496 XM weather issues

Dave Siciliano said:
Seems to be the units that have weather only. Those that also have radio seem to be working. They seem to diligently be working on getting to the bottom of it.
Click to expand...

Thanks for the updates Dave. :) Since we only subscribe to the weather and not the radio, it looks like it won't do any good to try the refresh thing for our 496?
 
dmccormack said:
I love XM too. But I'll take cautious "Unable" over, "I hope he's right" anyday.
Click to expand...
Always a good plan.

I have a storm scope in my plane that gives me a much better tactile idea of what is happening over XM NEXRAD. Jesse states he will use his eyes but that is not always a solution once you are in the clag. If that is the technique used, best to stay out or on top of the clouds. I have done that when I could see big stuff towering up and asked for vectors to avoid.

I flew my Florida trip with XM and my storm scope. Together they gave me a really good picture of what was happening. I was glad that the only time I did have to deal with thunderstorms I was landing before getting to them and taking off after they passed.

As for the 496/XM issues, I am wondering if there is some sort of Y2009 issue. Considering that there was also a M$ issue with the Zune recently I cannot help but wonder if there is a gremlin in the was that some code might have been written that deal with dates. But I have not seen anything to convince me that there is a realition, it is just that my spidey senses are tingling.
 
Plane is in for annual so I can't check XM WX but will do so asap. I use a flight cheetah 190 w/ a seperate XM WX device. If someone can supply contact info. for Derek, I will email him with pro /con results based on non-Garmin product.

Thanks for sharing!
 
Dave Siciliano said:
From the chief engineer at XM:

I have been talking/emailing a lot of you regarding the 396/496
problems-- thanks to all for both your time and patience. I regret that I haven't been able to fix everything. For now, I don't have any answers, just questions that some of you might be able to help with.

I would appreciate it if anyone can DISPROVE any of the following:

1) The only units affected are Garmin

2) Specifically, only the Garmin "hockey puck" units are affected (i.e,
396/496--- what does the 696 have?)

3) A refresh (refresh.xmradio.com) fixes things EXCEPT for people who DO NOT subscribe to the audio channels.

4) For those who subscribe to weather ONLY (no audio), neither a refresh or activate/deactivate works, all you see is a blank audio screen and/or "waiting for data" in the subscription level box.

5) The problems first started occurring New Year's Day.

How you can further help: I am trying to pinpoint the start time of the "anomaly". Please let me know (offlist is fine) when your box last worked and when you first noticed it not working. Paul Safran says his worked until 5pm-ish New Years Day. Anyone have their box crap out earlier? Anybody have their box crap out mid-flight? And by "crap out"
I don't mean you lost winds aloft for a couple hours, or the METARs went missing, etc.---these are Garmin bugs I already know about---I mean the problems where you are not geting WX data AT ALL, possibly accompanied by a funky subscription level message.

Also, if anyone has a 396/496 that has NOT been affected, please let me know the software version number if you can (displays lower right corner on startup).

Wish I had better information. All I can say is the certified units and most (maybe all, hard to prove a negative) non-Garmin units are fine.
Otherwise, the XM system is fine; the XMWX system is fine. So far, this appears to be related to Garmin 396/496 software only.

Thanks again,

Derek
Click to expand...
How should we reply to XM with this information? Just post here or write to them direct?
Mine is a 496 running v3.6 with no radio subscription.
First noted about mid day on 2nd Jan, but I didn't fire the unit up before then.
I've tried refresh and deactivate etc with no luck.
DKC
 
Actually, he was asking folks on another board for this. I cross posted it so you would be aware of what is going on. I'm sure if he wants more reports, he'll request them from others like us on POA.

Best,

Dave
 
Derek just asked that you send him an e-mail if you have useful information. He is at Derek.deBastos AT xmradio.com

Best,

Dave
 
WILCO! Thanks for the contact info. Dave!
 
smigaldi said:
Always a good plan.

I have a storm scope in my plane that gives me a much better tactile idea of what is happening over XM NEXRAD. Jesse states he will use his eyes but that is not always a solution once you are in the clag. If that is the technique used, best to stay out or on top of the clouds. I have done that when I could see big stuff towering up and asked for vectors to avoid.

I flew my Florida trip with XM and my storm scope. Together they gave me a really good picture of what was happening. I was glad that the only time I did have to deal with thunderstorms I was landing before getting to them and taking off after they passed.
Click to expand...


Doh!

I was so fixated on XM I forgot (duh!) to mention the a/c had a stormscope.

I agree 100% -- the combination is a fantastic set of tools.
 
My 396 with xm weather worked just fine on 12/31/08 on a trip from hilton head to tampa. On saturday 1/3/09 it did not work at all. My friend who flew his cirrus with avidyne had no problem. It looks like a garmin issue to me. kevin
 
I'll drop a note to Derek, but post it here, too.

We have a Garmin 496 with software release 3.6 and the XM WX Aviator package plus audio. It hasn't been turned on in in a month or so, but I had no problems getting weather today without trying any of the fixes.
 
I've had the problem with weather on 496 as well. I called in yesterday to XM and was told that a reset is what was needed. Called again this morning and the young lady said my account needed to be deactivated then reactivated. No joy.

I called back later and got someone more knowledgeable and she said that there had been many problems and were waiting on Weather WX to fix the issue and that Garmin would have to issue a software fix to take care of the problem.

I called Garmin and the guy told me that they did not know why some worked, some didn't, but that 396, 495, and new 696's had all been affected, again some, but not all of each had been affected.

I did download the 'WebUpdater'
http://www8.garmin.com/products/webupdater/howtoinstall.jsp
...which installed new software on the unit *and* on the antenna... still, however, no joy.

The Garmin guy says a fix is imminent. The only heartburn I have had during all of this is the attitude of XM... They are collecting $49/month but the attitude is 'not my problem' go bother someone else.

Ken
 
10PM EST, Monday, 5 January 2009... I just turned on my 496.
It is downloading XM Weather without any problems.
Software Rev 3.60
The last time I used it was Tuesday, 30 December 2008.
 
gprellwitz said:
I'll drop a note to Derek, but post it here, too.

We have a Garmin 496 with software release 3.6 and the XM WX Aviator package plus audio. It hasn't been turned on in in a month or so, but I had no problems getting weather today without trying any of the fixes.
Click to expand...
It looks like that if you have audio the WX system works. Simple fix... give us all a temporary audio subscription. Oh no !!! That would be customer service. Meanwhile Garmin is blaming XM and vice versa.
DKC
 
The latest update:

Garmin 396 and 496 radios appear to be the only ones affected, starting January 2. Those with an additional audio subscription are still working, but those with only a weather subscription are not. Nobody knows the cause of the problem, but they are definitely working on it.

If yours is out, you can add an audio subscription free for one month by calling the XM aviation number at 1-800-985-9200 and give them the promo code MARINE1MO. You will need to cancel the audio subscription within a month to avoid a charge (about $7)--assuming they have a fix by then.

Time to complete this including time on hold was about 18 minutes. My 396 started working immediately afterward.

Thanks to Dave S. for passing on the info.

Jon
 
4CornerFlyer said:
The latest update:
Garmin 396 and 496 radios appear to be the only ones affected, starting January 2. Those with an additional audio subscription are still working, but those with only a weather subscription are not. Nobody knows the cause of the problem, but they are definitely working on it.
Click to expand...

I do not have an audio subscription and mine is working.
 
TMetzinger said:
I don't think XM is a good tactical tool. At best it shows what happened 7-10 minutes ago, and at worst it can be much older. Now a 'spherics device is real time, and it and the mark one mod zero eyeballs make good tactical tools.

XM Nexrad in my opinion is terrific for figuring out which areas (many miles wide) you'll want to avoid while you're still many miles away.

In Dan's case, it sounds like the area he was avoiding was big enough that the age of the NEXRAD didn't matter, and his eyeball backed it up.
Click to expand...

Dave Siciliano said:
I agree Tim. We've chatted about this many times on here. Great strategic tool to see the total picture, which way things are moving, where the front is and weather ahead. I use the on-board radar and storm scope for closer in work (tactical). Still, after flying with it several years, not having it takes away a lot of good information. I prefer to have it if possible. Don't think other folks would pay these fees if they didn't agree.
Click to expand...

Agree with both. Remember that a 10 minute update cycle (plus a couple more minutes for processing) would yield data at least 12 minutes old to your box. A fast-moving cell (40 MPH) would traverse 7.5 miles in that time. I've seen stuff build in the mountains much faster than that (iow, not moving, but building from no rain to rain).

20 miles is not enough buffer, especially if you're headed in the same general direction but at cross-angles to the cells/line.

dmccormack said:
XM trend data will show where the cells have been and where they are heading, and whether the cell is expanding or dissappating. So with 10 minutes of historic data (even if the data is 15 minutes old), you should have a very good idea where you can and cannot go.
Click to expand...

In my experience, it requires more than 10-15 minutes of data. 30 is more like it. For the reasons mentioned above.

Now, I DO have a stormscope on board - the combination of the two makes for a much better picture than either one alone. While I would fly without XM, it is much more valuable on long cross-countries in unfamiliar areas than it is in areas where the weather is familiar (central-south Texas, for example). Without XM, my risk analysis becomes different - it enables me to have more up-to-date data, meaning that I can adjust the profile in marginal conditions... and make trips that I might otherwise have second thoughts because conditions are rapidly changing. It was particularly beneficial on one long trip when a hurricane was coming ashore in the Gulf.....
 
wsuffa said:
20 miles is not enough buffer, especially if you're headed in the same general direction but at cross-angles to the cells/line.
Click to expand...
Exactly. This is what I was trying to say. Use your eyes if you can with the XM. If you're in actual and you can't use your eyes you *NEED* to be using all the resources you can get which means you ask ATC what they have for radar and take their advice into consideration.

Personally, I never need to be anywhere *that bad* so I stay the hell away from embedded stuff. Not worth it.
 
jesse said:
Personally, I never need to be anywhere *that bad* so I stay the hell away from embedded stuff. Not worth it.
Click to expand...

It's all part of the risk equation. Sometimes you don't know about "imbedded" until you're in the soup. If you fly a lot of IFR on the east coast, especially in the mountains, then you need to have all the tools you can.

It's also part of the reason I have a turbocharger. Higher up can get you out of the soup sometimes to see more clearly. And on the east coast, you can take terrain out of the equation.

OTOH, there are times (like a time I did ABQ-Four Corners) where the clouds are high relative to the ground and staying below is the best option.

Assuming other risk-related matters are met, and the right tools are available, I'll fly with a forecast of imbedded. But I won't do it under all circumstances.

As for reports from ATC, if they're busy, you won't get it. AUS and SAT would volunteer the info sometimes. Potomac is less likely to. And Chicago will outright assign planes at altitudes that lead to icing, then offer little help for them to get out - because they have nowhere to put them (heard that near JOT as I was headed into ARR one night). The likelihood of ATC info and their cooperativeness becomes part of the risk equation, too.
 
Try walking through an unfamiliar room in the dark. You reach out with your hands to feel your way through. If you feel a wall or a table, you deviate as needed to go around it. But you have no way of knowing what's more than a couple feet away from you, so it's hard to plan an efficient route.

Now, if before entering the dark room, somebody handed you a map, showing where all the walls and furniture are, you could memorize the map and plan a good route through that room.

But that map wouldn't tell you if somebody had just moved a chair right in front of you, so you'd still need to feel about with your hands, just in case the current situation differs from the map. But the ability to draw up a good "plan" reduces the need for deviation, and likely leads to a straighter line through the room.

Trying to meander through thunderstorms works the same way. We have real-time mechanisms (radar, stormscope, eyeballs) that keep us from bumping into anything, but can't see very far, and delayed mechanisms like Nexrad that can't ensure we don't bump into anything, but tell us where we can go that will reduce the likelihood of needing to deviate (as instructed by our real-time mechanisms), resulting in a plan more likely to result in an efficient route.

The problem is that some are viewing the Nexrad as if it was both of these mechanisms. They're memorizing the map, and then sprinting through the dark room, rolling the dice that nobody moved the chairs.
-harry
 
Let's try this one more time...

XM WX provides useful data that coupled with a secondary data point (StormScope, view out the window, ATC reports, PIREPS, etc) can provide information to help safely navigate around convective activity.

Cell location, size and movement trends -- even though 10-15 minutes old -- displayed on an XM screen can be used by a pilot to avoid same. Risk increases the closer to perpendicular to the cells movement your route becomes.

If the Cell is moving north and you're moving south -- Unless the cell does a spin move and chases you down, you're good to go.

I give a 20 mile buffer when the a/c has a Stormscope. I've watched cells go by right and left wings with nary a ripple (Out west where the cells exceed 30k feet 20 miles is probably inadequate -- Adjust Accordingly).

Instead of 30 minutes with the 496 screen I call up AFSS or log in to a terminal.
 
wsuffa said:
And Chicago will outright assign planes at altitudes that lead to icing, then offer little help for them to get out - because they have nowhere to put them (heard that near JOT as I was headed into ARR one night). The likelihood of ATC info and their cooperativeness becomes part of the risk equation, too.
Click to expand...

Declare an emergency and start deviating on your own.
Watch how fast they offer you help.
 
wsuffa said:
Agree with both. Remember that a 10 minute update cycle (plus a couple more minutes for processing) would yield data at least 12 minutes old to your box.
Click to expand...

XM has a 5-minute cycle.

In my experience, it requires more than 10-15 minutes of data. 30 is more like it. For the reasons mentioned above.
Click to expand...

And that's why the 496 gets turned on when I start preflighting, so by the time I take off I have 30 minutes of data. There are some distinct advantages to a portable system, one of which is certainly the battery! :yes:
 
flyingcheesehead said:
XM has a 5-minute cycle.
Click to expand...

Unless they've changed it recently, my real-life experience was updates somewhere between 5 and 15 minutes, with the average close to 10. I find that I cannot rely on 5 minutes in all circumstances.

And that's why the 496 gets turned on when I start preflighting, so by the time I take off I have 30 minutes of data. There are some distinct advantages to a portable system, one of which is certainly the battery! :yes:
Click to expand...

Yep, an advantage to portable. I'm still using the older WxWorx receiver and a mil-spec tablet PC.
 
I've posted this before, but on-board radar in my plane is the primary tactical took I use; storm scope is also important if it shows strikes.

One a recent trip to Myrtle Beach, nothing showed on the 496 although there were obvious build ups we could see visually. On-Board radar showed red convective stuff I circumnavigated. After I had passed through, that showed up on the 496. For rapidly building or rapidly moving weather, the 496 definitely has lag time. Remember what Scott said about filtering and some systems just not showing up.

A 496 provides a lot of great information, but one must know it's limitations and augment those when necessary. In the Baron, with on-board radar, I penetrate systems I wouldn't have gone near in my A-36 with storm scope and 396. Not only radar, but higher wing loading, more power, back up systems and K-ice. Still, if the on-board radar went out, I'd give rapidly building systems a lot of leeway.

Best,

Dave
 
XM has a 5-minute cycle.
Click to expand...
But the Nexrad data isn't an instantaneous "snapshot" in time. By the time a fresh broadcast reaches your XM receiver, it represents a composition of data across the spread of time from about 1 to 6 minutes in the past:
http://www.wxworx.com/news_pdf/Flying4-07.pdf
Then as it sits in your garmin, it ages up to an additional 5 minutes before the next broadcast comes down. So even when everything is running perfectly, some of the data you're looking at is up to 11 minutes old.
-harry
 
If the Cell is moving north and you're moving south -- Unless the cell does a spin move and chases you down, you're good to go.
Click to expand...
Unless a new one forms behind it.

The assumption that "the only cells that exist are the ones I can see on my Nexrad" is one of the fallacies that causes pilots to overestimate the safety of relying on this data. Knowing where there was convection 5 or 10 minutes ago tell you where it's not safe to go, but it doesn't reliably tell you where it _is_ safe to go.
-harry
 
How is this discussion any different than anything else in aviation. I don't think that a single person in this thread has said "I require XM for all flights and rely on it for skirting within 3 miles of embedded thunderstorms". Everybody here is saying the exact same thing. Use it as a tool, but just that. Don't put your life in the hands of a 396/496 without a backup plan. It's just another arrow in the quiver.

It's just funny watching a bunch of people all argue the exact same point with one another.
 
flyingcheesehead said:
XM has a 5-minute cycle.
Click to expand...

Well....
The radar sweeps - Time 0
The image data is assembled and processed - Time 0 + X
Image data is transmitted to WXWorx - Time 0 + X + Y
Image data is transcoded and uploaded ....
Image data is downloaded...

The data may refresh every five minutes - but when you get a refresh at 13:05 that data may reflect a radar sweep from 12:55 or earlier. I think the "freshest" image I ever saw was 8 minutes old.
 
Last edited:
FlyNE said:
How is this discussion any different than anything else in aviation. I don't think that a single person in this thread has said "I require XM for all flights and rely on it for skirting within 3 miles of embedded thunderstorms". Everybody here is saying the exact same thing. Use it as a tool, but just that. Don't put your life in the hands of a 396/496 without a backup plan. It's just another arrow in the quiver.

It's just funny watching a bunch of people all argue the exact same point with one another.
Click to expand...

Yep...
 
TMetzinger said:
Well....
The radar sweeps - Time 0
The image data is assembled and processed - Time 0 + X
Image data is transmitted to WXWorx - Time 0 + X + Y
Image data is transcoded and uploaded ....
Image data is downloaded...

The data may refresh every five minutes - but when you get a refresh at 13:05 that data may reflect a radar sweep from 12:55 or earlier. I think the "freshest" image I ever saw was 8 minutes old.
Click to expand...


Good thing weather is as fast as naval warfare.
 
mantakos said:
Unless a new one forms behind it.

The assumption that "the only cells that exist are the ones I can see on my Nexrad" is one of the fallacies that causes pilots to overestimate the safety of relying on this data. Knowing where there was convection 5 or 10 minutes ago tell you where it's not safe to go, but it doesn't reliably tell you where it _is_ safe to go.
-harry
Click to expand...

What are you flying? A dirigible?
 
From Derek at 2:51

Best,

Dave

Bug found, bug band-aided on the XM end, Garmin software update to follow.

This should've never happened. Bad programming, bad discipline, bad lots of things.

I think all 396/496 units should return to normal without any refresh needed. If this is not true for anyone, try an online refresh first
(refresh.xmradio.com) and then call me if that doesn't work.

Thanks for your patience.

Derek
 
What are you flying? A dirigible?
Click to expand...
It doesn't matter whether you're pedaling a tricycle or flying an F-16, as airspeed doesn't factor into this, it depends on the age of the data you're looking at versus the rate of change of the conditions, i.e. how long it takes for a cell to form.

What matters is the time it takes for a cell to go from displaying a radar profile that you'd be willing to fly through, to the time that the cell is potentially dangerous to fly through.

It's not about "how fast does the red spot move laterally?", it's about "how much time does it take for a red spot to emerge from a greenish-yellow area?"
-harry
 
I think all 396/496 units should return to normal without any refresh needed.
Click to expand...
Cool. My 396 is receiving XM again. I didn't do a refresh today, but I did one yesterday, though I dunno if that means anything.
-harry
 
FlyNE said:
How is this discussion any different than anything else in aviation. I don't think that a single person in this thread has said "I require XM for all flights and rely on it for skirting within 3 miles of embedded thunderstorms". Everybody here is saying the exact same thing. Use it as a tool, but just that. Don't put your life in the hands of a 396/496 without a backup plan. It's just another arrow in the quiver.

It's just funny watching a bunch of people all argue the exact same point with one another.
Click to expand...

More or less. The one big thing that caught my eye was the view that a 396 is better radar than the controllers have. This often isn't the case and not using the controllers as a resource is silly if they have active radar.
 
Mine wasn't working on the drive in this morning, but I went out at lunch and it is working again. Maybe they sorted out the issues.
 
kbell101 said:
Mine wasn't working on the drive in this morning, but I went out at lunch and it is working again. Maybe they sorted out the issues.
Click to expand...

Yep, XM found a work-around for Garmin's software bug and that fix will take care of things for now. See post #75.

And for anyone who jumped all over XM for this issue, an apology might be in order.
 
You must log in or register to reply here.
Back
Top