Thanks - "what" high record of accidents? My comments refer ONLY to
"fly-by-wire" types - the subject is high technology/automation. The media
never stop talking about the "3" A320 accidents in the 80s: Habsheim,
Bangalore, Strassberg. If you really study these, you will find
extraordinary HF/CRM factors involved, and zero aircraft failure. Since
then, Warsaw (extreme weather), the test flight A330 (another special case,
the design feature involved - ALT CAPTURE mode + eng failure - which has
been shared by twin designs accross the range of manufacturers), and the
recent Gulf Air (still under investigation - but no initial signs of a
design factor involved).
I see little value in "knocking" the competition, but must "balance" the
record a little (over the same period). Look more closely at some other
(fatal) accidents: possible reversal of rudder hydraulic actuators (recent
NTSB findings) [ possibly 2?], and engine separation [3]. Are these HF/CRM
or design? Perhaps a broader look at the facts will allow us to realise
that the "high visibility" of the Habshiem accident created a media
"bandwagon" opportunity (neatly fuelled with misinformation from supposedly
informed sources), and that we have all been duped into the belief that
A.I. aircraft are somehow especially dangerous due to bad design. Now,
with the real record out there, and the swelling fleets of
A319/320/321/330/340 safely going about their business, isn't it about
time, as rational creatures, for us to kill this "mind set", and recognise
that we should refine advances in technology rather than constantly
knocking them?
Remember that monoplanes were considered dangerous in the twenties!
John Bent
At 11:03 26/03/97 -0100, you wrote:
>Dear John:
> I couldnīt agree more with most of the things that you say in your last
>e-mail, but still, you havenīt answered why is that such a superb design,
>has a superbly high record of accidents.I really think AIRBUS has gone too
>far too soon , after all we are only humans, and we need more time to get
>used to changes.
> Sorry for my english, regards
> Alejandro Ponce
>
>----------
>> 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
>> >
>> >
>
>