Posts by I ain't Spartacus

Re: I would expect a longer process for re-certification

ChrisG,

I don't disagree with you. However, I'm cautious. I've only read newspaper reports so far - and neither crash investigation is complete. The Ethiopia crash is barely even started - and even the info from the Lion Air crash is only preliminary.

If true, I find the info from the Seattle Times really disturbing. Because it implies failure everywhere:

1. Boeing didn't fully understand the requirements the airframe imposed on the MCAS design until test flying - which is fair enough that's why we test. But then on finding such radical differences, didn't re-asses the system. Or even report the problem back to regulators. The documentation wasn't updated.

2. Boeing also seem to have misunderstood what their own software could do. MCAS should only have authority to move the stabiliser by 0.6°. Then on test flying that was upped to 2.5° without telling anyone. But in reality the authority is unlimited, since the system has no memory of what it's previously done - so it will keep adjusting the stabiliser until it reaches the stop - setting which will crash the aircraft.

3. Why is there a stabiliser setting which can cause unavoidable aircraft loss anyway? I'm no expert, but I can imagine there might be reasons for this, but it does surprise me a little.

4. Finally failure of regulation. The FAA push less important stuff off to self-certification. But only the FAA get to decide what bit they'll certify and what bits Boeing get to. The Seattle Times allege that FAA management were pushing the certification team to push more-and-more areas off to Boeing in order to get the plane certified quicker. Either because the FAA's resources have been cut, or because of pressure to get the plane into service to meet competition from Airbus' A320Neo. If true this suggests regulatory capture, pressure from government due to lobbying or underfunding - or some of all three.

Re: Odd

There's a standard procedure for trim runaway - an already existing problem where the auto-trim system isn't working. And Boeing decided that MCAS failure should be treated in the same way. Which is to disable the the stabiliser trim motor - and do it by a manual wheel. The problem being that MCAS doesn't fail in the same way as trim runaway, so pilots weren't thinking that was the problem and responding in the way Boeing had hoped for.

Re: Pull Breakers

Jos V,

I guess you'd expect the planes to be going fast. If they'd got the throttles set to high power for climb-out, but weren't climbing because the stupid MCAS is trying to kill them, then the plane is going to be gaining speed instead of altitude. Which perhaps they were too busy to notice, or wanted to keep high power as they were trying to get the plane to go up, if only the computer wasn't actively working against them.

Re: I would expect a longer process for re-certification

But it takes a lot of turning. It's some large number of turns between full trim both ways - which matters if you're in full nose-down trim and in a hurry to avoid hitting the ground.

It should have been "go to" rather than "get to" though.

Re: I would expect a longer process for re-certification

The article doesn't quite say 40 seconds - even if the headline does. You've got 40 seconds to respond after MCAS has triggered in that fault condition - in order to kill MCAS and recover.

But the normal response of the Lion Air pilots was to adjust the trim from their joysticks - which used the same motor as MCAS does to adjust the trim of the aircraft. So they are warring over the same system as MCAS uses. MCAS operates every ten seconds, and can move that trim all the way to the end if the pilots don't stop it. But they can keep countering it successfully, as the Lion Air pilots did for 8 minutes.

The correct procedure is to kill the trim motor power, which stops MCAS from killing you. The rush is then that if MCAS has trimmed the aircraft nose-down you have to get to the manual trim wheel, and turn that for a while until you've got back to level trim. Though as long as MCAS hasn't managed to move the stabiliser trim all the way to the stop yet, your work-out correcting it with the trim wheel will be less. And normal flight controls (pulling back on the stick) will overcome that nose-down trim, again so long as MCAS hasn't moved it all the way to the stops.

Re: Why not just disable the system and put the planes back in the air?

DaveK,

I've forgotten who now, but an airline cancelled an order for 50 737MAX yesterday. It's got a lot of orders. So Boeing can survive that. But on the other hand a lot of the orders are for huge numbers of the things, so it only takes a few airlines cancelling to be losing hundreds of orders.

Re: I would expect a longer process for re-certification

If the Seattle Times piece I read is true, then I think the aircraft will need to be re-certified. Or at least the MCAS fix will not be quick - and will need lots of work.

This boils down to two quesions:

1. Can you make MCAS not kill everyone, by flying the plane into the ground, without a major re-design?

2. Can the plane safely be flown with MCAS disabled.

The answer to 1. is easy. You can turn it off at the slightest sign of sensor error. Even though it only operates on one sensor, it has access to two - and the plane has other sensors that can be compared with it.

But the answer to 2 is the killer. Can the plane be flown safely with MCAS turned off? The FAA were told that MCAS only needed authority to change the stabiliiser pitch by 0.6°. And that was considered safe, as it could be easily compensated for by the main flight controls. But the Seattle Times said this was then changed in test flying to 2.5°. So does that mean the plane becomes dangerous without MCAS? It's because the engine cowlings generate more lift as the plane's angle of attack rises - and if this needed 4 times as much correction as first thought - then does it mean the plane is unsafe due to being longitudinally unstable? The certification files were then not updated to show this changed MCAS design.

But according to Seattle Times there's worse. MCAS keeps on working. It looks at the AOA data from it's single sensor and says do I need to push down on the nose? But doesn't apparently take account of earlier actions it has already taken. Thus if the AOA sensor is knackered it will just keep pushing the nose down until it's moved the stabiliser all the way to the stops! Which looks like a software design error to me. And also means that the certification documents that say it only has authority for a 0.6° correction are utter bollocks!

If all the above is true and you take an alarmist/worst-case attitude, then you could argue that flight testing showed the airframe to be unsafe and MCAS has a fundamental design flaw over-and-above the only operating on one sensor fuck-up.

Pen-y-gors,

In the scheme of things Trident and HS2 are pretty cheap. The Trident replacement's entire build and 30-year operating costs are expected to be a bit less than one year's NHS budget. So cancelling the Trident replacement entirely would basically allow about a 3% increase in the NHS budget - so it's not an enormous effect.

On the other hand £100bn is enough to make a serious space program.

Re: Why add new modules

The problem with gravity, is that it requires extra structural strength. And that means extra weight. It also adds mechanical complexity - which means more astronaut time spent repairing it. I don't think we've got the lifting capacity for that yet - though that should change in the next 5-10 years.

I'd be amazed if that kind of space station is less than 50 years away. Either with much bigger/cheaper launch or space based manufacturing. For now, if we want a bit of gravity, I suspect it would be easier and cheaper to build a moon base. If we can find moon based water and build a fuel plant, the economics of space flight completely changes.

Everything in spaceflight is about baby-steps. We've built, and made a decent success of the ISS. But it's a machine, and at some point it's going to become cheaper to build a new one, that it is to keep maintaining the old one. Or maybe add new core modules to the current ISS (using its robot arms to help with placement - then de-orbit the old knackered bits - though I don't know if those arms are up to the job that the shuttle could do.

But launch costs are plummeting. And that changes everything. 20 years ago it was $400m for a shuttle launch, with a new module. Falcon Heavy is now $90m odd.

4 years ago a Falcon 9 got you 25 tonnes to LEO for $60m. Going reusable dropped that to $40m. But if they really can reuse those rockets the promised 30 times (if they can even manage 10) - then launch costs can drop into the tens of millions.

Suddenly if instead of tens of thousands of dollars per kilo we can fly stuff around for thousands or even hundreds of dollars per kilo, then stuff like pharmaceuticals or computer chips can bear that cost - if they're good enough.

Re: all a waste of money

What's the running costs of ISS though? That huge figure comes from adding up all the historical costs of ISS over the 21 years since they launched it - and also includes design and build cost. So the question is what extra science can you get from giving up on ISS now?

Also that huge ISS figure probably includes shuttle launches at $1bn a time. Rather than the $400m they actually cost - the billion figure coming from adding in design, re-design and building costs. But shuttle was built before ISS was even an idea - and though some people talked about shuttle costing a billion a launch the point is that cancelling it didn't save you that, it only saved you $400m a launch.

Also the ISS does some science that we simply can't do with robot probes. Which is the science of how to live in space. Which may, or may not, be important - depending on whether we ever have space-based industry. Which depends on whether there are any useful processes we can do in microgravity, which again we can only really find out by having a space station.

The other important thing about the ISS is the foreign policy aspect. It's one of our few remaining areas of cooperation with Russia - as well as one of its original purposes which was to keep all those Soviet rocket engineers from being sacked and going off to work for Iran and North Korea.

As happens the ISS has also given the perfect excuse for NASA to develop the COTS program, which has given us a huge growth in the private space industry, so we now have all these shiny space capabiliities like SpaceX - which we otherwise wouldn't have had. And that lowering of launch costs makes robot science missions a lot cheaper too.

Sadly probably true. As the saying goes, "no bucks, no Buck Rogers."

Or perhaps to create my own version, "no pork, no giant flying sausage." OK, that one probably needs some work...

Re: Shame the UK doesnt have laws to deal with monopolies for the general public's benefit

In the future (short term) those rules stay on our books and the Competion and Markets Authority will enforce them - instead of handing the bigger cases over to the EU, as they do now. For example, didn't they just stop the Sainsbury's Asda merger?

Actually one consequence of us leaving the EU might not be our rules getting watered down, but the EU's. The German and French governments are still complaining about the Commisison stopping the Siemens Alstrom merger, and are suggesting changing EU rules to allow the creation of "European Champions" - in order to supposedly compete better globally.

Re: amazing...

That would be a rather odd view of history. Settling a war with a royal marriage had gone out of fashion a hundred years before. The politicians had started becoming the main movers of European history in the 18th Century - a process that was accelerated by the Napolenoic wars and especially the revolutions of 1848.

Only the Tsar was fully in control of government by WWI - and the Russians were considered to be out of date, or even backward. Kaiser Bill was one of the reasons the war happened, but he also wussed out at the last minute and tried to avoid, then limit, German mobilisation in order to avoid fighting on two fronts. Had he been fully in charge, he might even have stopped the war - although equally he might have changed his mind again.

France was a republic, and the British royal family had influence, but little actual power. Edward VII did quite a bit of the spadework for the entente with France - but that was as a diplomatic schmoozer, not the architect of the policy. He was sent to do it.

Re: Acceptable?

I believe that according to Christopher Clark one driver of WW1 was actually the French banks,who loaned lots of money to the Russians and Serbs to buy arms (made in France), and then when they couldn't afford the repayments suggested that a nice little war might loot enough of Austro-Hungary to pay the instalments.

That doesn't tally with the history of WWI as I learned it. Though I admit my knowledge is 20 years out of date, so new sources may have been discovered.

But it wasn't Serbia and Russia pushing for war. It was Austria-Hungary and Germany. I believe the Serb nationalists who killed Archy Duke did have links to the Serbian army - but it wasn't an authorised/planned operation, and Russia were certainly not in a position to give immediate support.

Also the Russian army simply didn't have any plans for war with Austria-Hungary that didn't also involve fighting Germany as well. As the Tsar found out when he ordered a partial mobilisation (only the units on the Austria-Hungary border) and it turned out they couldn't do it after 3 days of trying and had to fully mobilise.

That military planning inflexibility was part of the cause of the war. The Kaiser found the same thing when he tried to change his mobilisation to only being on the Eastern border and avoid threatening France.

My understanding was that Austria-Hungary were being reckless, because Germany had given them guarantees of support. And that the German military were pushing for action because Russian military reforms and rearmament meant that they expected the Russian military to be much more effective by about 1916.

The Schlieffen plan had already been updated to move forces from the French border to the Russian, because the Russian army were more effective and faster mobilising than they had been ten years before. And the German military were horrified by the idea of a two front war, hence wanting to knock France out quickly - which is why they only had 8 corps (16 divisions) in Poland to stop the Russian army and 7 armies (over 100 divisions) on the French border. And why the plan demanded the invasion of Belgium - despite the risk that would bring Britain into the war - as it was the only way to get room for a knock-out blow on France.

Re: H&S not

In the early 20th Century there was a brief craze for Radium toothpaste. Because who wouldn't want a glowing white teeth? Ah, the good old days.

linky after a quick search

Re: Acceptable?

I think it should be pointed out that we weren't really arming Johnny-Prussian in 1914. Although there were a few embarassing things that it turned out only they supplied (when they suddenly stopped), such as khaki dye for uniforms. Admittedly almost everybody else who had dreadnoughts seems to have got them from us, such as Austria-Hungary (so good they named it twice).

So it wasn't so much the arms dealers, as the governments buying so many that caused that. Plus a horrible miscalculation on what modern war would be like. And a German (and Austro-Hungarian) political leadership who were both hilariously incompetent and dangerously belligerant. With dishonourable mentions to the pisspoor diplomacy of Grey for Britain and the Russians.

On the other hand, Britain did rather insist on its right to arm the South in the US Civil War - because just because they were fighting to retain slavery was no reason not to take their money obviously...

Re: amazing...

Nah, Britain was quite nice and fluffy by that point. If Johnny-Continental cut up rough then Britian wouldn't do anything so expensive ungentlemanly as to invade - but simply nick a few of their colonies and impose a naval blockade, until they jolly well stopped.

British foreign policy was aimed at making sure no European alliance got too strong in comparison to any of the others - while doing as little as possible. So that Britain could float down the river in splendid isolation occasionally sticking out a paddle to steer (to misquote Lord Salisbury ten years later).

Re: A distinct sort of accident...

You do need to remember that increasing safety standards mean that crashes are becoming less and less frequent. And safety features built into aircraft are therefore working, to some extent that we can probably never measure accurately.

So we now have problems where the saftey systems are so complex that the pilots sometimes aren't able to diagnose and resolve the problems when they themselves go wrong - but then we have many fewer crashes to suggest that those safety systems are also doing their job most of the time.

So while I agree that we now need to look at user interface to try and avoid confusing the pilots with too many contradictory warnings when the complex systems crap out on them - we shouldn't forget that crashes are getting more complex partly because we're not having many of the stupidly simple ones anymore. For an example see that Qantas airbus 1,000ft bounces flight, where the copilot had over 1,000 different warnings in under 5 minutes to try and scroll through on his screen making it basically impossible to get any information out of such a mess.

Re: after second death crash (OT)

El Reg even call themselves a tabloid. And have the red top to prove it.

The strapline "biting the hand that feeds IT" might be a clue too...

Re: I'm probably being silly...

But MCAS is a critical system. Because the plane is, if not dangerous, then at least less than pefectly safe without it working. And yet MCAS is allowed to operate with only 2 sensors, even though it's safety critical - given it can malfuntion and fly the plane into the ground.

So you need to have a way to diagnose if the MCAS is trying to save you from your own mistake, or if MCAS is screwing up because of bad sensor data and trying to kill you. And comparing its AOA readings to your artificial horizon (and other data) is therefore important in diangosing the problem - and should not just have been an optional extra / afterthought.

Re: Congratulations

And as the pilot joke continues it's just a bonus if you can re-use the vehicle.

I'm surprised he didn't send up a space cheese though. Surely he must have eaten the last one by now? Or if not that, then a bottle case of port.

Also suprised by the boring name of the recovery ship. Couldn't find a Banks ship called Finders Keepers, so how about the Just Read The Instructions?

Re: Are people still using google after all those miss steps by google?

You're right. I've dumped Chrome right out of my life. I now use Facebook's new browser, Slurp. I'm in the beta program and it's great! I only had to fill out a 350 page contract, and sign in blood on every page - but it's OK as I was allowed to use the blood of my children, so it didn't hurt at all.

Every web page I go to is now automatically linked to my Facebook timeline, so all my friends (and anyone else watching as it auto-changes your preferences to allow everyone to share the goodness) can now see what cool stuff I'm looking at and how intelligent I am.

...That Mister Man porn site has got so many likes...