Published traffic pattern altitudes should be eliminated
 

Hi Mark,
The publication of standardized traffic pattern altitudes should be eliminated. The authorities are setting us up for a collision. Random altitudes should be encouraged.
I understand the difficulty in accepting new procedures such as eliminating published standard traffic pattern altitudes but suggesting all aircraft arriving at an airport all operate at the same altitude sounds insane to me.
I have been applying randomness to my aircraft's track and altitude for more than 50 years thanks to having a thoughtful flight instructor introduce me to it all those years ago.
Why do not more pilots support my view? Is it wrong?
Thanks!
Dick

Well hell, I don't know.

In the 40 plus years of my flying I never had to make a radical change of heading or altitude to avoid a midair. Now there were numerous times that I had to take mild evasive action to avoid a possible midair. Now on those occasions if I had not taken those mild evasive actions would we have collided, I really don't know.

On two occasions I would have been placed into a position of colliding with another aircraft due to Air Traffic Controller mistakes, one on landing if I had followed the ATC's instructions I would have been turned right into the path of a C-130 and on the other occasion if had followed the ATC's instructions I would have flown right into a flight of four F-16. Fortunately I'm one of those pilots that look out the windshield before I make a turn.

That being said, I did have two very close friends kill each other in a midair, however, they were ferrying two aircraft, started fooling around with each other and managed to collide.

I never really forgave them for that, they were old and experienced enough to know better.


Oops, I take that back. I damn near nailed a hang glider going into Aspen (ASE) one day. If I had not seen him when I did, I would have ran right into him. Forgot about that one.

I was in Bagram airspace the other day, and we had a handful of TA's in a period of 5 minutes way before ATC pointed them out to us. TCAS is the best invention in the last 30 years. When you talk about the big ole goofy world, there is a lot of space, but the planes have to land sometime, usualy at an airport! They all get funneled to one point at one time in the same airspace. Hell yea, mid airs are something to be concerned with.

F-4 vs. F4..head to head at low level, missed by a wing span...didn't even know it had happened until the debrief......wonder how many others I missed?

JP, open FIR teaching basic aeros, look up before pulling up - we did..still succeded in getting very, very, close to someone at the top of the loop.

JP again, open FIR, low level nav...well we missed otherwise I wouldn't be typing this.....

Fly the grown up stuff now, with TCAS, thankfully, because my last "event" was a 180 X 0 with a Continental aircraft just North of Baghdad, on the airway, because of an ATC stuff on on the levels..

So mid-airs are too rare to worry about? ....my ar**.

My instrument instructor, the best CFI I ever flew with, died in a midair over Tehachapi California. They hit beak-to-beak. They were both VFR, in excellent weather.

He was in a C-180 and it came apart. Here's the Baron that hit him:

http://ships.bouwman.com/Planes/baronmidair.jpg

http://www.avweb.com/newspics/baronmidair3.jpg

I recall the FAA doing a study circa 20/30 years ago about the midair collision risk and discovered that the highest risk was within ten miles of an airport with mixed IFR/VFR traffic.

Within the open FIR (Class G) airspace there is a certain amount of random separation. You might get close to another a/c but chances are you'll avoid it rather than hitting it so long as you take reasonable precautions, ie don't fly in IMC without radar service (although that's not foolproof).

Closest one I had was in early 1980s when I was f/o on B737-200 going to Alicante from UK. We'd just crossed Maella at FL330 southbound and were turning onto the new track and I had just passed a full position report (required in those days) and was recording the fuel figures for a fuel check when the Captain uttered an expletive and we were pulling up in a 45 deg turn to the left. As I looked out I saw an opposite direction a/c (can't recall type) go flashing underneath with no more than 100 ft vertical separation.
The lookout and correct action by the Captain saved our lives. Turned out it was an ATC error - the other a/c had been cleared through our level on another frequency.

Ok now we have TCAS etc but the midair collision risk is very real and anybody who thinks it isn't is living in cloud cuckoo land!

When I did my commercial training at Hamble in 1969 two students died after their two aircraft collided in the circuit which was right hand. One was turning crosswind and the other was joining. I found this event a sobering experience.

Worst Mid air collision in history Part 1- Flight Kazakhstan 1907- Flight Saudi Arabian 763

Salute!

"big sky theory", you bet. BUT................

We ain't all flying random flight paths to random places from other random places.

So with airways and approach procedures and busy airports, then the "big sky" theory does not apply. We have hundreds of planes trying to follow the "line" in the sky or all heading for the same place. Worse, we have all the automation which ought to allow better lookout, but for some reason it doesn't show in the stats.

The air traffic control in the early days of Viet Nam were basically advisory calls by the GCI sites ( CRC's). We took off and ANNOUNCED our flight path and altitude, and pressed thru clouds or haze or smoke, etc. Few, if any, mid-airs. And we had plenty of traffic in a small area. The CRC's would advise of potential conflicts, but that's all. No airways, and only "lines in the sky" were for approach patterns, and then we were under great RAPCON folks' care.

While it is true that the sky is big, we must subtract all the "wasted" space. We must realize we have dozens of planes trying to fly the same lines. The general aviation and the fighter mid-airs usually happen when folks ain't clearing with their eyeballs or radar, or when they violate the rules of engagement ( see GF's post). The commercial aviation close calls seem to be related to two planes trying to get to the same place at the same time, and/or lack of attention by ground radar controllers. I am impressed by TCAS, especially the replay of a close call. Great learning tool, and also great for preventing an actual collision.

So the "big sky" is not a player for most of the commercial pilots, wouldn't you agree?

Gums sends...

a rememberance of the big sky theory.

that was what was used in the USA ...then there was a collision over the Grand Canyon...before I was born mind you.

then things changed..

besides pulling our legs, why did you post the original post?

As we are all flying the magenta line, guided by GPS, our flightpaths in an airway are matching precise, not like in the old days where we relied on different navigation methods, and we stayed somewhere within the 10 NM radius. Opposite traffic in an airway nowadays WILL hit you unless one takes evasive action. Luckyly we have TCAS. Yes, the sky is big, but we all tend to fly in the same narrow spaces between waypoints, and exactly above, behind and below each other.

"As we are all flying the magenta line, guided by GPS, our flightpaths in an airway are matching precise, not like in the old days...."

Don't they still train pilots to fly slightly off-set? Excuse my ignorance, the biggest I ever flew were navajos and king airs under part 135 - so during cruise, I was above most GA aircraft and below the heavy metal. However, I WAS trained to fly slightly off the center line of the airway.

rsiano asks a good question. It is by no means a joke.

Here is a paper by Robert Patlovany which was published in the premier journal in the field of risk analysis, on exactly this question. He comes to the conclusion, as rsiano asked, that random is better than (some of) the current regimentation.

I have looked rather hard at mid-air collisions between aircraft on scheduled commercial operations, before and after TCAS. Keeping in mind the growth of traffic, and that there have been two collisions in cruise between TCAS-equipped aircraft, it is not at all clear from the statistics that TCAS is a win. I tried to discuss this on this forum some three years ago, which was mostly unproductive, so I took it elsewhere (the IEEE Risk Factor blog).

The posters who suggest that some of the conventions lead to convergence are following a line of thought which led Patlovany to his study. It converts into a good argument for free flight. However, free flight requires TCAS, and that is another story, for TCAS still suffers from technical and algorithmic anomalies (although the latest RTCA version is free of the one I was most concerned about).

PBL

PBL

Anybody here remember Dave Gunson, the Air Traffic Controller from Birmingham who used to give an afterdinner talk that was widely circulated on tape (that's a clue as to how long ago!). ( Including details about the French Air Traffic Controllers strike....and how it affected his operations)

He raised exactly the point about ATC funneling traffic into small spaces.

Mid air collisions too rare to worry about. Who said this? Unless the answer is one of the Wright Brothers......its a big sky only when you are alone in it!

GGR

Ex ATC

rsiano,

I think this thread should be closed as your theory is a joke!!:ugh:

However, while flying a mate's aircraft in the UK on a direct from a farm strip to Leicester [thus a totally random track], I alarmed him by doing a quick diversion to the right as we had a dead-on closure with a C150. He'd asked me to not fly any level rule so I stuck to 2,750'AMSL. This guy was going to come straight through the front windscreen!!:uhoh:

So, you can stick the "Big Sky" theory and just count luck if you've been flying for a long time and never had a problem. Incidentally, when almost abeam our [now laterally displaced] position, this guy saw us and made an instinctive bank away until he realised it was too late anyway!

Now, would you like the GPS induced head-to-head stuff on airways with ATC error over a 40-year airline career?

Wake up to yourself!:=

G'day ;)

Aahh, that's reminded me of another - B757 vs para glider north of Venice.
Para pilot must have crapped himself since he'd easily see (and possibly hear) us before we noticed and took avoiding action :ooh:

mary meagher,
I have 'What goes up might come down.' by David Gunson which is, I guess, the piece to which you refer.

Had a near miss yesterday out of a small airfield in Germany. Copilot saw a Cessna flashing by no 100m away. We were leaving the traffic pattern 500ft above pattern altitude to keep clear of incoming traffic. It wasn't of great help in the aftermath...

Yes and no...while there is 30,000,000 mi3 available aircraft (I mean the usual commercial stuff) fly along airways. The more accurate location and navigation systems become the more precisely flown a given routing is. At the end of the day, while we might have 30,000,000 mi3 available we restrict ourselves to very precisely defined lines through that 3 dimensional space.

This 30,000,000 figure also does not take into consideration wake-separation, aircraft sizes nor the congestion around airports.

fc101
E145 driver

Relative Risk
 

Midairs are down the list when it comes to accidents.

Many captains fly a 1 mile right offset on airways and NATs. I did.

At least you don't offset 1 mi LEFT when in UK, Oz, NZ, or Japanese airspace. ;)