On March, 2019, when an Ethiopian Airlines 737 MAX crashed shortly after takeoff:
its impact in a field near Addis Ababa created a hole about 32 feet deep, 92 feet wide, and 131 feet long.
The plane's airspeed indicator reached 500 knots (roughly 575 mph) just before the plane crashed, and passengers would have experienced negative G-forces before impact. It had been in the air for just six minutes.
The thing is, this crash should have never occurred. Five months earlier, a 737 MAX crashed shortly after takeoff, nose-diving at high speed into the Java Sea and killing all aboard. Within weeks of this 1st crash, the FAA made a frightening prediction:
A Federal Aviation Administration analysis document dated December 2018, weeks after the first crash, predicted there would be more than 15 additional fatal crashes of the MAX over its lifetime. The document was made public Wednesday (12\11\19) at a House Transportation Committee hearing.
So the federal agency that is tasked with ensuring aviation safety is A-OK with a commercial aircraft that will crash an additional 15 times - killing over 150 people each time? Because if the FAA wasn't A-OK with such an aircrft, then why didnt it ground this brand-smacking new one before an additional, I don't know, ONE crashed?
Yea. 👁️👃🏾. $$$$$.
The 737 MAX is the newest version of the famed Boeing 737, a plane that first entered commercial aviation in 1967. Over the ensuing decades, Boeing has constantly and incrementally improved upon the original design of the 737 without creating too much difference between successive versions. The similarities between versions allowed for both ease of FAA certification and 737 pilot upgrade training; indeed, it was these two factors that necessitated the creation of the now infamous Maneuvering Characteristics Augmentation System:
a feature of a Boeing 737 MAX flight control system that attempts to mimic pitching behavior similar to the Boeing 737 NG, especially in low-speed and high angle of attack (AoA) flight.
IANAP, but to me “low-speed and high angle of attack flight ” applies to takeoff more than any other phase of flight. And both crashes of the 737 MAX occurred within minutes of takeoff.
Note that the main purpose of MCAS - “to mimic pitching behavior similar to the Boeing 737 NG” - would be in keeping with Boeing’s goal of reducing costs associated with aircraft certification and pilot training. An analysis of why low-speed, high AOA flight characteristics differ so much between the NG and MAX versions of the 737 will disclose why the 737 MAX is Deadly by Design.
The 737Max Engine Conondrum
The NG's engines, which were designed for wings with higher ground clearance, had to be modified to fit on the NG's relatively low-ground clearance wings. Internal modifications resulted in the NG's engines flat-bottom nacelles.
As this modification was insufficient to achieve required ground clearance, the engines were also moved forward on the wings:
However, these modifications were child's play compared to the problem of getting the Max engines to fit properly on the NG wings. The Max's engines are not only super fuel efficient, they're also HUGE
!
And they hang way out in front of the wings.
Prob is, the size, placement and performance of the Max's engines can create a "divergent condition", or an unstable aircraft:
R. John Hansman, a professor of aeronautics at the Massachusetts Institute of Technology, in a March 28 interview:
As I understand it, at high angles of attack the Nacelles — which are the tube shaped structures around the fans — create aerodynamic lift. Because the engines are further forward, the lift tends to push the nose up — causing the angle of attack to increase further
This reinforces itself and results in a pitch-up tendency which if not corrected can result in a stall. This is called an unstable or divergent condition. It should be noted that many high performance aircraft have this tendency but it is not acceptable in transport category aircraft where there is a requirement that the aircraft is stable and returns to a steady condition if no forces are applied to the controls
So the only way to get those super fuel efficient engines mounted on the Max creates a passenger jet with the flying characteristics of an F-14. No way will commercial airliners buy 6,000 such "high performance" aircraft, let alone would the FAA grant it an airworthiness directive. Add to that the cost of training Max pilots to the level of Naval Aviators, and the 737Max would never get off the ground. But if a "fix" could be found that tames the Max's peculiar maneuvering characteristics, then what nobody knows...
And that's just what's Boeing had in mind when it decided NOT to let anyone know about MCAS.
Boeing did not adequately explain to federal regulators how a crucial new system on the plane worked, the report says. That system was found to have played a role in the accidents in Indonesia last October and Ethiopia in March
The Federal Aviation Administration relied heavily on Boeing employees to vouch for the safety of the Max and lacked the ability to effectively analyze much of what Boeing did share about the new plane, according to the report by a multiagency task force. The system of delegation is now being scrutinized by lawmakers in the wake of the tragedies.
h\t - nytimes.
It's just there, in the background, to ensure that the MAX conforms to the flying characteristics of the NG so that NG pilots can upgrade to the MAX without all of that expensive pilot training required to fly a MCAS-less MAX. That's all...
As i am composing this article, the House Judiciary Committee is "marking up" the Articles of Impeachment against POTUS Donal J Trump ("J" for jenius) and I'm reminded of another time when another president, also facing impeachment, also had his FAA involved with granting an airworthiness directive to a crash-prone commercial aircraft; Nixon and the DC-10
The more things change...
One thing that hasn't changed since March and, apparently, will not be changing anytime soon, is the flight status of the 737Max:
Why you won't fly on a 737 Max again for quite some time
By Chris Isidore, CNN Business
Updated 1:23 PM EST, Tue December 10, 2019
New York(CNN Business)
Nobody knows for sure when Boeing will be able to secure approval to return the 737 Max to the skies. What's certain is no passengers will fly in a 737 Max for quite some time.
Quite some time? How about never? The only real fix would be to upgrade the MAX's wings so they could properly host those HUGE, fuel efficient engines, but to do that would require a complete redesign of the 737 - which sorta kinda defeats Boeing's 737 upgrade scheme. Boeing tried to outsmart fundamental aerodynamics with MCAS, but what had happened was, it has only outsmarted itself.
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