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Is this how air safety works?

  1. May 2, 2008 #1

    wolram

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  2. jcsd
  3. May 2, 2008 #2

    BobG

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    Depends on the risk. The discrepancy had a very low probability of causing a problem, but the problem could be catastrophic. Grounding the planes has a 100% chance of disrupting air travel.

    In this case, American's complaints don't tell the whole story. Because of the low probability, they were given 18 months to fix the problem, but fixed it wrong. It was somewhat reasonable for local officials to believe American would be given more time considering they were given a lot of time in the first place ("not an emergency"). In this case, they weren't given more time.

    Bureaucratic? Strong enforcement? Tough to say unless you know a lot about airplanes.

    Here's a more thorough story from the time of the groundings: American quickens pace of work on MD-80s.

    And one more story: Airline groundings end, but U.S. scrutiny tougher.

    American wasn't the only airline surprised by tougher enforcement by the FAA.
     
    Last edited: May 2, 2008
  4. May 2, 2008 #3

    wolram

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    I agree with what you say Bob, but what is the use of the FAA/other authorities if recommendations? can be stretched to suit the individual.
    It seems most air crashes are the result of (low probability) or the ability to stretch
    some recommendations.
     
    Last edited: May 2, 2008
  5. May 2, 2008 #4

    BobG

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    That depends on just how low the probability is. If the stance is that all regulations and recommendations are equally important to enforce, then the move is bureaucratic (or a political reaction to adverse publicity). If defects with the highest probability (even though still low) to cause a crash are enforced strictly while the least likely don't carry as high a priority, then it's good enforcement.

    I wouldn't know enough about airplanes to say one or the other in this case. I just know that knee jerk reactions to freak occurrences unlikely to ever happen again are taken too often in bureaucratic oganizations. About the only thing that holds reactions in check is when the knee jerk reaction carries an exhorbitant price tag.

    Example: 80% of pedestrian fatalities on US Interstates occur after dark with half (62% of the 80%) occurring on unlit portions of the Interstate. Lighting every single mile of the US Interstate sytem would significantly reduce pedestrian fatalities.

    Except it would be too expensive. Plus astonomers and other folks that like the night sky would complain. Plus the Interstate is no place for pedestrians, anyway. (Never mind that 28% of dead Interstate pedestrians were there involuntarily because their car broke down, they left their vehicle after an accident, or were thrown from their vehicle during an accident and presumably run over by drivers staring at the wrecked vehicles.)

    That's kind of a silly example since the fatality rates are so low (although reducing pedestrian fatalities are the reason for the emergency call boxes by the side of the interstate, but those are usually in the heavily travelled parts that also have lighting).

    Still, you have to know the risk and how many lives you're actually saving before you can really make a comment about which side is being unreasonable.
     
  6. May 2, 2008 #5

    mgb_phys

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    Wasn't it American Airlines that had the crash with the DC-10 cargo door .
    And the FAA decided not to demand a fix until the Turkish airline plane crashed and killed another 350 people a few years later?
     
  7. May 2, 2008 #6

    BobG

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    The reason they didn't 'demand' a fix via an FAA Airworthiness Directive is because McDonnell Douglas voluntarily issued a service directive to fix the door themselves. In fact, the Turkish plane was still on the assembly line and documents showed the modifications had been made, even though they hadn't. Regardless of who issued the directive, it's not going to do any good if someone falsifies the documents*.

    *The airliner was modified with the interim measure of providing clear directions, in English, on how to properly latch the door, which is kind of curious since the plane supposedly had the new latch. In any event, the ground crewman couldn't read, period; let alone English.
     
  8. May 2, 2008 #7

    mgb_phys

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    So have planes become so safe and crashes so rare that the FAA/CAA is just pointless bureaucracy? Are the checks more about making sure the correct paperwork is in place rather than any actual safety consideration, like NASA and the shuttle.

    A bigger worry than being in the pocket of the airlines is being in the pocket of the aircraft makers. Aviation safety bodies are controleld by the goverment.
    The aircraft makers create lots of jobs. They also produce planes vital for national security. It wouldn't be in the country's interest for anything to happen to Boeing/Airbus would it?

    I take your point about streetlighting. In the UK hospital infections kill twice as many peole as die on the roads. But we have stiffer penalties for using a cell phone, drink driving and yet more speed cameras.
     
  9. May 2, 2008 #8

    russ_watters

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    Looking at the stats, if anything, those rates are too high to compare to airline fatalities. But it is tough to find stats low enough to compare with airliner fatalities, so those will do fine.
     
  10. May 2, 2008 #9

    russ_watters

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    No....
    Yes, but, if the FAA went away, you can bet the airlines would start testing the waters to see just what kind of crash rate is acceptable to the passengers. Standards would drop unutil an unacceptably high number of planes dropped.
     
  11. May 2, 2008 #10

    mgb_phys

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    Market forces! Like McDonalds finding out exactly how bad a burger is acceptable to customers!

    The goverment does limit the airline's liability to $25k/passenger - so in a crash the plane is worth more than the passengers, and the plane is insured.
     
  12. May 3, 2008 #11
    I'm sure that's for an automatic payout in a freak accident. If negligence can be established no court is going to keep to that limit.
     
  13. May 3, 2008 #12

    russ_watters

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    That's the kind of economic analysis that ended the Pinto, though. Execs are supposed to be smart enough to see past the crash itself and see the secondary effects. You know, the part where people stop flying the airline that has a crash every other week.

    Interestingly enough, the Pinto case study is taught in engineering ethics classes. I wonder how/if it is taught in business classes.
     
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