EFB take off power calculations valid for sea level alt only?

[KorEl]

I recently did some flights from high alt airports like Bogota and realized that the EFB take off calculations were wrong. It seems that high alt it is not taken into account resulting in power and speed settings much lower than those required. Can you please cheek?

[rdr]

I can confirm this observation.

I performed EFB takeoff calculations for SPJC (elevation 113ft) and SKBO (elevation 8358ft) with a manual configuration of TORA 3000m, Wind 0/0, OAT 20C, ALT 1013 hPa. The plane has been spawned at the airport and the airport configured in the FMC as departure airport. In both cases, the calculated takeoff parameters are identical: FLEX 53, V 151/151/156 and MTOW 167.6. The airport elevation does not seem to make any difference.

[rdr]

P.S.: the TOW was 145t

[richboy2307]

Hi, our EFB is capable of making calculations for up to 6,000ft Pressure Altitude as that's what normal A320Neos are capable of, and what we have data for. Anything higher would require a special high-altitude operations package from Airbus, which is not simulated in this version of the A320neo. 

That being said, the primary factor for things like speeds is the runway length and preference given for 2nd segment climb performance. Try to FORCE TOGA for higher altitude operations as the FLEX data may be unreliable.

Thanks!

[rdr]

8 hours ago, richboy2307 said:

Hi, our EFB is capable of making calculations for up to 6,000ft Pressure Altitude as that's what normal A320Neos are capable of, and what we have data for. Anything higher would require a special high-altitude operations package from Airbus, which is not simulated in this version of the A320neo. 

That being said, the primary factor for things like speeds is the runway length and preference given for 2nd segment climb performance. Try to FORCE TOGA for higher altitude operations as the FLEX data may be unreliable.

Thanks!

Thanks for the response but please note that we were talking about the A300-600 and not the A320neo 😉 Anyway, if the EFB takes into account field elevations up to 6000ft that's fine but I would assume that field elevations above 6000ft were cut-off to 6000ft rather than to sea-level.

[richboy2307]

On 8/8/2024 at 1:50 AM, rdr said:

Thanks for the response but please note that we were talking about the A300-600 and not the A320neo 😉

Oops! My bad, misread the aircraft category tag.
But yes, even in the case of the A300, same limitation for data applies. 

On 8/8/2024 at 1:50 AM, rdr said:

Anyway, if the EFB takes into account field elevations up to 6000ft that's fine but I would assume that field elevations above 6000ft were cut-off to 6000ft rather than to sea-level.

That would make more sense but I believe it defaults to 0 pressure altitude for the moment. In anycase, use of FLEX would not be advised for high alt airports. I'll flag this for further investigation however. Thanks!