Quote:
Originally Posted by Dowly
The stroking of the pointy end of the Boeing in this thread is astounding.
|
Dowly, when someone can't contest the evidence, and all I've done is follow the evidence trail of the actual
Preliminary Accident Report, and reported without bias what I found there, and what
Juan Brown, blancolirio of You Tube, commercial pilot for 30 years, presently flying 777s loaded with passengers has to say, then they merely admit I'm right by making up a colorful catch phrase like yours above. However, several facts are crystal clear.
* Boeing was absolutely clear and complete in its communication with Ethiopian Airlines, alerting them that the trim overrun situation in the Lion Air crash was definitely a trim overrun situation and probably an error involving MCAS and a jammed angle of attack sensor. Boeing required the addition of a page to the Aircraft Operations Manual an requested that the 737 Operations Manager of Ethiopian Airlines brief all pilots on the possibility, emphasizing that this is merely a variation of the trim overrun memory procedure in place for the past 52 years.
* The pilot followed the memory procedure for switching the elevator trim cutout switches to "cutout," which kept MCAS from executing any more actual trim changes to the airplane. The data flight recorders confirmed that the cutout switches were in the correct position, by recording MCAS commands to enter down trim that could not be applied because the electric trim switches were turned off.
*The flight recorder shows that the pilots neglected to fly the airplane by reducing throttle (airspeed steadily increased to 500 knots, twice the Vmo for the 737 Max at under 10,000 feet. No competent pilot would have allowed the plane to exceed even 300 knots. Because of neglect of rudimentary flying skills, this plane exceeded 500 knots. Indeed, overspeed alarms at high volume were sounding throughout the entire last half of this 10 minute flight. The throttles were never touched.
* Trim controls were unable to be manually adjusted due to the extreme overspeed condition of the plane, putting extreme aerodynamic loads on the elevator trim screw and manual trim system. The plane was literally in danger of coming apart before it even hit the ground.
* Unable to trim the plane, but clearly in control of altitude, according to the altitude plot, the pilot decided the proper thing to do was to "put the terrorist back in control of the aircraft" (my words). Ironically, he could actually have done this safely and I'll detail how.
First, fly the friggin' airplane. First thing you learn in flight school before you crawl into that Cessna 172 is "Aviate, navigate, communicate" in that order. First keep the plane in the air, then figure out where you are with a now stable airplane, then communicate with crew and ground to decide what to do next. These guys forgot to fly the plane. First thing they should have done, since they were in generally level flight is to divide jobs. Pilot works the controls and only does that. Co-pilot throws switches, debugs the problems and communicates. This isn't my idea. It's 100 year old established and time tested emergency procedure, known to every flight crew on the planet.
Pilot should instantly have seen that his speed was threatening to tear the aircraft apart, then asked the co-pilot to reduce throttles to level cruise levels. After several seconds the plane would be flying level at less than 250 knots, unloading the trim system and allowing the copilot to easily trim the elevator. But suppose the trim couldn't be done manually. As the altitude plot clearly shows, the pilot had altitude control! At no point since the cutout switches were engaged had MCAS made the tiniest change to elevator trim and the pilot was climbing using yoke pressure alone! They no longer had an MCAS emergency. They had a gross overspeed emergency and never realized or reacted to it with appropriate actions.
* Leaving the gross overspeed condition to become deadly, the pilot engaged the cutout switches, turning MCAS back on. He did this to be able to try the electric trim switch on the yoke. And it WORKED. He actually was able to trim the plane all the way neutral. He then had five seconds of controlled level flight before MCAS reengaged, and on the basis of the jammed angle of attack sensor moved the trim all the way to full down, crashing the plane.
Although turning the cutout switches back on was totally against Boeing and Ethiopian Airlines procedures, airline captains are like old time ship captains. They are free to elect to ignore procedure in order to save the airplane. Ironically, this could have worked in a strictly controlled manner.
First, the pilot, confining his job to flying the plane manually only would have to lay out the entire plan to his co-pilot. "Here's what we're going to do. I am going to tell you to switch the elevator trim cutout switches to "on" so I can use the electric trim switch. When you do I'll trim the plane neutral. As soon as I release the switch I'll tell you to move both elevator trim cutout switches to "cutout." You only have five seconds to do that before MCAS takes over again and if it does it will give us full down trim. Repeat that back to me." When they both demonstrate full comprehension, the pilot would give the command to reengage the elevator trim cutout switches. He would use the electric trim on his yoke (which turns MCAS temporarily off) to trim to neutral. Immediately he would order "cutout" and the co-pilot would have 5 seconds to throw both switches, an eternity when your life's on the line. It would be against procedure, but it would have worked. I asked Juan if that would work and his reply was "Yes, only if very carefully coordinated."
However that extreme measure wasn't necessary. The pilot had altitude control. All he had to do was reduce throttle, trim straight and level with throttle, assess his altitude and if he needed more, establish throttle settings and attitude for climb to a safe altitude. He then could have again trimmed straight and level throttle and attitude. At that point the elevator would be entirely unloaded, flying at proper airspeed and the co-pilot could have easily manually trimmed to neutral.
This incident, which should have been only a momentary annoyance, was allowed by bad piloting skills, and an unfortunate succession of faulty pilot decisions, to become a life-ending disaster. That's the very definition of pilot error.
Of course if anyone wants to persuade people, providing better facts and better reasoning based on actual aviation experience that I'm wrong, all my statements are falsifiable. But merely proclaiming them to be "The stroking of the pointy end of the Boeing" is just an exercise in informing people that you are unable to dispute what I say.