IFR AT 9K - No Guarantees!

Guest Discussion
1

IFR AT 9000’ – No Worries Right?
THINK AGAIN

What better way to end four days at South-By-Southwest (the annual pilgrimage to Austin, Texas for music lovers and people in the business – kind of like CirrusÂ’ annual migrations – all converging on Austin for 5 days to listen to the countryÂ’s best new talent and study a wide range of issues relating to todayÂ’s complicated music industry) than a smooth ride back to Atlanta on a mostly clear day.

All was well with our beautiful flight originating out of Austin Bergstrom International departing from RW17R –

  • 626SR turn 120 degrees after departure, cleared for takeoffÂ….

And so up we go to niner thousand with a nice tail wind pushing us toward home as we settle in for our four hour mission back to FTY, with an intermediate refueling and stretch my tired legs stop in Jackson, Mississippi. From KJAN we again request nine thousand where we know weÂ’ll find smooth air. Level at nine thousand, check list complete, leaned for best power (ok, forget I said that), whatÂ’s left to do other than a little engine monitoring and a lot of daydreaming, right? Well, almost until seemingly from no where, our TCAS comes alive with a target – 100Â’ separation simultaneously accompanied by the audible TRAFFIC – TRAFFIC – accompanied by

  • 626SR VFR traffic 12 oÂ’clock, opposite direction your altitude;
  • NO CONTACT request vector;
  • 6SR, assume you have traffic;
  • NO; NEED A VECTOR – (meanwhile exercising our responsibility for the safety of the flight we were already in a steep turn to the right, accompanied by a steep descent to some indeterminate new unassigned altitude)
  • 6SR turn right immediately to 090 and descend to 8,000Â….
  • 6SR heading 110 and level at eightÂ…
  • 6SR, traffic no longer a factor, resume own navigation and climb back to niner thousand approvedÂ….

WOW, I hadn’t really bargained for that….and so now I began to review what just happened or better yet, what hadn’t happened! My best estimate, assuming the other “pilot’s” altimeter was set correctly so his mode C report meant something (a big assumption under the circumstances) was that we were within ½ mile and 100’, closing rapidly.

Upon brief reflection, I requested Meridian Approach track the VFR aircraft flying at an IFR altitude in the wrong direction and apply whatever justice they deemed appropriate….they tried but failed. They did track the aircraft to a field, but, the airport manager claimed not to have seen any airplanes arrive. So, the negligent and/or incompetent pilot is still out there exercising the “privilege”, placing the rest of us at great risk!

Shortly thereafter, I was handed off to Atlanta Center and a very quiet radio; so, still reeling a bit from my experience, I asked the controller if he had a minute and assuring me that he did, I briefly relayed my experience and suggested that I wanted to file a reportÂ…somewhat to my surprise he responded that he had noticed the target in his airspace at that altitude a bit earlier!

I was offered phone numbers for both Meridian and Atlanta. I called for several reasons – 1) first and foremost, to thank the Meridian controller for his tremendous help; 2)to ask why the Atlanta controller did not send up/ set-off alarms that a VFR plane was at an IFR altitude going the wrong direction (I was sadly informed that it happens “all the time” and that the controllers don’t have time to deal with them all!) and 3) to file a “preliminary mid air report”…(my first and I hope my last experience of this type.

So what can we learn? 1) I canÂ’t afford to daydream and not constantly scan all resources continuously; 2) an IFR flight plan is no guarantee of traffic separation 3) although not very pretty, the systems workedÂ…both on the ground and in the air; for that I am both grateful and able to write this post!

Happy flying and please be safe…

John Gordon
Atlanta

2

John,

As you know being IFR is NOT a guarantee that you will not have a traffic conflict with a VFR aircraft. The system only assures separation from other IFR aircraft and the responsibility to avoid a collision when in VMC rests squarely with the pilot.

Let me give you some possibilities to consider.

First, if you did not actually SEE the other aircraft you really can’t be sure he was at your altitude. He may have set his altimeter incorrectly or perhaps he was using a setting from 300 miles back. Perhaps his encoder was not calibrated correctly (there is no requirement to calibrate it if you never fly IFR). Perhaps he really thought he was at 8500 or 9500 because that’s what the altimeter said. It is important when VFR to recheck the altimeter on a regular basis so you are at the altitude you want to be at.

That brings up another issue - namely turning on your own and changing altitude without seeing the other aircraft. When you do that you might inadvertently give away some separation that existed. If the other aircraft’s altitude has not been verified by ATC then lateral separation is much safer than vertical. Waiting for a vector for the turn would make it much less likely that you would make your turn in an incorrect direction. As it turned out you turned the same way the controller told you to, but without the benefit of seeing both your target and the other’s target on radar your initial turn may be incorrect and create a hazard where none existed before.

Skywatch and TIS are specifically NOT to be used for avoidance maneuvers for those reasons. See AIM 4-4-15.

I’m glad you are OK and I agree that the issues you raise are valid but I would like to have you and others consider that a self designed avoidance maneuver without the other aircraft in sight could potentially have disastrous consequences.

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I totally agree with every thing you say; and as you can determine from my post, I tried to get a vector – when it was not immediately forth coming I am afraid my instincts took over based on what I saw depicted on the display and I exercised my best split second judgment as pilot in command for what I believed was in the best interest for continued safety of the flight.

Again, you are correct re: deviations based on the TIS system. Can you tell us the rational behind that standard; i.e. that lateral deviations are not approved based on the data, as in my case it was pretty clear that the target appeared slightly to my left thus explaining the deviation to my right. I am confused why that is not a better choice than continuing on in a hazy sky where forward visibility is reduced and no target is immediately discernable to the eye. It seems to me a course correction would be better choice than no attempt to avoid what would appear to be a conflict?

Thanks for taking the interest to reply to my original post – I sincerely appreciate the perspective and while I hope this dilemma is not one I have to face again, I would like to be as best prepared as possible should it recur.

John

4

John,

All good questions to which I may not have good answers.

Separation may be either lateral or vertical. In the case of an unknown target the vertical component is unknown so a change in altitude may easily be in error. Lateral separation depends on knowing the location, speed and direction of the unknown target. Since you are not sure which direction and at what speed the other plane is going any lateral deviation may put you directly in his course. The ground radar has position, speed and track so is better able to provide an appropriate avoidance vector.

Sometimes even when visual it can be confusing what action to take to avoid a collision. In the 60s there was a collision between two airliners in which one saw the other and it appeared to be on a collision course. One plane was at (I think) 10,000 feet and the other at 11,000 feet. The lower one saw the higher one and based on cloud “horizons” determined it was at his altitude. He climbed right into the other aircraft. This was before TCAS but the point is that unless you are absolutely certain of the exact location of the aircraft you are trying to avoid, an avoidance maneuver based on limited data can be catastrophic.

By the way, this thread would probably get far better exposure on the Member’s Side.

5

John,
This is from the POH Skywatch supplement"
"Do not maneuver solely on traffic information shown on the display.

My best guess is that they’re imagining the scenario where one plane gets visual contact and begins the appropriate “right-of-way” or other emergency action based on the direction of flight of the other plane.

If the other plane began a random (to the first pilot) maneuver, it’s too easy to imagine it devolving into the high-speed aeronautical version of the “stutter-step” - that awkward maneuvering that sometimes occurs when you’re walking towards another party and both keep altering path in the wrong direction. THAT often ends up with both parties stopping and agreeing who goes which ways. At 200 mph this might not work out so well!