[SystemSafety] "FAA chief '100% confident' of 737 MAX safety as flights to resume"

Peter Bishop pgb at adelard.com
Wed Dec 2 09:59:51 CET 2020

It may be that several FAR regs are interlinked. FAR 25.143(g) seems to
be a general controllability requirement relating to the (pilot+plane)
combination. The stall characteristics reg §25.203(a) is a specific case
where controllability is important, etc.

The MAX might have transgressed more than one, so trying to pin it down
to a single reg might not be helpful.

The main thing is that all these regs are there to maximise plane safety.

And the focus of this discussion should be HOW those regs are met.
Personally I prefer plane physics.


On 01/12/2020 22:29, Dewi Daniels wrote:
> My understanding is that MCAS was introduced to comply with FAR
> 25.143(g), which states:
> When maneuvering at a constant airspeed or Mach number (up to
> VFC/MFC), the stick forces and the gradient of the stick force versus
> maneuvering load factor must lie within satisfactory limits. The stick
> forces must not be so great as to make excessive demands on the
> pilot’s strength when maneuvering the airplane, and must not be so low
> that the airplane can easily be overstressed inadvertently. Changes of
> gradient that occur with changes of load factor must not cause undue
> difficulty in maintaining control of the airplane, and local gradients
> must not be so low as to result in a danger of overcontrolling.
> Yours,
> Dewi Daniels | Director | Software Safety Limited
> Telephone +44 7968 837742 | Email d
> <mailto:ddaniels at verocel.com>ewi.daniels at software-safety.com
> <mailto:ewi.daniels at software-safety.com>
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Peter Bishop
Chief Scientist
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