747V3 reverse thrust is wrong

[anubhavs 66]

There's very likely an FSX limitation at play here - ever tried the reversers in the default aircraft? The FSX engine model (which all jet addons have to use at some base level, regardless of what's being shown on the cockpit displays) is crappy with this stuff. I know I've brought this up with our coders in previous development cycles and I'm basically positive we've done all we can with what FSX gives us. I will ask about the discrepancy vs. OP's video, but seriously guys - you're not buying a real plane here, it's not going to be 100% identical in every conceivable way. It's the best we can do operating on what's now a nearly 11 year old simulator.

I just checked btw and max reverse at that temp seems to be around 76% on our GE's at 25C in the current beta - 58 is definitely not our max reverse, wherever you saw that. Also - what really matters here is the aircraft's stopping distance and the wear placed on the brakes. Reversers simply save brake wear and life - they don't make the aircraft stop any faster. The combination of autobrake setting and reversers result in a preset deceleration rate, regardless of how much reverse is actually used. This means the airplane's going to stop in the same distance regardless of what combination of autobrake and reverser levels are actually used. If more reversers are used, less brakes are used to achieve the same stopping distance.

Thanks for the clarification Ryan.

 

And for the record - kudos to the OP for even spotting this.

[ErichB 3,643]

 

 

A simple "Thank you for your feedback, we appreciate it. It has been noted internally to be looked into." could have avoided all of this, IMHO.

 

No, that would not have been an appropriate response at all - considering the subject title.   Kyle's post was absolutely dead on and to the point.  If you want to make ignorant posts directed at professionals on the internet and claim your post as fact,  you'd better not be too concerned about your 'feelings' when you get the response you were baiting.

[RaptyrOne 1,411]

No, that would not have been an appropriate response at all - considering the subject title.   Kyle's post was absolutely dead on and to the point.  If you want to make ignorant posts directed at professionals on the internet and claim your post as fact,  you'd better not be too concerned about your 'feelings' when you get the response you were baiting.

 

Well I would totally disagree that the OP made "ignorant posts" Erich. Maybe he came across to some people as being too direct but why not re-read his entire post? He is not aggressively accusing anyone of anything, or saying that it is "fact". He is merely noting his observation and asking a question about his observation. Why is that ignorant? Ignorance is derived from NOT asking questions. I think the OP is quite the opposite of being ignorant. How many people even  noticed the reverse thrust % I wonder? The OP is the very opposite of ignorant. Not sure where that leaves those that accuse him of being such....

 

Kyle, shut this down already :-)   :-)   :-)

[anden145 2,285]

He stated that the reverse thrust was wrong without knowing all the facts.

 

*SIGH*

 

Reap what you sow...

[ArjenVdv 190]

The same person who posted this thread had previously asked if we were going to model the short field package that KLM had (based on this exact video if I recall correctly).

 

So I am getting accused of making wrong statements, and you do the same thing yourself? Source? Here you go.

 

 

 

I can clearly make out 94 on the EICAS. I am not sure whether this is exclusive to KLM, but if it is, then my best guess would be that it is meant for short runways such as St Maarten. Some sort of short field package maybe?

In that thread, I also made the obvervation about the reverse thrust, and because most people always avoid the question by trying to debunk my obversation as hard as they can, they are provoking speculation. That was the mere thing I did: speculating as to why I made the observation about the reverse thrust. "Maybe what I was seeing was exclusive to KLM, an airline option?" You are not happy with me saying that,, but also not happy with me generalizing my observation over the entire 747 fleet? 

 

So videos are not reliable sources for development? First you are coming up with silly examples that are put completely out of context, and are heavily dramatized. I would never criticize a pilot or human being, because a technique I had seen in a video was supposedly the better one. A video of a display screen showing the behaviour of a machine, is exactly the same as directly looking at the display itself in real life, if you are just noting what numbers are there. If however, you are trying to answer the question WHY the numbers are there, that's the moment when a 747 type rating or 747 expertise becomes a requirement. As you could have read in my original post, I made no assertions why the numbers are different, I noted the difference, speculated a bit, and asked a question. Yet, everybody is insulted and putting everything out of context.

 

Secondly, you - PMDG - have stated yourself, years ago already, that you are using video recordings of the aircraft, in order to simulate all the quirks and behaviours of the systems and mechanics (such as the engines). According to your logic, you are a video scholar. Why would you use something that you have considered as unreliable, as a source for you development process?

 

All this, is called hypocracy, and having double standards. This kind of mentality is and the exact reason why I, just like KriVa, had stopped posting on this forum since 2013. 

 

 

Now Ryan came in, who was the first person after three pages of flame wars without any substansive counter argument, who was not avoiding the question just for the sake of waving things off. He clearly mentions the 747 has a maximum available reverse thrust of 76% N1, instead of 95% N1 in the real 747 GE. Even though the 58% was caterogical and a mistake of me, my initial statement of the maximum available reverse thrust being wrong - even though it was rude and arrogant - was actually correct. Yet, even after his confirmation, I am still being called "ignorant". Laughable. It is quite obvious who the ignorant people are. A comment such as Ryan's, was all that I asked for. Thank you very much Ryan, I had only hoped I could have got this answer without all this in between. 

 

And this is going to sound arrogant and rude again, but I bet there would not be anyone on the forums having the balls to admit that my statement was correct, just because they hated the tone of my original post. If you are butt hurt because I insulted your PMDG religion, I am hereby very sorry. 

 

 

 

 

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Arjen Vandervelde

[Flamin_Squirrel 71]

So the balls to admit that my statement was correct, just because they hated the tone of my original post. If you are butt hurt because I insulted your PMDG religion, I am hereby very sorry. 

 

 

 

 

 

 

• 0

Arjen Vandervelde

No, you're still wrong. Your statement was that rpm doesn't go above 58% in reverse, which the developer has stated is not the case.

[mwilk 1,106]

Three pages fighting over a product that hasn't been released yet. On Christmas morning too.

[ubersu 78]

Why has this thread not yet been locked?

 

David Jones

[pcubine 143]

Freighter with GE Engines. F2 pressed for 3 seconds.

[mwilk 1,106]

i use a fantastic FSUIPC lua script, which sets a button to toggle reversers at idle. Then if you want, you push throttles forward for more power. If i find the link for the script i'll post it here.

If you find it, I'd be very interested. That's one thing that X-Plane does.

[Werner747 107]

And this is what I meant with "PMDG has become like a religion." This is what is wrong with the PMDG community. People are so much in heaven with their products that any critisism is completely unheard of. Such a mentality is very bad for product quality in general...

You seem to have missed the part about the people who are part of the team are also type rated pilots - they won't overlook details like this.   That and the fact that you have to understand that quite often people have a tendency to point to it and say "you are wrong - this is how it should be".   95% of these people have no idea what they are talking about.   This is where the problem begins.

 

To maybe expand a bit on the statement leading to your post I quoted, and also alluding to your own statement about the quality of PMDG products, we trust them because we know what kind of quality they produce.   It is not that we don't want to see any mistakes or turn a blind eye to it, but the fact of the matter is that before you can come out and say something is wrong, you need to be able to back that up with facts, which you cannot do unless you have ALL the background information, like for instance you are a Boeing engineer or a pilot that flies the aircraft.   I have flown literally thousands of hours on these airplanes on the sim and I would battle to notice all the nuances that brings this beast to life.   I have read and re-read many manuals and all the stuff that Joe Public can get his hands on, and I will never know as much as the guys that do this for real - that is just a fact of life.

 

I would suggest that rather than making accusations along the line of "PMDG has become like a religion", just ask a question rather than make a statement saying they are wrong.   Better yet, have a look at recent forum topics - you will notice there was another discussion about this very same subject a few weeks ago.   That is another thing - people making the same statement more than once and then expecting the team to consistently give the same answers and not to become irritated, not only because of the repeat but also because the statement is false.  

 

Not looking for an argument, but there you have it - my 2c.

 

Regards

[lodestar 186]

 

 

If you find it, I'd be very interested

 

http://forum.simflight.com/topic/69388-throttle-manager-to-allow-axis-forwardreverse-toggle/

[leghorn 76]

If you find it, I'd be very interested. That's one thing that X-Plane does.

This is exactly where i got the idea at first. Turned out, someone already made it. Here's the link. http://forum.simflight.com/topic/69388-throttle-manager-to-allow-axis-forwardreverse-toggle/

 

It's a bit messy to set it up at first, specially if you use multiple throttle axes. It's worth it at the end, though

[Manny 1,293]

I just wasted 10 min of my life.

[Qavion 19]

Also - what really matters here is the aircraft's stopping distance and the wear placed on the brakes. Reversers simply save brake wear and life - they don't make the aircraft stop any faster.

 

 

I'd just like to point out that this is not true in all cases. Carbon brakes don't wear well if they don't get any heat into them during braking. Adding lots of reverse on a long dry runway may actually wear out the brakes prematurely.

 

https://airlinesafety.wordpress.com/2014/04/03/how-to-get-the-most-out-of-carbon-brakes/

 

Also, during rejected takeoffs, the deceleration rate is not fixed. 3000psi is applied to the brakes with only the antiskid and torque limiting system to stop the tyres shredding or the gear self-destructing. On a wet or slippery runway, the antiskid may cut in frequently to help stop skidding/aquaplaning. Reversers will most definitely help decrease the stopping distance in these situations.

 

Noise abatement is one of the primary reasons for not using reverse or using only idle reverse.

 

Cheers

John H Watson