FMS NAV DATA Download

[coa787]

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

[Polar742]

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.

[coa787]

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?

[Minuteman]

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?

[Doug Taylor]

Originally Posted by coa787

...Also, what does "MX" mean?

Motocross

or

Maintenance!

[BobDDuck]

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.

[Minuteman]

Originally Posted by BobDDuck

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.

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).

[coa787]

Thanks, guys.

[Berkut]

Originally Posted by BobDDuck

I think our MX guys get in with a laptop and plug into an upload port and send the data that way.

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.

[N519AT]

In the King Air with the Pro Line 21 avionics, the FMS database is updated with a floppy disk drive on the center pedestal.

[taseal]

someone actually goes in the plane and uploads it. I know what u are asking

[Screaming_Emu]

They're kinda like the underpants gnomes, but they're they update gnomes...come in the middle of the night

[Berkut]

Originally Posted by Screaming_Emu

They're kinda like the underpants gnomes, but they're they update gnomes...come in the middle of the night

And much like the underpants gnomes, we have no idea how we're going to make a profit.

[killbilly]

Originally Posted by Minuteman

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).

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.

[roundout]

Originally Posted by N519AT

In the King Air with the Pro Line 21 avionics, the FMS database is updated with a floppy disk drive on the center pedestal.

What is a floppy disk?

Funny how the most up-to-date avionics suite uses a 20 year old media for service.

[Polar742]

Primus Epic took either a LAN hookup to the laptop, DVD or CD media or a PCMIA card

[woodreau]

Originally Posted by killbilly

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.

For a Collins FMS-4200 the navigation database and the aircraft performance database total about 8 megs.

[Chief Captain]

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.

[Polar742]

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.... (sorta) However it is only an INS after all....

[Chief Captain]

Originally Posted by Polar742

We have the whole world in our databases.

What type of airplane and FMS?

[Polar742]

Originally Posted by Chief Captain

What type of airplane and FMS?

Old shop:

E145 with Honeywell FMS delieverd from Embraer with Worldwide database
E170 out of Brazil with same

New shop:
747-200 Litton 92 INS (FMS's Poppa) has worldwide database but with alot of fixes missing
747-400: (disclaimer - not checked out, but their memos are must read for us)Some sort of Honeywell magicbox Data base is so big they have to leave out some waypoints in a straight line on an airway

[Chief Captain]

I didn't know INS's had databases. I thought it was all LAT/LONG format...

Thanks for the info though!

[Polar742]

Originally Posted by Chief Captain

I didn't know INS's had databases. I thought it was all LAT/LONG format...

Thanks for the info though!

The only INS's I've used are the Littons. I know there were 2 other models and they required constant waypoint updates. I don't know if they had a database or not. I know one was called a "Carousel", and I can't remember the other one.

[Chief Captain]

I guess I'm thinking of the Carousel INS (that Concorde had). Is this picture the Litton FMS?

http://www.airliners.net/photo/Air-F...SCD/1281653/L/

[Polar742]

that is not a Litton. I believe that is an FMS. Look up an Atlas cockpit shot. they all have Littons