AF 447 Thread No. 6

[Lyman]

AlphaZuluRomeo

Yes, I was speaking of Alpha protections lost. I was party of a very long discussion on Rudder/Vertical Stabiliser issues long ago, and understand reasonably well the RTLU.

The PITCH is protected "IN" 'g' ? OR "BY" 'g'? Its PROT is time discrete, as it prevents transient exceedance of PITCH loads.

It demonstrably does not prevent high angles of Attack see: "the climb"

In fact, as long as the a/c rotates within a 'g' envelope, there seems to be no functional limit of PITCH UP.

Now here is the problem with that, as I see it.

447 entered the climb without a STALL protection, and STALLED. She climbed at a rapidly inceasing PITCH value, but with a controlled RATE OF CHANGE.

Wasn't PF using 'g' prot as his NORMAL LAW "stand-in"? No immediate and seat crushing PITCH UP, but a steady excursion toward the STALL AoA?

So I see "G" PROTECTION as a de facto airframe limiter, which not only prevents over load, but allows LOC, and in Losing Control, "G" PROT, having allowed it, prevents recovery "FROM IT".

How can I say that? Because the TRIM started to LOAD the airframe, in STALL, when to unload it, or allow it to be unloaded, would facilitate recovery.

Nothing Earthshattering about this, it is a point of view. Will you attempt to see it that way for purpose of understanding?

Climbing UP, PF had an airframe that appeared NORMAL, but was rotating to absurd PITCH UP. By that I mean, his climb was incremental, and indicated no disaster in the offing. (possibly).

If PILOT/PLANE communication is critical, wouldn't the a/c have annunciated to the crew[/I] that pilot input was being g managed?

In a perfect world, one then says "but he should have known this", no denying. Was there an clear alert that instructed the manual pilot that basic, and life protecting systems were operating the Plane, and not he?

I have a sinking feeling that the PF was possibly unaware "g" was molding his inputs to an incremental PITCH UP that he may have sussed was not potentially very hazardous. Otherwise, why the gruff Stick demands?

add. "Attitude" and 'g' PROT are not related. There can be (have been) circumstances where 'g' PROT might have wanted to be sent packing?

The chronic application of PITCH UP by this pilot is made easier to understand (by me), when one imagines the environment, the lack of "Response", and the inappropriate nature of some of the cueing.

THS. There is a command in medicine, that applies to the inappropriate automatic application of TRIM:

"First, do no harm"...... perhaps engineers should have a short 101 in patience at onset of disaster, as well as Physicians.