Questions about internet weather download in flight vs ADS-B

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Questions about internet weather download in flight vs ADS-B

6/17/2018 9:56 AM

Hook

Joined: 11/12/2011

Posts: 672

Questions about internet weather download in flight vs ADS-B Modified By Hook on 6/17/2018 9:58:40 AM

I may be ferrying a plane from Pennsylvania back to Washington state in a couple of weeks. I expect weather to be a large concern, so I'd like to "see" ahead as best I can. This plane does not have ADS-B Out installed yet, but I will have a SkyGuardTWX ADS-B In unit. Of course, that means I can't count on good (or any) weather or traffic data except maybe during the initial legs, when I'm in dense airspace (with presumably ADS-B Out equipped aircraft often/always in my vicinity).

Thus, I'm curious about the "Attempt internet weather download while in flight" option. One of the two tablets that will be in the plane has cellular service. I just checked T-Mobile's data coverage and it's pretty darn good along my route (supposedly, anyway).

Question 1: I presume that while the tablet is connected to the SkyGuard via WiFi, that there's no way for iFly to connect to the internet?

Question 2: I presume that if the tablet was not connected to SkyGuard that it would attempt to do Nexrad weather updates on a regular basis using the cellular internet capability of the tablet?

Question 3: Assuming the answers to #1 & #2 are "yes", would I be better served to turn off the SkyGuard unit once out of Cleveland's and Chicago's vicinity and thereby know that I am getting weather data viat the internet? I'd lose possible traffic info, but weather is of greater concern to me than traffic once I'm out of busy airspace. Besides, I'll be using flight-following anyway.

I'd like one of the iFly staff to chime in on #1 and #2 to make sure my presumptions are correct (or not).

Thanks.

Powrachute PC 2000; Aventura II; Cherokee 180

6/17/2018 12:37 PM

Hook

Joined: 11/12/2011

Posts: 672

Re: Questions about internet weather download in flight vs ADS-B Modified By Hook on 6/17/2018 12:39:07 PM

Some followup questions:

After iFly comes up and does some housekeeping, like uploading user settings, how much data (Nexrad, etc.) is downloaded every update-cycle?
What is that cycle (how often are updates-over-the-internet done)?
Does the number of selected U.S. states effect the amount of data downloaded? That is, is every state you have selected for data updated every update cycle or only for X miles around you? Would it behoove me to select only the current state I'm flying over and nearby states as I go along to minimize the data being downloaded over my mobile service?

Powrachute PC 2000; Aventura II; Cherokee 180

6/17/2018 1:30 PM

JohnnyBlackCT

Joined: 12/31/2017

Posts: 161

Re: Questions about internet weather download in flight vs ADS-B Modified By JohnnyBlackCT on 6/17/2018 1:31:10 PM

You don't need ADS-B out to receive weather information via ADS-B. You just need to be within range and receiving a ground station. Personally, I would not try to use cellular while flying. I'm not sure it's even legal.

6/17/2018 2:21 PM

Hook

Joined: 11/12/2011

Posts: 672

Re: Questions about internet weather download in flight vs ADS-B Modified By Hook on 6/17/2018 4:15:24 PM

You are incorrect about ADS-B In, and I hope you haven't been relying on it in your aircraft if you don't have ADS-B Out installed. Read up on it. If you have ADS-B Out, then you have transmitted to you taffic and weather within a "hockey puck" around your aircraft. If you do not have ADS-B Out, then any traffic or weather you are receiving is by happenstance. It's because another aircraft around you is transmitting ADS-B Out and you are receiving a portion of his/her hockey puck. Though, you are receiving any direct ADS-B Out info from other aircraft that are transmitting -- if you are in range and have the input antenna(s) for the type of ADS-B out they're transmitting. (Which most receivers provide an input antenna for both kinds.) But again, you will not trigger the ADS-B tower to send you weather info, or traffic info for aircraft around you that do not have ADS-B Out in their aircraft, if you are not transmitting ADS-B Out yourself.

This is by design by the FAA. They want everyone (but will settle for most) to have ADS-B Out by end of next year per regulation (the stick), but offered a carrot with traffic/weather over ADS-B In -- for those who installed ADS-B Out. Trouble is, everyone's been freeloading the carrot without consideration of the limitation of what they're receiving if they don't have ADS-B Out. Which is dangerous. If you don't have ADS-B Out, then odds are great that you are not receiving the complete picture of traffic or weather around you.

Powrachute PC 2000; Aventura II; Cherokee 180

6/17/2018 5:06 PM

David

Joined: 1/3/2011

Posts: 521

Re: Questions about internet weather download in flight vs ADS-B

I understand the how the FAA's carrot and stick approach functions as far as traffic goes, but that's certainly news to me on the same approach for weather radar. I saw a big change in traffic coverage when I added ADSB-out, but nothing really seemed to change with the weather radar performance.

C177RG: iFly 720, Stratux 978/1090 ADS-B in, AHRS, BMP, Stratus ESG ADS-B out. RV-3: 8" Samsung Tab A, Stratux 978/1090 ADS-B in, AHRS, BMP, Stratus ESG ADS-B out.

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Questions about internet weather download in flight vs ADS-B

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