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I came across a mention of a display of "graphical aircraft system synoptics" on this page. I think in context that it means "status display" or "summary page"- the page that shows flap position, hydraulic pressure, etc.

However, synoptic isn't even a noun in some dictionaries. Google searches for the word turned up only passing references to the term, not a solid definition. The actual word usage seems very aviation-specific. What does the term actually mean and how does it differ from "system status" or "summary page?"

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    $\begingroup$ In this context synoptic would not be a noun, as it describes what something is like, making it an adjective. $\endgroup$
    – Jpe61
    Sep 9, 2019 at 22:45
  • $\begingroup$ Synoptic is an adjective form of the noun synopsis $\endgroup$
    – crasic
    Sep 10, 2019 at 20:12
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    $\begingroup$ @Jpe61 In real world usage like "system snoptics", "Subsequent Boeing aircraft (B-747-400, B-777) do incorporate synoptics", or "aircraft synoptics and electronic flight charts", it is a noun, not just an adjective, as it comes after another noun. (Although use as an adjective also appears sometimes). Compare similar adjectives like short, concise, or abbreviated. Could those words be substitued in, e.g. "system shorts", "incorporate concises", or "aircraft abbreviated and flight charts" $\endgroup$
    – Cody P
    Sep 10, 2019 at 20:18
  • $\begingroup$ @crasic Sounds like you have a good start to an answer there. If you could move that to the answer section and elaborate on what it means in sentences like The Boeing 757 cockpit does not provide subsystem synoptics, it would be helpful. $\endgroup$
    – Cody P
    Sep 10, 2019 at 20:22
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    $\begingroup$ The only place I've ever encountered this word was in Christian theology. $\endgroup$
    – vsz
    Sep 11, 2019 at 5:05

3 Answers 3

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Synoptic refers to the active system diagrams that are selectable, usually on one of the middle displays above the center console. If you want to know what the hydraulic system is up to, you can select the Hydraulic Synoptic and an active diagram of the hydraulic system appears, showing what's pressurized and what's not, valves open and closed, the pressure values, quantities, etc. There will be one for most of the major systems, hyper simplified compared to a normal system schematic because only the essential information is presented.

enter image description here

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Oddly enough, I was able to find quite a few descriptions for the word, all of them defining synoptic as presenting a summary or a general view of something, and in my opinion, the meaning of the word is best described in Wiktionary by the etymology of the word:

Ancient Greek συνοπτικός (sunoptikós, “seeing the whole together or at a glance”), from σύνοψις (súnopsis, “a general view, synopsis”), from σύν (sún, “with”) + ὄψις (ópsis, “view”)

Synoptic displays are ment to give a simplified, but comprehensive enough view of the current state of a system. You'll find them pretty much everywhere where operators of complex systems need comprehensible information of what is going on in the system, even my car has synoptic displays...

I'd say "system status", "summary page" and "synoptic display" are pretty much the same thing, of course the last being by far the fanciest :)

@John K already described a fine aviation related example of a synoptic display.

Some references:

Wiktionary

Merriam-Webster

Wikipedia

OneLook dictionary Search

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  • $\begingroup$ Your definition would align with how I've seen 'synoptic' used in scientific data ... for image data, it's something that's been reduced so you can see the whole image on a typical monitor (reduced to 1024x1024 these days) ... for time-series data, it's a plot showing the current value in context so you can easily tell if it's going up/down/etc. $\endgroup$
    – Joe
    Sep 10, 2019 at 17:19
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I very much concur with @Jpe61 for the origin and definition.

I would add that a synoptic display is more precisely what an aviator or other complex machine operator wants. It is a visual graphic that conveys the status/summary at a glance without having to actually focus on a read out.

One example would be the picture shown in @JohnK 's answer. A simple summary page could be done in text, but one would have to read through the text to determine the current status of any given hydraulic pump. Similar displays are used for fuel tanks.

With the number of instruments and displays in a cockpit, and all the various tasks you have to do, you need all the instruments and displays configured in a way that convey's the most relevant data in the shortest time possible in the most intuitive of ways so the pilot doesn't have to dedicate too much attention to any given display...especially if it's required elsewhere.

As another illustration, there has been some dismay among pilots shifting from analog altimeters to Digital HUD. The issue is that an analog (needle) display, once you're familiar with it, you can see where the needle is in the scale out of the corner of your eye and you don't have to actually look at it to snap out of a dive at precisely the correct altitude, but with a digital display where the numbers are constantly changing on a steep dive or climb, you actually have to focus on the display to discern the altitude. That's far less intuitive and can cause a loss of either situational awareness of other events or delay response to other activities requiring concentrated attention. (Such as might be the case while an attack/bomber is attempting to hit a target in hostile airspace --though this example is not so much a problem for commercial or private pilots.)

One final illustration. If a simple summary or status page in text was sufficient, why wouldn't you simply have a read out in text format of airspeed, altitude, compass heading, etc? You'd almost be flying a literal desk with Word, PDF, DOS screen, or paper print outs feeding you all your information. There would be no way for a flight crew to process the information in that medium in a sufficient fashion to be able to effectively fly the plane.

Though it might be easier for a random individual off the street without any training to fill in for any given pilot and be comparably effective.

Synoptic is thus the best and most precise word for the kind of instruments and medium for displaying your situation and status summaries. Synopsis being the summary data (data or situation at a glance) and optic being the visual medium for that data (presented in ideal visual format).

As for the actual definition: Webster's Fourth ed College Dictionary has

synoptic:1 of or constituting a synopsis; presenting a general view or summary

synopsis:a statement giving a brief, general review or condensation; summary

So synopsis is the summary, synoptic is the presentation of that summary.

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