Cruzinchris
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Cruzinchris
.....and ADS-B is the law of the land, will Mode C transponders still have usefulness?
After 2020.....
- Thread starter Cruzinchris
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Capt. Geoffrey Thorpe
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Light and Sporty Guy
Legally? You still need it everywhere you need ADS-B.
Practically? ADS-B can't be relied on to work - radar is still required for traffic separation.
Practically? ADS-B can't be relied on to work - radar is still required for traffic separation.
Topper
Pre-takeoff checklist
We have dual transponders in the 310. The 327 is acting up, we also have an old king that is working well. We are upgrading to a lynx l3 and keeping one of the non adsb transponders as a back up. I prefer to keep the newer 32$ as a back up, but hate to put money into it. Plus I don’t think we really know how atc will treat us if we lose our adsb transponder and go to a backup no adsb transponder. I figure which ever one I keep should last since it will never be turned on.
Jim
Jim
TigerGene
Pre-takeoff checklist
Those old King transponders are cheap as dirt on the used market. Garmin 327s are more expensive to replace and repair. Keep the King, buy a spare for $100, and ditch the Garmin which would bring more on the used market anyway.
Unit74
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I'll tell you this much.....
I have a 345 and still have the MRX PCaS. By far the MRX talks to me much more than the Garmin boxing valid alerts. I don't trust the Garmin ADSB algorithms one bit. I had the MRX light up last Friday 4 miles 400 feet above and descending. The Garmin box splashed the alert 1 mile same altitude. I was 155 kts and it was a Mooney. We passed him to my left and wave at each other. He was not talking to approach, I was.
Do the math....... by the time the OODA loop figures it out, it's already trading paint with another bird.
I very much so enjoy Mode C aircraft with the MRX. Layers of awareness......
I have a 345 and still have the MRX PCaS. By far the MRX talks to me much more than the Garmin boxing valid alerts. I don't trust the Garmin ADSB algorithms one bit. I had the MRX light up last Friday 4 miles 400 feet above and descending. The Garmin box splashed the alert 1 mile same altitude. I was 155 kts and it was a Mooney. We passed him to my left and wave at each other. He was not talking to approach, I was.
Do the math....... by the time the OODA loop figures it out, it's already trading paint with another bird.
I very much so enjoy Mode C aircraft with the MRX. Layers of awareness......
NavAir
Pre-takeoff checklist
I like the MRX also. It has saved my bacon a time or two. I'll equip with ADSB eventually, but I'm not getting rid of the MRX either...
tspear
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Timothy
steingar
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I think the mode C transponder that came out of my aircraft will become a hangar decoration (along with the busted ADF). I can't imagine anyone in the US having any use for them. Perhaps someone might need them overseas, I don't know.
tspear
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Any one who went with the UAT transponder but still flies abroad but at a lower altitude. Last I looked ADS-B requirements in most of the Caribbean, Mexico, and Canada were fairly minimal. But a Mode-C transponder was still required.
Tim
Capt. Geoffrey Thorpe
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Because that is what the FAA has determined and written into the FARs. Anywhere you need ADS-B, you still need mode-C.
Outside the 1% (pulling a number out of my butt) of the continental US where ADS-B is mandated (not counting class A), the FAA is still going to have to rely on radar / mode-C. Plus, You don't get primary returns from ADS-B so there is no way to detect gliders, or non-electric aircraft, so radar does not go away. Also, without radar, you could just pull the plug on the ADS-B and go stealth mode - that would be convenient for someone at an airport like where I am - just take a shortcut through the Class B and no one is the wiser. Or in the case of a "bad person" you could go anywhere, do anything and not be detected. Also, on the other other hand ADS-B is easy to spoof.
tspear
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@Capt. Geoffrey Thorpe
I must be missing something. If you fly now outside the Mode C Veil, and have no transponder under VFR (assuming VMC), eyeballs are the primary method of conflict avoidance and technically what ATC and pilots rely on. ATC only provides separation from other IFR traffic. Now if you are IFR in that situation, ATC will go old school and you will have to use reporting points and such measures that were in use before radar covered the vast majority of the country.
None of this has changed. And as for stealth mode, that has always existed regardless of transponder.
Tim
I must be missing something. If you fly now outside the Mode C Veil, and have no transponder under VFR (assuming VMC), eyeballs are the primary method of conflict avoidance and technically what ATC and pilots rely on. ATC only provides separation from other IFR traffic. Now if you are IFR in that situation, ATC will go old school and you will have to use reporting points and such measures that were in use before radar covered the vast majority of the country.
None of this has changed. And as for stealth mode, that has always existed regardless of transponder.
Tim
tspear
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If you are asking me, the answer is yes. And the rules have not changed, you can fly IFR with no transponder Mode-C or ADS-B in large portions of the country. Without Mode-C, you will likely have to follow airways (even if GPS/WAAS equipped) and do reporting points. I had a transponder fail going to TN, so I flew around there for a bit going "old school" technique before radar.
Tim
Brad Z
Final Approach
While ADS-B requirements in §91.225 become effective January 2, 2020, §91.215 has not been amended so Mode C transponders will still need to work and be used as they are today. Remember that TCAS uses Mode C interrogations and is the last line of defense from collisions in equipped aircraft.
steingar
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I suspect after 2020 we'll see a bunch of accidents where folks crash after running out of gas trying to stay clear of controlled airspace.
Capt. Geoffrey Thorpe
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I've had ATC pick me up as a primary target without a transponder.
I seriously doubt that I could sneak across the Class B without them noticing.
tspear
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Agree, just was not going to address the remainder of your original post:
Tim
denverpilot
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I believe the Garmin alert range is adjustable... I'll have to check though. Or you can.
Unit74
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It's not adjustable. The algorithm is set by Garmin Engineers. In fact, I went around with them with my GDL88 on the matter and even THEY could not explain exactly how it chooses to alert. What I do believe is it gives a terrible sense of security and make flying more dangerous because operators will believe the box will alert sooner than it actually does.
denverpilot
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Interesting. I hadn’t tried yet. It does alert a little late on some traffic, but still (I believe) in enough time to avoid an actual collision, having watched it now for a little while.
I don’t trust ADS-B at all, knowing how it’s engineered, so it’s just a “nice to have” that’s mostly annoying as hell during pattern work anyway. Even just doing laps with three aircraft will set it off constantly, which turns it into the Boy Who Cried Wolf most of the time.
Constant alerts teach pilots to ignore alerts. I really don’t need to know anything about something at 4 miles unless we have a very healthy closure rate.
Unit74
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Most of the time, in fact, I recall most if not all alerts are less than a mile. Covert AS into feet per second, then make some assumptions about the offending aircraft's speed. Literally seconds to react to it. And if your eyeball can't track it down that fast, well, you are now on a wing, literally, and a prayer if that's your thing. Since the average human has a perception reaction time of around 1.5 seconds, subtract that and then decide if the box is doing you any good. It's a better exercise to see aircraft on a display sooner rather than assume you will be alerted audibly later.
My MRX will start lighting up at 4 miles. It has never let be down sans one time from a Cub.
My MRX will start lighting up at 4 miles. It has never let be down sans one time from a Cub.
denverpilot
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It's probably let you down quite a bit... how would you know?
ADS-B isn't designed with any data confirmation or even re-tries built into it's complete mess of dual-frequency crappiness. All it takes is for the antenna to be partially blocked by the fuselage or wing to completely miss another aircraft on UAT. Cross-band, good luck finding any NOTAMS on whether or not a particular tower is broadcasting today. It's crap engineering. Total crap.As far as the alerts go, yeah, Garmin seems to do them fairly close in, but it's displaying them miles and miles out... if you include the moving map in a scan, you'll know the targets ADS-B itself hasn't screwed the pooch on, are there. I've noticed on the GTN 650 that de-cluttering the map a bit from the default settings tends to be better, both just for reading the important stuff on the map, and also for seeing traffic targets. The defaults are way too noisy for such a small screen.
If one flies with a GTN and a FlightStream, Garmin Pilot has a dedicated traffic view on the iPad that one can select... in dense airspace, if you're not using Pilot for approach plates or something like that (both FF and GP should do traffic overlays on the plates, but I'm not holding my breath on that one...) and you're out puttering around VFR/VMC, using that dedicated "second display" for traffic, isn't a bad idea.
But by the very engineering nature of ADS-B, you can NEVER fully trust it, ever.
Unit74
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Nothing is risk free. We can only attempt to buffer ourselves from it. People say the eyeball is the only way to be safe. Yet spotting aircraft at more than a mile out is almost impossible. something is better than nothing.
I think ads-b is a good tool. I had planes show up that would of otherwise been hard to see flying VFR. These are definitely to close for comfort encounters. Wonder how many close encounters we have had that have gone unnoticed before traffic alerts like ads-b. The other day flying IFR from Spokane to Boeing, I saw a conflict via ads-b before being diverted by ATC and was ready for action. By the time ATC notified us the controller said “I need you to go down NOW” followed by a 30° turn to the right. I had already deviated slightly to the right and was ready for a altitude change. I assume the other pilot was flying VFR. He was off altitude by 300 feet if so. The closure rate was very high and I was at 165kts. Ads-b is definitely not perfect, but a useful resource for alerting you of the unseen traffic. They are not to easy to pick out especially at high closure rates. It doesn’t alert you of all threats and is not a replacement for keeping your eyes out the window, but with a good scan at the instruments you know where to look for the ones that do show up.
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Sent from my iPhone using Tapatalk Pro
denverpilot
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It's a lovely tool, when it works. It has absolutely no engineering design work done on it to even check to see if it's failing.
Relying on luck for packet reception is not how one builds a safety system.
tspear
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LMAO, who said it was a safety system? ADS-B was designed for two things only.
Allow ATC to pack in more planes in congested airspace and reduce FAA costs by shifting the financial burden to airplane owner.
Weather and safety were after thoughts to try and make the price more palatable to small airplane owner. And you will notice that the airlines do NOT have to comply with ADS-B?
Tim
Raymo
Pre-takeoff checklist
The least expensive way to get to 2020 compliance is ADS-B via UAT (978 MHz), which works just fine with a Mode C transponder. This is only good in the United States, however, and under 18k ft.
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Velocity173
While it was promoted as a reduced seperation tool in terminal areas, that hasn’t come to fruition and in my opinion, probably won’t in the future.
FUSION (includes ADS-B) hasn’t reduced terminal seperation at all. You still have a 3 mile IFR min (some cases 2.5 or 1 horizontal) that the old single source ASR provides. ADS-B hasn’t and most likely won’t change those mins. The only reduction in terminal sep in recent years was the wake turb recat that occurred in 2013 but that has nothing to do with ADS-B.
Now, North Atlantic and GoM IFR? Yes, ADS-B has allowed reduced sep.
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Topper
Pre-takeoff checklist
What information is out there showing the airlines don't have to comply? I understand they have a 5 year grace period to update the gps source, but I thought they still had to be compliant with the rest of the mandate by 2020.
tspear
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Break ADS-B out down for 1090ES. There are two parts:
1. Mode S transponder with an extra message packet
2. WAAS data source.
Why was WAAS required? Because INS and GPS drift enough to to prevent ghosting when comparing primary radar and other data sources.
So, they do not have to have a WAAS data source for five more years? Golly gee willickers, they can magically comply by just installing a Mode-S transponder with an inaccurate position source? How is the FAA going to deal handle this? Oh I know, just use the ficking primary radar in a terminal environment.
Guess what, the airlines are NOT going to comply with the second piece for at least five more years, and you can bet that this timeline will get pushed out again. There is a huge chicken and egg problem with ADS-B out and WAAS in general for the airlines. Until all conditions are met, it does not save the airlines any money and in fact costs money. ADS-B out to effectively reduce congestion in the terminal space really depends on the concept of optimal descent profiles with a standard speed for all planes on the approach profile. In order for this to work, all airlines must equip full WAAS avionics and ADS-B out, and all terminal approaches must effectively be redesigned, including all SID and STARS, and most airline routes must be redesigned for sequencing further out, and the airlines must work together. One plane screws up, and the whole sequence is shot. This is a massive effort to make all this happen, and generally requires everyone to dance to the same tune and always have the same music. Southwest was an early adopter and stopped when the FAA was unable to actually allow the planes to be able to perform optimal descent profiles.
ADS-B is a ficking boondogle that is effectively stealing money from the small GA to reduce FAA costs; with the primary justification was this was needed to help airlines. If the FAA just wanted to shift the cost burden, they could have been a lot more honest, and just designed a system that met the needs of a cost reduction in VORs and radar supporting GA and outer areas of the terminal approaches; using basic GPS as a data source.
Tim (rather cynical about ADS-B)
denverpilot
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It was not designed for that, either. FAA has made it clear from the start that ADS-B could not and can not replace radar as primary. There was a limited test of whether it could assist with closer spacing at MEM for FedEx which has now been cancelled.
It’s a surveillance system to fill a surveillance database with. That’s all it was ever truly designed to be.
The rest of the stuff was bolted on haphazardly to make paying for it more palatable, as you point out.
The safety commentary comes from how it was marketed. Not what it actually is.
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Velocity173
Oh it’s been advertised to reduce separation by the FAA:
The improved accuracy, integrity and reliability of satellite signals over radar means controllers eventually will be able to safely reduce the minimum separation distance between aircraft and increase capacity in the nation's skies.
Others have been putting that out as well:
http://www.boeing.com/commercial/aeromagazine/articles/qtr_02_10/pdfs/AERO_Q2-10_article02.pdf
None of it, other than the non radar areas such as the North Atlantic, Alaska, GoM etc is true...yet. The min radar sep that exists today isn’t about equipment limitations, it’s about min distance for safety (wake turb).
You’d be hard pressed to find a controller that will list any real benefit on their end. My brother just told me today, the only benefit he has seen is that he can see a VFR’s tag before they enter his airspace. Said the annoying thing about ADS-B in, is all these yahoos with it are yapping about traffic that’s not even a factor. I’ve heard that as well just flying around and listening to the freq. You can tell it irritates the hell out of the controller and wastes air time. Another friend of mine sitting at the scope below said ADS-B changed nothing operationally wise in controlling traffic.
https://www.army.mil/article/177076...ntegrates_new_air_traffic_surveillance_system
denverpilot
Tied Down
The satellite ADS-B thing is really yet another extension to the bolt ons, and isn’t really Mode-S and isn’t really UAT.
They love to mix the terms just to keep the whole thing looking more viable and well-designed than it really is.
It’s a giant game of “name everything the same and tell the public it’s all for their ‘safety’ in the ‘nation’s skies’ and our ridiculous budget for this utter mess will be secure”.
They were starting to get noticed calling everything anyone ever built for the system “NexGen”, since how many Nexts and how many Gens do you get? LOL. So they decided to call everything, everything, “ADS-B”.
Of *course* a satellite signal showing where airplanes are over the North Atlantic far past reach of ground radar, allows some reduction of separation. Especially if you can also communicate with the aircraft over the same tech (slowly) or HF for any changes.
FAA announcing that as “an increase in capacity in the nation’s skies” is utter bull**** though. And they know it.