FFS Accelerate Stop Simulation

[mutt]

I’m talking about million $$ Full Flight Simulators, not Microsoft :):)
Recently conducted some tests in a B747 Classic simulator, (Old Smokey, this one came from your part of the world). We calculated a field length takeoff weight for a specific runway, no stopway, clearway using the Boeing Mark 7J computerized takeoff modules.
Approximately 1-2 seconds prior to V1, we conducted rejected takeoffs with all engines, engine out, with and without thrust reverse.
On approximately 10 attempts with various levels of drivers, none of the rejects resulted in the aircraft remaining on the runway~
So what should one determine from this:
1: The UK rebuilt FFS isn’t 100% accurate.
2: A field length limited high speed abort in a Classic 747 will result in the aircraft going off the end of the runway.
Comments….
Mutt

[Old Smokey]

Hi Mutt,

Not quite sure what you mean when you say (Old Smokey, this one came from your part of the world), I presume that you mean that it was bought from us. I never had any part in the fidelity checks of the B747 classic, but be assured that if you'd bought any of our B777 simulators that they will always accomplish the RTO 'better than the book'.


I suspect that your first point is the culprit "The UK rebuilt FFS isn’t 100% accurate". Did the rebuilder use the data pertinent to your aircraft version (Brakes / Spoilers etc.)?


And then there's the tweaker's dilemma, I've spent thousands of hours doing fidelity checks on other simulators, tweaking up one aspect of performance to fit the Manufacturer's performance data exactly, and losing it somewhere else in the process:}


Good luck with the new toy,


Regards,


Old Smokey

[ZFT]

As an initial step I would suggest checking that the QTG test 1.b.7.1 still passes correctly. Hopefully the MQTG is available for comparison.

That should at least tell you whether the sim is still performing to its original standard.

By inference, a classic sim is probably 15+ years old and is likely to have been modified quite significantly since initial build by either the manufacturer or operator(s) and errors can and do creep in.

Edited to state that Old Smokey's post seems to indicate that this is a -300 that was, I believe updated by the original manufacturer quite recently. I would have thought that the manufacturer would have performed a complete QTG run as part of their acceptance process. Should make it a lot easier to determine when the problem arose and if it's a data/software issue or a maintanance issue.

[Centaurus]

Mutt. Any idea of the fidelity status of the old Aer Lingus B737-200 simulator at Dublin? It's a very early simulator I believe and still in use.

[mutt]

Centaurus,
I've flown the EI 737 simulator a couple of times but thats all i know about it...
ZFT, yep we are talking about the ex-SQ -300 FFS, the QFT was done, but not to the limiting scenario that we are presently trying to replicate.
O_S, No comparison between Classic 747 and 744/777, for a balanced field calculated takeoff weight, the classic is scary. I can understand why people like 18-wheeler like the concept of V1-5 kts!
Our intention is to include Field Length limit takeoffs in recurrent training, but it doesnt help if the aircraft always goes off the end of the runway!
Mutt