Qavion
Just a couple more points re' throttle stagger. Yesterday's post was from my mental stockpile - what follows is from the books.
"Trim authority is limited to about 5% equivalent thrust below about 20,000' and 10% above. This corresponds to about +/-.03% EPR or +/-1.5%N1 (<20,000) and .05% EPR and 2.5% (>20,000)" (Boeing T.M.)
"For manual operation, trim is inhibited until the leading engine is within .1% EPR (5% N1) of the target thrust to allow intentional stagger during ground handling operations."
"Trim equalisation adjusts the trailing engine(s) thrust to match the LEADING engine up to the available authority limit and then downtrims the leading engine(s) when the difference exceds the authority"
"If the throttle lever of one engine is intentionally retarded beyond trim range (four times the trim authority level relative to the leading engine) that engine is removed from the trim function and trimming continues with the remaining three." (No trim is available with less than three operating)
Yesterday's point about using the second highest thrust as the trim reference (and the half knob diameter) came from one of the tech manuals but I cannot find it again.
So, to go back to the original question, how much stagger is "substantial"
Thanks for the welcome back, Q, - I still lurk, but less frequently. Redundancy's greatest reward is not having to get up at 6 o' clock daily.
