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> De: John Bent <jbent_at_glink.net.hk>
> A: crm-devel_at_db.erau.edu
> Asunto: Re: Design Philosophy -Reply
> Fecha: martes 25 de marzo de 1997 20:22
>
> A comprehensive understanding of the real facts regarding the certain
> "European Manufacturer" will reveal to you:
>
> 1. That the Pilot IS "in control" as ever.
> 2. That fixed thrust levers (in autothrust) have never contributed to an
> accident (moving ones have - some fatal). At the most critical time for
> engine failure (V1 on the runway) "moving thrust levers" DON'T MOVE!
Fixed
> thrust levers (in autothrust)teach pilots to look for REAL aircraft
> performance - speed and speed trend; not to look at a mechanical
feedback
> system which can fail!
> 3. That the 7,000 + pilots flying this technology take to the sidestick
> like ducks to water.
> 4. That a GREAT DEAL of human factors thinking has gone into these
designs
> - the automation is a "complement to man", not a replacement.
> 5. That flight envelope protections are arguably not for discussion any
> more, if you want improved levels of flight safety (avoidance of CFIT
> accidents). Bank and envelope limits are similar in concept to brake
> ant-skid, which has been with us for years (planes and cars), releasing
> the brakes when we apply them on wet runways! WHY ALLOW PILOTS TO
EXCEEED
> AIRFRAME, PERFORMANCE, AND AERODYNAMIC LIMITS? Designers can certainly
> allow pilots to skid on runways, stall, and break the airframe, but what
> REAL rationale is there for this?
> 6. That your doubts are understandable, in that you may be yet another
> victim of ill-informed media hype and inter-manufacturer rivalry which
> have developed a strong mind set against these superb designs!
>
> Power to automation - SENSIBLY AND THOUGHFULLY DESIGNED!
>
> A full appreciation of the facts will dispel your doubts!
>
> John Bent
>
>
>
> At 14:26 25/03/97 -0500, you wrote:
> >I do have a serious thought on this: there can be no doubt that
> >differences in levels of automation, and differences in tasks
> >automated exist among manufacturers and airlines. More important, I
> >believe, is the underlying understanding of the role and needs of the
> >pilot who is in "control". It is my opinion that a certain European
> >manufacturer has made a fundamental, fatal error in isolating the
> >pilot from essential aircraft feedback by making the (side) stick not
> >proportional, and disconnecting the throttles from movement by the
> >autopilot. What is the jet doing? What is the real power setting?
> >Moreover, it could be argued that the bank limit (55deg, I beleive)
> >is detrimental; someday a pilot will need to go beyond it to save the
> >jet and HAL won't let him. I conclude that an excess of accidents in
> >the life of this airframe has already occurred because the crew
> >couldn't cope with the automation and no basic, "manual flying" mode
> >is available. To be impartial, a noted safety researcher, Dr. C.
> >Billings, who has intensively studied automation accidents, does not
> >agree with my inferences. I should also state that I have some time
> >with fly-by-wire (F-16) which has built in limiters to keep the
> >pointy end forward and prevent stalls and departures (at least one
> >accident might have not occurred without them). There is no doubt
> >that automation will continue simply because the technology exists
> >and because of the assumption that it lowers workload and increases
> >safety. It has however grown without much consideration of the
> >human. Opinions my own. Geff McCarthy MD
> >
> >