globalexpress

I'm starting to fly light aircraft again and have already almost been run over once by a "weekend flyer" guy flying his T-6. Anyway, I was wondering if anyone is familiar with these portable, external ADS-B antennas once can purchase like the Stratus, or the one I'm looking at which is the XGPS170D.

Maybe someone can make sure i understand what an antenna like this will do for me. From what I understand, I'll be able to get real-time weather, TFR locations, stuff like that, which is a nice bonus, along with GPS location with the XGPS170D. But what I really want is to be able to see traffic around me.

From what I understand, since this XGPS170D antenna is "dual band," I'll be able to see 978 and 1090Mhz traffic. Since my rental aircraft don't have ADS-B "out" yet, but I know that there are ADS-B towers nearby, I'll only see the few aircraft that have ADS-B "out" and any Mode C aircraft that are +/- 3500' and 30nm of local ADS-B "out" aircraft. Is that correct?

From a real world perspective for you guys/gals that fly GA aircraft close to (within 30-40nm) of busy Class B airports with an ADS-B tower nearby, are there enough ADS-B "out" aircraft flying around that you get a pretty good picture of all the Mode C and ADS equipped aircraft around you? Or is using these ADS-B portable antennas kind of a waste for seeing "little airplane" traffic around you?

IDIOTPILOT

Personal experience, it’s definitely good to have but it has its limitations. You need a very good GPS with accurate altitude positioning. The built in iPad GPS isn’t going to give good altitude so other traffic’s altitude below or above will be very skewed.

I think the 3500’ and 30 nm is a general rule and not technical. Sometimes I’m always flooded with TIS info and sometimes I don’t even when I think I should.

Once you’re below 1500’ at a small GA airport you’ll lose the TIS info. This is when you probably want it the most. There’s a growing number of ADSB out GA planes but it’ll take a while.

I’d say this is good for being up at altitude, not talking to anybody, in moderately busy areas, especially when your visual scanning goes down.

globalexpress

Thanks. Why do you think you are losing your TIS info in the traffic pattern at small airports below 1500'? I fly in a busy area with lots of airliners/biz jets flying overhead so I "assume" there would be lots of ADS-B out aircraft that I can "eavesdrop" on, so therefore all the Mode C traffic will show up. But again, I have no real world experience with this stuff.

IDIOTPILOT

TIS comes from ground based antennas. You’re eavesdropping the signal meant for them from these ground stations. Low altitude away from an antenna, you’re going to lose the signal even if there is an ADSB out plane nearby.

Avidflyer9AF

If traffic is all you really want to get consider building yourself a Stratux (not stratus). You can build your own receiver for around $130. It does everything a Stratus does except AHRS. I use an Ipad Mini and this set up in my personal plane and work airplane. The first few times I flew with it, it was scary at the amount of traffic out there that you never visually acquire. I witnessed a double fatal middair in the traffic pattern in 2014 and ever since then I have a new found respect for other traffic out there.

globalexpress

Thanks much for your information.

globalexpress

Very cool. Never heard of it before. I did a quick google and it appears to be a "build it yourself" ADS-B out with a Rasp Pi. I have WingX Pro on my Android tablet. You think this Stratux is a good set-up?

bamike

You can buy the Stratux prebuilt from companies like Seattle Avionics (they call it Merlin ADS-B) or from Everlast Concepts. They work well with lots of apps. Ebay is also full of Stratux builds, expect to pay around 220-250 for them. They do have AHRS capability. I use mine all the time with an Ipad and an android phone at the same time (multiple devices can connect simultaneously over Wifi connection created by the stratux) and it works great. FltPlan Go is the app I use it with.

globalexpress

Thanks for the info!

sourdough44

I have the GDL-39 feeding the IPad mini. My system shows some traffic but not enough to count on it. It’s not as comforting as TCAS at work.

I just try to fly defensively, knowing traffic numbers are higher around Class B edges and busier airports. In many areas some form of ‘flight following’ can be very helpful.