Why does the FMC in B737 limit the climb speed to 230 knots on the VNAV mode until the leading edge devices are fully retracted? In the VNAN climb on B737, the FMC changes the target speed from V2+20kt at liftoff, to 230kt for acceleration at the preset accleration height, then to 250kt (below 10,000ft) as the leading edge devices are fully retracted along with the trailing edge flaps.

My question is: Why is the climb speed limited to 230kt on the VNAV mode until the leading edge devices are fully retracted, when there are only operating speed limits to trailing edge flaps as below?



For your information, I've found a discussion on this topic on another aviation website but no one seems to have a definite answer to this.

https://www.pprune.org/tech-log/570676-737ng-led-s-speed-limitations-ops.html

Does anybody have a good answer to this?
The non normal checklist QRH will answer your question.  If the LE flap transit light remains illuminated I.e the leading edge flaps and slats haven’t retracted or disagree with the flap handle position, then the QRH directs you to limit the speed to  230 kits until you have rectified the issue.  VNAV is honouring that restriction.

Hope that answers your question.