View Full Version : A330 navigation anomaly
Recently halfway across the Atlantic when suddenly the navigation system refused to accept the "5140N" style waypoints for NAT tracks. Data was changed to get us where we needed to be but it wasn't very pretty.
Is this a regular occurence on the A330? Have any of you guys had this problem?
Not really life-threatening but it can be a major headache. Info / opinions appreciated
SFly
Hi SFly
Any chance of some more information on this?? What message did you get on the MCDU?? Not in database?? Can't say I've ever heard of this problem. These waypoints should have been in the FMGS since before departure, or at least in the case of a re-route since before Oceanic entry.
If for whatever reason the system did refuse to accept 5140N etc, you could just create a new waypoint with those co-ordinates - no problem.
Any more info would be appreciated.
Cheers
Busta Level
10th May 2002, 10:37
Seems strange SFly.
Was it rejecting the waypoints whilst you were entering them, or was it as that waypoint became the 'to' waypoint? If so, what message did you get? Had you had a nav accuracy downgrade prior to this?
I've seen the former on several occasions (usually for waypoints on an RNAV departure) but never seen it reject waypoints in the air. Just what you need halfway across:eek:
Hand Solo
10th May 2002, 13:10
Certainly the A320 FMGC always been a swine for inputing Lat/Long format waypoints, possibly the most user unfriendly system on the aircraft! Did this occur after an update to the database, because we've noticed the quality of ours deterioriating exponentially over the last three months. Waypoints change names, drop out of routes and who knows what else! Perhaps you have the same supplier?
Sounds like the Database got corrupted.
One of the easiest ways to check for that is to go to the status page which lists the dates of the database and in the lower right side shows the number of pilot entered waypoints. If that number is negative the database has become corrupted and all sorts of strange things happen. The easy solution is to switch to the expired database (or one to be used soon, the non operational one is what we are talking about) and then back to the appropriate database. That will reload the database and clear up the corruption.
Cheers
Wino
Agreed about the possible database corruption, but the way I read SFly's post, the problem occurred mid-Atlantic. If you were in-flight and you change databases, we all know what happens - you lose EVERYTHING. If the system was going to reject the waypoints due to a database corruption, then surely it would have rejected them when they were entered into the F-PLN on the ground. Just thinkin' aloud!
Cheers all ;)
fantom
10th May 2002, 19:21
but no-one would change dbs in flight,would they?
there is probably a rat in it.
:p
Sfly,
Just out of curiosity, did you mean to say that one of the FMCs refused the input? If so, certainly you had the other available. You could play with the stubborn one while the good one did the flying.
I have had an FMC totally dump just after coast-out...just go blank....with the associated FMC failure messages. The other FMC worked perfectly, as I assume was the case for you. However, I am not familiar with the A330.
You don't know when the database was corrupted. It could have happened in flight.
The way I read his post it wasn't taking anything anyway and he was having to build everything. So If you have nothing, you lose nothing...
However, I have only done that on the ground when loading and couldn't make it do what I wanted.
Cheers
Wino
OK, agreed it could have happened in flight however the FCOM is explicit in its instructions about changing databases in flight - ie. don't do it. I have been there and done that one night when the chips were down and it was far more of a hindrance than a help! It was the only option we had left and it didn't work. ;) Besides, if you changed databases in flight in mid-Atlantic - that's a contingency maneouvre (spellin'??) required as you can no longer maintain your MNPS track.
Some more info would be great!!!:p
Cheers All