Today's pirep: WSI not so good

R

RobertGerace

Guest
WSI has been sending me messages that I need to fly for 30 minutes to get an update, and today is the day I got mine.

Result: 2 crashes, one big delay in getting weather information, and a cell on my radar that was not shown on WSI.

Anybody who has used Bill Gate's operating system is not comforted knowing that is what powers the MX-20. I actually got 2 General Protection Faults, and saw the blue-startup screen (not the blue-screen-of-death) on my MX-20 today.

I was moving along at over 3 miles a minute...and because WSI had been so flaky, I turned on my radar as I was IMC for about 45 minutes and wanted to know what I was flying into.

I knew the tops were not to far above, but was enjoying the practice...so I stayed IMC on purpose. The MX-20/WSI were showing no precip and the WX-500 was showing no strikes. However, my radar suddenly showed a level 2 cell 20 miles (6 minutes) in front of me.

I asked for and got 11,000 and broke out at 10,000. Sure enough there was a buildup there that I had to go around.

It's too bad that people have to keep messing with things that are good. WSI used to be great...
 
Linux is the true path to enlightenment, grasshopper. Sadly, Micro$not rules with dollars not quality. Oops, is my bias showing ?
 
No kiddin. The guru Michael Andrews has enlightened me to the true path. MX20 is Windows NT. Burned into ROM.
 
The odd thing about Micro$oft's licenses is that they specifically prohibit the use in hospitals, nuke plants, aviation and a handful of other "life/death" venues. Yet I see it every where. The controller on the lasik eye surgery machine... Winders. I nearly cancelled my wife's procedure when I saw the screen. I don't know how M$ gets away with it.
 
As a new MX20 user this thread is not so comforting. I have XM weather with the Garmin GDL69 receiver not WSI. I'll be flying to FL this wknd and to Kansas City next week, so there's bound to be scattered TS (or worse). It'll be a good test, and I'll report what happens. I'm hoping for 0 crashes and NEXRAD displays that match the stormscope and what I see out the window.
 
Lance F said:
As a new MX20 user this thread is not so comforting. I have XM weather with the Garmin GDL69 receiver not WSI. I'll be flying to FL this wknd and to Kansas City next week, so there's bound to be scattered TS (or worse). It'll be a good test, and I'll report what happens. I'm hoping for 0 crashes and NEXRAD displays that match the stormscope and what I see out the window.
Click to expand...

In this months IFR one of the editors stated that he was flying in the clear where his uplinked NexRad showed the center of a nasty cell which was actually about 10 miles away. Uplinked wx is way better than nothing or just a stormscope, but don't expect it to be accurate enough for close in work. OTOH if you just add an extra 10 miles to the buffer between you and the storms it ought to be OK.
 
lancefisher said:
In this months IFR one of the editors stated that he was flying in the clear where his uplinked NexRad showed the center of a nasty cell which was actually about 10 miles away. Uplinked wx is way better than nothing or just a stormscope, but don't expect it to be accurate enough for close in work. OTOH if you just add an extra 10 miles to the buffer between you and the storms it ought to be OK.
Click to expand...

That kind of stuff can happen if the storms are fast moving. With a low BER, and everything working at NWS, you will get updates every 4 to 8 minutes (5, on average). A high BER may result in missing the radar uplink file. A fast moving storm can cover a lot of ground in that time.

Example: on Monday, I was handed off from Washington Center to Clarksburg Approach. XM Weather/NexRad was showing a couple of cells developing south of Elkins, about 30 mile ahead of me. The showed on the Stormscope. I advised Clarksburg on check-in that I'd probably need to deviate left at some point to avoid the storms. The uplinked data has SCITs, which show the general direction and speed of the cells. Upper air winds were >70 kts. 30 seconds later, I asked for a deviation 30-degrees-left based on my estimates from the SCIT data. This was approved. On the next Radar update, the leading edge of the cell was shown as 10 miles right of my location. I started picking up precip and turbulance. On the next update, the cell was at the location I was on the previous update, and continued to grow across the path. So it was on the stormscope, too.

Good thing that Center had issued me a direct clearance instead of the full-route clearance via airways that KHEF/Potomac originally issued. Airways would have taken me over EKN.

I've seen errors in it before. This time, the data wasn't so much in error as it was the update times. You have to develop experience with the system, and be willing to make quick decisions based on all the data. I was IMC at the time, so the Mark II eyeball wasn't doing any favors.

Know the limitations.... and trust, but verify.
 
Bill, Great post for a newbie with this stuff. Thanks. Could you give me a little help with the acronyms? BER, SCIT??
 
Lance F said:
Bill, Great post for a newbie with this stuff. Thanks. Could you give me a little help with the acronyms? BER, SCIT??
Click to expand...

the Bit Error Rate (BER) for both satellites and any ground repeater is shown. Low values of BER indicate good reception. When a very high BER is associated with a source, it is shown as >999, which essentially means no signal.

[size=-1]Storm Cell Identification and Tracking (SCITs)

Don't worry about your combination not working properly. I have always found if you combine equipment made from the same manufacture you will do better as far as reliability [/size][size=-1]is concerned. The same people manufacture both the 69 and the mx20. What I'm saying is the people in the garmin AT department produce the two units. The 69 was made for the mx20 and is being retrofitted for the 1000 and the 530/430.
[/size]
 
Chris gave you the acronyms.

A bit-error rate of zero is perfect reception. If you have weak signal or interference it will cause errors in the bitstream. Some error-correction is built-in, but I find if the BER is over about 200/250 then some of the charts will not download. For voice or music, you can tolerate higher BERs because the ear ignores the errors.

The SCITs are interesting because they show storm cell movement and intensity. The really interesting ones are "shear cells" with high wind shear. Those can indicate possible tornadic activity.
 
Lance F said:
As a new MX20 user this thread is not so comforting. I have XM weather with the Garmin GDL69 receiver not WSI. I'll be flying to FL this wknd and to Kansas City next week, so there's bound to be scattered TS (or worse). It'll be a good test, and I'll report what happens. I'm hoping for 0 crashes and NEXRAD displays that match the stormscope and what I see out the window.
Click to expand...

Lance,

As I was gaining experience in weather flying, I flew SR-22's with my only on-board weather equipment being a Wx-500 and Flight Service via the radio. It's funny, but the more experience I get -- and the more tools I am fortunate enough to have and use, the less I am willing to take the risks I took earlier in my flying career.

I'm currently at a point where I won't fly thunderstorms without the uplink weather AND radar AND a Stormscope. Each provides different information.

The uplink composite radar is for planning purposes. I can see the general location, movement, and speed of cells, and be warned of hail...as well as given echo tops. I look at this as my 'big picture.' Up until my last weather flight, it had been extremely accurate. However, there is no guarantee...and the system tells me how old the data is. I've been told a cell can go from nothing to 30,000 feet in 10 minutes...so, uplink is not a panacea. But it is an awesome planning tool.

The on-board radar tells me what his happening for between 20 and 80 miles in front of me. Using the tilt feature I can examine the clouds to see if they are raining, and how high they are raining, and how hard they are raining. The harder the rain, the more likely they are turbulent and/or a cell. For all intents and purposes, when I see a rainshaft, I deviate.

I look at the Stormscope as both an 'early warning' of hard rain, as well as a big sign in the sky that says "Thunder Storm!" because you can have rain without thunder(storm), but you can't have thunderstorm without lightening.

The SR-22's Stormscopes kept me out of thunderstorms, but I did not fly IMC for long periods when that was the only tool I had. I would either find VMC or land.

As I said at the top of this thread, I stayed IMC for 45 minutes in convective conditions, but only with all of the above tools. Once I figured out that one part of the system was not behaving, I got and stayed visual.

I haven't given much thought to getting the WSI fixed...I'm hoping a new update will solve it. I've been busy with other gremlins. You see, I fly a Twin Cessna, and, well, I've got an exhaust valve starting to go bad in my right engine's #2 jug, and I've got low voltage causing the LOW VOLT indicator to come on, and the low voltage is causing my autopilot to do screwy things (quiet, Henning ;) ) :D :rofl:
 
Last edited by a moderator:
RobertGerace said:
Lance,
You see, I fly a Twin Cessna, and, well, I've got an exhaust valve starting to go bad in my right engine's #2 jug, and I've got low voltage causing the LOW VOLT indicator to come on, and the low voltage is causing my autopilot to do screwy things (quiet, Henning ;) ) :D :rofl:
Click to expand...

Ah, the curse of systems. But, it is really a blessing. :)
 
Each of these systems seem to have idiosyncrasies. On the P-Baron, we have the Garmin 530/430; so, we would go with XM and the 69. My avionics shop just met with the reps because if you don't fly this systems for seven days or more, you may have to wait a prolonged period for it to boot up. Then, there may be a password required and some folks haven't had the pass word work. Then there is the update issue.

Ahhh.. the joys of new technology!! Still, better than what I had before. I'm not pushed to be places like Robert. We haven't' upgraded yet; so, I'm going with the radar and stormscope for awhile, but sure see XM in my future.

Dave
 
Last edited:
Flew my MX20/GDL69 for the first time in real stuff today. I am now forever spoiled. This equipment is great. Watched the moderate rain move towards my airport my whole 2 hour flight. Monitored local METARS (my airport doesn't have any weather reporting) and my WX500 (no strikes). With all these tools I knew it would be close, and it was. My approach was GPS 28, and I got the airport right at minimums :yes: . It was the first time my wife had been with me on a full blown IMC instrument approach, and I was very grateful to have these tools to help me get in safely. Garmin could use me for a reference anytime!
 
RobertGerace said:
The harder the rain, the more likely they are turbulent and/or a cell. For all intents and purposes, when I see a rainshaft, I deviate.
Click to expand...

Robert, one tidbit to remember WRT radar is that the intensity of precip itself isn't as big a clue for turbulence as the gradient. IOW if you see an area of heavy rain that covers a fair amount of ground and the bands of lesser precip surrounding the area are relatively wide (several miles) the trbc may be minimal when compared to a cell where the intensity goes from light to heavy in a short distance. Contour shape is also a good indicator from what I've read. Nice round cells are less troublesome than one that takes on a bowed shape. Of course the widebeam GA radars will impart some bowed shape to a perfectly round cell too.
 
You must log in or register to reply here.
Back
Top