That’s good politics, I agree. The president looks like he’s doing something while the FAA does not have to act without evidence, which could later make FAA look unprofessional.
Anybody buying Boeing stock? 
It might be a good thing to do with some play money. Or not, time will tell.
Ibra wrote:
Actually, FAA are waiting for the few that in the air to land…
Yea, read it in the news just now It will be interesting to see what exactly the truth in all this is some day.
Mooney_Driver wrote:
Huge disgrace for the FAA in my opinion.
Actually, FAA had few inquiries on Boeing and B737Max not while ago before the new accident regarding the old accident using the “usual channels” but it was driven from the bottom rather than the top
But that did not factor the severity of the new accident, I think that explains their slow action (e.g. FAA & Boeing: “don’t worry we got this in BAU and we are already on top of it !” ) but they may pay a reputation price on that later…
I have question about technical on this.
What I read until now, from the lion air crash, is that this MCAS system has been added by Boeing to get this plane certified by the FAA, because one of the main difference from the traditional 737, is the bigger/heavier engines, that has to be positioned in a more forward/up position for ground clearance. This new position is changing the M/B of the plane, making is more prone to stall in high AoA.
So in addition to stall warning, stick shakers, PM attention, if yet the PF still wants to pull the yoke in a very high AoA situation (academic example is go-around in a microburst, where EASA allows pulling until stick shaker), a computer will – in any case – push the nose down:
-This is not documented in 737 training,
-The procedure to disable this system (in a moment where – I assume this should operate – stick shaker, stall warner and crew interaction is on-going), wasn’t taught but I suppose, can be found in the ad-hoc AFM chapter. Red, yellow one?
This is letting a very very thin margin to the crew to overcome this. I assume this is like a bit reverse case of AF447.
But let’s continue.
In the case the crew can’t disable it (which was the case, whatever the situation), is a full deflection of the sticks able to win again a full horizontal stabiliser position? This is more an engineer question, but I just wanted to know if there is a chance for the crew.
(not even mentionning the case of sensor malfunction and the fact there are only 2).
US AOPA article with an interesting angle by a pilot of the type. Basically he is saying that to get the (functioning) MCAS system to crash the plane you have to be an AF447-grade muppet.
Of course it is not publicly known what the cause of these two crashes was. It may have been a failure of the MCAS system, or something else.
@Peter, in that article you linked it says:
The “space-based ADS-B” satellite data the agency initially received was “very raw and very hard to interpret,” […] Aireon, the NTSB, and Boeing, were able to do some enhancements to that track return” […]
What do they mean raw and hard to interpret? I have read similar statements in other accident reports in the past. Were the FAA people looking at binary data and were not able to read them? No shit Sherlock… In that case it has nothing to do with how hard it is to interpret, it is simple incompetency of the people receiving the data.
Peter wrote:
US AOPA article with an interesting angle by a pilot of the type. Basically he is saying that to get the (functioning) MCAS system to crash the plane you have to be an AF447-grade muppet.Of course it is not publicly known what the cause of these two crashes was. It may have been a failure of the MCAS system, or something else.
Nice article, thx. I anyway find the guy short-sighted, or, let’s say, conciliant. “Our safety record is astonishing,”… until it’s not anymore.
“Basically he is saying that to get the (functioning) MCAS system to crash the plane you have to be an AF447-grade muppet”
It is a fudge or protection to prevent pilots from stalling, but a very sophisticated one: it runs on dynamic mode (Not static limit on AoA but mimics derivatives of AoA/Yoke from 737-8 to use existing stall protection) and it get activated/disactivated by a bunch of binary variables (flaps up, release yoke, 5 seconds trim, autopilot…) and it seems you need it on a critical moment for a successful take off path (going from 0ft to 33kft)
As with any automatic stall protections some will still crash if they don’t understand the native stall? Or what protect against it?
The simple rule of thumb if it is critical and has more than 10 line of codes, then it is very complicated and needs 10000page of docs…
greg_mp wrote:
is a full deflection of the sticks able to win again a full horizontal stabiliser position? This is more an engineer question, but I just wanted to know if there is a chance for the crew.
Only from secondary sources: no, you can’t overcome the full nose down trimmed stabilizer by pulling the column, not enough elevator authority.
Ex negativo, Boeing “make an already safe plane even safer” is confirming this in the description of the planned software patch:
According to Boeing, the enhancements include updates to “the MCAS flight control law, pilot displays, operation manuals and crew training. The enhanced flight control law incorporates angle of attack inputs, limits stabilizer trim commands in response to an erroneous angle of attack reading and provides a limit to the stabilizer command in order to retain elevator authority.
What that Boeing pilot is saying is that the system doesn’t activate unless other stuff has gone badly wrong beforehand and remained un-noticed by the crew.
