737NG A/T engagement

[sky-738]

Does any one can tell me under what circumstance can we engage the A/T switch? Like without IRS , we can not put the switch to on . I want to know more about the switch's using limitation. FCOM drive me crazy and still no answer.
Thanks

[sekmeth]

There must be a temperature on the TAKEOFF REF page entered to arm the A/T.

[sky-738]

Thx for this one , any more?