Musk-Kessler syndrome

"Some" came within a half-mile, which still has a small chance of collision.

Musk should send up a big kevlar net to catch that debris.

But there are lots of repeated opportunities. Lots.

A Kessler cascade would grind up everything in a wide belt. The night sky would be spectacular.

Close encounters are not collisions and do not cause debris and/or Kessler syndrome.

When two airplanes come within a few miles of another, it is considered a "close encounter" and investigations are made to find how this could happen.

Yet, on the road we do not consider anything more than 2 feet a "close encounter" and collisions still are relatively infrequent.

Not in gliders; it is SOP taught before you can go solo :)

Bill's right to start from the PoV that the Daily Wail has disreputable reporting practices that are solely intended to sell more papers.

Nonetheless I'm very uneasy about the proliferation of constellations of small satellites for several reasons, including

minimum vertical separation 1000feet, minimum horizontal separation at same altitude 5nm

Don't count on it. There are still numerous occasions where these limits are breached, both in commercial and private flying.

I was flying into Fullerton Field near Los Angeles. I was on Flight Following which is supposed to warn you about nearby traffic.

I looked up and saw a Mooney at the same level and opposite track, heading for a direct bullseye for my A/C. Under these conditions you have no idea what the other pilot may do. He may climb, dive, or do nothing. I banked 30 degrees and pulled up hard. He sailed right into the space I had just left.

Since then, technology has advanced to the point you can have your own traffic alert to warn you. It is called ADS-B:

Automatic Dependent Surveillance–Broadcast From Wikipedia, the free encyclopedia

Automatic Dependent Surveillance–Broadcast (ADS–B) is a surveillance technology in which an aircraft determines its position via satellite navigation or other sensors and periodically broadcasts it, enabling it to be tracked. The information can be received by air traffic control ground stations as a replacement for secondary surveillance radar, as no interrogation signal is needed from the ground. It can also be received by other aircraft to provide situational awareness and allow self-separation. ADS–B is "automatic" in that it requires no pilot or external input. It is "dependent" in that it depends on data from the aircraft's navigation system.

Also see

Flightradar24 From Wikipedia, the free encyclopedia

Flightradar24 is a Swedish internet-based service that shows real-time commercial aircraft flight tracking information on a map. It includes flight tracking information, origins and destinations, flight numbers, aircraft types, positions, altitudes, headings and speeds. It can also show time-lapse replays of previous tracks and historical flight data by airline, aircraft, aircraft type, area or airport. It aggregates data from multiple sources but, outside of the United States, mostly from crowdsourced information gathering by volunteers with ADS-B receivers, and from satellite-based ADS-B receivers.

So the primary rule as always is See And Avoid.

Even so, there are still a number of midair collisions each year. The classic problem is when you are flying a low-wing aircraft such as a Piper, and the other pilot is in a high-wing aircraft such as a Cessna. The wings block each pilot's view so they cannot see oncoming traffic. So keep your will and life insurance up to date.

On a sunny day (Fri, 20 Aug 2021 10:45:19 -0000 (UTC)) it happened Steve Wilson snipped-for-privacy@not.com wrote in <XnsAD8C44B58A94Fidtokenpost@144.76.35.252>:

I already told him to get the dump1090 program and Linux to see air traffic over his head... I am running it here 24/7 as one of many inputs to my xgpspc navigation program.

OTOH not all mil planes transmit data it seems.

fredag den 20. august 2021 kl. 12.45.25 UTC+2 skrev Steve Wilson:

The big boys have TCAS. Read some paper long ago that in a heavy traffic area, I think it was Boston, there was a serious TCAS alarm (where the system tells the pilots what to do) every ~120 flight hours, but more generally was something pilots experienced every few years

but that doesn't help much against small planes,

Are the numbers 1500 and 12,000 made up?

Is mentioning a Kessler cascade a "disreputable reporting practice" ? Did the Mail invent all this to sell papers?

The Mail linked to Space.com, so that site must be equally bogus.

Or when the air traffic controller gives conflicting commands:

On the night of 1 July 2002, Bashkirian Airlines Flight 2937, a Tupolev Tu-

The official investigation by the German Federal Bureau of Aircraft Accident Investigation (German: Bundesstelle für Flugunfalluntersuchung), (BFU), identified as the main cause of the collision a number of shortcomings on the part of the Swiss air traffic controller (ATC) service in charge of the sector involved, as well as ambiguities in the procedures regarding the use of the traffic collision avoidance system (TCAS) on- board.[5]:110[BFU 1]

A year and a half after the crash, on 24 February 2004, Peter Nielsen, the ATC on duty at the time of the collision, was murdered in an apparent act of revenge by Vitaly Kaloyev, a Russian citizen whose wife and two children had been killed in the accident.[6][7][8][9]

fredag den 20. august 2021 kl. 17.59.13 UTC+2 skrev Steve Wilson:

The Russian pilots had never had any TCAS training in a simulator and it was not clear enough that they should never do the opposite of the TCAS resolution advisory

Obeying the controller's command is deeply embedded in the pilot. He responds to hundreds of commands every day, and perhaps encounters a TCAS command rarely or never. After all, the job of the controller is to keep planes separated, so they should never need TCAS.

I have to admit I would be severely tested If I ever found myself in a situation where the controller gave commands that conflicted with a TCAS warning. What if the TCAS was broken?

At least with the conroller, you know he can see you on his radar, and even has automatic alerts of airplanes coming too close to each other. You know the system works, your see it every minute you are in the air, but you are not so sure of TCAS.

I believe modern flight management systems even have ADS-B interfaces so the pilot can see conflicting traffic in his own airplane. But I don't think it is available in Boeing and Airbus commercial aircraft.

It is the same with AOA (Angle of Attack) displays. The information is available, but it is never used. It would have been invaluable in many crashes, such as Air France 447:

fredag den 20. august 2021 kl. 18.36.53 UTC+2 skrev Steve Wilson:

that's why they need to practice it in the simulator

probably more likely that the controller is wrong, he's far away looking at many planes

afaiu TCAS have several levels of warnings of distance and and approach speed before the ultimate command to climb or descend

"aviation author Captain Bill Palmer has expressed doubts that an AoA indicator would have saved AF447, writing: "as the PF [pilot flying] seemed to be ignoring the more fundamental indicators of pitch and attitude, along with numerous stall warnings, one could question what difference a rarely used AoA gauge would have made""

That is completely false. You would use it all the time, especially during landings or when banking hard. Military fighters use it for landing and avoiding stall-spin accidents. These are one of the most common fatal accidents in general aviation.

The problem with AF447 is the copilot was using his sidestick and following his training to point the nose up. When the command pilot returned from using the bathroom, he could not see the position of the copilot's sidestick, and had no indication of the attitude of the aircraft. If he had AOA, he would have seen instantly what the problem was and been able to correct it immediately.

fredag den 20. august 2021 kl. 19.05.03 UTC+2 skrev Steve Wilson:

I think he point was not that it wouldn't generally be useful, but that in this case the PF did so many other things wrong so he doubt that would have helped in this case

not if the copilot kept overriding his input

The only thing he did wrong was to hold the A/C in a stall. Without AOA, there was no way to tell what the plane was doing. The indications were so wierd that the command pilot was too confused to see what was happening.

This is another case of Airbus design flaws. The plane switched itself into Alternate Mode, which has completely different characteristics than normal mode. It is stupid to change the flight characteristics in an emergency situation, let alone any other time in normal flight. Boeing does not do idiotic things like this, but they do have their own flaws.

No, you simply say "My Airplane" and the copilot must relinquish control. Or you can turn control over to the copilot in a similar fashion.

I was flying at 25,000 feet at midnight over the Sierras when there was a loud bang and the engine quit. My flight instructor said "What did you do?". I said "Nothing. It's your plane, you fly it."

I grabbed the flight manual and found the section on engine failures. It read "Turn the Auxilary Fuel Pump On High." I reached over and did so.

Then I read further down. It said "If you are above 15,000 feet, turn the fuel pump on low." It was too late. I had flooded the engine, and we woulr never get it back. Meawhile we were over the Sierra Mountains where it is impossible to land safely and we would probably end up in a ball of flaming aluminum.

I went to the navigation computer and pressed the emergency button. This told it to list all the airports within a certain radius. I forget how much, but it said the only nearby airport was Reno, Nevada, and we happened to be directly above it. My instructor called the tower and declared an emergency.

The tower replied "6 Zero Victor, You are cleared to land, runway of your choice." Then the tower kicked all the other incoming aircraft into holding patterns while we circled down through the clouds and landed. This did not please them.

It turns out the regular fuel pump had a nitrided shaft with very close clearances. The nitriding flaked off and the shaft had seized. The loud bang was when a narrow section of the shaft broke as it was designed to do when the shaft seized, thus saving the engine from debris as the pump gear was stripped. This would have destroyed the engine.

The landing was successful. We left the airplane in the middle of the runway since we had no power to taxi. When we got out of the plane, our legs were so weak and shaking that we almost collapsed on the tarmac.

We were very lucky.

lørdag den 21. august 2021 kl. 00.53.52 UTC+2 skrev Steve Wilson:

he obviously didn't relinquish control, in the CVR transcript there are numerous "dual input" warnings

Hmm. In a car, cranking it for a bit with the throttle wide open fixes a flooded engine. Isn't there some similar method with aero engines?

Sounds fairly harrowing, for sure.

Cheers

Phil Hobbs

Curious. That would indicate the command pilot recognized the situation and was trying to correct it. That contradicts what I have read on the accident.

Obviously the copilot was frozen in fear, and the command pilot was not vigorous enough. Perhaps a smack across the chops might have helped.

There are other more extreme remedies.