ERJ FMS - Which one(s)?

[Skull-One]

ERJ GPS - Which one(s)?

I am trying to help a friend out with some research. He's wanting to know what FMS we have in our airplanes. The UNS-1K and FMZ-2000 are simply the INTERFACES for the GPS system, IIRC. I was wondering if anyone knows what the standard GPS for the EMB-145, EMB-140, and EMB-135 is/are?

Thanks in advance.

 

[Skull-One]

Just so people understand.... The FMS has to receive GPS information from somewhere (i.e. the GPS receiver). That receiver must have a name/model number. I am just wanting to know which one(s) we have on the ERJ series.

 

[jtf]

At the airline I fly for about half our 145s have single Honeywell FMS units (I don't know the model number). I have heard that the Honeywells are the most common for EMBs, but I don't know that for a fact. The other half of our 145s have dual Universal FMS units (again, I don't know the model number). I much prefer the Honeywells due to their being a lot more user friendly and I have witnessed (more than once) the Universals (while coupled to the autopilot) turn the airplane for no understood reason between waypoints. The universals were definitely not programmed for the turn, but the aircraft went anyway (about 15 degrees of turn off course and a couple of pilots saying, "What the ____ is going on?" before the autopilot was manually disconnected from the FMS.

 

[Skull-One]

No, the Honeywell and the Universal are the FMS *INTERFACES* not the GPS. I need to know the actual *GPS* model.


I prefer the Universal, FWIW and have about a year and a half behind each. Sounds like the Universal went into approach mode on you or was not set to "OVERFLY" the waypoint.

Had the same problem when I first used it.

Personally, I think the Universal flies the airplane much more accurately than the Honeywell does. George does a lot of weaving with the Honeywell. Not so much with the UNS-1K.

 

[msw]

I don't think the GPS "card" or "circuit board" inside an FMS unit has a "make/model number". At least not one that any pilot would know. And I think you got your terminology wrong. An FMS is an FMS is an FMS. It's not an "interface". Where did you get that terminology?

A Universal UNS-1C (that's what's in the King Air I fly) is an FMS, not an "interface". That FMS has navigation receivers built into it; in the case of the UNS-1C FMS, it has a VOR/DME receiver inside of it (possibly more than one) and a GPS receiver inside of it also. But they are "built into" the unit, and are "transparent" (mostly) to the user. My guess is that the "GPS" inside the FMS box (unit) is probably just a circuit board with maybe another small computer attached; it receives the GPS signals (there is even a separate GPS antenna on our bird, for the FMS - separate from the OTHER GPS antenna that feeds the stand-alone KLN90B in the ship) and that "internal-to-the-FMS" GPS receiver feeds those signals (position data) to the FMS computer. The other position data that the FMS uses (derived from the VOR/DME sensors/receivers) is also fed into the FMS computer, so that, theoretically, the FMS computed "position" is more accurate than a GPS position only. I'm not 100% positive, but I think that some of the really really really high end expensive FMS's in use on things like GV's and BBJ's etc also have the capability to feed other, additional, NAV data sources into them; like Inertial Navigation System data, and maybe VLF/Omega, or who knows what. Which supposedly makes them even MORE accurate.

But your average Universal or Honeywell FMS is going to have an internal GPS receiver built into it. Maybe Honeywell or Universal bought that GPS circuit board/receiver from some other company before they stuck it inside their FMS box, but who cares? You can't access it or play with it (separately) anyway! It just does it's thing "behind the scenes". Didn't you know that's why they call it FMS: "F&!%ing Magic Sh@t."

Maybe there's an FMS engineer on the board who can expound more on this.

 

[Skull-One]

I might.... But my understanding of it is... "UNS-1K" = FMS Interface. The GPS itself has a different designation.

I could very well be wrong............. I, too, would like to hear from an Avionics Guru on this one.

 

[Spot]

From the Universal website, www.uasc.com

Describing their FMS units in general:

System Features
High resolution, sunlight readable, color flat panel display
Internal 12-channel GPS/GLONASS receiver
Pilot and Company route storage
Nav Database includes SID/STAR procedures, airways, holding patterns, approaches, plain-language navaid references, and more.
Procedural leg guidance per ARINC 424
Heading Mode and PVOR Tracking
VNAV with computed Top-of-Descent, Target Vertical Speed and Vertical Direct-To.
Holding patterns with auto entry
3-D Approach Mode for “ILS-like” guidance on all non-precision approaches
Fuel Management
Performance Management for specific aircraft
Frequency Management option
UniLink compatible
TAWS compatible
LAAS and WAAS upgradeable

 

[Spot]

In looking at Honeywell's website, it looks like their configuration is a stand alone FMS that receives GPS input from their GPS module called GNSSU. They give an example of the NZ-2000 FMS receiving GPS data from the GNSSU. I thought though that their GNS-XLS was both an FMS and GPS but could not find the info on that.

So for the RJs, my guess is that it would depend upon which manufacturer is in the cockpit. Even then, some mfg may use integrated FMS/GPS and others may use separate modules. With a specific mfg and model number we should be able to determine which of the two it is.

 

[j41driver]

All of this begs the question....why do you care? When I'm flying I know that I have an FMS and I know it uses GPS as one sensor to fix it's location, but that's about where my interest stops. Maybe I'm strange like that.

 

[Skull-One]

Not to get snappy, but if you had read my original post you would know why I care. A friend is wanting the information for some research he is doing and I thought I'd try to help him.


Thanks for the input on the Honeywell, guys. Any idea on the Universal UNS-1K?

Thanks again.