Search found 26 matches

by Thorkel
Tue Jan 14, 2020 12:58 pm
Forum: Civil Aviation
Topic: Boeing 737MAX Grounding, General Discussion Thread, January 2020
Replies: 1740
Views: 190499

Re: Boeing 737MAX Grounding, General Discussion Thread, January 2020

I'm not muddling the discussion. Most of the differences at the OS level for safety criticality come down to deterministic completion times for all operations, in addition to being able to run on fault-tolerant, hardened hardware. BSD and some flavors of Linux have been used for medical safety purp...

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by Thorkel
Tue Jan 14, 2020 12:27 pm
Forum: Civil Aviation
Topic: Boeing 737MAX Grounding, General Discussion Thread, January 2020
Replies: 1740
Views: 190499

Re: Boeing 737MAX Grounding, General Discussion Thread, January 2020

... No, I can assure you it isn't any less complex. Oh, and the kernel is certified for safety-critical use just as it's certified for PCI-DSS and it's certified for use in mainframes for financial transactions. It's far more robust and fault-tolerant than Linux. IBM's Z mainframes no longer run Li...

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by Thorkel
Tue Jan 14, 2020 12:10 pm
Forum: Civil Aviation
Topic: Boeing 737MAX Grounding, General Discussion Thread, January 2020
Replies: 1740
Views: 190499

Re: Boeing 737MAX Grounding, General Discussion Thread, January 2020

Not sure if this has been posted before - just came across this paper, written by somebody from Boeing surprisingly (although on their own dime), on the performance of pilots from a US airline when completing memory line items. It includes how well they did at executing the runaway stabiliser checkl...

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by Thorkel
Mon Jan 13, 2020 12:31 am
Forum: Civil Aviation
Topic: Boeing 737MAX Grounding, General Discussion Thread, January 2020
Replies: 1740
Views: 190499

Re: Boeing 737MAX Grounding, General Discussion Thread, January 2020

"No issues" is incorrect. That's not real-world safety. Thousands of aircraft are flying today with known, potentially dangerous issues (and airlines too, but that's another avenue). It begs the question as to why the MAX must be held to a different standard. Real-world safety has a cost ...

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by Thorkel
Mon Oct 28, 2019 12:08 pm
Forum: Civil Aviation
Topic: Updated: Final report of Lion Air JT610 has been released
Replies: 231
Views: 45519

Re: Updated: Final report of Lion Air JT610 has been released

If I am correct, when the 737MAX returns to service it will still have the same Functional Hazard Analysis grading of "Major". As such, the original assumptions made by Boeing may be found to be correct. From what I understand, the issues with MCAS revolve around pilot control when MCAS e...

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by Thorkel
Sun Aug 04, 2019 11:46 am
Forum: Civil Aviation
Topic: Boeing 737MAX Grounded Worldwide Q3 2019
Replies: 4380
Views: 663563

Re: Boeing 737MAX Grounded Worldwide Q3 2019

Thorkel, thanks for the VxWorks overview. What’s your guess on an OS for the computers aboard the MAX? I personally doubt there is one. At the risk of teaching people to suck eggs you could kind of put OSs on a spectrum. At one there’s ‘No OS’ (and no BIOS/EFI or anything like that). The processor ...

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by Thorkel
Sun Aug 04, 2019 1:39 am
Forum: Civil Aviation
Topic: Boeing 737MAX Grounded Worldwide Q3 2019
Replies: 4380
Views: 663563

Re: Boeing 737MAX Grounded Worldwide Q3 2019

Not to dispute this, but in modern processors (e.g. Intel PC processor families for the past 15 years or so) you actually don't know this even if you write directly in the machine code. This is another reason to stick to ancient architectures that are now decades old. This is correct. All modern pr...

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by Thorkel
Tue Jul 09, 2019 2:27 pm
Forum: Civil Aviation
Topic: Boeing 737MAX Grounded Worldwide Q3 2019
Replies: 4380
Views: 663563

Re: Boeing 737MAX Grounded Worldwide Q3 2019

No real mention of schedulers or operating systems, though. https://en.wikipedia.org/wiki/VxWorks#Notable_uses says 787 used VxWorks for an OS. I wonder if they regret that decision. VxWorks parent was run by a bunch of greedy SOBs that make Boeing look like a non-profit organization. Yeah, I devel...

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by Thorkel
Tue Jul 09, 2019 7:46 am
Forum: Civil Aviation
Topic: Boeing 737MAX Grounded Worldwide Q3 2019
Replies: 4380
Views: 663563

Re: Boeing 737MAX Grounded Worldwide Q3 2019

Thorkel, thanks for the informative post. Ada slipped my thought process since I never used it. Assuming you are right about Ada on the 777, what OS do you think was used on that project? Or maybe Ada comes with it’s own runtime environment to do periodic scheduling? As far as the 737, my guess is ...

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by Thorkel
Tue Jul 09, 2019 5:01 am
Forum: Civil Aviation
Topic: Boeing 737MAX Grounded Worldwide Q3 2019
Replies: 4380
Views: 663563

Re: Boeing 737MAX Grounded Worldwide Q3 2019

I agree with this. That’s what we did years ago. They are probably reprogramming some C or C+ routines/objects in assembly language to get more speed. It is labor intensive but easy to check for errors with software simulations. One of my first thoughts when I heard about the "slow response ti...

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by Thorkel
Fri Jun 28, 2019 10:44 am
Forum: Civil Aviation
Topic: Boeing 737MAX Grounded Worldwide Q2 2019
Replies: 3768
Views: 411952

Re: Boeing 737MAX Grounded Worldwide Q2 2019

The other thing, in terms of timeliness, is that if these chips are associated with real-time constraints is they won’t be running anything approaching a ‘normal’ OS. They’ll be no pre-emotive multitasking or anything like that (again, doesn’t help for worst case execution times). It’ll be single t...

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by Thorkel
Thu Jun 27, 2019 10:46 pm
Forum: Civil Aviation
Topic: Boeing 737MAX Grounded Worldwide Q2 2019
Replies: 3768
Views: 411952

Re: Boeing 737MAX Grounded Worldwide Q2 2019

I disagree with that assessment its quite possible that Boeing has just run out of processing power for the amount of tasks the computer is required to perform. I think they will need change both (software and hardware) upgrades probably needed because now MCAS software needs to deal with more situ...

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by Thorkel
Wed Jun 12, 2019 2:06 pm
Forum: Civil Aviation
Topic: Boeing 737MAX Grounded Worldwide Q2 2019
Replies: 3768
Views: 411952

Re: Boeing 737MAX Grounded Worldwide Q2 2019

We would have a hard time justifying a human based control having a PFD of less than 0.1. If the safety case has a low initiating event frequency, multiple layers of protection, and you end up with an acceptable residual risk then that’s fine - in other words, in the NG case, people can be a long w...

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by Thorkel
Wed Jun 12, 2019 11:39 am
Forum: Civil Aviation
Topic: Boeing 737MAX Grounded Worldwide Q2 2019
Replies: 3768
Views: 411952

Re: Boeing 737MAX Grounded Worldwide Q2 2019

There was nothing telling the pilots what it was as the light wasnt there, by the time they flicked through 200 odd pages to find the answer to something that even ETs MAX Simulator (which boeing has now admitted didnt act like a MAX in flight) couldnt teach them, they were dead. To me the question...

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by Thorkel
Mon May 27, 2019 5:26 am
Forum: Civil Aviation
Topic: Updated: Qantas saying it is almost ready to select Project Sunrise aircraft
Replies: 1494
Views: 288118

Re: Updated: Qantas saying it is almost ready to select Project Sunrise aircraft

AJ is on record saying that PER isn’t going anywhere when the MEL and SYD go non stop. Which seems to make sense as I have heard PER has one of, if not the, largest UK ex-pat community around and therefore O&D should be strong enough to sustain the route without the MEL tag-on. IMHO depending o...

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by Thorkel
Mon Apr 08, 2019 11:43 am
Forum: Civil Aviation
Topic: B737MAX Grounded Worldwide Q1 2019
Replies: 6476
Views: 746001

Re: B737MAX Grounded Worldwide

b) The aero issue MCAS was designed to deal with was IMHO not catastrophic or hazardous and Boeing and the FAA both agreed. There was no carelessness in this assessment. No carelessness in deciding that the potential failure of a control system designed to operate solely in the flight regime near s...

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by Thorkel
Thu Apr 04, 2019 8:54 am
Forum: Civil Aviation
Topic: AIrbus to update A320 flight warning system after VARA incident in 2015
Replies: 3
Views: 1156

Re: AIrbus to update A320 flight warning system after VARA incident in 2015

Airbus is to upgrade the flight warning system on the A320 after an incident onboard a VARA A320 operating PER-OCM (Boolgeeda - an Iron Ore mine located in northern WA) Pedantic, but Boolgeeda is just the airport - not a mine. Boolgeeda airport services multiple Rio Tinto mines in the area (Brockma...

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by Thorkel
Thu Mar 21, 2019 3:06 am
Forum: Civil Aviation
Topic: B737MAX Grounded Worldwide Q1 2019
Replies: 6476
Views: 746001

Re: B737MAX Grounded Worldwide

If you are not going to hold Pilots responsible for making mistakes and blame it all on the machine (which can and will fail sometimes) then why have pilots at all? Just replace them with computers now and every time they crash just bankrupt the manufacturer. Systems will fail - Pilots have to be a...

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by Thorkel
Thu Mar 21, 2019 12:06 am
Forum: Civil Aviation
Topic: B737MAX Grounded Worldwide Q1 2019
Replies: 6476
Views: 746001

Re: B737MAX Grounded Worldwide

Guys, trim is your friend. USE IT!! Yep - and if the electronic trim controls on the column is working correctly - as they were - it at first glance does not appear unreasonable to use them to keep the aircraft trimmed if you don't know the failure modes associated with MCAS. This, I think, is part...

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by Thorkel
Tue Mar 19, 2019 2:50 am
Forum: Civil Aviation
Topic: B737MAX Grounded Worldwide Q1 2019
Replies: 6476
Views: 746001

Re: B737MAX Grounded Worldwide

Here is an FCOM for NG: https://aviation-is.better-than.tv/B737NG_FCTM_(31-10-05).pdf Section 8.16 concerns runaway stabilizer trim: Runaway Stabilizer Hold the control column firmly to maintain the desired pitch attitude. If uncommanded trim motion continues, the stabilizer trim commands are inter...

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by Thorkel
Tue Feb 05, 2019 7:08 pm
Forum: Civil Aviation
Topic: Australian Aviation Thread - February 2019
Replies: 560
Views: 75452

Re: Australian Aviation Thread - February 2019

The large Miners such as BHP & Rio Tinto have their HQ's in Melbourne, this would drive some demand for the seats up the front for their execs visiting their African operations. BHP does, but Rio doesn't have its HQ in Mel. Rio has a couple of small-ish offices in Melbourne, but officially the ...

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by Thorkel
Mon Jan 14, 2019 4:14 am
Forum: Civil Aviation
Topic: Emirates announces 2019 schedule changes
Replies: 78
Views: 16800

Re: Emirates announces 2019 expansion outline

For SYD I am not surprised that they are cutting a daily frequency, but interesting that it has cut one of their long-standing 1-stop flights. With all the capacity that was added into SYD (extra 1 daily QR, EY going to 2 x daily A380 and the 4th daily EK A380 flight), it was obvious that things we...

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by Thorkel
Sat Nov 10, 2018 10:45 am
Forum: Civil Aviation
Topic: B787-10 future prospects?
Replies: 219
Views: 28387

Re: B787-10 future prospects?

The 787-10 has kind of the same "small wing" syndrome as the A321. It wants further, but lacks the wing with 40t payload, (280 passengers, headwind, reserves and well filled cargo containers); <5000Nm http://i298.photobucket.com/albums/mm262/ferpe_bucket/343787-10and350-900realPilotsPRcha...

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by Thorkel
Sat Feb 18, 2017 10:47 am
Forum: Civil Aviation
Topic: The 787 and 9-abreast
Replies: 270
Views: 29873

Re: The 787 and 9-abreast

Ok, first post - be gentle :) Just to bring an example in to play here, these are the cheapest prices of a one-way direct flight from SYD to LAX (first route I could think of with multiple types flying on it), one month from today, on skyscanner. VA1 - 773 (9Y) - AUD$1037. AA72 - 773 (10Y) - AUD$111...

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