Quote:
Originally Posted by MercFE
Down for on is standard for just about every switch on Boeing products...
Although the position and strobe switch is set up with off in the middle...
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Not to be too curmudgeonly, but I suspect the term "down" in this statement may be subject to some interpretation. If switches are located in the overhead, this denomination of "up" and "down" really gets muddy. Mix that in with a user's perspective (sitting in the pilot's chair, or reaching forward from the FE's chair) and it's amazing to see how many different interpretations one can come up with!
The standards document which Boeing provided in the first part of this century as a design guideline to vendors clarified this wording by stating that the preferred ON position is either "up" for a switch mounted on a vertical panel, or "forward" for a switch mounted on a non-vertical panel accessed by the flight crew (ie the overhead panel). There was also similar wording for pushbutton switches; I can't recall the exact statement but it would generally be interpreted to say that a pushbutton is intended to actuate the function when the button is depressed, thus the "pushed in" state is the desired ON state.