Pinecone
En-Route
Lack of basic English language vocabulary??????
GPS suspend/unsuspend
- Thread starter ahmad
- Start date
dtuuri
Final Approach
Me too, it's a "Course Selector". Shoulda been "CRS" on the button and "MAN" or "AUTO" on the annunciator, imo. Suspend? That's what the wings do. Sequencing? Thats what the tower does. YMMV.
dtuuri
Final Approach
Now, my way, the "CRS" button would have been toggled to "AUTO" and this behind-the-curtain business you speak of would happen in secret. No confusion for the poor pilot trying to be a pilot instead of a geek.
MauleSkinner
Touchdown! Greaser!
But then you have to push it up to 360 times to set your course.
dtuuri
Final Approach
??? In MAN (you'd say OBS), you just set with the CDI knob or the cumbersome (dangerously distracting and time-consuming) digital input field process.
MauleSkinner
Touchdown! Greaser!
Why does the knob that you set your COURSE with say “CDI”? That’s not ”intuitive”.
dtuuri
Final Approach
If you want to discuss non-intuitive VOR terminology, start a new thread. This thread is for non-intuitive GNS/GPS terminology.
midlifeflyer
Touchdown! Greaser!
Have you looked at US literacy and reading comprehension rates? I've seen stats indicating literacy at about 80% with more than half of adults reading at or below an 8th grade level.
MauleSkinner
Touchdown! Greaser!
Seems like carrying VOR terminology over to GPS would be intuitive, but as they say, those who ignore history are doomed to repeat it.If you want to discuss non-intuitive VOR terminology, start a new thread. This thread is for non-intuitive GNS/GPS terminology.
RussR
En-Route
I don't think it's a stretch to assume that Garmin picked the label OBS back in the day to ensure that it intuitively meant "makes the identically named physical knob on the CDI effective". Because of course, the knob on the CDI had said OBS for decades. So that is kind of intuitive in the original sense.
The SUSP function is kind of a secondary function of that same button, that has now become the primary function, hence the now non-intuitiveness.
The reason it doesn't all seem to make sense now is only because we're still using GPS units where the original architecture was designed back when VOR was still the primary navigation method. The GNS series design is OLD. The 430 started shipping in 1997, which means that certainly the design work started a few years before. So, almost 30 years ago! Remember the tech in those days? Pentiums were the latest big thing. Many people still used 386-based computers. Windows 3.1, and even DOS was still common. Almost nobody had cell phones. Etc.
The SUSP function is kind of a secondary function of that same button, that has now become the primary function, hence the now non-intuitiveness.
The reason it doesn't all seem to make sense now is only because we're still using GPS units where the original architecture was designed back when VOR was still the primary navigation method. The GNS series design is OLD. The 430 started shipping in 1997, which means that certainly the design work started a few years before. So, almost 30 years ago! Remember the tech in those days? Pentiums were the latest big thing. Many people still used 386-based computers. Windows 3.1, and even DOS was still common. Almost nobody had cell phones. Etc.
dtuuri
Final Approach
OBS means Omni Bearing Selector. Since the button had nothing to do with Omni, they should have labeled it BS.
RussR
En-Route
I'm not sure why you say it has nothing to do with OMNI. That button literally made the OBS knob on the CDI active. I.e., it engaged OBS mode. Hence, OBS is a reasonable name.
Prior to the GNS series, I had a GNC-300XL which had a separate annunciator panel, one of the buttons on which did the same thing, kind of a "source selector". Same functionality.
dtuuri
Final Approach
Well, Russ, I'm mostly kidding, but I can offer a serious explanation for the underlying kernal of truth behind my tongue in cheek reply: The OBS knob on a CDI indicator is labeled to describe what it sets, a bearing for the omnigator device. A bearing is a course. The OBS button on the GNS-530 on my Redbird simulator, AFAIK, manually (using the CDI knob) or automatically sets a course for the GPS signal. It toggles who chooses — the PIC or the box. If the annunciations reflected that function (MAN & AUTO) it would make more sense to me. I feel the OP's pain because I'm trying to wrap my mind around it too. I'm not fully familiar at this point, so maybe there's a reason my idea won't work.
Pinecone
En-Route
Because that was what it was called when we only had VOR or NDB.
MauleSkinner
Touchdown! Greaser!
But the knob on the CDI said “course”.
RussR
En-Route
Unless I'm missing your point, I'm pretty sure the knob on most King and Garmin CDIs made for the last few decades says OBS on it.
MauleSkinner
Touchdown! Greaser!
You are correct…I think “course” didn’t come along until HSIs. but bottom line is “CDI” is the needle and/r the instrument, not a course selection.
luvflyin
Touchdown! Greaser!
Yup. And that seems OBviouSly what they were relating to when naming the button. But then, there was this SUSpend sequencing thang that had to be dealt with when ‘missing’ and making sure that that the pilot didn’t just go direct to the missed approach ‘fix’, rather than flying the missed approach ‘procedure.’ Like having to actually fly/navigate a plane rather than just pushing buttons. And when ‘holding.’ Like actually ‘holding’ and not just doing a HILPT. So now should we find room for another button becomes a discussable point. It might have been better to have not named it either OBS or SUSP. When the decision was made to not find enough real estate on the panel to add another button, maybe they shouldn’t have flipped an OBS on this side and SUSP on the other side coin and name it something else. MUL to reflect that it’s a multi function button?? Or maybe just X. Anything to force pilots learn what it was, and how it worked.
Last edited:
MauleSkinner
Touchdown! Greaser!
I’d just point out that inhibiting auto-sequencing of waypoints (the terminology used in the system I fly) at the FAF appears to be a TSO requirement, not something specific to equipment that doesn’t have the capability to provide guidance through the missed approach procedure (certain Garmin equipment, in this discussion.)
dtuuri
Final Approach
Gets more confusing all the time.
MauleSkinner
Touchdown! Greaser!
More studying required.
John Collins
En-Route
dtuuri
Final Approach
More studying required.
This is correct? "I’d just point out that inhibiting auto-sequencing of waypoints (the terminology used in the system I fly) at the FAF..." My 530 seems to SUSP at the MAP.
MauleSkinner
Touchdown! Greaser!
Been a few years since I’ve flown a 530…but my LEGS page shows INHIBIT as soon as I cross the FAF.
whenever It actually goes into SUSP, it‘s not allowed to sequence past the MAP without user input.
dtuuri
Final Approach
Maybe that's for transitioning from GPS to ILS/LOC at the FAF?
MauleSkinner
Touchdown! Greaser!
No, that happens at Localizer intercept.
luvflyin
Touchdown! Greaser!
Yeah. When push the OBS after missing what your actually doing is 'unsuspending'
dtuuri
Final Approach
INHIBIT isn't an approved label in the above TSO Table 2-6, so does your FMS also use SUSP at the MAP? Why do they say sequencing is inhibited so early in the approach? I could guess that it's maybe less confusing than springing it on you at a busier time and at a more critical altitude.
MauleSkinner
Touchdown! Greaser!
It’s an older system. Who knows what’s changed. But the systems that I can say with certainty what they do suspend sequencing at the FAF.