This is an excerpt from a report made to the Aviation Safety Reporting System. The narrative is written by the pilot, rather than FAA or NTSB officials. To maintain anonymity, many details, such as aircraft model or airport, are often scrubbed from the reports.
I was flying VFR above the Class C airspace at 5,500 feet in a Diamond DA40. I was monitoring Approach but was not receiving services due to radio congestion and I would be staying clear of the Class C airspace below.
I saw the airliner turning towards me on my EFB and G1000 flight display as I was transitioning over the Class C airspace, just northeast of ZZZ1 airport. Initially it was well below me, however the Controller cleared them to climb and I became concerned, as their trajectory would conflict with my flight path.
Indeed, just a few moments later, their turn continued directly into my path. Their rapid speed (nearly 300 knots) and vertical speed brought them dangerously close to my path at 5,500 feet as I was passing just northeast of the airport.
I turned back when my G1000 issued a traffic alert and clearly saw the airliner converging. I could not out-climb this E175 so I stayed level at 5,500.
The airline pilot notified ZZZ Approach that they received a TCAS Resolution Advisory (RA) and would be descending. They descended below me and continued their turn before climbing back on course.
Had the airliner not taken evasive action, they would have most certainly crashed into me.
They did not seem to have visual contact, but they were converging on me from below and behind.
ZZZ Approach did not seem to notice the potential conflict. They did not call me out to the airline pilot, despite my plane being equipped with ADS-B and enhanced surveillance, which should have indicated my selected altitude of 5,500 feet, as well as my selected heading.
ZZZ Approach also cleared the airliner to continue their climb despite this potential conflict, further support for the fact that they must not have noticed me on their radar scope.
Utilizing ADS-B data I was able to verify that my ADS-B and enhanced surveillance were working as expected.
Primary Problem: Procedure
ACN: 2052704
You were not in a good spot to not be talking to ATC and receiving services. Sitting just above the C is probably worse than being at 2,500 in the C. If you feel ATC is too congested to be talking to you, circumnavigate the airspace at altitudes that make sense for the flow of traffic at the big airport and there will not be issues. As a VFR pilot it was YOUR responsibility to avoid that conflict. If you are not prepared to do that, fly at a different altitude in different airspace. It is legal to be VFR on your own in that airspace, but it is exceedingly unwise. Talk to ATC. It’s counter intuitive, but around approach airspace, the busier they are the happier they probably are to be talking to you so they know exactly who you are, where you are, and where you are going to be.
Flying ABOVE class C airspace and receiving no separation service from approach OR En Route is dangerous. While frequency congestion might be your concern, let ATC manage that because you are placing yourself in the pathway of climbing AND descending IFR aircraft that might require some frequency changes. Plus, radar outages for ADSB happen especially during these solar storms events. Another thing, APPROACH might think you where called out as traffic already with center because you are in en route, class E, airspace. Not sure if center frequency was monitored here but this situation is quite scary for everyone involved. Please be smarter, you wouldn’t fly over an active volcano, right? You would fly AROUND it. So don’t fly over airspace and monitor the wrong frequency in VMC, while operating VFR, complaining about separation services you aren’t receiving. Not trying to be mean here but pointing out some things I haven’t seen in the thread yet.
Class C Airspace was designed a long time ago and changes to size/shape are incredibly difficult (my facility is in the middle of redesigning our Class C). If you look at traffic levels when it was originally designed and compare it with current traffic levels at many of these airports, it’s clear there will be issues. If you want to stay clear of conflicts, imagine doubling the size (lateral and vertical) and stay clear of that. These conflicts happen regularly because VFR pilots don’t want the “inconvenience” of possibly being routed away from traffic, but also wonder why ATC didn’t avoid them.
The jet was doing 300kts below 10? Doubt it. What else is wrong in this account?
Take evasive action, like turning 90 degrees to the flow based on ADSB tracks, even if you don’t see them. I do this often, and usually I eventually see them and am glad I turned.
So just to confirm, you were flying VFR and mad no one provided separation services for you? See and avoid dude. Controllers are not responsible for your separation with other AC, you are. Outside of class C B D under 10k traffic calls are not mandatory with unidentified targets. Enjoy our free services though!!!
Zid controller
You missed the point – the airliner was under positive control and was receiving radar services. A traffic alert and, if appropriate, vectors, should have been issued to the E-175.
Last I heard my taxes pay for those services. Nothing “free” about them. Your attitude suggests you work for the government.
Terminal ATC in the US does not utilize supplied ADSB headings or velocity. It was wrong to assume that what you might have dialed in is known to everyone else. Your target position and vector is calculated by ATC software only. And even what comes in via ADSB-Out has been calculated based on previous target history, etc by the ADSB ground based computers.
Hate to tell you this, but ADSB is not foolproof in any way. Also just because you can pull your ADSB data did not mean it was high enough quality to be used for ATC tracking and/or safety calculations.
There a lot of moving parts to tracking, sensor input, collision detection look ahead, etc. While this incident might look easy at first glance, the devil is in the details.
He was over Class C and properly equipped. Why didn’t ATC alert the jet including ‘altitude indicated xxxx not verified’?
You lost me at the E175 doing 300 knots in a Class C.
IAS 250 is probably 275 TAS combined with a 25 knot tailwind routinely displays 300 GS on TCAS.
I think being a class C has to do airliner traffic, and they tend to keep climbing after takeoff.
Although legal, what should be often isn’t and there’s a risk overlying a C.
TAKE IMMEDIATE EVASIVE ACTION, over
Or….had he not had ADS-B he may not have seen the airliner.
Both are nice to have…eyeballs and ADS-B.
A highly maneuverable DA-40 vs. a very visible “airliner”…in Vmc…
“Had the airliner not taken evasive action, they would have most certainly crashed into me.”
Personally, I would stop worrying about ATC radio calls, stop staring at my EFB and my G-1000 …look out the window, maneuver my light general aviation aircraft, as required, to acquire & maintain visual contact, and stay well clear of the faster, but less-maneuverable transport category aircraft…
“Primary Problem: Procedure”?
I don’t think so.
How well can you see below and behind you? Had this pilot not been monitoring “departure”…. But becasue the airliner had TCAS, they got an RA telling them to descend, which they reported, so they would not get violated for not climbing as cleared. And TCAS is what helped. This is a problem with ADS-B. It tries to be TCAS lite, but no RAs. And that is what we really need for when you can’t see the traffic.
How many times have you had flight following and were told of aircraft that you never saw and then got the call, “traffic is no longer a factor”? — You never saw them, yet you knew where to look for them, but your MARK-IV eyeballs just couldn’t spot that other flying machine.
Gotta keep your head on a swivel…always.
I fly IVO SeaTac Int’l Class B: It is a ‘flying circus’ around here, so it’s my habit to “Check 6” (including my ‘belly’) religiously, regardless of what actually shows up on any electronic cockpit display. Can you rely on Flight Following to keep safe from ALL other traffic, in this environment …nope.
In this instance:
“I saw the airliner turning towards me on my EFB and G1000 flight display as I was transitioning over the Class C airspace, just northeast of ZZZ1 airport. Initially it was well below me, however the Controller cleared them to climb and I became concerned, as their trajectory would conflict with my flight path.”
He’s operating under VFR in Vmc. As soon as he “saw” the traffic on his “flight display”…he should have made an aggressive attempt to acquire it with his eyeballs…and maneuver his own plane in a way that would ensure he could “see and avoid”…regardless of what the airliner did.
He’s only at 5,500’…I’m guessing if he just looked ‘down’…he could’ve probably picked up the larger aircraft sooner.
The way this story reads, even though he was “concerned”, he did nothing except drive straight ahead until “…my G1000 issued a traffic alert and (I) clearly saw the airliner converging.”