What does "throttle is staggered" mean? and how is it related to adjustment of MEC(Main Engine Control) in B737-300(CFM56-3C)?and which are safety issues regarding that?
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3$\begingroup$ You’ve asked 3 questions and given us very little to work with. You’re rolling the dice that someone with a maintenance manual and very specific experience might jump in here, but you’d have a much better chance if you provided a full quote in context. Then those with similar experience could at least stand some chance of deciphering a probable reason. $\endgroup$– Michael HallJan 6 at 14:23
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1$\begingroup$ P.S. “Staggered” just means the levers are not in the same position… $\endgroup$– Michael HallJan 6 at 14:59
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$\begingroup$ Michael, what is the risk of throttle stagger? $\endgroup$– DYNAMICSJan 6 at 15:16
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1$\begingroup$ Where does your information about the term "throttle stagger" come from? I mean, did you hear it in a movie, read it in a flight manual, or what? $\endgroup$– tedder42Jan 6 at 15:19
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2$\begingroup$ Saeed, per my first comment, tedder42's comment, and John K's answer, you need to explain where the term comes from! If John's interpretation is correct and it comes from a pilot gripe then I don't see any real risk, it's more of an annoyance that they don't match. But please clarify your question so we don't play these guessing games, and if you are in a position to fix the aircraft then by all means you need to get absolutely clear with the pilot and other maintenance personnel on both the meaning of the gripe and corrective action!!! Don't fix airplanes off random internet advice. $\endgroup$– Michael HallJan 6 at 16:18
1 Answer
If I was a mechanic looking at that snag, I would assume the pilot is complaining the two thrust levers are way out of alignment when engine N1s are matched. They are usually never 100% perfectly aligned, but most pilots will start to complain if the stagger is more than, say, a quarter of the width of the lever handles.
This makes setting power a pain in the butt, and can be an issue in an abnormal procedure when you have to set go around thrust on a missed approach, and more care and tweaking is required by the pilot setting thrust. Basically, higher workload in abnormal situations is the risk factor.
The engine being non-FADEC, there is a need to check the rigging/adjustment between the thrust levers and the fuel control system, or within the fuel control system itself.
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1$\begingroup$ Does "snag" have the same meaning as "gripe" or "squawk"? (pilot initiated maintenance action request) I haven't heard that term before... $\endgroup$ Jan 6 at 20:21
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1$\begingroup$ Yes. Maybe a Canadian thing? I assumed it was common term in US as well. $\endgroup$– John KJan 7 at 3:30