New start material strenght calculation for operating horn from crashed plane. Part 2 4

[RedSnake]

Can anyone help me check if this calculation works so far?
There are so many conversions between different units ..
The calculation is made by a free software but I assume that their calculation models are correct.

My own assumption is that the elevator is heavier at the front edge as there are hinges made of MIL 1430 N and since the lever and its attachment also are , there are also steel details on the other side and the rest is aluminum.
I have chosen to see it as a simple bar to begin with.

And the calculation is made to check which load the fixed joint must withstand for the elevator's own weight.

I intend to present it in steps so if I got something wrong I can adjust it before the next step.
If it's okay with you people?

Best regards Anna

“Logic will get you from A to Z; imagination will get you everywhere.“
Albert Einstein

 

[Alistair_Heaton]

They used to be pretty stand alone with thier own labs electron microscope etc. They still have surveyors and avionic techs/system people which are the bulk of the issues these days. But a lot of the lab work is contracted out. They unfortunately are kept quiet busy with the off shore accidents.

I know one of the avionic steam instrument guys through meeting him a few times over the years excellent at his job but he definitely is never allowed to speak to the public.

 

[Alistair_Heaton]

It's worthwhile browsing their accident report library for similar accidents.

I go and have a look every three months or so. Always learn something.

 

[RedSnake]

SHK did an excellent job with the SAS Q400 gear issues but the final finding that it was colossal flaws with SAS maint standards and QA did not go down very well locally.

I'm not sure how accident commissions work in other countries, but since it is the Swedish taxpayers, who pay their salaries.
All the work they do, is a matter of principle of public record and you are allowed access, you can ask to get any public documents, you may have to pay an administration cost after the report is completed but they can't refuse you.
If it is not classified information and there is very little information that is, only information provided by individuals and possibly foreign state secrets and military items.

I would think that it is more difficult to hide things when anyone can come in and review what is done afterwards.

And since SAS is partly owned by the state in principle by the Swedish people, it would have been the scandal of the century if someone had tried to hide something and it had then been discovered.

/A

“Logic will get you from A to Z; imagination will get you everywhere.“
Albert Einstein

 

[Alistair_Heaton]

The investigation side of things was open. It was them digging that alot of people objected to. They had already decided to get rid of the fleet and it would have stopped being a sas problem and they would have received compensation from the OEM and free cancellation of orders.

As it occurred they had to sell the fleet for a highly knock down price, And then had to compensate for degradation of the aircraft sales for the bad publicity.

The whole thing was a mess. Speaking from experience flying it you can slam that machine into the deck 12 times a day for 10 years with no gear issues if you do the maint right.

 

[RedSnake]

Yes I now from own experience what pressure washing mashines can do.

The final outcome of the investigation was that the cause was not a lack of maintenance but over-cleaning of the landing gear, with pressure washers being used that washed out the corrosion preventative coatings between the eyebolt and the actuator rod end.

Someone thought it was a good idea to high pressure wash our robots during a vacation break. !?
They hold IP67.

First digit Protection against touching and penetrating objects.
IP6X Dustproof

Second figure Protection against penetrating water.
IPX6 Flush tight
IPX7 Waterproof (immersed in water)
IPX8 Pressurized waterproof (immersed in water)

NONE of the above can handle high-pressure washing, it probably took a week for us to get the plant up and running again. ..sigh.. also a mess..

/A

“Logic will get you from A to Z; imagination will get you everywhere.“
Albert Einstein

 

[Alistair_Heaton]

That's what they want to public to think in Sweden. But the complete picture is pretty dirty.

British Airways has similar dirty laundry but they haven't had it so publicly disclosed. The amount of toxic fume events that are occurring on their airbus fleet is pretty nasty.

 

[RedSnake]

I have thought about this a few times, maybe you should keep an eye on the SHK website for any jobs coming up

Thanks by the way, for believing in me, and my potential
It actually means a bit more when it comes from someone who actually knows more about something than oneself.

Anna

“Logic will get you from A to Z; imagination will get you everywhere.“
Albert Einstein

 

[waross]

Thank you for your patience Anna.
Do I understand that the end stops are on the horn and not on the elevator?
Does this sketch make sense?

If the sketch is valid, then by examining your copies of the pictures of the failure, you may be able to determine the direction that the weld was broken.
I think that it is possible but very unlikely that the pilot could apply enough force to break the weld.
If at any time the plane fell backwards aerodynamics could easily put the horn on the stop and twist the weld off.

Bill
--------------------
"Why not the best?"
Jimmy Carter

 

[Alistair_Heaton]

I don't really with this investigation stuff.

I am just a willing information source.

Bill it makes sense to me. And I think your correct.

 

[RedSnake]

No problem
Yes but that is the left side elevator, as you have drawn it.

Might this help.
I am quit shore it wasn't broken by the pilot but att max stop up.
I have been sure of that all the time but it felt easier to start with their calculation and exclude it, but when I do not understand how they made the calculation it becomes hopeless :-(
Had actually forgotten that was where it started, with this thread going here and there all the time LOL

And I do not know why he at SHK made the calculation in the other direction ?
If you read the material report properly, they have rightly written that it was not so.

But of course if the pilot was pushed against the steering wheel, it could have been brolen or if the plane rolled counter clockwise.
But that did not seem likely as the left wing was the only part that was okey on the plane before it hit the ground

/A

“Logic will get you from A to Z; imagination will get you everywhere.“
Albert Einstein

 

[Alistair_Heaton]

To me that's been broken laterally with the Y connection of the horn going to the ->

In that case your going to get a high shear load at the bottom of the tube weld. Which will very quickly hit fast fracture load (not helped by the crap welding)

Lateral loads like that won't have been even considered because in normal operations its constrained to only move in 1 2D plane.

Anyway after two weeks of sim and line checks I off to the farm to play with wires and computer networks.

BTW in the sim we got the examiner to suddenly shift the CoG outside the envelope to the rear. It wasn't pretty, we lasted long enough to get the flaps in with full FBW onine and its protections saved us. With it in the basic direct down grade mode it was only hilarious because it was in the sim. Between the 2 of us we had 18 000 hours of experience neither of us lasted very long... The examiner lost it in less time than we did. BUt to note the sim flight model is only for the certified flight envelope. So it might not be completely realistic what it did to us.

 

[RedSnake]

To me that's been broken laterally with the Y connection of the horn going to the ->
Do you meen as the green arrow or the red one ?

I off to the farm to play with wires and computer networks

You know where to find me if you need some advice on top sleeves or cable lengths LOL
Change a cable a day then you might avoid pain
or I can lend you a hand ;-)
Do not know how I should be able to send it over though. LOL
Now I'm a real tease....

/A

“Logic will get you from A to Z; imagination will get you everywhere.“
Albert Einstein

 

[Alistair_Heaton]

The end of the elevator going vertically up in reference to the plane axis. Putting a moment on the end of the tube and horn.

Decided not enough day light to do it now and finish in one session. And the family are in the house and will just bitch that the power is off

 

[RedSnake]

Like this?

What I call against the maximum stopp up.

Best Regards A

“Logic will get you from A to Z; imagination will get you everywhere.“
Albert Einstein

 

[Alistair_Heaton]

As if it's folded up against the rudder and fin

 

[RedSnake]

Yes I agree that it was there the stabilizer ended up, exactly as in the film you linked to.
But I do not agree that it broke in that direction to begin with.
It will take me some thinking ;-) and preparing to be able to explain it properly.
Me and my pictures in my head LOL

Best regards A

“Logic will get you from A to Z; imagination will get you everywhere.“
Albert Einstein

 

[Alistair_Heaton]

To me the fracture doesn't look torsional it looks shear initiating on the bottom of the tube with the crap weld then it goes through the virgin metal with pretty standard fast fracture faces.

 

[RedSnake]

Nice! warm and cozy
I wished I had a fireplace at home, I like making fires.
But I see you're cheating, with a flamethrower LOL
I have a fireplace in the my summer cottage but it is not possible to be there in the winter :-(

I think, this thing about looking at the flames in a fire is the same phenomena as just sitting on a stump in the woods and just listen to the wind in the trees.
Just beening here and now, probably some genetic thing from the past, not much time for that unfortunately :-(

But I do have some onions, I have grown them myself

I think the fracture is as you are saying diffrent in diffrent places.
It might even have been broken in many diffrent directions at diffrent stadges.
When I figured out a good way to show and explain it, I will .. just need some time to put something together...

/A



“Logic will get you from A to Z; imagination will get you everywhere.“
Albert Einstein

 

[Alistair_Heaton]

Its my soldering torch for the copper pipe with MAPP gas in it. No pissing about with me!

 

[RedSnake]

I have a bit of a linguistic problem here!
Do you mean you use it because it's the fastest way to get it done and you have more important things to do?
Or do I need a "get out of yale free card" because I pissed you off, with my teasing?

I do it the old fashioned way, mostly because it's good training, if I would get lost in the woods or something
(which of course would not happen as I have a pretty good local sense), or it might just be an excuse to sit longer by the fireplace and watch the fire ;-)

/A

“Logic will get you from A to Z; imagination will get you everywhere.“
Albert Einstein