How not to get into a mid air collision.

[Shiny Side Up]

In short, keep your eyes outside and your brain in gear. But I feel this needs to be expanded upon since traffic seems to be a lot of pilots boogeyman. Maybe this will help, maybe not, but lets give it a try. I'd like to pepper this with diagrams, but as of yet I don't feel the creative need to make pictures so bear with me, that might follow. You will know it is time to turn the page, when you hear R2D2 beep like this...

Lets begin now.

The front 90 degrees

One will hear often that when traffic is about you need to keep your "head on a swivel". To some degree that's true, but some people seem to take that litterally. They think traffic is around, suddenly they have that panicked frantic "looking everywhere" thing going on. If anything, that just makes matters worse. They don't see anything. I could go into how to process the information how your brain strives to take snap shots, but I won't, suffice to say that if you're moving your head fast, you get an image just like a fast moving camera. At best things will be an indistinct blur.

So if we can't see things well looking everywhere, then we have to think about where is our attention best spent, and that's in front of us. Remember that you're moving forward in the airplane. Anything that you might run into is in that quadrant - as opposed to things that might run into you, we'll get to that in a minute. Here's some points to ponder before we move on.

a) Anyone who's the same speed, flying at a perpendicular course to yours at the same altitude, will collide with you if they are at your 45 degrees.

b) Anyone faster than you, flying at a perpendicular course to yours at the same altitude, will collide with you they will be greater than 45 degrees, but still always ahead of the wing (90 degrees).

c) Anyone slower than you, flying at a perpendicular course at the same altitude, will be less than 45 degrees off your nose.

At the moment, lets keep thing also where traffic is flying at the same altitude, we'll get to climbing and descending. As you can see from above, when traffic in general that is on a collision course, has to be in your front arc. If one considers that traffic in the vicinity of GA aerodromes are generally flying at speeds close to one another, then in most likelyhood "conflicting traffic" if they are, is going to appear in the same places in relation to you. Something to note, is that in general, the faster you are, the more responsibility you have to keep your eyes ahead, but then it narrows the arc into which you will have conflicting traffic. Where should most of your attention be?

If we also consider that traffic that is approaching closer to a head on course, but less than a perpendicular course, is going to be more dangerous due to a higher closure rate, this traffic also will appear closer to the center of our field of view. On the other hand, traffic that is on a collision course outside our front 180 degrees must be on a shallower converging course so that our closure rate with them will be slower, giving us more time to react to them. Keep in mind that slower traffic will be ahead of us on such a course - giving you more opportunity to see them, and if its the opposite, faster traffic converging from behind, well now we're in the territiory of you being in their front arc for such a collision to occur. They're running into you. While having faster traffic running into you from behind seems to be a lot of pilot's biggest fear, hopefully if everyone kept track of what's in front of him, this wouldn't happen. But one should also remember that unless there is a drastic speed difference between aircraft, that this is also the least likely scenario to encounter, in some ways its the one that once you're in it, well you might as well not worry about it, you won't be able to see them coming. But lets not worry too much about that yet. Remember that we can really take care of a lot of our problems by keeping most of our attention forward (in the 45 degrees right and left of the nose) and when we can, give a little attention to our sides, and if you can sometimes peek behind you, but don't spend a lot of time there unless you're somewhat certain that's where your prime danger lies - which as we've figured is often unlikely.

Keep in mind that looking forward also makes it easier to fly your airplane. Which brings us to...

Worry about what you're doing first

Even while traffic may be sometimes concerning, pay attention to what you're doing. It does you no good to spot someone all the while getting yourself into an inadvertant spin. But more specifically, if we keep ourselves right side up, flying straight and level, its going to enable us to spot things easier. Traffic at your altitude is going to be right on the horizon. Remember, you can only run into airplanes at the same altitude as you are. Some pilots I find spend a lot of time trying to look above their wings or below them (depending on their configuration) when if something is behind your wing its either higher or lower than you. As above. If someone is behind your wing and going to collide with you, well its too late to be looking. At some point prior to that unfortunate event they were in a much more visible space (assuming you're flying most general aviation airplanes, I won't get into biplanes and other things in this - though I'm aware things are somewhat different.)

The second part of that is if you're flying reasonably straight and where you're supposed to be it makes it easier for people to see you. That's our next part of the lesson in traffic avoidance.

Make Yourself Visible

While some may worry a lot about lighting their airplane up like a Christmas tree, if you want to be seen, then be where people expect you to be. I'm not worrying a lot about the radio in this case, its all about leaving and joining. Think about the places where there's the highest likelyhood of other airplanes being. Think about when you're in one of those places. Downwind for instance. In general adhere to the pattern you're supposed to be flying, especially if you suspect there's other traffic about. The guys that are hardest to see, are guys who are doing something unexpected. Flying excessivly wide from the field, not flying parallel, flying high, flying low. Don't be one of those guys, or if you are, be extra careful. IF you're certain you're by yourself, fill your boots, but don't be the odd man out. Sometimes this makes you play a game of follow the leader, and sometimes you're going to have to do approaches non standard, or at least something you're not used to to play the game. Never assume, however, that they see you and are going to keep track of you. But help them out.

In particular when joining into a traffic pattern put yourself in a position to be seen. Be at the right altitude when you're supposed to be. One of the worst things people do constantly is descend into the pattern.

Above and Below

Much is made of the terrors of high wings meeting low wings. The thing is that obviously these guys didn't take off in such a "formation" but rather joined up somewhere, usually in the circuit. At some point previous to the two aircraft ending up in close proximity above and below, they likely were on a converging course where one or both aircraft could have seen each other. We really have a failing when both pilots aren't looking, but its all too common. Three places where this happens.

a) High wing joins downwind perpendicular to low wing aircraft already on downwind, or vice versa. One or both of these aircraft are not at the correct altitude when this happens (or they would have collided then, or preferrably seen each other).

b) Same as above, but on the turn to base with airplanes turning onto base, and the other joining straight onto base.

c) As above, but on the final leg.

The reasons why this happens don't really matter. Sometimes one or both of the aircraft are aware of each other, some times its a case of "me first" stupidity, but most of the time they're oblivious to one another's presense.

With speed differences this accident is unlikely. A fast aircraft should be able to see a descending slow aircraft ahead of itself (if again he spends most of his attention forward - see where I'm going with this?) The other way around, well a slow airplane descending won't catch a faster one for obvious reasons, or at least the combination is unlikely in most traffic pattern. Now remember what we said earlier about aircraft travelling similar speeds on collision courses.

Keep in mind that climbing in an aircraft it should be tough to collide with someone, unless one of the aircraft is doing something really out of the ordinary (like flying the wrong way around the pattern - also known as a "Winters Air Park special") or a straight in approach on the wrong runway. If everyone is doing what they're supposed to be doing, don't be flying through the departure end of an aerodrome and you won't have this worry. When you are departing, get yourself clear of the pattern before manuvering.

Not if I see you first!

At the end of all this though, you will still have to manuver to avoid traffic. Hopefully though it will give you a leg up on spotting them sooner. If you do though, take it upon yourself to avoid them. Don't wait for a radio discussion, if you must talk, fly first then tell people what you've done, not the other way around. My personal preference is to avoid people without telling them, since if they find out you did it just panics them and they start flying erratically. Something of a helmet fire it causes. The erratic behavior makes them harder to avoid. The motorcycle analogy is best. Pretend you're invisible. Imagine that they don't or won't see you. Never operate under the assumption that they do. Even if they say they do. Air combat in the old days (and still to some degree today) was largely decided by who saw who first. Imagine they're going to bounce you if they see you.

Nothing drives me nuts more than two guys converging who keep flying at each other even when one sees the other. Worse when they don't but they have an inkling where each other are at due to the infernal radio. You've all heard that conversation. Don't be one of those people. Just like thunderstorms, you don't want to try and dodge other pilots at close range.

Well hope this helps. Try not to make it scary out there.

[Rookie50]

Good post. Also (this is where someone unexpected popped up for me) don't fly transiting right across the departure / arrival path, close to a runway and close to circuit height.

I was once descending to join a straight in downwind, just above circuit height, boom a guy flys right across my path in front of me, converging path but just in front. Not chatting to anybody. I saw him and took evasive, he never saw me. Maybe 2 miles from the departure end of the runway.

[Colonel Sanders]

I have learned a few things over the decades.

a) if the other moving object is stationary
in the window and getting bigger, you have
a problem. I learned this lesson in both
boats and airplanes, a very very long time ago.

b) aircraft can only collide if they are at the
same altitude. This is important to learn

c) 99% of pilots make the mistake of turning
to avoid a collision. This increases their cross-
section and increases the probability of collision
and is such is usually a poor choice, but few
pilots think in three dimensions. Under stress,
they revert to two-dimensional creatures.


About 10 years ago, I was doing an airshow
at Oswego, NY with Freddy Cabanas and Gary
Ward. As briefed, Freddy joined up right wing
on Gary in the monoplane, and I joined up
left wing on Gary and called "in position".

I guess Gary was distracted, and didn't
hear or see me, and made one of those
high-roll rate turns into me that monoplanes
do so well.

Freddy thought I was dead. Not much time
to dither. I pushed hard on the stick and put
-5 G's on the meter and Gary passed overhead.

Note that I did not turn, as an AvCan chairborne
expert would have. I did not try to fight gravity
and climb above Gary. I was wings-level beneath
him, because if aircraft are at different altitudes,
they cannot collide.

I know a little about operating aircraft in close
proximity to each other. I even know a little
about joinups.


Reminds me. Years later, we're at an airshow
with a couple of L39's. It was very important
to the Inspector that we did not fly the L39's in
formation. This did not make much sense to
me, because I have spent much of my life flying
formation, but one does not argue with the people
who are in charge of the paper.

So, the two of us flew in trail, and of course quickly
lost sight of each other, driving outbound then
inbound with 800 knots closure and no visual on
each other.

One of the most dangerous things I have ever
done in an airplane. To keep the Inspector happy.


Reminds me of another time, some really dangerous
flying was required to push some paper to get someone
qualified. I won't go into the details, but I find it
really disappointing when the paperpushers completely
loose sight of what their objective is - SAFETY. And
in fact, they attempt to instigate accidents in order to
obtain regulatory compliance.

As a grumpy old guy, I find this insane.

[Shiny Side Up]

a) if the other moving object is stationary
in the window and getting bigger, you have
a problem. I learned this lesson in both
boats and airplanes, a very very long time ago.

The problem here of course is that the eye is better at picking up moving objects than it is stationary ones in the windshield, for a variety of reasons. The point of the above is to give people a clue where to look for the most concerning of these. I find a lot of pilots, while reasonably paranoid of traffic, just aren't very good at spotting traffic, and often do things that are counter productive to spotting it. As seems to be a favorite topic in the flight training forum, its a matte of priority. For example, you'll see pilots spend an inordinate amount of time trying to spot stuff they think is in their six o'clock position, like the "omnivision" window is a big help. Silly marketing tool just produces drag.

But what's worse is that frequently you have to tell people to do something to avoid now rather than something drastic later. "Um, he's right there, lets not get too close for comfort."

b) aircraft can only collide if they are at the
same altitude. This is important to learn

Very true, though its possible for them to be on a collision course at differing altitudes. The thing is, in a majority of the circumstances, one plane is, or should be visible by the other pilot, if not both. You can also only run into things that are in front of you in the plane. It doesn't have reverse.

c) 99% of pilots make the mistake of turning
to avoid a collision. This increases their cross-
section and increases the probability of collision
and is such is usually a poor choice, but few
pilots think in three dimensions. Under stress,
they revert to two-dimensional creatures.

In this case though, we should be clear that you're talking about a close encounter avoidance maneuver. For most pilots not flying formation, the closest they're going to be getting to other airplanes is in the circuit. When you spot someone at a distance, its easy enough to change course to avoid, and in lots of cases you don't have to change much. Pilots I've discovered though really have a hard time thinking outside certain boxes though.

For example, you're on downwind and someone is ahead of you. He's getting bigger in your windshield, what do you do? You have some space and time though. Lots of people will suddenly remember one of their instructor's ill placed references to slow flight and suddenly do something weird with throttle and flaps and usually suddenly weaving about the sky drunkenly in an attempt not to catch up. Instead of following the guidance of the AIM as it spells out how to avoid people if you're overtaking them from behind. Put yourself in a position where you're now no longer on a collision course then worry about slowing down if such is necessary.

The worst though is everyday I see someone do something that greatly increases their chances of colliding with someone else. Often I feel it has to do with the "me first" syndrome which plagues society, but I digress. This week, I think I saw at least 4 pilots descend into the established traffic pattern, even after they had established radio contact. People wonder why I hate the radio, sometimes there's just no point to it. You get this response all the time: "I hear that you're in front of me, I can't see you but I'm still going to come at you." Madness. Heaven forbid you might lose a minute or two of fuel before you get on the ground. I'll confess to some irritation when it looks like someone is coming at us and the student goes "but we're the ones on downwind, what do we do?" They are miffed to be inconvenienced too.

[sigh]

One should keep in mind that I spend a majority of my flying in uncontrolled airspace. It really should work out just fine if everyone was reasonable, and didn't act like they do on the highway. But then I guess someone's got to make money selling PCASes so people can have the illusion of "safety".

[pelmet]

I guess Gary was distracted, and didn't
hear or see me, and made one of those
high-roll rate turns into me that monoplanes
do so well.

Freddy thought I was dead. Not much time
to dither. I pushed hard on the stick and put
-5 G's on the meter and Gary passed overhead.

So, what was said on the ground when you met up with him?

[Colonel Sanders]

No point in tearing him a new one. He simply
didn't know I was there. Notably, he did not
have "formation" (yet) on his ICAS SAC card
(although even 10 years ago he was a superb
solo surface acro performer).

He apologized, and I told him no biggie. He's
a good friend and the best airshow pilot you've
never heard of.

http://www.youtube.com/watch?v=fYYrmazbH7E


You can't get angry at everyone that tries to kill
you.

[Colonel Sanders]

you're on downwind and someone is ahead of you. He's getting bigger in your windshield, what do you do?

Barrel roll around him?

http://www.youtube.com/watch?v=wtaFzFkohPU


It's not as stupid an answer as it first seems -
about +3G's is all.

During the barrel roll, you will travel about
twice the distance he does, and thus will
obtain longitudinal separation.

When we're doing the Candy Cane, as Rob
Holland calls it, I'm always hollering at Eric
to slow down, because I'm always getting
behind because of this.

[AirFrame]

c) 99% of pilots make the mistake of turning
to avoid a collision. This increases their cross-
section and increases the probability of collision
and is such is usually a poor choice, but few
pilots think in three dimensions. Under stress,
they revert to two-dimensional creatures.

In this case though, we should be clear that you're talking about a close encounter avoidance maneuver. For most pilots not flying formation, the closest they're going to be getting to other airplanes is in the circuit. When you spot someone at a distance, its easy enough to change course to avoid, and in lots of cases you don't have to change much. Pilots I've discovered though really have a hard time thinking outside certain boxes though.

The problem with many midairs is the "blossom effect"... In which you don't see the airplane until the last minute because a tiny dot approaching and not moving in your viewscreen gets a lot larger all of a sudden at the last minute. That is entirely a close encounter avoidance manoeuver.

I was flying along fat, dumb, and happy one day in my RV, heading to the local $100 hamburger spot for lunch. I picked up the 180 on floats coming at me head on with "just enough" warning time. It was close enough that I didn't want to waste time debating my actions. I pulled, rather than pushed, and added 200' to my altitude. I reasoned that a floatplane likely has very little "smash" compared to a lightly loaded RV-6. I agree with the Colonel that pushing makes gravity work for you. It also would have kept the other airplane in sight. But the RV's positive-G capability is greater than its negative-G capability, so I chose positive.