I thought I was getting the hang of this until............

[bruce]

Well, when is a near miss not a near miss?

I was flying IFR KSBA to KPSP at 11000ft, minding my own business & admiring the cloud formations. The radio came to life informing me of traffic 10 o'clock 6 nm converging indicating 11600ft, I was not immediately visual & called "looking". I was given updates, 5 nm converging. I called "still not visual". I eventually saw the other aircraft in my 10 o'clock at about 2nm very slightly high & closing. I was expecting to be given some form of avoiding instruction, none came. As aircraft got closer I decided to take avoiding action, called 11000 descending 10000. I started to descend & at about 10800ft the other aircraft passed down my left side at something less than 2nm. I then called climbing 11000ft.

This was the first time I had had an encounter of this type at this close range. I am aware that under IFR you must have the controllers permission before changing altitude however at the time, in those few seconds after initially seeing the other aircraft, I decided to take matters into my own hands ie. self preservation!

Put in the same position, what would you have done? Over to you--------- in the comfort of your armchairs!

[seippg]

Well, in my mind, the reason to give traffic is to let you know so you can avoid it, not watch it like a movie. I'd have done what you did, adjusting my flight path and tell ATC what I did.

I sound so smart. One day, real world, I was flying over NJ VFR, transitioning over McGuire AFB around 3500 ft in a PA28...straight over the top 90 degrees to the runway. I was talking to Approach. I watched a KC10 departing, in awe of it's size and thinking about the wake turbulence behind it. Then I heard the controller turn them directly toward me. At first I thought...this can't be real. And I watched it taking the turn, climbing and turning. I'd like to say I talked...I didn't. I made a climbing right turn, trying to calculate the best heading out of its way. At that moment the KC10 saw me and I heard him say "Approach, we've got a light aircraft straight ahead" at the same time the Approach Supervisor (another voice) gave the KC10 a turn and traffic on me. Neither of them heard each other. My heart's racing. I hear the KC10 pilot chewing on their a$$ as I'm booking at the anciently slow speed of 105KIAS out of there. Climb? Descend? I turned north and just flew level for a bit...settling myself down. Finally, I tuned in the VOR and flew back toward home. My passenger thought it was all cool...thought I handled it well...no big deal. Heh. Well. That's not something I ever want to see again. I *should* have immediately told approach what I was doing! It would have helped them. I cussed myself out over that for days.

[Mark Hargrove]

Curiously, I had a very similar experience on Sunday, IFR from KLAX to KSNA, flying the ILS full approach. I got traffic called out to me just as I started my course reversal at SAGER. Conditions were partial IMC -- I was in and out of clouds at 3500' -- but I could see the traffic on my TCAS. The traffic was showing as 900' below me, level. As I continued the HILPT, the traffic was moving directly across the front of my airplane, from 2:00-12:00 according to my TCAS -- I still couldn't see him. ATC made several position calls, but the visibility was marginal. As I re-intercepted the localizer and crossed SAGER inbound, the traffic was showing directly below me on the TCAS, and suddenly climbing -- I got a TCAS alert when it was 500' below, and then it suddenly was showing 200' below, and slightly behind me. From there we separated quickly and ATC called "traffic no longer a factor" but I was sweating bullets. I never made visual contact. I was nearly to SNAKE before I got my brain back under control to slow the airplane and get configured for the approach.

It's amazing how a little detail like trying to avoid a mid-air collision can distract you from flying an approach

[rgrazian]

Hi Bruce,

In real life, even under IFR, it is the pilot’s responsibility to “see and avoid” in visual conditions. You did the right thing. The FAR's allow you to deviate under those circumstances.

See Instrument Flying Handbook Chapter 10, page 294.

“ATC does not provide separation for an aircraft operating:
2. On an IFR clearance:
c) At any time in VFR conditions, since uncontrolled VFR flights may be operating in the same airspace.”

[seippg]

Curiously, I had a very similar experience on Sunday, IFR from KLAX to KSNA, flying the ILS full approach. I got traffic called out to me just as I started my course reversal at SAGER. Conditions were partial IMC -- I was in and out of clouds at 3500' -- but I could see the traffic on my TCAS. The traffic was showing as 900' below me, level. As I continued the HILPT, the traffic was moving directly across the front of my airplane, from 2:00-12:00 according to my TCAS -- I still couldn't see him. ATC made several position calls, but the visibility was marginal. As I re-intercepted the localizer and crossed SAGER inbound, the traffic was showing directly below me on the TCAS, and suddenly climbing -- I got a TCAS alert when it was 500' below, and then it suddenly was showing 200' below, and slightly behind me. From there we separated quickly and ATC called "traffic no longer a factor" but I was sweating bullets. I never made visual contact. I was nearly to SNAKE before I got my brain back under control to slow the airplane and get configured for the approach.

It's amazing how a little detail like trying to avoid a mid-air collision can distract you from flying an approach

I have to say, that kind of nags at me. People flying under different wx conditions in the same airspace. Someone in the soup can't see a VFR guy who's not using wx. It's entirely possible he was flying by the rules in his version of the world but would probably have been in violation flying in yours.

[rgrazian]

seippg,

In the r/w running into a VFR plane in the soup is unlikely. Even in different weather, most folks on PE are talking to ATC. I'd bet that was a drone.

However, I have read of incidents with planes busting out of the clouds on an approach at a non-towered airport and having a close call with VFR plane scud running in the pattern.

[Keith Smith]

This is a great topic. I don't agree that "avoiding" would include a random 1000ft descent. You could pontentially violate the separation that was being afforded to yourself and another IFR aircraft (3 miles or 1000ft in terminal airspace, or 5 miles or 1000ft when working with an enroute controller).

You may deviate from an assigned altitude in an emergency, of course....but having an aircraft pass within 500ft vertically, that you can see, who appears to be level, would not pass the sniff test for an emegency. You can use relatively motion to know if you're on a collision course (laterally) and then make a slight left or right turn to avoid that happening (ignoring that you have 500ft already and allowing for the fact that the VFR aircraft might start a descent).

Now, if you did NOT have the traffic in sight, then it gets a bit more hairy, because the '500ft' that you have is unverified unless that aircraft is receiving radar service and has had the Mode C readout checked by ATC. That's why we issue "....altitude INDICATES..." on the traffic point outs with aircraft that are not receiving flight following. In that case, if you don't have traffic in sight, and they're that close, AND the altitudes haven't been verified, that's a full on emergency and you do what you need to do.

I can tell you that in busy corridors, I have past all sorts of aircraft with 1000 and 500ft vertical clearance on many occasions. It is truly a common occurrence...and as long as you see the plane, not cause for concern. Just watch 'em really close for any changes

[rgrazian]

I agree that a 1000 descent does not meet the "emergency" criteria. Although it looks like Bruce only descended 200ft. I have been very close to traffic in a busy terminal (see picture my brother snapped of a 737 passing below the Cessna I was flying; ATC was talking to both of us). However, I have not yet been in a situation under IFR that would require collision avoidance deviation. If I ever was, I would follow the logic: “Aviate, Navigate, Communicate” I feel a reasonable course of action would be to do whatever necessary to avoid the collision, quickly get back to assigned heading/altitude, and notify ATC of and deviation? Thoughts/suggestions? Who knows the DPE may ask me this question.

This is great stuff…!

[Keith Smith]

That he only dropped 200ft isn't material...his stated intention was to drop 1000ft from 11k to 10k, that's the part which could cause an issue.

If you feel you're going to collide....ABSOLUTELY do ANYTHING you need to avoid it. That's not the issue. But...with some experience in converging operations, you can quickly tell if you're going to overlap (in terms of a point over the ground, regardless of altitude). In this case, the aircraft passed behind.

Here's an example: http://www.youtube.com/watch?v=LFaftfkMyUU. Start at 6mins 45sec. Notice the aircraft is moving left to right relative to us...that means it's going to pass ahead of us. If it wasn't moving (relative to us) and was just getting bigger, it would mean we were going to 'collide', ignoring altitude.

[rgrazian]

Hi Keith

My question/statement was more along the lines of the best course of action during a true collision avoidance maneuver under IFR. Clearly knowing the difference between an emergency and converging traffic with a safe margin is an important part of ADM. Cool Video. It looked like a perfect day for flying. Days like that are why we do what we do…

The three most common expressions in aviation are, "Why is it doing that?", "Where are we?" and "Oh Crap".