* Posts by SkippyBing

2048 posts • joined 21 May 2008

Airlines in Asia, Africa ground Boeing 737 Max 8s after second death crash in four-ish months

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'If you modify an existing model of aircraft such that the modification alters the flight characteristics significantly, then the new model should undergo new C of A testing'

Not so, under the current regulations there are grandfather rights and you only have to certify the changes. This makes sense when all you're doing is stretching, or shortening, a basic airframe, e.g. A320 to the A321, A319 and A318, or Boeing 777-200 to the 777-300. The question is when do the cumulative differences make it a completely different aircraft? I'd suggest when you've gone from carrying 84 pax 1500 miles to 200 pax 3000 miles over 50 years...

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Re: A programming error?

'the software seem to always assume that the sensors are correct and the pilots are not'

Actually the software realised it wasn't sure what was going on and handed over to the pilots. It turns out suddenly handing a difficult situation to a pilot who is mentally relaxed doesn't work well...

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Re: Background

'As I understand it, it does warn about what it is doing.'

My understanding is that the pilots were unaware it even existed prior to the Lion Air incident, and therefore there's no indication that it's doing anything.

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Re: According to the BBC...

This would probably be classed as LOC-I, Loss of Control Inflight, which is also an option under the ICAO Air Accident Taxonomy.

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Re: Background

'You can describe MCAS like that'

Which is why I did, mainly because I found it too depressing copying and pasting the full explanation of the certification issue I made four months ago.


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Re: Background

Strictly it's not a new stall warning system, it's an anti-stall feature that trims the aircraft nose down to prevent it stalling. If it gets erroneous data it can continue to trim nose down when there's no need to. The trim moves the whole tailplane, whereas the pilot's controls only affect the elevator, consequently it's almost physically impossible to pull out of a fully trimmed dive.

It doesn't work in the opposite sense, so it shouldn't trim the aircraft into a stall, although the normal trim could do that, although I'm not sure it has full trim authority*.

*i.e. the automatic system may not be able to trim to the limits.

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It also looks like SWA ticked the AoA display option on their 737 Max aircraft which means they also get a warning if the two sensors disagree. So if it is the same problem Lion Air had SWA pilots have a bit more information to work with.

Only 35 of SWA 737s are this variant at the moment, although they've got over 200 on order...

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Worth noting Ethiopian can't be that bad as they're allowed to fly into European airports. There's a disturbingly long list of airlines from the developing world that aren't due to maintenance and training concerns.

Incidentally you can cover static ports (the ones that are flush with the skin) you basically get a little plug that sticks in the hole. Clever designers make sure the tube part has a hollow core so if it gets broken on removal the static port still works.

UK joins growing list of territories to ban Boeing 737 Max flights as firm says patch incoming

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Currently it has full nose down trim authority, which means you have to be pulling something like 50kg back force on the control column to keep it in level flight. I'm assuming they did this rather than limit it to avoid potential problems with the limit, after all there's no situation where it'd actually need to wind it all the way forwards right?...

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Re: Avionics experts and the court of public opinion....

The grounding is because they're not sure why a second 737 Max has ploughed in in only six months, for a type that's only been in service since May 17 that's a terrible record. If you don't know why an aircraft has crashed it's often considered a good idea to stop flying them until you know why. For a similar example look at the Comet, until they know for certain why these things are crashing it's not worth the risk. Although if you think it is you can probably get a used example quite cheaply now.

Sure, we've got a problem but we don't really want to spend any money on the tech guy you're sending to fix it

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Re: Travelling to client sites

Always go west if you can, you essentially just have really long days which the body is better at adapting to than short ones. Mainly because going to bed 8 hours earlier than usual just results in lying there wide awake.

I once had to go to Brunei for work. Handily it had to be by the end of the financial year and I'd already booked leave to go to visit friends in the US in March. So in a rare outbreak of sanity they let me fly LA-Hong Kong-Brunei rather than coming back to the UK and going via Dubai. I still didn't feel brilliant when I finally got home but I did manage to go out for someone's birthday.

Long phone is loooong: Sony swipes at flagship fatigue with 21:9 tall boy

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No F****ing Notch


Not so smart after all: A techie's tale of toilet noise horror

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Re: Toilets, health trackers, sexual innuendo

I believe HR have talked to him about that and he's no loner allowed to do it.

Crash, bang, wallop: What a power-down. But what hit the kill switch?

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Re: Not Unique...

Surely the cats should deal with the mice?

Airbus will shutter its A380 production line from 2021

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Re: Airbus should sue airlines for trashing the brand

Try Etihad, I have never been on a more than 1/3rd full Etihad flight from London to Abu Dhabi or vice versa. Makes the A380 flight a dream in economy. God knows how they're solvent.

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Re: Just to big to win

To be fair far more of Rolls-Royce's A380 engines stayed on the aircraft...

Granddaddy of the DIY repair generation John Haynes has loosened his last nut

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They also do MoTs and servicing which I didn't know until I had to tow my mates TVR there. More surprisingly they got it working.

Fun fact: GPS uses 10 bits to store the week. That means it runs out... oh heck – April 6, 2019

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To be fair the first GPS satellite were proposed in the early seventies and the first launch was in 1978 so 64 or 128 bit anything was probably seen as a bit ambitious.

Personal data slurped in Airbus hack – but firm's industrial smarts could be what crooks are after

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'The Chinese already appear to have lifted the design of the Sikorsky Black Hawk'

I think owning some probably helped with that.


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'Its military division is also responsible for a number of helicopter designs in military service worldwide, including the Puma medium-lift helo flown by the RAF.'

Although that's rather by accident, the RAF Pumas are probably the most original still in service having only been upgraded after about 40 years of use and technically having the model designation SA330 for Sud Aviation the company that was merged to form Aérospatiale before that merged to become Eurocopter, before that became Airbus Helicopters. They bear very little relation to the version now produced by Airbus, the undercarriage is narrower, there's less cabin space, and the gearbox has less of a tendency to let the rotorhead fly off so you plummet to your death. I mean I still wouldn't get in one but that's not really Airbus' fault.

It's 2019, and a PNG file can pwn your Android smartphone or tablet: Patch me if you can

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Re: Errrrr.

Theoretically I could, but it's a five or six mile drive, then I have to pay for parking. Or I can do it from home. It's a tough call but generally I have better things to do than waste an hour of my weekend physically going to the bank. Double that in the week.

Techie finds himself telling caller there is no safe depth of water for operating computers

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Re: Annoying pedantry

I believe in some instances a large part of the cost of mil spec equipment is that the company involved has to employ people to deal with the MoD's* tendering process. Obviously for a laptop it's going to jack the price up a lot, whereas for a warship it'll be a rounding error, because why would you have a different tendering process?

*Fairly sure it's Treasury mandated so the NHS etc. will have similar issues.

Sad relics of UK launch capability returned to Blighty while NASA fiddles with Boeing crew

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Re: Galileo

As long as they're above 60000' before they hit the FIR boundary I think they're all good. Plus as it seems to be the RN and RAF defending Ireland on the quiet I'm not sure it'd be a problem...

Army had 'naive' approach to Capita's £1.3bn recruiting IT contract, MPs told

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Re: Who wouldn't want to join?

The relatively high levels of employment* don't help either as the Armed Forces have always struggled to recruit when there are other jobs available where you get to stay at home.

*I'm aware of the arguments that the figures are fudged but it's still at a high level by historical standards.

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Re: That would make sense

'Perhaps add an incentive for further education - matching every quid the soldier pays in tuition costs or university fees.'

It's called Enhanced Learning Credits, either three lumps of £2K that can be used to pay for up to 80% of a training course of your choice (with some benefit to the service) or when you leave you can cash them in for University Tuition. Doesn't kick in until you've done six years of service from memory, and if you're within 2 years of leaving or have left within 10 years you can pretty much spend it on what you want.

It's really not advertised highly enough to potential recruits.

There're also Standard Learning Credits which is up to £175 a year for the same purpose. Which is how I have a forklift licence.

What happens when a Royal Navy warship sees a NATO task force headed straight for it? A crash course in Morse

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Re: Azipods in reverse?

'I think that's unlikely since the MS Queen Elizabeth (90,000 tonnes) have them compared to the Queen Elizabeth Class (65,000 tonnes ).'

See this article for the Alpha design with 4 Azipods


I'm trying to track down the Naval Review article that said they couldn't get off the shelf pods powerful enough. It's worth remembering the MS QE is about 5-6 knots slower than HMS QE and drag scales with the square of speed, hence MS QE has 2 x 17.6 MW Azipods and HMS QE has 4 x 20 MW induction motors driving two shafts (two per shaft in tandem).

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Re: Azipods in reverse?

'I would think nearly all recently constructed vessels above (and possibly below) certain tonnage thresholds are designed with azimuth thrusters - providing flexibility and agility to what would otherwise seem rather ponderous indeed.'

I think the main disadvantage with azipods is that it increases the draught which may be a more important consideration for certain roles. The QE Class Carriers were originally designed with azipods but when it was realised that they'd have to be specially made as there weren't off the shelf ones powerful enough they went back to a more traditional drive train.

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If the thought of being served by stewards is attractive, the navy have just stopped the practice. Mainly because they were struggling to fill the places anyway.

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Re: Please tell me that all this is public info

I suspect it's moved since then and it's not as if the exercise wasn't widely publicised.

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Re: Azipods in reverse?

Pulling allows the prop to be more efficient as it's encountering undisturbed water rather than the turbulence you get after the pod has moved through it. Theoretically a prop at the bow would be more effective than a traditionally placed one, but then you get other problems, and the rudder would be less effective as it wouldn't be directly in the accelerated water.

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Re: About those "machinery breakdowns".....

That's nothing, before she was finally decommissioned HMS Fearles stopped having a daily fire exercise as they were having enough actual fires.

Nobody in China wants Apple's eye-wateringly priced iPhones, sighs CEO Tim Cook

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Re: Re "Idiot tax"

'And the other tax costs much much more dearly than a thousand dollars once in four years.

I'm going to have to see some maths on that.

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Re: Its worse than he is making out.

'And yet China is still Apple's third largest market after the US and Europe.'

What a country of >1 Billion people is its third largest market? Who'd have thought the population of the third largest market would equal the first and second largest added together.

New Horizons probe reveals Ultima Thule is huge, spinning... chicken drumstick?

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'Rounding out the suite is REX, the Radio Science Experiment, which is designed to measure atmospheric pressure and temperature.'

I'm going to guess low and quite cold.

It's 2019, the year Blade Runner takes place: I can has flying cars?

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'the fictional road-and-sky craft relied on a system called an aerodyne'

Aerodyne just means a heavier than air flying machine, aerostat means a lighter than air one. So the fictional craft didn't rely on a system called aerodyne, they were aerodynes.

'Year-long' delay to UK 5G if we spike Huawei deals, say telcos

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9 Months delay?

I mean as major infrastructure programmes go in this country that doesn't really seem that big a deal.

Dutch boyband hopes to reverse Brexit through the power of music

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'They're in serious danger of becoming The-Lefty-Mail.'

You don't really need the 'in serious danger of becoming' bit.

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Did they not think to audition people who could sing?

Who's watching you from an unmarked van while you shop in London? Cops with facial recog tech

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Re: One simple trick to avoid being photographed

Are you saying you get the stuff delivered to your house and pay using your own credit card?

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One simple trick to avoid being photographed

Shop online like any sane person this time of year. Most places will even wrap it for you which saves a massive faff on Christmas Day.

Happy Christmas! Bloodhound SSC refuelled by Yorkshire business chap

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'I'm not going to qualify as a submarine commander by sinking my canoe for 30 seconds, am I?'

No, for that you'd need to get it to surface again.

Spending watchdog points finger at Capita for 1,300 shortfall in British Army rookies

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Re: TBF...

'I was a soldier in the 60s and 70s. There was always the chance that the balloon might go up and we would be in action.'

There have only been two years since 1945 when there hasn't been a UK death in combat. 1968 and oddly 2016.


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Re: TBF...

'Back on the subject of the article, Private Eye has been covering this for years. Why governments keep doing the same thing - handing over public jobs to the same big companies who have no expertise and a shite track record - I really don't know.

I have this vague feeling that when awarding public contracts you can't take past performance into account. I'm trying to remember where I read that, certainly on the one occasion I got to score two competing contracts there was no section for taking it into consideration.

Amazon robot fingered for bear spray leak that hospitalised 24 staffers

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'An Amazon spokeswoman told The Register that employee safety was the firm’s top priority'

No it isn't, if it was they'd be bankrupt but with lots of employees wrapped in padding in a perfectly heated well lit environment. The same as with any organisation, ensuring its own survival is number 1, even the best company in the world only has safety as its number 2 priority.

Brit boffins build 'quantum compass'... say goodbye to those old GPS gizmos, possibly

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Re: Ah demonstation just in time. Norway / Finlands GPS knocked out by A.N. Other

'OR...presumably why there were lots of errors and shipwrecks until one had a better idea of one's location in such tempestuous waters...'

Yeah, that was pretty much cracked pre-GPS though, if you're out of sight of land you don't need GPS level accuracy and if you're in sight of land visual fixing is more than good enough.

Boeing 737 pilots battled confused safety system that plunged aircraft to their deaths – black box

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Re: Aircraft Systems

But the trim wasn't running away, it was moving a bit and then stopping which it does in normal operation. Probably on occasion it stopped when the pilots did something they expected would counteract the automatic trim and it appeared to work. If it was the only problem they had to deal with then it might have been a higher priority, but there was also an airspeed indication mismatch and a stick shaker active on one pilot's controls. Figuring out that a bit of trim movement is the most pressing issue would have been helped by knowing MCAS existed and has full authority over the stabiliser.

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'This feature is pretty much covered by long-established procedures already. '

Well it obviously isn't or they wouldn't have crashed.

Boeing claim the runaway trim procedure deals with the issue, however runaway trim presents as just that, the trim motoring all the way to the stops, MCAS is an intermittent nose down trim that the pilots may think they've countered with the standard actions because it stops and they don't know about MCAS. If you've got more than one thing going wrong, and they did because one pilot's control was shaking to indicate approach to the stall, and their airspeed indications were mismatched, the trim occasionally motoring nose down and then stopping may not register as important until it's too late.

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Re: AoA sensor replaced prior to fatal flight

It appears, based on reading the FDR data by people more knowledgeable than me that the previous flight's pilots had overcome the MCAS issue by diagnosing a failure that required isolation of the trim system. As they didn't know about MCAS they wouldn't have known that's what the problem system was but the effect was to remove it from the equation anyway. However this may have meant the next crew were starting from square one when it came to diagnosing what was going on with the various issues that they were presented with or have been primed to expect a reversal of the usual trim system rather than starting from scratch. Neither of which are great situations to be in.

'Has the cockpit been found to determine the state of the MCAS switches?'

There aren't any as such, and the pilots weren't told it existed previous to the accident. The trim cutout switch position can be determined from the FDR and I believe they hadn't been activated at the time of the accident.

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Lion Air is not a small airline, they're the Asian equivalent of RyanAir or EasyJet and the largest in Indonesia, bigger than the national airline Garuda. They were also the launch customer for the 737 MAX. The pilots were Indian and Indonesian with 6028 and 5174 flying hours respectively, does that answer your slightly loaded question?

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Re: planes/cars

'Yes, surely it's those rusty, dirty contacts that were the problem, and just needed a good cleaning. On a 3-month-old plane.'

You don't work on a lot of aircraft do you?

Compared to the production run of the average car even the 737 is a niche product, meanwhile all the parts are subjected to a drop in pressure and temperature that would stop the average automotive engine running every time they fly a sector. So after three months a contact may well just need a clean because it wasn't installed correctly in the first place or even just because.

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