Using Spice to verify a circuit works

[Jan Panteltje]

On a sunny day (Tue, 18 Jun 2019 00:44:08 -0400) it happened bitrex
<user@example.net> wrote in <t_ZNE.134651$3T5.3827@fx45.iad>:

On 6/18/19 12:19 AM, Jan Panteltje wrote:
On a sunny day (Mon, 17 Jun 2019 21:49:17 -0400) it happened bitrex
user@example.net> wrote in <yqXNE.41731$IQ6.21299@fx09.iad>:

The 737 Max handled very much like a 737 there were not huge engineering
surprises there. It was just different enough that they wanted to avoid
a different type rating. It was more of a bean-counting problem than an
engineering problem.

No, that plane is unstable by nature due to the position of the engines if I understand it right.
They wanted to fix that with some software.
That worked, then they 'simplified' the software, removed a G sensor, and that did not work.
The basic plane designs sucks.
A good plane flight strait without correction.

If you make a paper airplane, and it is bad, it will do strange things,
you could than add all sorts of systems to make it fly right
but it would still be a POS.

Just like the F35.


The Space Shuttle was a total brick without electronic flight controls
it is pretty much impossible to fly, much less land the orbiter without
them.

In the (unlikely, never happened) case of a total electrical or computer
failure on final approach the only option the crew would have had would
be to bail out, a safe landing is impossible. It was a "glider" in name
only.

So... only thing it ever did that was in any way useful was fix Hubble.
But NASA should not have send up the wrong Hubble mirror in the first place.

Had US stayed with Von Braun's mars plan it would rule the solar system.

All politics, that shuttle, create a monster for some political purpose.
And it killed people too.
WAY more expensive than what SpaceX is now doing with reusable boosters,
so back to rockets.
NASA even had nuclear rockets that could just reach any place in the solar system,
project scrapped because somebody cried 'radiation'.
Those who ventured to America were not stopped by fear of falling of the flat earth,
these days it is all old women and politics requiring more old women in command.
I was reading today some university or whatever joke it was here is now only accepting women,
is that not discrimination ;-)


One side effect of what we call 'demon-crazy' or whatever the word, is that idiots select idiots
and are then ruled by same (trump an example).
That one party system is what makes China stronger, that and no religious Pi is 4 crap.
They are on the backside of the moon, and soon maybe have astronauts walk there,
next mars, if global war does not interfere.
OTOH wars cut the crap and create things that really work,
much came out of the last WW, including rockets, radar, etc etc

better stop here.

Ants, yes ants.

 

[Jan Panteltje]

On a sunny day (Tue, 18 Jun 2019 00:37:50 -0400) it happened bitrex
<user@example.net> wrote in <zUZNE.59350$935.48043@fx46.iad>:

On 6/18/19 12:19 AM, Jan Panteltje wrote:
On a sunny day (Mon, 17 Jun 2019 21:49:17 -0400) it happened bitrex
user@example.net> wrote in <yqXNE.41731$IQ6.21299@fx09.iad>:

The 737 Max handled very much like a 737 there were not huge engineering
surprises there. It was just different enough that they wanted to avoid
a different type rating. It was more of a bean-counting problem than an
engineering problem.

No, that plane is unstable by nature due to the position of the engines if I understand it right.
They wanted to fix that with some software.
That worked, then they 'simplified' the software, removed a G sensor, and that did not work.
The basic plane designs sucks.
A good plane flight strait without correction.

If you make a paper airplane, and it is bad, it will do strange things,
you could than add all sorts of systems to make it fly right
but it would still be a POS.

Just like the F35.


I don't believe it was dynamically unstable inherently like some (most?)
modern military combat aircraft are.

Toss it like a glider with no electronic flight controls, trimmed for
level flight, and it will probably enter a phugoid like most (all?)
large passenger aircraft do.

From what I have read, increasing engine power with the new engine positions
gave it a tendency to stall.
They moved the engine position to get better fuel efficiency?

The paper plane analogy holds.

As to the mil dynamically corrected fighter planes,
Russian S400 and S500 will just blow all of that out of the air.
Israel already has a F35 that was hit.. maybe even by a simpler missile,
F35 'stealth' is an illusion, a 35 $ camera can see the F35 IR signature hundreds miles away.
F35 a US snake oil sales product.

Look at the paranoia now Turkey (not the animal) is buying those Russian systems
'but they will figure out how to detect the F35' (quoted from the news).

We will see, trump just announced sending thousands of troops to the middle east.
If that fire ignites there will be no more Israel, and possibly no more US government,
Mr Xi and Mr Putin will divide the US up in a Chinese and Russian part in a Washington conference.

All 'merricans will have to learn a new language, either Mandarin or Russian.

In the EU, when / if? UK leaves it, English will be no longer be an accepted language
it will likely mostly be German and French.
I am so glad, here they started teaching French in kindergarten, been there several times
no problem with that language,,, learning things as a small kid helps really.

 

[bitrex]

On 6/18/19 1:20 AM, Jan Panteltje wrote:

On a sunny day (Tue, 18 Jun 2019 00:44:08 -0400) it happened bitrex
user@example.net> wrote in <t_ZNE.134651$3T5.3827@fx45.iad>:

On 6/18/19 12:19 AM, Jan Panteltje wrote:
On a sunny day (Mon, 17 Jun 2019 21:49:17 -0400) it happened bitrex
user@example.net> wrote in <yqXNE.41731$IQ6.21299@fx09.iad>:

The 737 Max handled very much like a 737 there were not huge engineering
surprises there. It was just different enough that they wanted to avoid
a different type rating. It was more of a bean-counting problem than an
engineering problem.

No, that plane is unstable by nature due to the position of the engines if I understand it right.
They wanted to fix that with some software.
That worked, then they 'simplified' the software, removed a G sensor, and that did not work.
The basic plane designs sucks.
A good plane flight strait without correction.

If you make a paper airplane, and it is bad, it will do strange things,
you could than add all sorts of systems to make it fly right
but it would still be a POS.

Just like the F35.


The Space Shuttle was a total brick without electronic flight controls
it is pretty much impossible to fly, much less land the orbiter without
them.

In the (unlikely, never happened) case of a total electrical or computer
failure on final approach the only option the crew would have had would
be to bail out, a safe landing is impossible. It was a "glider" in name
only.

So... only thing it ever did that was in any way useful was fix Hubble.
But NASA should not have send up the wrong Hubble mirror in the first place.

Had US stayed with Von Braun's mars plan it would rule the solar system.

The Space Shuttle was very much a dual-use vehicle and it scared the
shit out of the Soviets. It also launched about a dozen or more military
payloads most of which are still classified.

The large delta-wing configuration was dictated by the DoD - a pure
scientific research reusable spacecraft wouldn't need them and could
have been closer to the original concept:

<https://en.wikipedia.org/wiki/Space_Shuttle_design_process#/media/File:Faget_shuttle_concept_P208.jpg>

and the large delta wings meant it had to be mounted lower down on the
stack which caused problems later. But the large delta wing
configuration also made the Shuttle a formidable weapons platform
reasons left as an exercise to the reader

All politics, that shuttle, create a monster for some political purpose.
And it killed people too.
WAY more expensive than what SpaceX is now doing with reusable boosters,
so back to rockets.
NASA even had nuclear rockets that could just reach any place in the solar system,
project scrapped because somebody cried 'radiation'.
Those who ventured to America were not stopped by fear of falling of the flat earth,
these days it is all old women and politics requiring more old women in command.
I was reading today some university or whatever joke it was here is now only accepting women,
is that not discrimination ;-)


One side effect of what we call 'demon-crazy' or whatever the word, is that idiots select idiots
and are then ruled by same (trump an example).
That one party system is what makes China stronger, that and no religious Pi is 4 crap.
They are on the backside of the moon, and soon maybe have astronauts walk there,
next mars, if global war does not interfere.
OTOH wars cut the crap and create things that really work,
much came out of the last WW, including rockets, radar, etc etc

better stop here.

Ants, yes ants.

 

[Jan Panteltje]

On a sunny day (Tue, 18 Jun 2019 01:50:38 -0400) it happened bitrex
<user@example.net> wrote in <PY_NE.47505$ud1.836@fx39.iad>:

On 6/18/19 1:20 AM, Jan Panteltje wrote:
Had US stayed with Von Braun's mars plan it would rule the solar system.

The Space Shuttle was very much a dual-use vehicle and it scared the
shit out of the Soviets. It also launched about a dozen or more military
payloads most of which are still classified.

The large delta-wing configuration was dictated by the DoD - a pure
scientific research reusable spacecraft wouldn't need them and could
have been closer to the original concept:

https://en.wikipedia.org/wiki/Space_Shuttle_design_process#/media/File:Faget_shuttle_concept_P208.jpg

and the large delta wings meant it had to be mounted lower down on the
stack which caused problems later. But the large delta wing
configuration also made the Shuttle a formidable weapons platform
reasons left as an exercise to the reader

One of my favorite movies is
https://en.wikipedia.org/wiki/Def-Con_4
it was brought down by a technician turned hacker commanded by the evil ruler.

BTW I am not sure Russia had much fear for the shuttle, they tried building their own
and soon realized they were copying a useless POS
Russian rockets still today bring people to the ISS (an other useless endeavor,
but now they make some money playing taxi to the ISS.

In the same way (tm) it would have been cheaper to launch an other hubble with a rocket then to fix it using the shuttle.

Now all focus is on high speed missiles and underwater nuclear armed autonomous mini crafts that will just silently lure in front of US harbors
and attack if given the command.. or a 'we are still there' de-activation command sequence is not received for some time.
Mr Putin presented some new tech last year:
https://edition.cnn.com/2018/12/27/europe/russia-hypersonic-missile-intl/index.html

Remember China did a test successfully shooting down one of their own GPS like low orbiting sats..

That is the sensitive spot, ISS, and other low orbiting platforms, communication satellites, etc can just be shot down,
deorbited even by ONE hacker, there is a hacker in the UK that did control a satellite already more than 10 years ago.
Even a simple replay attack from what a control station transmits can send fatal information to satellites.

People have NO idea how vulnerable all that space ju^H^Hstuff is .
Or the world for that matter.

The creation of fear for Russia just to get more money from the people for defense, well it is like McCarthy stile:
https://en.wikipedia.org/wiki/Joseph_McCarthy

Creating a common enemy to distract from the failures of the current leadership.

It looks that Trump is willing to attack Iran just to distract from his failures so he can win the next election.
Very dangerous, it is all about his ego, not about the people or the country.

 

[Bill Sloman]

On Tuesday, June 18, 2019 at 5:13:42 AM UTC+2, John Larkin wrote:

On 17 Jun 2019 18:21:49 -0700, Winfield Hill <winfieldhill@yahoo.com
wrote:

John Larkin wrote...

We're supposed to rework the economy of the
entire world based on climate simulations.

What could possibly go wrong with that?

What's going wrong, is that the world is
melting down, as many are nay-saying, and
we will end up with flooded cities, and
devastated farming and living areas.

That's what the simulations have been predicting for decades.

They haven't. They've been predicting pretty much what has actually been happening. Sea level rise isn't going to get serious until the Greenland and/or West Antartic ice sheets start sliding off into the sea fast. That's not easily predictable

https://en.wikipedia.org/wiki/West_Antarctic_Ice_Sheet

> We should all be dead by now. We aren't.

Nobody ever claimed that we should all be dead by now.

Actually, nothing much is happening, except that crop yields and life
spans keep getting better.

Crop yields get better, until there is a drought. Life spans ditto.

Sea level has been creeping up a couple of mm per year since the LIA
ended around 1850.

But isn't going to "creep up" when the Greenland and/or West Antarctic ice sheets start sliding off into the ocean. They have about 10 metres of sea level rise locked up at the moment, and when ice sheets slide off (as they did at the end of the last ice age) sea levels can rise by a metre per century (up to 2.5 metres per century for some centuries

http://noc.ac.uk/news/global-sea-level-rise-end-last-ice-age

Admittedly, the total sea level rise then was 120 metres, but it happened one ice sheet at a time.

This is a Golden Age for humanity, and will be until we get the next
ice age.

Interglacials are "golden ages" compared with ice ages, but we've already put enough CO2 into the atmosphere to rule out a flip back to an ice age until the CO2 level gets back down below 300ppm - it's currently 414.7ppm and rising steadily.

There's anxiety about whether we'll get the planet warm enough to flip it into a hot spell - as it did 56 million years ago for the Paleocene-Eocene Thermal Maximum

https://en.wikipedia.org/wiki/Paleocene%E2%80%93Eocene_Thermal_Maximum

--
Bill Sloman, Sydney

 

[Bill Sloman]

On Tuesday, June 18, 2019 at 3:41:14 AM UTC+2, bitrex wrote:

On 6/17/19 8:29 PM, Tom Gardner wrote:
Nobody in their right mind would sign-off a complex circuit
solely on the basis of a spice simulation. But Boeing is
planning on doing the equivalent for their 777X!

 "Specifically, Boeing is “reducing the scope and duration
 of certain costly physical tests used to certify the
 planemaker’s new aircraft,” Reuters reported over the
 weekend.
 We're thus told that engineers working on Boeing's new
 777X airliner project are intending to use computer
 simulations instead of real-world flight tests to
 validate their engineering decisions."

What could possibly go wrong with that?

https://www.theregister.co.uk/2019/06/17/boeing_certification_simulation_tests/


https://www.reuters.com/article/us-france-airshow-boeing-certification-e/exclusive-boeing-seeking-to-reduce-scope-duration-of-some-physical-tests-for-new-aircraft-sources-idUSKCN1TH0A3


Boeing hasn't started a clean-sheet design in decades and they'll likely
be selling variants of the 737 through the year 2080 so it'll probably
be OK.

Simulation lets you test all kinds of edge-cases repeatedly that would
be extremely dangerous to do even once in the real world.

The 737-Max hasn't been OK.

--
Bill Sloman, Sydney

 

[Bill Sloman]

On Tuesday, June 18, 2019 at 3:06:51 AM UTC+2, John Larkin wrote:

On Tue, 18 Jun 2019 01:47:25 +0100, Tom Gardner
spamjunk@blueyonder.co.uk> wrote:

On 18/06/19 01:35, John Larkin wrote:
On Tue, 18 Jun 2019 01:29:15 +0100, Tom Gardner
spamjunk@blueyonder.co.uk> wrote:

Nobody in their right mind would sign-off a complex circuit
solely on the basis of a spice simulation. But Boeing is
planning on doing the equivalent for their 777X!

"Specifically, Boeing is “reducing the scope and duration
of certain costly physical tests used to certify the
planemaker’s new aircraft,” Reuters reported over the
weekend.
We're thus told that engineers working on Boeing's new
777X airliner project are intending to use computer
simulations instead of real-world flight tests to
validate their engineering decisions."

What could possibly go wrong with that?

https://www.theregister.co.uk/2019/06/17/boeing_certification_simulation_tests/

https://www.reuters.com/article/us-france-airshow-boeing-certification-e/exclusive-boeing-seeking-to-reduce-scope-duration-of-some-physical-tests-for-new-aircraft-sources-idUSKCN1TH0A3

We're supposed to rework the economy of the entire world based on
climate simulations.

Er, no. Climate modelling, which is very different.
But back to the main point...

Boeing can do non-destructive and destructive tests
on their products, so simulation isn't /necessary/.
I'd argue that simulation definitely isn't /sufficient/.

Precisely what destructive and non-destructive
tests can we do with the climate?


What could possibly go wrong with that?

Wrong question. A better question is whether
modelling (not simulation) will help us understand
possibilities and consequences in situations
where tests are impossible.

What's the difference between climate modelling and climate
simulation?

Actually, we do go directly to production on electronic instruments
based on Spice simulation.

John Larkin's average time to egineer a "new" product is two weeks - or so he has told us.

Tweaking an existing product to suit a new customer isn't all that demanding, and he probably can get away with relying on Spice simulations most of the time.

Two weeks engineer time isn't a big investment.

--
Bill Sloman, Sydney

 

[Bill Sloman]

On Tuesday, June 18, 2019 at 2:37:53 AM UTC+2, John Larkin wrote:

On Tue, 18 Jun 2019 01:29:15 +0100, Tom Gardner
spamjunk@blueyonder.co.uk> wrote:

Nobody in their right mind would sign-off a complex circuit
solely on the basis of a spice simulation. But Boeing is
planning on doing the equivalent for their 777X!

"Specifically, Boeing is “reducing the scope and duration
of certain costly physical tests used to certify the
planemaker’s new aircraft,” Reuters reported over the
weekend.
We're thus told that engineers working on Boeing's new
777X airliner project are intending to use computer
simulations instead of real-world flight tests to
validate their engineering decisions."

What could possibly go wrong with that?

https://www.theregister.co.uk/2019/06/17/boeing_certification_simulation_tests/

https://www.reuters.com/article/us-france-airshow-boeing-certification-e/exclusive-boeing-seeking-to-reduce-scope-duration-of-some-physical-tests-for-new-aircraft-sources-idUSKCN1TH0A3

We're supposed to rework the economy of the entire world based on
climate simulations.

The climate simulations have been running since the 1990's. The planet is warming up a trifle faster than the collected simulations predicted - which is to say that the simulations that predicted a trifle more warming were more nearly correct.

All the simulations are various sorts of tractable over-simplications of a very complex reality, but they are informative.

Your preference is for believing what Anthony Watts is paid to tell you by the people who are making money out of extracting fossil carbon, and want to keep making money out of it for as long as possible.

> What could possibly go wrong with that?

Lots of things. But ignoring the fairly predicable effects of sticking even more CO2 into the atmosphere has its own rather obvious downsides.

--
Bill Sloman, Sydney

 

[Bill Sloman]

On Tuesday, June 18, 2019 at 4:10:06 PM UTC+2, mako...@yahoo.com wrote:

The climate simulations have been running since the 1990's. The planet is warming up a trifle faster than the collected simulations predicted - which is to say that the simulations that predicted a trifle more warming were more nearly correct.

lol just choose the right prediction is all

https://medium.com/message/how-to-always-be-right-on-the-internet-delete-your-mistakes-519a595da2f5

Nobody "deletes their mistakes". All the simulations get published and compared, and the predictions look rather like a Gaussian distribution.

The IPCC looks at the lot and reports the likeliest prediction - the peak of the distribution - and a range - full width at half maximum.

It isn't perfect, but they've done pretty well over the last decade or so.

It's a whole lot better than hoping that problem isn't actually real.

--
Bill Sloman, Sydney

 

The climate simulations have been running since the 1990's. The planet is warming up a trifle faster than the collected simulations predicted - which is to say that the simulations that predicted a trifle more warming were more nearly correct.

lol just choose the right prediction is all

https://medium.com/message/how-to-always-be-right-on-the-internet-delete-your-mistakes-519a595da2f5

m

 

[John Larkin]

On Tue, 18 Jun 2019 04:19:24 GMT, Jan Panteltje
<pNaOnStPeAlMtje@yahoo.com> wrote:

On a sunny day (Mon, 17 Jun 2019 21:49:17 -0400) it happened bitrex
user@example.net> wrote in <yqXNE.41731$IQ6.21299@fx09.iad>:

The 737 Max handled very much like a 737 there were not huge engineering
surprises there. It was just different enough that they wanted to avoid
a different type rating. It was more of a bean-counting problem than an
engineering problem.

No, that plane is unstable by nature due to the position of the engines if I understand it right.
They wanted to fix that with some software.
That worked, then they 'simplified' the software, removed a G sensor, and that did not work.
The basic plane designs sucks.
A good plane flight strait without correction.

If you make a paper airplane, and it is bad, it will do strange things,
you could than add all sorts of systems to make it fly right
but it would still be a POS.

Just like the F35.

The F35 will be OK. Fighter planes don't dogfight any more. F35 is an
electronics and missile platform.

I suspect that manned fighter planes and bombers will be obsolete soon
anyhow.


--

John Larkin Highland Technology, Inc

lunatic fringe electronics

 

[George Herold]

On Monday, June 17, 2019 at 11:13:42 PM UTC-4, John Larkin wrote:

On 17 Jun 2019 18:21:49 -0700, Winfield Hill <winfieldhill@yahoo.com
wrote:

John Larkin wrote...

We're supposed to rework the economy of the
entire world based on climate simulations.

What could possibly go wrong with that?

What's going wrong, is that the world is
melting down, as many are nay-saying, and
we will end up with flooded cities, and
devastated farming and living areas.

That's what the simulations have been predicting for decades. We
should all be dead by now. We aren't.

Actually, nothing much is happening, except that crop yields and life
spans keep getting better.

Well life expectancy is going down in the US for the first time*,
but I don't think that's because of the climate.

I read some report that said climate change would be a net good for the
higher latitudes, (Canada, Northern US N. Asia, etc.) and net bad for the
tropics and lower latitudes. (Sorry my friends in Oz)

George H.
(Well, I guess it alos went down during the Spanish flu outbreak, ~1918-20)

Sea level has been creeping up a couple of mm per year since the LIA
ended around 1850.

This is a Golden Age for humanity, and will be until we get the next
ice age.


--

John Larkin Highland Technology, Inc

lunatic fringe electronics

 

[Jan Panteltje]

On a sunny day (Tue, 18 Jun 2019 07:04:12 -0700) it happened John Larkin
<jjlarkin@highlandtechnology.com> wrote in
<6mrhge59b3k4a67k83rv1lqp8bnv57s0l7@4ax.com>:

On Tue, 18 Jun 2019 04:19:24 GMT, Jan Panteltje
pNaOnStPeAlMtje@yahoo.com> wrote:

On a sunny day (Mon, 17 Jun 2019 21:49:17 -0400) it happened bitrex
user@example.net> wrote in <yqXNE.41731$IQ6.21299@fx09.iad>:

The 737 Max handled very much like a 737 there were not huge engineering
surprises there. It was just different enough that they wanted to avoid
a different type rating. It was more of a bean-counting problem than an
engineering problem.

No, that plane is unstable by nature due to the position of the engines if I understand it right.
They wanted to fix that with some software.
That worked, then they 'simplified' the software, removed a G sensor, and that did not work.
The basic plane designs sucks.
A good plane flight strait without correction.

If you make a paper airplane, and it is bad, it will do strange things,
you could than add all sorts of systems to make it fly right
but it would still be a POS.

Just like the F35.

The F35 will be OK. Fighter planes don't dogfight any more. F35 is an
electronics and missile platform.

We have those on order, there was one here last year,
and really, going by the sound I thought one flew over here yesterday.
There are 'air force days' somewhere not so far away, sort of where people can go
and look what's there, not in the airport close to here this year.
Anyways, F35 is not stealth, it is not stealth in the IR and it is not stealth in low frequency radar.
It is also detectable by passive radar (via radio and TV station reflections, so also low frequency).
It is a bad fighter, has only one engine (so more easily shot down),
about everything you can think of in that thing is *wrong* including that fan for VTOL in some models.
What the electronics in it does I have no idea, but it cannot make it fly better.
It is a taxpayer payed scam.

I suspect that manned fighter planes and bombers will be obsolete soon
anyhow.

Perhaps, sure missiles, rail-guns, lasers, what have you these days, will also be used.
In a real global nuclear war after the first exchange not much will fly I'd think, but I could be wrong.
For smaller scale conflicts it may or may not work,
I like the F16 a lot better.

And the other side MIGs, do not know what China has..
But China invented the gunpowder and had rockets before any of us westerns,
so who knows what they can come up with, now they already can shoot down sats.

 

[legg]

On Tue, 18 Jun 2019 10:50:33 -0400, bitrex <user@example.net> wrote:

On 6/18/19 6:58 AM, Bill Sloman wrote:
On Tuesday, June 18, 2019 at 3:41:14 AM UTC+2, bitrex wrote:
On 6/17/19 8:29 PM, Tom Gardner wrote:
Nobody in their right mind would sign-off a complex circuit
solely on the basis of a spice simulation. But Boeing is
planning on doing the equivalent for their 777X!

 "Specifically, Boeing is “reducing the scope and duration
 of certain costly physical tests used to certify the
 planemaker’s new aircraft,” Reuters reported over the
 weekend.
 We're thus told that engineers working on Boeing's new
 777X airliner project are intending to use computer
 simulations instead of real-world flight tests to
 validate their engineering decisions."

What could possibly go wrong with that?

https://www.theregister.co.uk/2019/06/17/boeing_certification_simulation_tests/


https://www.reuters.com/article/us-france-airshow-boeing-certification-e/exclusive-boeing-seeking-to-reduce-scope-duration-of-some-physical-tests-for-new-aircraft-sources-idUSKCN1TH0A3


Boeing hasn't started a clean-sheet design in decades and they'll likely
be selling variants of the 737 through the year 2080 so it'll probably
be OK.

Simulation lets you test all kinds of edge-cases repeatedly that would
be extremely dangerous to do even once in the real world.

The 737-Max hasn't been OK.


True, but for more complicated reasons than simply in which venue they
tested the relevant aspects of flight control software. Not like it
wasn't tested by real test pilots in the real world, too. That also
didn't seem to reveal any problems to them. From what I've read though
either venue would have been sufficient, in hindsight.

That is to say neither simulation nor the real world can help you test
edge cases by itself if you don't know and can't think up what it is
you're looking for

Actually, the single sensor 'fix' was the result of test flight
issues. It just wasn't re-test-flighted.

RL

 

[John Larkin]

On Mon, 17 Jun 2019 20:17:29 -0700, John Larkin
<jjlarkin@highlandtechnology.com> wrote:

On Mon, 17 Jun 2019 21:41:09 -0400, bitrex <user@example.net> wrote:

On 6/17/19 8:29 PM, Tom Gardner wrote:
Nobody in their right mind would sign-off a complex circuit
solely on the basis of a spice simulation. But Boeing is
planning on doing the equivalent for their 777X!

 "Specifically, Boeing is “reducing the scope and duration
 of certain costly physical tests used to certify the
 planemaker’s new aircraft,” Reuters reported over the
 weekend.
 We're thus told that engineers working on Boeing's new
 777X airliner project are intending to use computer
 simulations instead of real-world flight tests to
 validate their engineering decisions."

What could possibly go wrong with that?

https://www.theregister.co.uk/2019/06/17/boeing_certification_simulation_tests/


https://www.reuters.com/article/us-france-airshow-boeing-certification-e/exclusive-boeing-seeking-to-reduce-scope-duration-of-some-physical-tests-for-new-aircraft-sources-idUSKCN1TH0A3


Boeing hasn't started a clean-sheet design in decades and they'll likely
be selling variants of the 737 through the year 2080 so it'll probably
be OK.

They will start on the NMA, the New Midrange Aircraft, in the next few
years. The CEO just said so in an interview with Aviation Week.

Just read that they expect it to be in service in 2025.


--

John Larkin Highland Technology, Inc

lunatic fringe electronics

 

[John Larkin]

On Tue, 18 Jun 2019 05:01:59 GMT, Jan Panteltje
<pNaOnStPeAlMtje@yahoo.com> wrote:

On a sunny day (Tue, 18 Jun 2019 00:37:50 -0400) it happened bitrex
user@example.net> wrote in <zUZNE.59350$935.48043@fx46.iad>:

On 6/18/19 12:19 AM, Jan Panteltje wrote:
On a sunny day (Mon, 17 Jun 2019 21:49:17 -0400) it happened bitrex
user@example.net> wrote in <yqXNE.41731$IQ6.21299@fx09.iad>:

The 737 Max handled very much like a 737 there were not huge engineering
surprises there. It was just different enough that they wanted to avoid
a different type rating. It was more of a bean-counting problem than an
engineering problem.

No, that plane is unstable by nature due to the position of the engines if I understand it right.
They wanted to fix that with some software.
That worked, then they 'simplified' the software, removed a G sensor, and that did not work.
The basic plane designs sucks.
A good plane flight strait without correction.

If you make a paper airplane, and it is bad, it will do strange things,
you could than add all sorts of systems to make it fly right
but it would still be a POS.

Just like the F35.


I don't believe it was dynamically unstable inherently like some (most?)
modern military combat aircraft are.

Toss it like a glider with no electronic flight controls, trimmed for
level flight, and it will probably enter a phugoid like most (all?)
large passenger aircraft do.

From what I have read, increasing engine power with the new engine positions
gave it a tendency to stall.
They moved the engine position to get better fuel efficiency?

More fuel-efficient engines have giant fans, and they would scrape the
ground. Landing gear was extended as far as practical, and then the
engine was moved forward and up. Airbus did similar things.

Moving the engine changed flight dynamics and introduced a hazard,
which Boeing fixed with software, badly.

Most planes nowadays have computer based "flight laws" that stabilze
things. Airbus planes are flown with a joystick that inputs data to a
computer.




--

John Larkin Highland Technology, Inc

lunatic fringe electronics

 

[bitrex]

On 6/18/19 6:58 AM, Bill Sloman wrote:

On Tuesday, June 18, 2019 at 3:41:14 AM UTC+2, bitrex wrote:
On 6/17/19 8:29 PM, Tom Gardner wrote:
Nobody in their right mind would sign-off a complex circuit
solely on the basis of a spice simulation. But Boeing is
planning on doing the equivalent for their 777X!

 "Specifically, Boeing is “reducing the scope and duration
 of certain costly physical tests used to certify the
 planemaker’s new aircraft,” Reuters reported over the
 weekend.
 We're thus told that engineers working on Boeing's new
 777X airliner project are intending to use computer
 simulations instead of real-world flight tests to
 validate their engineering decisions."

What could possibly go wrong with that?

https://www.theregister.co.uk/2019/06/17/boeing_certification_simulation_tests/


https://www.reuters.com/article/us-france-airshow-boeing-certification-e/exclusive-boeing-seeking-to-reduce-scope-duration-of-some-physical-tests-for-new-aircraft-sources-idUSKCN1TH0A3


Boeing hasn't started a clean-sheet design in decades and they'll likely
be selling variants of the 737 through the year 2080 so it'll probably
be OK.

Simulation lets you test all kinds of edge-cases repeatedly that would
be extremely dangerous to do even once in the real world.

The 737-Max hasn't been OK.

True, but for more complicated reasons than simply in which venue they
tested the relevant aspects of flight control software. Not like it
wasn't tested by real test pilots in the real world, too. That also
didn't seem to reveal any problems to them. From what I've read though
either venue would have been sufficient, in hindsight.

That is to say neither simulation nor the real world can help you test
edge cases by itself if you don't know and can't think up what it is
you're looking for

 

[John Larkin]

On Mon, 17 Jun 2019 22:00:56 -0400, bitrex <user@example.net> wrote:

On 6/17/19 9:04 PM, John Larkin wrote:
On Tue, 18 Jun 2019 01:47:25 +0100, Tom Gardner
spamjunk@blueyonder.co.uk> wrote:

On 18/06/19 01:35, John Larkin wrote:
On Tue, 18 Jun 2019 01:29:15 +0100, Tom Gardner
spamjunk@blueyonder.co.uk> wrote:

Nobody in their right mind would sign-off a complex circuit
solely on the basis of a spice simulation. But Boeing is
planning on doing the equivalent for their 777X!

"Specifically, Boeing is “reducing the scope and duration
of certain costly physical tests used to certify the
planemaker’s new aircraft,” Reuters reported over the
weekend.
We're thus told that engineers working on Boeing's new
777X airliner project are intending to use computer
simulations instead of real-world flight tests to
validate their engineering decisions."

What could possibly go wrong with that?

https://www.theregister.co.uk/2019/06/17/boeing_certification_simulation_tests/

https://www.reuters.com/article/us-france-airshow-boeing-certification-e/exclusive-boeing-seeking-to-reduce-scope-duration-of-some-physical-tests-for-new-aircraft-sources-idUSKCN1TH0A3

We're supposed to rework the economy of the entire world based on
climate simulations.

Er, no. Climate modelling, which is very different.
But back to the main point...

Boeing can do non-destructive and destructive tests
on their products, so simulation isn't /necessary/.
I'd argue that simulation definitely isn't /sufficient/.

Precisely what destructive and non-destructive
tests can we do with the climate?


What could possibly go wrong with that?

Wrong question. A better question is whether
modelling (not simulation) will help us understand
possibilities and consequences in situations
where tests are impossible.

What's the difference between climate modelling and climate
simulation?


Actually, we do go directly to production on electronic instruments
based on Spice simulation.


Simulation is better at catching fails early than validating success.

I sometimes design by fiddling and simulation, and don't actually
understand the circuit until after the sim works. Why not?

in my experience, if the initial assumptions are valid, if something
works in the sim then there is a very good chance it will work
consistently IRL. But there's also no guarantee that the real circuit
will perform consistently either just because it does on a breadboard,
during one test run.

but again if the initial assumptions are valid, if something is going
wrong with the sim then there is a 0% chance the real circuit will
actually work to specification. Zip. Zero. None.

No, simulations can, and do, fail but the hardware works fine. There
are several reasons for that, one obvious one being bad models.


--

John Larkin Highland Technology, Inc
picosecond timing precision measurement

jlarkin att highlandtechnology dott com
http://www.highlandtechnology.com

 

[John Larkin]

On Tue, 18 Jun 2019 15:42:01 GMT, Jan Panteltje
<pNaOnStPeAlMtje@yahoo.com> wrote:

On a sunny day (Tue, 18 Jun 2019 07:04:12 -0700) it happened John Larkin
jjlarkin@highlandtechnology.com> wrote in
6mrhge59b3k4a67k83rv1lqp8bnv57s0l7@4ax.com>:

On Tue, 18 Jun 2019 04:19:24 GMT, Jan Panteltje
pNaOnStPeAlMtje@yahoo.com> wrote:

On a sunny day (Mon, 17 Jun 2019 21:49:17 -0400) it happened bitrex
user@example.net> wrote in <yqXNE.41731$IQ6.21299@fx09.iad>:

The 737 Max handled very much like a 737 there were not huge engineering
surprises there. It was just different enough that they wanted to avoid
a different type rating. It was more of a bean-counting problem than an
engineering problem.

No, that plane is unstable by nature due to the position of the engines if I understand it right.
They wanted to fix that with some software.
That worked, then they 'simplified' the software, removed a G sensor, and that did not work.
The basic plane designs sucks.
A good plane flight strait without correction.

If you make a paper airplane, and it is bad, it will do strange things,
you could than add all sorts of systems to make it fly right
but it would still be a POS.

Just like the F35.

The F35 will be OK. Fighter planes don't dogfight any more. F35 is an
electronics and missile platform.

We have those on order, there was one here last year,
and really, going by the sound I thought one flew over here yesterday.
There are 'air force days' somewhere not so far away, sort of where people can go
and look what's there, not in the airport close to here this year.
Anyways, F35 is not stealth, it is not stealth in the IR and it is not stealth in low frequency radar.
It is also detectable by passive radar (via radio and TV station reflections, so also low frequency).
It is a bad fighter, has only one engine (so more easily shot down),
about everything you can think of in that thing is *wrong* including that fan for VTOL in some models.

Aircraft carriers are big billion-dollar targets. Vertical takeoff and
land lets small ships become carriers. Or any field or parking lot
become an airport.

What the electronics in it does I have no idea, but it cannot make it fly better.
It is a taxpayer payed scam.


I suspect that manned fighter planes and bombers will be obsolete soon
anyhow.

Perhaps, sure missiles, rail-guns, lasers, what have you these days, will also be used.
In a real global nuclear war after the first exchange not much will fly I'd think, but I could be wrong.
For smaller scale conflicts it may or may not work,
I like the F16 a lot better.

And the other side MIGs, do not know what China has..
But China invented the gunpowder and had rockets before any of us westerns,
so who knows what they can come up with, now they already can shoot down sats.

China is struggling to build commercial planes and especially
struggling to build jet engines. The engines are really hard.


--

John Larkin Highland Technology, Inc
picosecond timing precision measurement

jlarkin att highlandtechnology dott com
http://www.highlandtechnology.com

 

[bitrex]

On 6/18/19 1:14 PM, John Larkin wrote:

On Mon, 17 Jun 2019 22:00:56 -0400, bitrex <user@example.net> wrote:

On 6/17/19 9:04 PM, John Larkin wrote:
On Tue, 18 Jun 2019 01:47:25 +0100, Tom Gardner
spamjunk@blueyonder.co.uk> wrote:

On 18/06/19 01:35, John Larkin wrote:
On Tue, 18 Jun 2019 01:29:15 +0100, Tom Gardner
spamjunk@blueyonder.co.uk> wrote:

Nobody in their right mind would sign-off a complex circuit
solely on the basis of a spice simulation. But Boeing is
planning on doing the equivalent for their 777X!

"Specifically, Boeing is “reducing the scope and duration
of certain costly physical tests used to certify the
planemaker’s new aircraft,” Reuters reported over the
weekend.
We're thus told that engineers working on Boeing's new
777X airliner project are intending to use computer
simulations instead of real-world flight tests to
validate their engineering decisions."

What could possibly go wrong with that?

https://www.theregister.co.uk/2019/06/17/boeing_certification_simulation_tests/

https://www.reuters.com/article/us-france-airshow-boeing-certification-e/exclusive-boeing-seeking-to-reduce-scope-duration-of-some-physical-tests-for-new-aircraft-sources-idUSKCN1TH0A3

We're supposed to rework the economy of the entire world based on
climate simulations.

Er, no. Climate modelling, which is very different.
But back to the main point...

Boeing can do non-destructive and destructive tests
on their products, so simulation isn't /necessary/.
I'd argue that simulation definitely isn't /sufficient/.

Precisely what destructive and non-destructive
tests can we do with the climate?


What could possibly go wrong with that?

Wrong question. A better question is whether
modelling (not simulation) will help us understand
possibilities and consequences in situations
where tests are impossible.

What's the difference between climate modelling and climate
simulation?


Actually, we do go directly to production on electronic instruments
based on Spice simulation.


Simulation is better at catching fails early than validating success.

I sometimes design by fiddling and simulation, and don't actually
understand the circuit until after the sim works. Why not?


in my experience, if the initial assumptions are valid, if something
works in the sim then there is a very good chance it will work
consistently IRL. But there's also no guarantee that the real circuit
will perform consistently either just because it does on a breadboard,
during one test run.

but again if the initial assumptions are valid, if something is going
wrong with the sim then there is a 0% chance the real circuit will
actually work to specification. Zip. Zero. None.

No, simulations can, and do, fail but the hardware works fine. There
are several reasons for that, one obvious one being bad models.

Yeah and they can fail because there's e.g. no noise to make an
oscillator start which falls under "initial assumptions" I'd say.

Guess I've been fortunate to never use a model that didn't seem to
represent reality in the cases I used it but I don't use Maxim regularly
(at all.)