747 PMDG 747 Flight Model

[Kevin van den Heuvel 0]

Hi everyone,
I have a question regarding the following statement on product features(747)
''Flight Model - Engine and flight modeling is within 5% of the actual Boeing aircraft performance charts, including data and parameters specific to the Pratt & Whitney, General Electric and Rolls Royce engine types.''

Could anyone explain me what exactly they mean with ''within 5 % of the actual Boeing...'' ?

[Jim Young 2,356]

The way I read it is that Boeing has aircraft performance charts regarding the Pratt & Whitney, General Electric, and Rolls Royce engine types.  The PMDG 747 flight modeling and engines are within 5% of those specifications.  I suspect, the closer a flight simulation aircraft is to the real thing, the better the engine and flight modeling.  I also suspect it might be very difficult to get to the actual or exact parameters as a simulator such as the PMDG 747, sitting inside a computer system, and a real Boeing 747 aircraft sitting outside in the real world, would result in different conditions so exact modeling would be super difficult to achieve in any case.

Hopefully, the PMDG 747 will still be a simulator that creates much joy with those who purchase it even though it might be outside the real world aircraft specifications by perhaps .001% of the real thing and sometimes 4.999% of the real thing.  I'm sure that the number of passengers/virtual passengers and their luggage/virtual luggage would have a major impart too. 

In any case, you'll be able to do more research soon after you get full privileges for posting as a Member of AVSIM.  Thanks for joining!

Best regards,

Jim

[Jim Young 2,356]

Okay.  I just gave you full privileges for posting.  Enjoy!

[pedrotrindade 335]

In my view it means that is 95% accurate with the real thing.

BTW, welcome to AVSim Kevin, have fun.

Cheers

[Chock 17,769]

As others have noted. FSX and P3D are not intended to be professionally-rated flight simulators, but that does not mean companies such as PMDG do not try to make things as accurate as they possibly can be, and so in comparison to all of the things which the real Boeing 747 does, PMDG have managed to get theirs to perform within 95 percent of the real thing's behaviour, based on data from Boeing on how the real thing works, and they have checked that against the real aeroplane and various high level professional training simulators. So, if you push the throttles up to full, the engines will spool up to at least a 95 percent accurate rate compared to what the real engines would do, and if you shove the stick fully forward at 210 knots at 15,000 feet, your simulated PMDG 747 will pitch down in such a way as to behave within 95 percent of the way a real one would, it'll burn fuel to at least that level of accuracy, run out of oil at that accuracy, etc, etc. This is very impressive for a 70 quid bit of software running on a PC simulator which you can buy off Steam for 20 quid.

To make sense of how good that actually is, it helps to know a bit about 'proper simulators' (i.e. the kind of thing you see airline pilots training in) and how they are rated...

There are lots of things such professional simulators (depending on their Level Rating) have to do to a certain amount of accuracy to be acceptable as Level Rated training devices. A 'Level A' commercial simulator used for training pilots, has to be a realistic physical representation of the actual aeroplane cockpit, but it doesn't necessarily have to be able to simulate everything the real aeroplane does, since it is only for 'Level A training scenarios'; for example, it doesn't need to be on a motion platform, it doesn't have to have working circuit breakers, doesn't need to simulate ATC, doesn't need to simulate wet runway behaviour, or to simulate an airport environment, but its simulated movements - i.e. what you see through the windows of the cockpit mock up as it 'moves' when 'flying' - have to occur within 300 milliseconds of the control inputs the trainee applies to the yoke, rudder and throttles, so that it looks to the trainee like it is 'flying' like the real thing. It is the fact that those inputs which are checked and monitored to ensure they happen that quickly and are close to what the real thing would do which are part of the certification process for that simulator which enables it to be authorised as 'Level A'. A more highly-rated Level D commercial simulator has to pretty much replicate the real thing to a point as to be virtually indistinguishable from the real thing in every way, so, for example, it has more stringent requirements on how its motion platform reacts to control inputs, i.e., they have to be within 150 milliseconds of the control inputs (much closer to how the real thing flies), and so you could say that a Level D simulator is twice as accurate as a Level A simulator in the way it simulates flight. This is why those things cost millions of Dollars,

From that you can tell that it is how closely a simulator replicates everything the real thing does which is a function of its rating as a professional training simulator. The fact that PMDG's 747 is 95 percent accurate then, is very impressive for a home simulator, and although none of that is monitored for accuracy (since FSX and P3D are not intended to be professionally rated simulators, as it would need to be if it were going to be certified for training) much of what the PMDG 747 does is nevertheless good enough to be on par with many of the requirements of professional training simulators, and for many aspects of the lower level professional simulators, the PMDG 747 is actually more accurate in that it simulates more stuff of the real thing.