FMS NAV DATA Download

coa787

coa787

Unknown Member
Here's a question that has been on my mind for a while; How does the NAV DATA get downloaded into the FMS of aircraft? I know that there is a twenty-eight-day cycle. Just curious.

Thanks
 
When MX gets the updates. Usually 2 of the 28 day cycles are loaded, so if there is a delay or an airplane has anyother issue, it will still have a legal database.
 
Yes, but how exactly does the data get loaded? Is it by satellite link or is there some code to send the data to the FMS?

...Also, what does "MX" mean?
 
Typically, a nav database provider (Jeppesen) provides an nav database in ARINC 424 format to an avionics supplier (Honeywell, Teledyne, Smiths, etc.) after being paid by an operator.

The avionics supplier transcripts the database into its own format, occasionally introducing errors and usually encrypting it.

The avionics supplier makes the database files available to the operator by either mailing electronic media, or by downloading via the internets. Usually the operator distributes the files via floppy disk or PCMCIA card and the data are uploaded via an airborne data loader (ARINC 665, I think).

How does Garmin do it with their compact flash cards?
 
I think our MX guys get in with a laptop and plug into an upload port and send the data that way. There is a data card slot on our FMS units but we don't have anything in there. I guess that's where stored flight plans would go.

When we were going to go to EFBs (pre BK II) the plan was to install wireless nodes at all the hubs, so every time a plane taxied by the node it would update all the charts and manuals as needed. Of course that never happened.
 
BobDDuck said:
When we were going to go to EFBs (pre BK II) the plan was to install wireless nodes at all the hubs, so every time a plane taxied by the node it would update all the charts and manuals as needed. Of course that never happened.
Click to expand...

Do you know once of the big reasons that didn't happen? Most airports claimed WiFi was theirs and anyone wanting to use it has to periodically pay large sacks of money at each location.

An alternative (that I think FedEx uses) is an infrared datalink that can be put on jetways or other support equipment that get near the aircraft.

For some European operators it's actually cheaper to have data management units with GSM cards that function as modems when on the ground (ACARS doesn't have nearly enough bandwidth and Connexion is kaput for now).
 
BobDDuck said:
I think our MX guys get in with a laptop and plug into an upload port and send the data that way.
Click to expand...
That's the way I've done it. Download updates to the laptop, then plug into the unit with a special cable and transfer it over.
 
In the King Air with the Pro Line 21 avionics, the FMS database is updated with a floppy disk drive on the center pedestal.
 
Minuteman said:
An alternative (that I think FedEx uses) is an infrared datalink that can be put on jetways or other support equipment that get near the aircraft.

For some European operators it's actually cheaper to have data management units with GSM cards that function as modems when on the ground (ACARS doesn't have nearly enough bandwidth and Connexion is kaput for now).
Click to expand...

Curious. How big are the data files? IR doesn't have a hell of a lot of bandwidth, either. But I suppose if it's just a big, tabled text file then that might not be a big deal.
 
N519AT said:
In the King Air with the Pro Line 21 avionics, the FMS database is updated with a floppy disk drive on the center pedestal.
Click to expand...

What is a floppy disk?

Funny how the most up-to-date avionics suite uses a 20 year old media for service.
 
Primus Epic took either a LAN hookup to the laptop, DVD or CD media or a PCMIA card
 
killbilly said:
Curious. How big are the data files? IR doesn't have a hell of a lot of bandwidth, either. But I suppose if it's just a big, tabled text file then that might not be a big deal.
Click to expand...

For a Collins FMS-4200 the navigation database and the aircraft performance database total about 8 megs.
 
From what I understand, the files are very small. I'm told that the plane doesn't fly around with data for the entire globe, just specific geographic regions. So a SWA plane may have N. America, and an EasyJet plane may have Europe.

I also remember reading on the Honeywell site some time ago that their latest and greatest FMC/CDU combo had a whopping 8MB (yup, mega) of storage space. A 767 pilot told me thatmost of the planes in his fleet only have 256kb of storage.
 
We have the whole world in our databases.

One thing to remember, the computer technology in most airplanes is far, far behind the times.

If you ever used a Commodore 64, an Atari 1200, a Tandy, or a TI-99, you're getting the idea.


Then again the Litton is so old, we have to put the punch cards in it....:sarcasm: (sorta) However it is only an INS after all....
 
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