A320 TOGA and N1 Values

[ryanf]

Hi Roberto,

can you tell me, if I select TOGA thrust on take-off, should I see N1 at or close to 100% or does the N1 value depend on other factors such as ambient temp etc.?

The reason I ask is if I select TOGA in PM on take-off, I only get to around 90% N1 - I thought TOGA should give you every ounce of thrust that the engines can provide....

thanks,
Ryan.

[dodiano]

Never check N1 on takeoff cause we look at the EPR where the TLA and thrus indicators are set but it should give more than 90% will have to check though on tomorrow`s flight!

Regards

Roberto

[ryanf]

Thanks Roberto!

BTW, where do I see the EPR indicated?

thanks,
Ryan.

[dodiano]

Just above the N1 Gauges that is the EPR!

Regards,

Roberto

[sergejv]

I think it's only for IAE engines.

[ryanf]

Thanks guys.

I could not find the EPR indication on the PM display only N1 and N2....

If its only for IAE engines, how does it work for CFM engines i.e. what indication should I check for TOGA - should it be 100%?

thanks,
/Ryan.

[dodiano]

Oh yes we use IAE engines have no Idea about CFM Engines.

Regards,

ROberto

[sergejv]

N1 limitations for CFM56 Engines is computed by FADEC and it depend of many parameters:
Flaps setting, temperature, wind, QNH and others.
Sergey

[dodiano]

Yeah but temperature and QNH is affected only in FLEX takeoff when it is Toga it should give everything it has... I remember there was a protection that wouldn´t allow the parameters to exceed 99% when in TOGA for N1 will check that out cause I don´t remember really!

Take care,

Roberto

[sergejv]

Please see FCOM 3.05.06 P3