Re: Design Philosophy -Reply
Geoffrey McCarthy (GMCCARTHY_at_FALCON.AL.WPAFB.AF.MIL)
Tue, 25 Mar 1997 14:26:12 -0500
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