Originally Posted by
WHBM
Now those with long memories may recall another overstretched aircraft, the MD-11. That, too, got a "clever" bit of software to overcome design aspects. LSAS. Longitudinal Stability Augmentation System. Even the name sounds similar to MCAS. Did one of the onetime McDD engineers who stayed on after the Boeing takeover have anything to do with the more recent concept.
And again, those with long memories will recall that the MD-11 had a hull loss rate substantially out of kilter with norms, and was well known for ending up on its back and burned out alongside the runway on landing, exactly at the point where LSAS had been designed to kick in.
There were even discussions about it on PPRuNe at the time. One who seemed to understand its technicalities wrote "I seriously wonder if the FAA would be as accommodating now". Hmmm ...
Md-11 Lsas
Until the investigation is complete i’m not presuming MCAS was the official cause, but regardless, worth keeping in mind that well known graph (amongst engineers), the bath tub curve - that graph shaped like a bathtub - worth googling if anyone is not aware of it. Question to the certifying folk - how many ‘real world condition’ sectors does a new type have to fly before being approved for commercial operation? Is that even a requisite?
Have some questions about MCAS in general too, maybe someone here can answer?
One can only presume the engines were engineered in that position due to their increased aerodynamic lift profile. An economically motivated trade-off between; (being competitive, pushing the envelope, increasing system complexity), and, (cost, safety, simplicity, and reliability). I used to work on some 737-200’s - probably the first jet I was able to sit jump seat too. Thanks for reigniting some nostalgic memories with that post.
I have no visibility to the design spec, but if there is no vote comparison for sensors that provide critical data, essential to airworthiness, then my eyebrows are raised :/