
U-2 spy plane caused widespread shutdown of U.S. flights - happyscrappy
http://www.reuters.com/article/2014/05/03/us-usa-airport-losangeles-idUSBREA420AF20140503
======
Lazare
Kind of a misleading headline.

U-2s have been flying over Southern California at over 60k feet for 50 years
(that is, after all, where they're based), and there are other more modern
planes that also routinely fly at that altitude.

If we're pointing fingers, the new ERAM system that was just installed (in
December, I believe) in the LA ATC is a more likely culprit, although even
that isn't likely the whole story; this can't be the first high flying plane
in the last 6 months. So, more likely an edge case that took 6 months to crop
up, or maybe a new bug caused by a recent patch. But as the article notes, the
FAA isn't talking, so we still don't know.

"U-2 spy plane caused widespread shutdown of U.S. flights" is a cool headline,
but an accurate one would be "We still aren't sure why new computer system
caused widespread shutdown of U.S. flights".

~~~
twistedpair
ERAM is a quite troubled project. Just read the Inspector General's report.
Sadly, many decades after the Mythical Man Month and much learned about
software project management, we continue to see such efforts flounder.

[http://www.oig.dot.gov/sites/dot/files/ERAM%20Final%20Report...](http://www.oig.dot.gov/sites/dot/files/ERAM%20Final%20Report%5E9-13-12.pdf)

~~~
RachelF
The ERAM report is sad. I guess if Uncle Sam pays when you oveerrun your
budget, it is a bonus.

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dotBen
If a U2 can set its own altitude on the transponder the other possibility here
is that the flight operator set it to an incorrect altitude that appeared it
was flying in the same airspace as commercial planes but not within standard
corridors.

This would generate significant number of collision warnings, given how busy
LA regional airspace is, and that in turn might have demonstrated a limit to
the number of simultaneous collion events this new ATX system can handle.

~~~
crystalmace
That sounds plausible

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spingsprong
I wonder if it's because can fly higher than 65,535ft.

~~~
Retric
"the maximum altitude transmitted by a U-2 transponder is FL600: even if the
aircraft is flying well above it, the Dragon Lady’s mode C will show no higher
than 60,000 feet." Which might be the issue if there was an off by one error
in the code.

~~~
abruzzi
I want to know why a spy plane has a transponder. Can it be turned off when
flying over Cuba?

~~~
mikeash
Because it's a legal requirement to fly in a lot of airspace, to ensure that
you show up on radar, and it's far easier to install one than to wrangle an
exception. Of course it can be turned off, just like any other piece of
equipment.

~~~
twistedpair
Even the B-2 bomber had a retractable radar reflector to defeat it's stealth.
When flying in civilian airspace the reflector would extend so ATC could track
the plane. Standard stuff to prevent collisions.

~~~
mikeash
Why would they have a retractable reflector rather than simply using a
standard radar transponder? Sounds like BS.

~~~
twistedpair
To start with, a reflector is passive, so it can't fail like a transponder.
Failing is a problem when flying an intentionally very hard to see/detect
airframe in dense civilian airways. Transponders only provide a secondary
radar hit, while many (older) systems are looking for a primary hit to locate
aircraft, which a reflector would do.

Before calling BS you could just Google it too. ;) For example, here is a nice
explanation of the F117's reflector.
[http://en.wikipedia.org/wiki/Lockheed_F-117_Nighthawk](http://en.wikipedia.org/wiki/Lockheed_F-117_Nighthawk)

~~~
mikeash
Any system that relies on a primary hit is going to have trouble. Something as
simple as a composite glider is not going to show up well[1]. I'm not aware of
any ATC system that relies on primary returns.

As for Googling it, that's an interesting picture. It's not retractable, but I
suppose the point is made. Perhaps the B-2's is retractable. I did Google it
this time and found nothing but some random airliners.net forum posts, not
exactly reliable.

[1] [http://www.dg-flugzeugbau.de/radar-reflector-e.html](http://www.dg-
flugzeugbau.de/radar-reflector-e.html)

------
mikecb
More details, and more expert analysis, available at the Aviationist[1].

[1] [http://theaviationist.com/2014/05/03/u-2-freezes-lax-
radar/](http://theaviationist.com/2014/05/03/u-2-freezes-lax-radar/)

~~~
digitalmarks
Given the number of new/identified aircraft spotted in the last few months
there's a strong possibility this was simply not a U-2.

[http://theaviationist.com/2014/04/23/two-different-black-
pro...](http://theaviationist.com/2014/04/23/two-different-black-projects/)

~~~
mikecb
While that is a possibility, there's nothing to suggest it is stronger than
the reported id of the plane, so I'll stick with U-2.

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hudibras
Quick sea story. To avoid interfering with launch and recovery operations,
there is a 3-mile radius cylinder (the "stack") around U.S. aircraft carriers
that military aircraft have to get permission from the tower to enter. One
time, while operating off the coast of Pakistan, a U-2 called us up and asked
permission to enter the stack, "at Angels Sixty."

Or in other words, 10 miles directly above all the other aircraft. They got
permission.

~~~
gone35
Nice. That story reminded me of the good ol' SR-71 speed check one [1]. I'm
sure I'm not alone in this among my fellow HN 'Aviation Week' enthusiasts:

[1]
[https://groups.google.com/forum/m/#!topic/rec.aviation.stori...](https://groups.google.com/forum/m/#!topic/rec.aviation.stories/ueI6JKeEomo)

------
troymc
Note that the failure was in a new-ish, recently-deployed air traffic control
system named ERAM (En Route Automation Modernization), and its backup system:

[https://en.wikipedia.org/wiki/ERAM](https://en.wikipedia.org/wiki/ERAM)

~~~
astrodust
Do they fuzz systems like this, or do they just ship it as soon as the test
suite passes?

It seems like there's a whole world of hurt waiting to arrive if people can
start to inject data into these systems.

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jkaljundi
So, what variable max values were not accounted for and tested in the
software?

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sschueller
Could it be that the U2 has sending an ADS-B signal with incorrect altitude to
hide its actual location?

I would think that would be a feature of such a plane and it may have been
activated by mistake.

~~~
jjwiseman
I captured ADS-B packets from a U-2 in the LAX area (using an RTL-SDR dongle)
on 2013-06-18. If you want to see them for yourself, the decoded packets (hex)
are at
[https://dl.dropboxusercontent.com/u/7443278/Mode%20S%20Captu...](https://dl.dropboxusercontent.com/u/7443278/Mode%20S%20Captures/mode-
s-capture-2013-06-18.raw) (along with other aircraft).

The U-2 I picked up is ICAO ae094b, registration 68-10336[1]. You can decode
the packet information using dump1090[2]:

    
    
      ./dump1090 --net-only > out.txt
    

Then in another terminal:

    
    
      cat mode-s-capture-2013-06-18.raw | nc localhost 30001
    

Then in out.text, look for "ae094b". You'll see packets like

    
    
      *0206042b1365a5;
      CRC: ae094b (ok)
      DF 0: Short Air-Air Surveillance.
        VS             : Airborne
        CC             : 1
        SL             : 0
        Altitude       : 60000 feet
        ICAO Address   : ae094b
    
    

[1]
[http://www.airliners.net/search/photo.search?regsearch=68-10...](http://www.airliners.net/search/photo.search?regsearch=68-10336)
[2]
[https://github.com/MalcolmRobb/dump1090](https://github.com/MalcolmRobb/dump1090)

------
scoot
Altitude (appears) out of bounds, therefore we assume it is at an unknown
altitude, so could be at any altitude, therefore any plane on a collision
bearing regardless of altitude must be diverted.

------
notduncansmith
Wonder why nobody posted this on Sunday Bloody Sunday. Still, today is a
Beautiful Day for a drone story.

------
fleitz
Protip: don't fly above 65535 ft. Or book a flight with ' ; -- drop tables:
air

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nfoz
She moves in mysterious ways.

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thrill
I sincerely doubt the accuracy of this article. The U-2 has been around for 50
years and only now has an ATC system been "overwhelmed" by it?

~~~
lallysingh
Is the system at LAX new?

~~~
kevinchen
Yes, that's what it says in the article.

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kator
The idea that a flight routing system wouldn't take into consideration the
altitude of the planes involved seems a bit like a movie rather then reality.

Now if they said the problem was the U-2 was moving so quickly that the
calculations of all the planes in the air ground the systems to a halt maybe
that would make sense.

Something smells very Hollywood here with this story.

~~~
mikecb
U-2s don't fly very fast (~500mph). For comparison, a 747 cruises at about
570mph.

