During climb, if it can’t reach the target altitude in 125 seconds, it sets climb thrust, displayed as THR REF on FMA.
Any insights during descend ?
I have never seen it go IDLE - FLCH SPD. Even when it can’t reach it in 125 sec, FMA shows THR but actual thrust is at Idle.
Why so? IDLE - VNAV SPD/PATH exists. Why not display IDLE for FLCH when it’s really setting Idle thrust ??
I am aware it then transitions to HOLD but my question refers to the first AT mode displayed (THR) as we select FLCH during descent.