Posted on 03/18/2019 1:14:55 PM PDT by SeekAndFind
Flight data recovered from the wreckage of an Ethiopian Airlines jet showed clear similarities to another deadly crash of one of Boeings top-selling 737 Max aircraft last October, according to the French accident investigator that downloaded the information.
Ethiopian Airlines Flight 302, a Boeing 737 Max 8, went down shortly after takeoff from Addis Ababa on March 10, killing all 157 people on board. That occurred less than five months after a Lion Air jet crashed into the Java Sea in Indonesia during a similar stage in its flight, killing all 189 passengers and crew. Both 737 Max 8 jets were delivered to the airlines just months before their fatal flights.
The U.S. on Wednesday joined dozens of other countries in ordering airlines to ground the planes after the Federal Aviation Administration said it found new evidence that may link the two crashes.
Investigators who verified the data from the doomed Ethiopian Airlines jets flight data recorder found similarities between the Lion Air and Ethiopia crashes, which will be the subject of further study during the investigation, French accident authority BEA said in a statement Monday. That echoed statements from Ethiopian Transport Minister Dagmawit Moges a day earlier.
Data from the other black box the cockpit voice recorder has also been extracted and has been handed over to Ethiopias accident investigator, BEA said. The U.S. National Transportation Safety Board, which is participating in the investigation of Ethiopian Airlines Flight 302, also verified the data, BEA added.
Scrutiny has increased on the federal approval process for the new Boeing Max jets, which have been flying for less than two years.
(Excerpt) Read more at cnbc.com ...
“The average media minion doesnt know a wing flap from a mud flap.”
And folks, this is the winnah! for this group.
My suspicions is that the stall avoidance system software needs fixing, but even more important, there are a lot of pilots out there (in certain areas) who really shouldn’t even be piloting a Cessna 150.
Have they posted the DFDR data from the ET flight yet? They did for FLT JT610 awhile back ... showed AoA difference of 20 some deg btw L and R sensors.
I do control systems. Depending on MTBF on the sensors and the safety criticality, I will calculate the number of sensors needed. Then I will tell the customer the #. If the customer says too expensive then I will tell the customer to FO. 2 /3 vote on safety critical sensors dont make it safe. How accurate, precise, critical, .....
OK. Thanks for the info. So you would also be calculating how often the sensors would need to be serviced to maintain the desired level of reliability. Correct?
Yes, and I would add, the pressure on Boeing to make the MAX and legacy 737's the same type rating was driven by airlines' motivation to lower training costs, since crews would be unavailable for revenue trips while in training, and simulators would have to be built for the MAX type, and there would be an entirely different monthly bid for the flights in the MAX, a separate instructor cadre, flight manual, etc...
So Boeing went along with the airlines' demands to keep the customer (the airlines) satisfied. If they didn't, the airlines might have bought airplanes from Airbus.
Plenty of blame to go around for both airline management practices and Boeing.
1. The early Lockheed L-188 Electra crashes caused by an unusual vibration in the wing that caused the wing to sometimes fall off--which required a fix with stronger engine nacelles.
2. The early Boeing 727-100 crashes caused by pilots not award of the deep stall issue that caused the plane to go into an uncontrollable stall if the angle of attack (AoA) is too high. That was fixed with better pilot training and the installation of a "stick shaker" to warn of excessive AoA similar to what was installed on production BAC 1-11's.
Yes! Fly the airplane by the basic instruments and controls. Basic pilot instruction.
If the sensors don't agree, give an alert to the pilot, and turn off MCAS.
1. The early Lockheed L-188 Electra crashes caused by an unusual vibration in the wing that caused the wing to sometimes fall off--which required a fix with stronger engine nacelles.
2. The early Boeing 727-100 crashes caused by pilots not award of the deep stall issue that caused the plane to go into an uncontrollable stall if the angle of attack (AoA) is too high. That was fixed with better pilot training and the installation of a "stick shaker" to warn of excessive AoA similar to what was installed on production BAC 1-11's.
There was a Braniff Electra that crashed in 1959 on a flight between Houston and Dallas that was to continue to New York. There were lots of people from the oil business in Houston on that flight. My father had friends who knew people on that flight.
The following tweets from Trevor Sumner, CEO of Perch Experience, of what really happened to the Boeing 737 Max, may be one of the best summaries of the events that led to the two recent airplane crashes, and also why Boeing's "software upgrade"response is a farce.
1of x: BEST analysis of what really is happening on the #Boeing737Max issue from my brother in law @davekammeyer, whos a pilot, software engineer & deep thinker. Bottom line dont blame software thats the band aid for many other engineering and economic forces in effect. Trevor Sumner (@trevorsumner) March 16, 2019
Some people are calling the 737MAX tragedies a #software failure. Here's my response: It's not a software problem. It was an
* Economic problem that the 737 engines used too much fuel, so they decided to install more efficient engines with bigger fans and make the 737MAX. Trevor Sumner (@trevorsumner) March 16, 2019
This led to an
* Airframe problem. They wanted to use the 737 airframe for economic reasons, but needed more ground clearance with bigger engines.The 737 design can't be practically modified to have taller main landing gear. The solution was to mount them higher & more forward. Trevor Sumner (@trevorsumner) March 16, 2019
This led to an
* Aerodynamic problem. The airframe with the engines mounted differently did not have adequately stable handling at high AoA to be certifiable. Boeing decided to create the MCAS system to electronically correct for the aircraft's handling deficiencies. Trevor Sumner (@trevorsumner) March 16, 2019
During the course of developing the MCAS, there was a
* Systems engineering problem. Boeing wanted the simplest possible fix that fit their existing systems architecture, so that it required minimal engineering rework, and minimal new training for pilots and maintenance crews. Trevor Sumner (@trevorsumner) March 16, 2019
The easiest way to do this was to add some features to the existing Elevator Feel Shift system. Like the #EFS system, the #MCAS relies on non-redundant sensors to decide how much trim to add. Unlike the EFS system, MCAS can make huge nose down trim changes. Trevor Sumner (@trevorsumner) March 16, 2019
On both ill-fated flights, there was a:
* Sensor problem. The AoA vane on the 737MAX appears to not be very reliable and gave wildly wrong readings. On #LionAir, this was compounded by a Trevor Sumner (@trevorsumner) March 16, 2019
* Maintenance practices problem. The previous crew had experienced the same problem and didn't record the problem in the maintenance logbook. This was compounded by a: Trevor Sumner (@trevorsumner) March 16, 2019
* Pilot training problem. On LionAir, pilots were never even told about the MCAS, and by the time of the Ethiopian flight, there was an emergency AD issued, but no one had done sim training on this failure. This was compounded by an: Trevor Sumner (@trevorsumner) March 16, 2019
* Economic problem. Boeing sells an option package that includes an extra AoA vane, and an AoA disagree light, which lets pilots know that this problem was happening. Both 737MAXes that crashed were delivered without this option. No 737MAX with this option has ever crashed. Trevor Sumner (@trevorsumner) March 16, 2019
All of this was compounded by a:
* Pilot expertise problem. If the pilots had correctly and quickly identified the problem and run the stab trim runaway checklist, they would not have crashed. Trevor Sumner (@trevorsumner) March 16, 2019
Nowhere in here is there a software problem. The computers & software performed their jobs according to spec without error. The specification was just shitty. Now the quickest way for Boeing to solve this mess is to call up the software guys to come up with another band-aid. Trevor Sumner (@trevorsumner) March 16, 2019
I'm a software engineer, and we're sometimes called on to fix the deficiencies of mechanical or aero or electrical engineering, because the metal has already been cut or the molds have already been made or the chip has already been fabed, and so that problem can't be solved. Trevor Sumner (@trevorsumner) March 16, 2019
But the software can always be pushed to the update server or reflashed. When the software band-aid comes off in a 500mph wind, it's tempting to just blame the band-aid.
Follow @davekammeyer if you want to dig in. Trevor Sumner (@trevorsumner) March 16, 2019
You let him or her fly in the jump seat behind the Captain and then during the flight, you give him or her seat time flying & landing the airplane. The problems arise in an emergency when the Captain must give his or her all attention to the critical problem at hand, while the First Officer (co-pilot) continues to concentrate on flying the aircraft, keeping it functioning as an airworthy flying aircraft.
Furthermore some foreign cultures preclude the junior officer from informing the Captain of mistakes he or she is making in trying to correct the problem at hand. The first officer is considered as a subordinate when they should be considered a seamless member of the flying team. You might have noticed no problems in the USA, Great Britain, France, Germany, etc.the countries that live by rank, status, and senior operator is King are having the troubles. I am not saying this is the crash cause, but..it should be considered with the other facts and evidence of what went wrong.
“Why did the First Officer (Co-Pilot) on the Ethiopian Airlines crashed B737MAX aircraft have only 200 active flight operating flying hours on the B737MAX aircraft.”
When I flew my first trip on the B-737, my experience was about 30 hours in a 737 simulator and 25 hours in the airplane with a line check pilot. 200 hours doesn’t seem like much but it could take over two and a half months to accumulate. More important would be the background and type of flight education and experience prior to being hired by Ethiopian. My experience, Military trained, fighter and multi-engine “heavy” experience over a 6 year period of time, was more than this Co-pilot may have had.
Avoid third world airlines.
“I read somewhere that a pilot said it was similar to recovering from runaway trim on a 727 which was a common simulator exercise. “
You read it in my post you responded to.
AUTOMATED pivoting of the horizontal stabilizer SOUNDS neat.. But I think this feature crosses the red line of practicality.
“An airplane can stall at any airspeed.” It is exceeding the Angle of Attack for the current flight situation that will stall the aircraft.
An old saying, “pull back on the stick and the nose will go up, continue to pull back and the nose will go down.”
What causes the nose to go down is the angle of attack has been exceeded and the airplane has stalled. All aircraft are nose heavy and, when stalled or engine power quits, the nose will lower.
All speculation.
200 flight hours on the B737MAX may be OK for operating in the USA, Europe, cockpit environment where the two air men operate as a seamless team (Sully & his CoPilot worked together....Sully handling the problem and the Copilot continuing to fly the airplane. Ditto for the SWA Captain & her CoPilot......She centered on handling the problem and the CoPilot continues to fly the aircraft safely to landing, In both these instances, the crew (2) continued to perform as one in seamless communication & operation. They are trained to do this under the truism that no man is an island and no man stands alone in an aircraft operating emergency!!!
In an emergency there is little room or time for panic, so the crew reaction must be immediately automatic & calm, but allow for pragmatic, controlled actions by both airmen working together as one!!!
The sensors are redundant, but non-voting. They only have 2, IIRC, whereas 3 are required for a single bad sensor to not be able to cause catastrophic failure.
However, I am also astounded that this system and the AFM were approved as is.
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