Mid-Air Collision

[Colonel Sanders]

There was a recent mid-air and I thought there were a few things worth mentioning on the topic.

Most mid-air collisions occur where there is an unnatural concentration of aircraft, which includes:

1) extended runway centerline (final)
2) overhead a VOR
3) between database waypoints

In the old days, we only had to worry about #1 (the biggie) and #2 - people holding or passing overhead a VOR.

However with the advent of incredibly precise GPS navigation, when we get incredibly precise pilots and autopilots, you can now have mid-air collisions out in the middle of nowhere, on invisible lines between published waypoints in GPS databases. Frankly, being a sloppy pilot could be rewarded, sometimes.

Without TCAS, and driving around in a non-radar environment, we mostly rely on the "big sky" theory, which is basically the notion that a random mid-air is about the same probability as winning the lottery.

Most pilots don't keep a very good lookout, and even if they wanted to, the visibility out of their aircraft is often very restricted. There could be an aircraft in very close proximity and you would never see it (eg directly above or below). Many mid-air collisions occur as a tremendous surprise to the pilots involved. A friend of mine in a low-wing turned final and hit a high-wing that was below him. Neither pilot saw the other aircraft, and my friend woke up sitting on the runway numbers after his composite aircraft splintered into a million pieces.

Sometimes pilots do see other aircraft, and generally they do a pretty poor job of avoiding them. First thing you check: Is the other aircraft stationary in the windscreen and getting bigger? If so, you have a real problem.

Most pilots instinctively bank to avoid another aircraft, and usually a bad idea. Not only does it take a while to roll into the turn, it actually increases your cross-section and increases the probability of a collision.

Here's a secret for you: aircraft need to be at the same altitude to collide. Most pilots don't use the vertical very well - they often pretend they're driving a car.

Next, most pilots would probably climb to avoid a collision. Wrong answer again. You are fighting gravity.

Why not let gravity help you? A really nice airshow pilot tried to kill me once, and I instinctively shoved the stick forward. Put some negative G on the accelerometer, but he passed overhead without touching.

Think about it.

[767]

Good post Colonel Sanders.

I would also like to add something regarding the use of radio. Before I begin, I just want to remind everyone that you always fly the plane first before anything else. I also want to remind that the radio does not eliminate the responsability of looking outside the windscreen.

Now, speaking of radio, I think it is a good safety aid to have on board the aircraft. For example, if you plan to be over town A in the next 5 minutes, and on the radio you realize that someone else is also going to be there once you get there, then start resolving the conflict as soon as possible (once aircraft is under control). Call up the other pilot and resolve. In this case, one should pass north of town A and the other should pass south of Town A, or whatever the situation may be. The sooner you can resolve, the better it will be, instead of waiting for last minute adjustments. Radio should be used to predict where everyone will be in a given time. Finally, what i just stated should be done when conditions permit. Make sure you dont cause frequency congestion, and I wont list everything becuase there are a million things, but common sense should be used. LOOK OUTSIDE please. Lets hope that the mid air collsion doesnt repeat again.

p.s. I am not linking any of the above to the mid air collision case that just happened recently.

[Beefitarian]

I have considered that and think it's probably a good idea. I think I will also bank for two reasons.

1.08 When two aircraft are approaching head on or approximately so and there is danger of collision, each pilot shall
1.decrease airspeed.
2.increase airspeed.
3.alter heading to the right.
4.alter heading to the left.

And in case it's the Colonel in front of me I don't want to just dive into the guy.

Does anyone fly a set distance from the center line of the track between the two places they're going?
You are in an airplane, flying an extra mile to be half a mile to the right of where everyone else might be wouldn't be difficult. You're not really tracking a VOR radial. You could move the track over between published waypoints the same way.

[172pilot]

-Turn on the transponder in uncontrolled airpace

-Consider a PCAS device, like the xrx or mrx from Zaon

-Consider making a radio call on 126.7 before switching to a MF or ATF and mention you are switching over. Monitor 126.7 on a second radio. Read an article the other day that made a good point that some pilots dont switch to a ATF while close to an uncontrolled airport, and stick with 126.7, whether intentionally or not.

[Colonel Sanders]

some pilots dont switch to a ATF while close to an uncontrolled airport

uh, that's because ATC wants it that way when you're IFR. Without a second radio, you're hosed as far as getting onto UNICOM any reasonable distance out.

[172pilot]

some pilots dont switch to a ATF while close to an uncontrolled airport

uh, that's because ATC wants it that way when you're IFR. Without a second radio, you're hosed as far as getting onto UNICOM any reasonable distance out.

Sorry, I should have stated VFR.

[lownslow]

Another way to find other airplanes on a sunny day is to look at your shadow. It mostly only works in the circuit but just yesterday it was the only way I knew there was another airplane headed straight for me in a blind spot.

LnS.

[Colonel Sanders]

Shadow is a great way to spot other traffic. If
you have two of them, life is going to get interesting!

Another trick I use to spot traffic ... I probably
shouldn't mention this, but ... I dive down and
look up and around.

Traffic at the same altitude as you will be on the
horizon, traffic below you will be hidden in the
ground clutter, and traffic above you will be
easy to spot in the sky

[Shiny Side Up]

some pilots dont switch to a ATF while close to an uncontrolled airport

uh, that's because ATC wants it that way when you're IFR. Without a second radio, you're hosed as far as getting onto UNICOM any reasonable distance out.

Its a frequent problem that they don't when they're VFR too. Ultralight flyers are generaly the worst culprits I've found, since they tend to follow terrain features and rarely consult stuff like maps. That being said, I'm sure that Aerostar whom I dodged one day certainly wasn't at an IFR altitude when he burned through the circuit. Mind you he didn't seem to know that Class C airspace existed around Calgary either.

The biggest problem as I see it is that there are far too many guys out there just ripping around careless and clueless. Keeping your eyes peeled is the only thing that's going to keep yourself safe. Even then, your number might be up if one of them sneaks up on your six, because you won't hear or see him comming.

I think my biggest peeve when it comes to avoiding people is when I hear two pilots on a frequency, determine that they might possibly be on a collision course, and then keep flying towards each other. You hear stuff like: "I'm about a mile back from the strip now and I still don't see you!" all the friggin time. Not sure why people don't seem to realise that early conflict resolution is preferable to late.

[Beefitarian]

I don't remember if I was PPL yet or still just a student decades ago but.. The proceedure returning from the practice area was to call up over X lake. It was really a small pond. Being a weirdo that thinks doing things accurately in an airplane is right, I lined up nicely with X lake and was waiting to be right over it to call inbound.

Just as I was going to key the push to talk switch. Someone calls in Airplane-registration over X lake inbound...

Good thing I had such a strong heart. I have no idea where that guy really was but fourtunately he was no where near X lake. I looked above, below and in all directions. Gathered myself came around and repositioned to make the call again.

It kind of sucked but I'm sure glad he was just calling in and lying about where he was.

[Colonel Sanders]

I don't care how many hours you have, when you hear someone else call your position and altitude, your head is going to be on a swivel

[cptn2016]

Student here, just finished up my cross countries, this topic is of particular interest to me right now. I think I have a solid understanding of what to do and when, but reading the discussion has got me thinking about some related points:

VFR flight, 3500' cruise altitude. You overfly an airport that's at 1440' (2000' above aerodrome alt, so you're ok there, correct?). You're on 126.7 at this point, but in the CFS it says that within 6500' & 5NM you must contact the UNICOM on 122.200 (I'm paraphrasing here, I don't have a CFS with me at the moment). From my understanding, this means that it is mandatory that I switch to 122.200 5NM out, notify them that I'll be overflying the airport at 5500', then I switch back to 126.70. Should I wait for a response? Do I need to let 126.7 know that I'll be switching briefly to the UNICOM?
This seems to contradict what an instructor told me that if I'm overflying at 2000' or more, I don't need to switch to UNICOM at all (could be I misunderstood as well).

On the same topic, I know when landing, I switch to UNICOM or the MF 5 miles out, let them know where I'm coming from and my intentions, and proceed to make the usual calls as I inspect, cross over, descend, etc. etc. How about when taking off? My understanding is straight out to 500', turn towards your SHP, and report 'clear of the aerodrome'. How far away should that be? When you're 2000' or higher? 5 NM or further?

[Colonel Sanders]

As a rule of thumb, if I am 3000+ feet above a small airport, I wouldn't say anything on the radio. You might lurk on the UNICOM out of boredom, or just in case they are dumping jumpers, but other than that, there should be no conflict because you are well clear of any traffic joining, in or departing the circuit.

re: calls departing ... they are kind of gratuitous. You are consuming precious bandwidth to tell people that they have nothing to worry about. If the freq is very busy - say on a sunny weekend - consider skipping "clear of the zone" calls.

[cptn2016]

Thanks! So in the above situation, since I'm below 3000AGL, I ought to switch to the MF/UNICOM and let them know I'm passing overhead?

As for the clear of the zone call, I'll keep that in mind. I've been consciously making an effort to drop the 'any conflicting' lately, so I'll try to remember this one as well! Also I wanted to know, if I do make a call saying I'm clear of the zone, what distance would be considered clear of the zone?

[CpnCrunch]

See:

http://www.tc.gc.ca/eng/civilaviation/r ... htm#602_96
http://www.tc.gc.ca/eng/civilaviation/p ... .htm#4-5-2

As far as I'm aware, the only rules are:

- don't fly lower than 2000 feet above an aerodrome unless you are landing
- if you fly within 5nm and 3000 feet above a MF aerodrome, you must call them on the radio

I think it's permissible to fly 2000 feet above an uncontrolled airport without saying anything, but that's not necessarily a good idea. I prefer to stay at least 4000 feet above an airport if I'm overflying it - that way you generally avoid all traffic landing/departing. If you're only 2000 feet above, you could be in conflict with traffic descending to the circuit. There is more chance of collision if one aircraft is descending, because it's more difficult to see traffic below. It seems that these might have been factors in the recent accident, as one plane was descending to land and the cross-country plane was thought to be flying at 2000 feet or lower (see http://www.calgaryherald.com/news/alber ... story.html).

[CpnCrunch]

Just as I was going to key the push to talk switch. Someone calls in Airplane-registration over X lake inbound...

Good thing I had such a strong heart. I have no idea where that guy really was but fourtunately he was no where near X lake. I looked above, below and in all directions. Gathered myself came around and repositioned to make the call again.

It kind of sucked but I'm sure glad he was just calling in and lying about where he was.

I wouldn't be so sure of that...it could be that he was RIGHT BELOW you or something! I think if someone makes a call saying they are in the exact same position as you, it's time to start crapping yourself.

[Beefitarian]

I somehow managed to keep control of the plane, both my bowels and bladder.

He never matterialized near me, I'm sure I looked everywhere and my eyes where very good at the time. He continued to the airport we both intended to land at and he should have been my traffic at some point to follow. I'm absolutely positive he just said he was at the same spot as me while being where ever just because he was inbound and that was the proceedure, it was too far for the controlers to see with their binoculars. Once closer he was probably basically in the right area and the pesky controllers were none the wiser. Now days you couldn't do that there because they have secondary radar.

That has been my concern with uncontrolled airports. If a person doesn't know where they are, isn't honest about where they are or does not call at all. Hopefully it won't happen but you could be following proceedures and be surprised. On radar in theory if a pilot is wrong about position there's a guy watching a representation of them flickering in their actual position on his screen.

[Colonel Sanders]

I've been consciously making an effort to drop the 'any conflicting'

Thank you.

if I do make a call saying I'm clear of the zone, what distance would be considered clear of the zone?

Generally 5 nm or thereabouts. As I said, it's very low priority.

concern with uncontrolled airports ... does not call at all

Please don't rely on your comm radio as a method of separating aircraft, especially at an uncontrolled airport, where someone may not have a radio, or may be on the wrong freq, have the volume turned down, have the wrong radio selected on the audio panel, may have a faulty ptt/ics configuration that provides carrier but no modulation, etc.

Look outside. Your eyeballs are your primary method of separation. Radio is a very distant second. When you need it the most - when it gets busy - it will fail on you, by design.

As previously pointed out, if the sun is out - the most dangerous time to be at an uncontrolled airport - look on the ground for ONE shadow.

[AirFrame]

Regarding collisions and whether you should pull/push/turn, keep in mind that the collision course is there because neither pilot knows the other one is there. If you see the other plane and have time to realize that a reaction is necessary, you probably have the upper hand. Anything you do will give you a head-start, and hopefully the other pilot will react in another direction.

That being said, Colonel is right, turning just increases your interference with the other aircraft. All you need is to miss it, you don't need drive a freighter through the gap. Gravity is on your side if you push, but a panicky shove on the control column could give you more negative G than your airframe, baggage, or possibly set belts could take.

I've only had two "near" misses, in both cases I had time to detect and react well before the other aircraft saw me. In one case, the other aircraft never did see me or the other three aircraft in the formation, despite our unplanned "starburst" to avoid him.

[Colonel Sanders]

Gravity is on your side if you push, but a panicky shove on the control column could give you more negative G than your airframe, baggage, or possibly set belts could take

True, but a mid-air collision would probably be even harder on your airframe, baggage, etc than a good push