I have been trying a number of A320 performance calculators for the FBW A320 neo, including a payware one. They are not all alike in terms of input information, and in some of them input is gathered from the Metar for the airport in use. So, this is not a 100% like for like comparison, but I thought it might be 'community spirited' to share my results. Input is only shown if it was requested, or gathered from the airport Metar. 

So the scene I set, was to set the departure of the FBW A320 Neo (today's latest development version)  at a gate at KSAN. A flight plan from KSAN to KPHX was prepared in simbrief, and inputted into the FMC. Passengers, fuel and cargo loaded to establish and set TOW. CG established as 24.1%. As the FMC in the FBW A320 does not calculate Flex, I used 39 as an average from the two lower results from other performance calculators. Likewise I 'borrowed' the FLAPS/THS of 1/UP1.0 from the pradz.de calculator for the FBW FMC.

The biggest variation to me is the SimStart flex of 70, which seems way off what the other calculators are suggesting.

https://www.dropbox.com/s/ihdtsw1lz663vd9/A320 NEO Performance Calculator Comparison.JPG?dl=0

 

7 minutes ago, SquadronLeader said:

I have been trying a number of A320 performance calculators for the FBW A320 neo, including a payware one. They are not all alike in terms of input information, and in some of them input is gathered from the Metar for the airport in use. So, this is not a 100% like for like comparison, but I thought it might be 'community spirited' to share my results. Input is only shown if it was requested, or gathered from the airport Metar. 

So the scene I set, was to set the departure of the FBW A320 Neo (today's latest development version)  at a gate at KSAN. A flight plan from KSAN to KPHX was prepared in simbrief, and inputted into the FMC. Passengers, fuel and cargo loaded to establish and set TOW. CG established as 24.1%. As the FMC in the FBW A320 does not calculate Flex, I used 39 as an average from the two lower results from other performance calculators. Likewise I 'borrowed' the FLAPS/THS of 1/UP1.0 from the pradz.de calculator for the FBW FMC.

The biggest variation to me is the SimStart flex of 70, which seems way off what the other calculators are suggesting.

https://www.dropbox.com/s/ihdtsw1lz663vd9/A320 NEO Performance Calculator Comparison.JPG?dl=0

 

65 tons is far below MTOW, so flex should be quite high. SimSmart seems correct. Why not try it with these settings? If you reach Vr safely before the end of the runway flex 70 is just right.

3 hours ago, SquadronLeader said:

The biggest variation to me is the SimStart flex of 70, which seems way off what the other calculators are suggesting.

The NEO has different motors than the CEO variants which is what the other calculators are using.  Flex temps will be much higher then what you are used to on the others.  SimSmart seems to have been able to get this to be very accurate.  I have been using it since it came out and can highly recommend it.

From the FBW site, useable Flex temps are between 45c and 74c:

'Flex temps are above ISA+29°C (44°C at sea level) and above current temp, but no higher than ISA+59°C (74°C at sea level). Usable Flex temps at sea level are from 45°C (or current OAT if it is higher) to 74°C.'

Edited May 3, 20224 yr by Flic1

2 hours ago, SquadronLeader said:

So the scene I set, was to set the departure of the FBW A320 Neo (today's latest development version)  at a gate at KSAN. A flight plan from KSAN to KPHX was prepared in simbrief, and inputted into the FMC. Passengers, fuel and cargo loaded to establish and set TOW. CG established as 24.1%. As the FMC in the FBW A320 does not calculate Flex, I used 39 as an average from the two lower results from other performance calculators. Likewise I 'borrowed' the FLAPS/THS of 1/UP1.0 from the pradz.de calculator for the FBW FMC.

 

The flat rate temperature near sea level (KSAN) is 44 C. So if you are not setting a Flex temp above that, you are getting full TOGA thrust.

Likewise the THS setting from the calculator is incorrect for the NEO as are the markings on the cockpit pedestal. You should be using the chart at the bottom of the FBW checklist (https://github.com/flybywiresim/manuals/blob/master/pdf/A32NX Documentation/FBW A32NX Checklist.pdf) although there is no need to enter the THS setting in the MCDU.

2 hours ago, Fiorentoni said:

65 tons is far below MTOW, so flex should be quite high. SimSmart seems correct. Why not try it with these settings? If you reach Vr safely before the end of the runway flex 70 is just right.

Reaching Vr before the end of the runway is not a good check!🙂 You should be at or above 35 feet by the end of the takeoff distance at V2 after having the engine fail one second before V1 on a continued takeoff.

 

Edited May 3, 20224 yr by Donstim

17 minutes ago, Donstim said:

Reaching Vr before the end of the runway is not a good check!🙂 You should be at or above 35 feet by the end of the takeoff distance at V2 after having the engine fail one second before V1 on a continued takeoff.

That's why I said "safely". Should probably have said "with a good margin" instead, alright.

All explained here and why I use and trust SimSmart (at least get the name right🙂) Its not way off at all. Watch and learn 🙂

But for THR RED/ACC and EGN OUT ACC

I use this link and enter ICAO code. Look up the Runway your using for that runway ENG OUT ACC

https://blackbox.oneengineout.com/airportdata/

Edited May 3, 20224 yr by Nyxx