Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Aviation Mishaps and Issues - Current and Ongoing (Investigations)

  1. Dec 16, 2009 #1
    I've noticed that several of us, if not many of us, are flyers, including one of the admins.

    I'd like to propose a thread to discuss current aviation mishaps, or at least ones which recently occurred. It's not a place to dig up old accidents, other than as they're related to current/recent ones.

    The purpose is to provide clear rationale for what may have happened while debunking the nonsense so commonly heard throughout the media, particularly when it's breaking news. Generally, the media does a better job further on down the road, after knowledgeable people of credible reputation begin speaking up to straighten out the facts and issues.

    This thread is also for aviation issues in general, such as the use of various technologies such as TCAS, ADS-B, and LAAS which provide either updated safety capabilities or extend safety-related technologies to areas where they did not exist before.
    Last edited: Dec 16, 2009
  2. jcsd
  3. Dec 16, 2009 #2
    So any mishap around that we can have a look at?

    I've got about
    50 hrs Allouette III
    30 hrs Bolkov Bo105C
    25 hrs Piper Cub
    60 hrs Beech Bonanza 2 versions
    260 hrs CT-114 Tutor
    1800 hrs F-5
    500 hrs F-16
  4. Dec 16, 2009 #3
    Hi, Andre - here's one:

    I heard http://news.yahoo.com/video/us-15749625/planes-nearly-collide-midair-16977012;_ylt=AlOYWBo7DcNCUSTLKvEmlViz174F;_ylu=X3oDMTE0amhjbW5jBHBvcwMxBHNlYwNNd1ZpZGVvSHViQnJvd3NlBHNsawN0aXRsZQ--#video=17171509" [Broken]this morning on Yahoo!'s repeat broadcast of a Fox News spot.

    Essentially, two airliners were vectored to within 200 feet vertical and 1.7 miles horizontal of one another. Their http://en.wikipedia.org/wiki/TCAS" [Broken]systems went off, and the pilots took the corrective action to avoid a collision.

    In the newscast, the following items were mentioned:

    1. "Their radar blips become one." I can certainly see this happening, as most http://en.wikipedia.org/wiki/Terminal_Control_Center" [Broken]radars are designed to cover airspace within a 30-50 mile radius of an airport, and the area covered by radar blips cover about a mile on the scope. Thus, if two aircraft are less than two miles apart, portions of their depictions will overlap.

    2. "They were within a blink of an eye of colliding." This is sheer nonsense, as one was vectored to line up behind the other. This is usually 20 or 30 degrees off the heading of the other, but never more than 90. At 30 degrees and with a 40 knot difference in airspeeds, , we're looking at at least 47 seconds until collision would have occurred. With a 90 degree heading difference, at 1.7 miles it still would have taken just over 30 seconds for collision to take place.

    That's not a "blink of an eye." That's a micro-nap, and more than enough time for the pilots to respond to their TCAS inputs. In fact, that's what TCAS was designed to do. It gives both aircraft non-conflicting collision avoidance instructions with enough advance warning to avoid a collision.

    3. Fox news also said the FAA was calling it an "operations error," meaning that it was due to human error on the part of an air traffic controller. This is probably the case, but the next statement caught my eye:

    4. "It is nearly impossible to eliminate all errors that are due to human factors." Yes, that is certainly true. What I take exception to is the lack of the fact that the system is currently quadruply-redundant, and consisted of the air traffic controller, TCAS, the pilot, and the copilot. Obviously, if they were in IFR conditions, the last two parts of that system would largely be out of the loop, but when I fly, and we're in the weather, I ensure that at least one of us is keeping an eye on the TCAS display, as it depicts traffic much further out than before they become a problem. Any potentially hazardous situation situation that went uncorrected would result in a query to ATC.

    I consider TCAS to be a very good application of technology. However, it's a precursor to http://en.wikipedia.org/wiki/Automatic_dependent_surveillance-broadcast" [Broken].
    Last edited by a moderator: May 4, 2017
  5. Dec 17, 2009 #4
    Have any of you pilots read Crichton's Airframe? I am wondering if he was mostly accurate (ignoring the thrillerized aspects)?

    If you are unfamiliar with the book it is about the investigation of an airliner crash. The style and story are typical Crichton so anyone who is particularly into aviation may not enjoy the book due to the contrived plot line ("you have one week to figure out what happened to this plane!").
  6. Dec 28, 2009 #5
    I have it, but I've not yet read it. I did get about half way through the first chapter, but found it a bit more stilted than most of his novels. I'm sure I'll pick it up again in a lull.

    It's been my experience that Chrichton springboards off known science very accurately, and does a very good job of remaining within the realm of the plausible (except for Timeline - that may be theoretically possible, but it's not very plausible, at least not with technology found in the next couple hundred years).
  7. Dec 28, 2009 #6
    Sorry about overlooking this thread.

    I agree roughly with your analysis, especially the sensationalism. A few additions.

    Sure the eyeballs mk-I in the cockpit should be the most important collision avoidance gadget. However human eyes are mostly triggered on movement and if two aircraft are on collision courses, straight and level, there is no relative motion. The other will stay in the same position all the way hampering detection. Curiously enough detection is easier in hazy weather than in perfect unlimited visitbilty. In the former aircraft still stick out as flies on the ceiling against a hazy background while in perfect visibility there may be too much clutter to have the other aircraft stand out against.

    But I seldom see commercial crews scanning the horizon for bogeys.
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Similar Threads - Aviation Mishaps Issues Date
Leap year issues... Dec 20, 2017
Issues with the Downsizing Movie Dec 20, 2017
Product name issues Nov 19, 2016
Masochist issues... D= Oct 8, 2015