No Survivors from Airliner Crash

[#1]

Looks like it was a problem with the angle-of-attack sensors and the way the signal from them was acted on.

"The aerodynamics around these sensor vanes, placed at the nose sides, is dependent on how the aircraft is flown. If there is a sideslip the airflow passing the sensors will be affected and the sensor values will differ.

The actual sensor value is also higher than the wing Angle of Attack (the airflow around a fuselage nose is curving upward), therefore a correction table is used to calculate the wing’s Angle of Attack. It’s the wing’s Angle of Attack which determines how close to stall the aircraft is."

The 737 has two of these sensors. Normally there are three. With three sensors a faulty one can be quickly switched out by software if the other two agree, but you can't do this with only two, not reliably anyway. So the original design allowed the MCAS to be switched out using two simple manual switches. However, this relied on a warning system that was an optional extra and not installed in many aircraft. Then a problem also arose in that some pilots weren't aware of these switches. Add to that the fact that the MCAS kept on trying to pitch the nose down if the sensors weren't switched out, and it did this continuously, not just once or twice. 

"MCAS was a function put there to cater for a very remote case. The pilot needs to maneuver close to the limits of the aircraft and way beyond normal flying practice, to save the aircraft from some emergency.

There was no need for the authority MCAS got. We know this today as the software fix only trims once for each elevated Angle of Attack event and limits the total trim amount to a safe level. This is regardless of the sensors being wrong or the function running wild."

https://leehamnews.com/2019/03/29/bjorns-corner-the-ethiopian-airlines-flight-302-crash-part-3/

[#2]

The thing I just don't get, maybe I've watched too many films, is we have this nose down anti stall automatic device. Shouldn't there be isn't there also an automatic "pull up" "pull up" ground proximity device that should take precedence.

[#3]

@billnotben  Actually, I would prefer the pilot to fly the `plane..... and the instruments give him the info that he needs to do it....

not the other way around.....

[#4]

@billnotben 

As far as I'm aware if an aircraft is in a stall/dive there are just "pull up" warnings repeated, and if it's in horizontal flight and there is a mountain top in front you just get a repeated "terrain" warning.

[#5]

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@shutter wrote:

@billnotben  Actually, I would prefer the pilot to fly the `plane.....

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Yes, that would avoid a situation where a plane went to, say, Edinburgh instead of, say, Düsseldorf.

[#6]

Could have been worse and landed in Swansea! 

[#7]

Hello Minivanman

I take it you never seen Edinburgh.

My brother and sister-in-law was a few minutes away from ibiza on a flight from Belfast when one of the engines failed (just shut off), the captain announced they had to return to Birmingham. All the people on board were given a ticket for a cup of tea and set up in a hotel for the night, when I asked him why they just didn't land in Ibiza, he told me some one from the Airline told them Brirmingham was the only place to fix the problem ?

Good luck

[#8]

@DE5T1NY 

A few to few times actually, many years ago and then later as one of my daughters lived up towards Inverness for a while. Crossing over the Firth of Forth from there by car and looking over towards that ironic railway bridge was quite an experience every time. Knocked spots of the Severn Bridge! 

[#9]

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@DE5T1NY wrote:

Hello Minivanman

 a few minutes away from ibiza on a flight from Belfast when one of the engines failed (just shut off), the captain announced they had to return to Birmingham.

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They must have been carrying a huge amount of excess fuel.  I know it's a relatively short flight, but even so.  They are supposed to have enough to divert to another airport in an emergency, but airports are quite thick on the ground in the Balearics and nearby Costas.  The less surplus fuel you land with, the safer it is, not to mention the cost of transporting the extra gallons.  Aircraft that get into trouble shortly after take-off do try to dump as much fuel as is safe before landing at the nearest airport.

[#10]

I don't know which airline this was nor the type of aircraft but the airline may have had maintenance arrangements in Birmingham. Also I am assuming Ibiza has limited facilities and the captain advised a more serious issue.

@Jonpe  aircraft generally carry sufficient fuel for a return trip. Look at the likes of Easyjet or Ryanair. They do a 25 minute turnaround which makes refuelling every time impossible.

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[#11]

A few years ago Ryanair were criticised by the Spanish authorities for carrying insufficient fuel to divert to the nearest Spanish airport when there was some kind of problem at their intended destination.  With a large number of diversions Ryanair had to declare an emergency a number (nine I seem to remember) times in a relatively short period in order to get landing clearance before the fuel ran out.

Malaysia Airlines were also criticised by the UK authorities for underfuelling to a point where a diversion to Manchester instead of LHR would have been impossible should there have been a need for it.

Aircraft flying to ordinary civil airports do not carry enough fuel for both trips.  Apart from the risk of landing with so much fuel on board, the cost in extra fuel required to carry the extra fuel would be prohibitive.  Refuelling is very quick which you may have observed where there are windows in the departure lounge overlooking the stands.  The moment the aircraft comes to a standstill and is immobilised, the fuel hose is attached and these things spew out a lot of fuel in a few minutes.  Twenty-five minutes is pretty standard for short haul aircraft, especially at less busy airports.  A Boeing 747 can be turned around in an hour.  I can't remember the record time, but it is (or at least was) held by an Australian team.

[#12]

Hello artmo

Didn't think to ask, but more or likely it was Flybe, your right about Ryanair, before the Belfast airport became George Best airport, you could sit in the bar and drink all day before traveling to Scotland (or else where not needed for this part) I met a friend whos young daugther was going over to stay with her daddy for a while, once she found out I was going to Coatbridge (where her husband lives) she phoned him and told him to wait at the airport in Glasgow for me (my flight was 30 minutes after her daughters) when arriving at Glasgow I spotted their dad waiting at the termial, so I went over and told him he didn't need to wait on me, but what a shocked to hear his daughters plane had not, lucky he quickly explained her fight had been caught in a jam of aircraft and had to encurcle around the airport till they got a slot to come in to land (15 minutes) it only takes about 15 minutes to get from A to B so they had flown 3 times that amount.

Good luck

[#13]

FAA STATEMENT, Regarding the software update by Boeing...

(hope it is not "fake news"  considering the issue date )

[#14]

Hello shutter

See it on their website 4/1/19 4:00pm Update April fool's tradition goes that you cannot play tricks on each other once 12 noon has passed. 

Good luck

[#15]

I was being a little facetious, with my comment..... however...

@DE5T1NY  12:00   ? ? ?  would that be "local" or G.M.T..    ? ? ?