TSB Report: Mid-Air Collision Saskatchewan May 2012

[Illya Kuryakin]

Fact number 3....the aircraft that will collide with you is not moving. It's maintaing a constant position relative to you. Beware stationary aircraft.
Illya

[white_knuckle_flyer]

Fun fact #1: Aircraft must be at the same altitude to collide.

Yes, but they don't all start out that way. As this accident shows visibility was made more difficult by the fact that a low wing was descending into the path of a high wing ( if I understand correctly ).

I hate to say it WKF, but you're falling into the trap of assuming people are coming at you. You have to be able to think about the problem of traffic in more logical terms. In this instance for a contact at your 2 o'clock position to be on a collision course, if they're flying roughly the same speed, they need to be almost going the same direction as you. Only if they're travelling faster than you are (an unknown since BPF didn't specify) would they be on a head on collision course - and consequently probably at a wrong altitude. Though using a bit of logic, your cirrus cruises at around 140-150 Kts, for someone to be on a collision course with BPF and going roughly an incorrect altitude for their track they almost need to be going twice his speed. If that was the case BPF would have been flying a Cub, cruising in the ~70 knot range. That means that BPF should have been fully in the Cirrus's frontal arc -but then we all know how awesome Cirrus pilots are at looking out the window. For some reason I doubt this was the case. The more likely scenario being that BPF and the Cirrus were cruising at roughly the same speed, or BPF at a slightly overtaking speed.

SSU, I'm going to make the assumption that you are a pretty smart dude, so I am going to read through this post several times more in the vain hope of grasping the physics involved. I do not presently get it.

I was assuming ( wrongly ) that BPF's scenario was more like a "clear and present danger" type, so assumed that the other a/c was on a track that converged more quickly. If both planes were travelling west ( or west-ish) wouldn't you have a whole lot of time to see the other plane, assuming that you weren't flying a heck of a lot faster ?

[pdw]

As this accident shows visibility was made more difficult by the fact that a low wing was descending into the path of a high wing ( if I understand correctly ).

The report doesn't mention the low-wing onto high-wing scenario (haven't found it in there). We had one of those near CYSN, the survivor-C140 pilot saying "just couldn't see him converging from up above".

[jeta1]

I don't usually broadcast much/any on 126.7 or other enroute frequencies...partly through laziness, partly because I just want to enjoy flying, and partly because I doubt the value of transmitting my position to the entire province. I do usually listen out though.

It would be nice to have a PCAS, but I'm to cheap to spend $1000 on it. TCAS is completely out of the question.

I guess I just accept the small possibility of air-air collision as one of the risks of flying and try to keep a good lookout.

Well, I must say I am often as guilty as you are here. Many of us have adopted that silent treatment... and the irony (or is it hypocrisy?...) is that we pretend to listen to those who may broadcast... but we don't broadcast cuz we dont believe in it... really?!?.... So I may have to rethink this. Many times I have been grateful to hear someone make the call and saw how close he was, then felt like an idiot for relying on him only to accomplish the see and avoid thing... Food for thought...

[CpnCrunch]

Well, I must say I am often as guilty as you are here. Many of us have adopted that silent treatment... and the irony (or is it hypocrisy?...) is that we pretend to listen to those who may broadcast... but we don't broadcast cuz we dont believe in it... really?!?.... So I may have to rethink this. Many times I have been grateful to hear someone make the call and saw how close he was, then felt like an idiot for relying on him only to accomplish the see and avoid thing... Food for thought...

Yes, very good point. I should get into the habit of transmitting more frequently.

[Shiny Side Up]

As this accident shows visibility was made more difficult by the fact that a low wing was descending into the path of a high wing ( if I understand correctly ).

The report doesn't mention the low-wing onto high-wing scenario (haven't found it in there). We had one of those near CYSN, the survivor-C140 pilot saying "just couldn't see him converging from up above".

Technically the Lake Amphibian isn't a "high wing" aircraft not to mention that the pilot sits well ahead of the wing, so any conflicts within his frontal arc are even more so and well within view. Especially since the Lake doesn't have an engine in front to obstruct any view. Even though the Piper was descending, the Lake still would have been in its front quarter ahead of its wing all the way until the point of impact. the only kind of airplane that has a "wing" blind spot ahead of the pilot is generally a biplane, or anything where the pilot sits behind the wing.

I was assuming ( wrongly ) that BPF's scenario was more like a "clear and present danger" type, so assumed that the other a/c was on a track that converged more quickly. If both planes were travelling west ( or west-ish) wouldn't you have a whole lot of time to see the other plane, assuming that you weren't flying a heck of a lot faster ?

Ok, something to think about then. Imagine you're driving on the high way. There's a vehicle beside you in the next lane. If he's travelling parallel to you, he will never hit you as long as his path remains parallel to yours. Now, if both vehicles are travelling the same speed, for them to collide with one another they have to be on a converging path. The steeper that converging path, the shorter the time to impact. There also however is a path where once you change the one vehicle's vector, its going to pass behind the other.

Take some toy cars, smash them together on a flat surface, push them at the same velocity. If you release the cars at the same velocity, if a car is at the 2 o'clock position to the other, what angle does it have to be released to impact the other?

Now do the same thing with this accident. Both airplanes are travelling roughly the same speed, on a right angle course. Are there wings in the way of either's line of sight?

It bears some playing around with some toy airplanes and thinking about the matter. Remember, airplanes are always moving forward.

The thing to remember about the high wing/low wing problem is for one to get into the other's blind spot, it must have at some point prior to that been able to see the other. Repeating myself, they didn't, after all, take off in that formation.

and the irony (or is it hypocrisy?...) is that we pretend to listen to those who may broadcast... but we don't broadcast cuz we dont believe in it... really?!?....

Its not the idea that's bad, but rather the execution. I don't believe most pilots are going to hear or listen when I broadcast, and worse, even if they do, they're unlikely to take action to avoid me. Pilots also are terrrible at saying anything important, or are very accurate - with the exception of when they are actually in the traffic pattern - when it might be said that its most critical to get a position fix. I should say that most pilots are excessively long winded that by the time they finish talking, I've already initiated avoidance, so replying to them is moot.

In the case of this accident, was there any reasonable landmarks these guys could have reported at, that the opposing pilot would have instantly recognized and thus taken appropriate action to avoid?

[pdw]

Even though the Piper was descending, the Lake still would have been in its front quarter ahead of its wing all the way until the point of impact.

Right, coming from from the left and above, the Piper should have been more visible to the Lake pilot. What about the much higher speed of the Piper ? I have the Piper calculated descending at 60ft per mile (in honkin tailwind) doing nearly twice the speed of the Lake, which is in left crab at just over a hundred knots. Yeah, so the Piper is descending at nearly 200ft per minute (lets say 3 ft per second) there if steady for the last 25 min/90 miles from Saskatoon; not much descent angle though.

The picture-animation of the tracks is off too, since the Lake should be shown as only half that distance from the Piper's track (not an even distance from the collision point) as illustrated there. Definitely not a 50-50- convergence .. .What would that be ... 65/piper-35/Lake ?

In the strong left crab the Lake pilot looks straight ahead out the right side of the windscreen, while the faster-tracking Piper pilot (left seat) did not see this traffic in time as it came from his right and below (with reference to the Piper's pitch-axis on that descent angle).

EDIT: Also here the Eastbound (still descending) is still 50ft above the Lake as the avoidance reactions initiate; the Piper's pilot evades left as the Lake pilot's right turn reaction also lifts it's left wing (the Piper's drops/reaches into it from above).

[Colonel Sanders]

This is really pretty simple.

Pilots that rely upon the radio to provide
separation, and spend their time looking
inside the cockpit, are vulnerable to mid-air
collisions which usually occur in places with
unnatural concentrations of aircraft, such
as the extended runway centerline at an
airport (very dangerous) or overhead a
VOR or on a GPS track between two published
waypoints such as airports, which pilots like
to fly very very precisely (cough).

Pilots that turn the radio off and

LOOK OUTSIDE

are much less likely to have a mid-air. Especially
if they are aware of their blind spots, and when
they should be extra vigilant. The circuit at an
uncontrolled airport on a sunny weekend is extremely
high risk for collision, with all of the pilots blabbing
on endlessly on the radio about all sorts of useless
stuff.

I like to fly very maneuverable aircraft with canopies
and very high rates of roll, so that if I need to look
around, I just do a quick 1/2 roll upside down to clear
the belly.

It's the one you don't see that will get you. So, see it.

The pilot of this aircraft was a good little straight and
level pilot:

http://www.youtube.com/watch?v=7Jkj63Vez98

[Big Pistons Forever]

It bothers me when a thread turn a into binary discussions. Sometimes the radio gives no useful information or is a distraction so Radio = Bad !

The radio is a tool, saying turn it off is just depriving you of potentially useful information. I think it is better to work at getting better at learning when you should be listening and when you need to tune it out.

You can't fix the guy who takes up airtime with wasted words, but you can fix what you say. So think before you talk; who you are, where you are, and what you are going to do, in the fewest words possible words works best and

Only Morons Say quote conflicting traffic please advise unquote

Finally your tax dollars pay for ATC. Flight following increases flight safety in many ways, Use it !

[trey kule]

"1. Both aircraft arrived at the same point and altitude at the same time, which resulted in a mid-air collision."

The sense I get from the above is sometimes accidents just happen. Blame is not necessary, or detailed analysis of tracks or winds. People do not need to be reminded to look outside. It is part of the VFR big sky theory, and that day it did not work..

From my point of view, I think the statement pretty much said all that had to be said about the accident.

[pdw]

In the case of this accident, was there any reasonable landmarks these guys could have reported at, that the opposing pilot would have instantly recognized and thus taken appropriate action to avoid?

The destination track of the N-bound Lake is 72 degrees to the left of the NE-bound Piper. Descending at 3 feet per second it looks like coming in (from the Lake-pilot's point of view) from almost 90degrees-left, about 10 seconds before the collision point is half-mile off the Lake's left wingtip still (Edit) ~ 80ft above = (10sec x 3ft/descent-rate) plus ~50 ft higher to begin with, ... isn't that from close-to and over the high-wing's tip ? The animation drawing of the tracks makes them appear same-speed however the track-math shows when the Piper is "half-mile" the Lake is only about 1/4 mile from the Piper's track (IMO need to advance the northbound plane about an inch along that dotted line for accurate visual perspective).

The Piper is determined in the Lake's 'west space' at 4k plus 500. It was also shaving previously at the same high speed descent angle thru 6000ft plus 500 and 8000ft plus 500 before that (about 7 minutes apart for each even-crossing at that speed), but there for about 2-3minutes each time being in the 'westerly space'. That might be a good place to find a landmark and give some kind of notice for each duration, seeing that in regular descents near an airport the decent through all altitudes is expected at 500fpm or more as opposed to the 200fpm drawn out for every 3 miles ahead of this accidental collision.

[Shiny Side Up]

It bothers me when a thread turn a into binary discussions. Sometimes the radio gives no useful information or is a distraction so Radio = Bad !

The radio is a tool, saying turn it off is just depriving you of potentially useful information. I think it is better to work at getting better at learning when you should be listening and when you need to tune it out.

The discussion isn't binary, but rather two things that are linked. Pilots are at greater risk of collision because they don't look outside enough, and that's compounded by their lack of ability to make the radio useful. In effect, most pilots might as well turn the radio off and the effect would be the same. I encounter a lot of licensed pilots who can't fly and listen to the radio at the same time. You have to harp on them about paying attention to what they're doing is more imporant than wht someone else is doing. You wonder if you gave them a stick of gum to chew how long it would take before they put it into a spin.

Ultimately the problem is that since many of them don't fly very well in the first place, 100% of their CPU is used up flying straight and level and any extra tasks - be it decipher what someone said on the radio, or talk themselves, makes things downright scary.

This is why I would say if you got a thousand bucks burning a hole in your pocket and want to be a safer flyer, you need to spend it putting fuel through some poor lycoming to make yourself safer, rather than ome gizmo that's going to give you the illusion of safety.

Personally I hate PCASes, since people tend to be mezmerized by them and will continue on a collision course and watch it rather than take evasive action.

You can't fix the guy who takes up airtime with wasted words,

Part of the problem. In iteslf the radio isn't a bad idea, but one of the skills that many pilots need is to be able to ignore someone who starts to blab. If I'm with a student and someone makes one of these calls and you see your student freeze as he listens, I always ask "so what did he say?" Nine times out of ten the answer will be "uhh, I don't know."

Exactly. So why did you forget to fly to listen to it? Don't drop the airplane to fly the radio.

People do not need to be reminded to look outside.

Actually they do. Ad nauseum unfortunately. When I fly with licensed pilots, its the single thing I have to tell them to do. The most often delivered critique of their flying. Don't get distracted by what's inside. Don't be consumed by all those little things.

With that said, I think we'll see more of these kinds of accidents as time goes on. People are gleefully blocking their windows with iPads, iPhones, garmins and everything else that can be mounted in their way to "help" them fly.

[trey kule]

Canada is blessed with a huge amount of ubcontrolled VFR airspace. With the possible exception of the US, more than anywhere in the rest of the world.

It is safer if people flew at the appropriate altidudes, and tried, when possible, even to fly at odd/even +500 when withing 3000 AGL.

Maybe people have to be reminded, but it is necessary to look at maps, engine instruments, fuel guages when flying cross country. I agee that the magic instruments make it interesting to spend more time looking inside, and maybe it is necessary to remind people...I stand corrected if that is such a problem

But as far as this accident goes. It can just be a very unfortunate time when both pilots were distracted. That is what the TSB deispariged remarks indicated to me.

It is sad, but these can happen and I see no reason to apply blame in this instance...there but the grace of God go I.

[Shiny Side Up]

Then you and I disagree. There is blame to be laid here, these things just don't happen due to bad luck. I'd place money on that there were things these pilots could have been doing to prevent this occurence.

You're right you do need to look inside once in a while, but I'd bet heads were down for a long time.

Of note, once one has a fix on where the airport is and inthe descent inbound as it appears the Piper was, heads should be strictly out the window. As one closes in on destination your chances of having an encounter are increasing - and there's no need to be looking at maps anymore. Especially if you're inbound to an uncontrolled place. Second note, when its VFR, it ain't the time to be prentend playing IFR guy.

[trey kule]

What can be learned from blame here. They are all dead.

As to the rest of your claims, I simply dont know, as ...well as the pilots are dead and cannot refute or confirm your claims.

[Shiny Side Up]

They can't learn, others can. No one learns nothing by attributing something that's preventable to bad luck. You don't have to agree with that.

edit: I think the thing that really bothers me about the report is while it condemns the "see and avoid" principle of collision avoidance, it makes no mention of the other systems that were in place: both aircraft were equipped with PCAS systems and transponders. It would seem odd that all of these extra layers would also fail. But then maybe its not so odd, in my experience PCAS units aren't the most reliable things, and this sort of thing happening seems to be really damning of their utility. Combine that with the problem I find with most users of such systems are ill prepared to actually interpret and act on the information they provide. In essence, the lesson here should also be pointed out that they also are not a sufficient means of traffic avoidance. Again drawing from experience, one of the bad things pilots do is put a lot of faith in such things.

If we are to learn more from this, two other things also jump out at me.

1) Pilot vision
2) Portable devices in the cockpit.

The first item is something to consider. Another problem I frequently encounter is that many pilots who medicals stipulate that they should be wearing glasses frequently don't. Anyone reading this who's under the illusion that they see well enough without them should take note. I got a bin of glasses lost by pilots who have frequented the aircraft - left behind in said planes to give you an idea of how frequently they aren't used, and once a co-worker had to be made to wear his on pain of dismissal. Reason for not wearing them: They weren't cool. Was ridiculous watching him squint at stuff all the time.

The second item I've already mentioned, something more common these days is to mount these things all over the place including in some very vision obstructing places. Of note the ZAON PCAS that the Piper was equipped with is usually placed on the dash right where the pilot needed to be able to look to see the other airplane....

[trey kule]

I am just not convinced this was preventable despite the Monday morning quarterbacking.
Anyway,we shall leave it at that

[pdw]

An early morning departure into the rising sun is also at issue; the passengers waking for arrival can be a distraction, the bright rays above the horizon / just above the cowling where that hard-to-see (tiny) traffic comes gradually creeping into view from far below. With sunglasses is hard enough for spotting traffic that is creeping into view right beside where the sun is also centered, besides any mounted gadgets. Again, .. .will be just as hard to avoid the similar situation in future if anything missed on understanding the full sequence presented by the report information.

I see it better now. The much faster descending aircraft is against the sun as the traffic (flying level) arrives into into conflict very fast out of obscurity from below. From the vantage point of the low-wing pilot / eye-level it must have been "stationary" there, right near the bottom of the right side vision field ... finally having it visual down near the edge of the right cowling/wing area as it enlarges there; likely only around a 'ten second'/1/2-mile separation.

[RatherBeFlying]

Remember that PCAS only picks up transponder replies. If you are out of radar coverage, PCAS won't see anything.

We glider folks are installing PowerFlarm, $1,800 US, which incorporates a PCAS function as well as its own active detection between PF units.

On my last flight I had two non-directional transponder alerts and spotted one. The other was a thousand below and less a worry.

Having had two close encounters with turboprop airliners, I really like the ADS-B detection which picks them up from far away.

Yep, it takes some learning to understand what's on the itty-bitty screen. In my case the Flarm information is repeated on my vario and flight computer. If I'm unsure of where the other guy is, I promptly go the other way or change altitude.