Increasing tech and decreasing separation.

[HJ1an]

I think those are the terms being used. Correct me if I'm wrong.

Now, I think tech improvement is good, but what I do not like about it is that when they talk about use of technology and automation or whatever (I did not really look closely at the subject matter) and decreasing amount of separation between aircraft in the skies.... I am not liking it one bit. The airlines always talk about safety, give numbers, statistics, odds, etc. But they are carrying people who are not trained to evacuate quickly or react to something in an trained manner when things go bad. In the military (and oil & gas industry), they are always talking about risks, and train for them, armed with the knowledge for that last bit of margin for error.

What it seems to me (the aviation industry) is that they are adding a safety net on one hand but taking out another safety net from another. Seems like cutting out the rope from the top so you can add that piece to the bottom to the same piece of rope.

Thoughts?

[jwocky]

1.) If you crash into another plane in 30,000ft altitude, it doesn't matter whether anybody aboard is trained to evacuate fast or slow or not at all.

2.) A plane built lets say in 2000 is aerodynamically often much more sophisticated than one from the 1960s. This includes also engine systems. A 747-100 and she was not the worst bird, has a wake of easily 10 miles and jet wash of about 5. A 747-8 while bigger and stronger, has a wake of 5 and a jet wash of barely 3 miles. Now, in the past, separation was done by get them a big horizontal distance and a relative small vertical one. Which led near big airports to those endless circles where you could see a lot of other planes. Never strategies implement now a continuous descend with relative moderate descend rates and have them circle unless it's after a go around, earlier. With the improvements in radar control, also on the ground, They can avoid to have too many planes with only minimal vertical separation in the same air space. A lot of incidents in the last decade were caused by mistakes with the vertical separation in the old stair step like descends. The modern computer systems can take the situation more dynamically, so continuous descend it is.

Just some thoughts

[HJ1an]

1.) If you crash into another plane in 30,000ft altitude, it doesn't matter whether anybody aboard is trained to evacuate fast or slow or not at all.

Haha, true. I guess I should make it clear that this doesn't have to do with the separation itself - rather the 'marketing' about airline safety. Don't get me wrong, I'm sure it is the safest it has been over the years in terms of engine, plane tech, training, computerized systems, atc, etc. As I've mentioned before, I have a friend in the military and some in oil & gas industries, they take these things extremely seriously. When the subject of airlines came about, it was interesting that they noted it seemed completely 180degrees different approach to things. Also, regular passengers do not know that by moving about in the cabin they are shifting the weight balance around. Move a bunch of them around, and complete that with a flight attendant shouting at them to sit down without giving a reason, and..

that makes me wonder.

2.) A plane built lets say in 2000 is aerodynamically often much more sophisticated than one from the 1960s. This includes also engine systems. A 747-100 and she was not the worst bird, has a wake of easily 10 miles and jet wash of about 5. A 747-8 while bigger and stronger, has a wake of 5 and a jet wash of barely 3 miles. Now, in the past, separation was done by get them a big horizontal distance and a relative small vertical one. Which led near big airports to those endless circles where you could see a lot of other planes. Never strategies implement now a continuous descend with relative moderate descend rates and have them circle unless it's after a go around, earlier. With the improvements in radar control, also on the ground, They can avoid to have too many planes with only minimal vertical separation in the same air space. A lot of incidents in the last decade were caused by mistakes with the vertical separation in the old stair step like descends. The modern computer systems can take the situation more dynamically, so continuous descend it is.

Now I'm very sure that if everything was working correctly, the computerised system can keep everything in track safely, but what if that goes wrong? I imagine this scenario would be that you're left with a bunch of planes in the air and doing the job the old ways, but with far more crowded airspace.

[jwocky]

HJ1an, it's a bit a weird math because it feels a little counter intuitive, but we can do this without big equations:

1.) For each aircraft, we can, while the computerized systems work, take in account that the time from reaching the approach area to being on the ground is shorter because the stair step and waiting phases just fall out.

2.) For all of them, we can dynamically determine where he will be in five minutes, this allows for a smoother model because everybody can just descend through with a constant V/S and courses. Merely on a technical level, you can even predict where flight 123 will be next week at this time. This works only with radar of course to control it.

So, now, under those two assumptions, we imagine the computers die a sudden death. What do we actually have? We have a lot of planes, but we know from each where it is and where it goes. The best thing is, they are already on trajectories that line them up to the runway, so all the critical cases we have to look for immediately, are where? Right, low and near the runway. The reast comes anyway in one by one. So, we need to bring those down and all newcomers to the entry points of the patterns because from there, we know V/S and course, no surprise until someone messes up.

[KL-666]

Two different things are discussed here:

1) Less separation between airways
2) Continuous descent

The latter is common practice already. Pilots go as far as they can on cruise level, and then plunge the plane down as fast as they can at at least v/s 2500. Only near the airport there are some atc instructions. All in all it is already almost sail in direct.

Less separation can be troublesome if automation fails. Especially with the circumstance that pilots are not trained anymore because of a too great trust in automation with the airline manament. Resulting in panic with the pilots when the automation fails. In the current constellation one would like some more separation. But on the other hand we could force airlines to train their pilots not to be afraid of flying the thing. Then less separation becomes viable.

Kind regards, Vincent

[jwocky]

Hi Vincent,

the point I try to make is, the continous descent is of course also controlled by ATCs, just not by airport approach because it starts much earlier. But by doing so, if you look closely at who is at what point in which position, you can see, horizontal separation in the air is also shorter than what it used to be while the vertical one actually appears to be bigger.

The other problem what if technology fails involves also the ATCs. I think, their training needs also something for what if ...

J.

[HJ1an]

The other problem what if technology fails involves also the ATCs. I think, their training needs also something for what if ...
J.

Yes, I believe that has happened before (though, again, being the lazy person that I am, did not look into it thoroughly). Wasn't it few years ago a region in the US had complete ATC-related failure ? (Ohio area I think?)

[legoboyvdlp]

Chicago?

[jwocky]

I remember there was a midair collision like 15 years ago over Switzerland that involved kind of pilot and ATC errors and some kind of too much reliance on technology. I have to look it up.

[IAHM-COL]

https://en.wikipedia.org/wiki/Tenerife_airport_disaster