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    Re: Benefits of Stigmatizing
    From: Werner Luehmann
    Date: 2010 Oct 9, 12:34 +0200

    I think Gary  got it right for the reason why and when  (periscopic) sextants
    were used last with commercial airlines (big jets). I definitely can confirm
    that with the arrival of the INS in the 747s in the early 70s (other aircraft
    such as 707's  where modified as well)  the sexants were disabandoned. I know
    that because in the mid seventies, when I was en engineering student, I
    attended a lecture of the (then already for years retired) Chief Navigator of
    Lufthansa German airlines. He told us those facts. No naviagtors, no sextants
    any more.  Later - as an graduated engineer - a joined Lufthansa's technical
    division (I am still there) my engineering colleagues also said that sextants
    were not overhauled any more since the early seventies (at least not for use
    with Lufthansa).
    A major driver for the airlines certainly was the possibility to save one crew
    member. Cost for cockpit crews were and are still an  important factor in
    aircraft Direct Operating Cost (DOC) . The last victim so far being the
    flight engineer (startet about with the introduction of AIRBUS A310). I am
    hearing already discussions in the aviation community for a
    single-pilot-cockpit (commercial). We'll see.
    > The use of LORAN and Doppler and, obviously
    > celestial, still required a navigator onboard so they were not
    > eliminated until the development of INS installed in Boeing 747s that
    > first entered service in 1970. INS is also a form of dead reckoning but
    > its rate of drift is less than one nautical mile per hour so was precise
    > enough for oceanic navigation. But it required three independent INS's
    > on each aircraft for redundancy so was an expensive proposition but must
    > have been less expensive that paying he salary of the navigators.
    > gl

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