Ours will sometimes creep into it- and that will get fixed at some point...  We aren't talking about burning available run time on real world engines here with our simulation, so it isn't viewed as mission critical.  If we were coding the actual EEC for the actual airplane- it would be different.

Weights... oh man where to begin.  I started to ponder my own sanity after reviewing the results of my own line's Average Weight Study.  We were using 175/180lbs for summer/winter weights at that time...  We ran an actual weight study on a half dozen flights and found that the average weights ran significantly higher.  215/225 rings a bell...  It might have been 235/245... i forget- but it was HIGH. 

I got to participate in an overweight departure investigation on an international carrier once...  Their paperwork was built entirely on an average weight program.  When the airplane was unloaded and weighed out at an intermediate (unplanned) fuel stop, the 767-300 was found to weigh almost 45,000lbs more than planned.

S&%t happens, but I still added that airline to my no-fly list.  :ph34r:

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5 minutes ago, rsrandazzo said:

Wes,

The classic 747 point is very valid.

I am routinely flying a non-EEC DC-3 and a non-EEC Citation S/II.  The goal on both is to get the power set at or above the target figure by 70knots.  Relatively easy to do in the DC-3, not so easy to do in the S/II.

We have left the pavement with anywhere from 5-7% over the target/one over target with one under target/etc... As long as both aren't grossly under- you call it good and go.  Any pilot who is going to fiddle with throttles and abort or refuse to fly because he can't get the power set to perfection prior to takeoff isn't going to make it in real world aviation.

Running up on redline is a different deal, obviously- and in that arena the EEC on the 400 should prevent it.  Ours will sometimes creep into it- and that will get fixed at some point...  We aren't talking about burning available run time on real world engines here with our simulation, so it isn't viewed as mission critical.  If we were coding the actual EEC for the actual airplane- it would be different.

Weights... oh man where to begin.  I started to ponder my own sanity after reviewing the results of my own line's Average Weight Study.  We were using 175/180lbs for summer/winter weights at that time...  We ran an actual weight study on a half dozen flights and found that the average weights ran significantly higher.  215/225 rings a bell...  It might have been 235/245... i forget- but it was HIGH. 

I got to participate in an overweight departure investigation on an international carrier once...  Their paperwork was built entirely on an average weight program.  When the airplane was unloaded and weighed out at an intermediate (unplanned) fuel stop, the 767-300 was found to weigh almost 45,000lbs more than planned.

S&%t happens, but I still added that airline to my no-fly list.  :ph34r:

I envy your DC3 flying. I remember my friend and instructor saying, 'just put the needle about here, and then leave it, I want your eyes on the runway / outside' - we didn't fiddle about getting the RPM and manifold just so, by the time we would have we would be in the air anyhow. Obviously, on longer cross country flights and higher altitudes these figures would become more important up in the air, but I never flew those. (And havent flow for real in years, sadly..)

As to weights, the classic case of the coin collectors in the rear cabin comes to mind. Talk about CG nightmares with several thousand KG in the rear cabin, unaccounted for. The airplanes are built with a buffer, If a 747-400ER can take off at 415,000kg with the same wing as the normal -400, there is a lot of room for error. I bet many 747-400 non-ER have taken off over 400,000kg in the past, without knowing it. If not more, as your example goes.

 

45,000lbs over on a 767 though... well, no comment there.... :blink: :bengong:

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13 hours ago, rsrandazzo said:

it might be next year.

Robert, I have been faithful to PMDG since the 747 v1 and only fly PMDG airplanes, but in that case I would be very disappointed by the professionalism of PMDG... If I were the developer, I would at least be very curious to find out immediately what drives this unwanted invisible hand that increases thrust in an uncontrolled way, thus compromising the precision of the simulation and doing something I DON'T want in the simulator I developed... Even because it seems that there are not so many other "visible" bugs to spend all the time fixing (at least this is my feeling... Yes, I mean this airplane looks almost perfect).

13 hours ago, rsrandazzo said:

your observation makes it pretty clear that you don't have any experience with the way these things are operated in the real world. 

(just for info, I work in the Engineering dept. of a CAMO of a big airline, so I hope I should know what having an aircraft airworthy means...).

Ok, waiting patiently, sorry if I caused you an unwanted waste of time.

 

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Did you, like, read the rest of his post and the other posts that followed afterwards?

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You do not need the Autothrottle System to fly the airplane. You do if you are flying a Cat III approach, but other than that, if it is working it is recommended to use as a full time system in most phases of flight.

It is recommended if you disconnect the A/P to also disconnect the A/T, like on a visual approach. There is a tendency depending upon pilot smoothness of corrections, that if you are prone to unnecessarily changes of the pitch, you can get out of phase with the A/T and it will be working against you. I have seen this a lot when pilots try to use the A/T on a 3 engine ILS approach. You can do it, but you have to be precise and smooth with your pitch corrections. When the power changes, the rudder requirement changes, and if you don't control it, the jet is flying you and you are not flying the jet.

So it is normally recommended to use manual thrust. It is good to just fly these jets without the automation for practice.

Those of us who were brought up in the non-glass world and without A/P's used to have to hand fly everything. I did this for 11 years in the Northeast Corridor as a regional pilot. All hand flown, non autopilot turboprops, for 8 to 10 legs a day in weather. To this day, I have zero problems with scan and control input corrections in the heavy jets because of that flying. Take the time to work on manual skills.

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