Category: Systems

Regulatory Insights

I can’t remember if my teacher was talking about maths or physics. His scholarly advice has stuck with me. When things get complex, they can seem overwhelming. Problems seem insolvable. So, it’s good to take a deep breath, step back and see if it’s possible to reduce the problem to its most basic elements. Do what could be called helicopter behaviour. Try to look at the problem top-down, in its simplest form. Break it into parts to see if each part is more easily comprehended.

Today’s international aviation regulatory structure, for design and production, follows the arrow of time. From birth to death. Every commercial aircraft that there ever was started as a set of ideas, progressed to a prototype and, if successful, entered service to have a life in the air.

This elementary aircraft life cycle is embedded in standards as well as aviation rules. Documents like, ARP4754(), Aerospace Recommended Practice (ARP) Guidelines for Development of Civil Aircraft and Systems are constructed in this manner. There are as many graphs and curves that represent the aircraft life cycle as there are views on the subject, but they all have common themes.

That said, the end-of-life scenarios for aircraft of all kinds is often haphazard. Those like the Douglas DC-3 go on almost without end. Fascinatingly, this week, I read of an Airbus A321neo being scrapped after only 6-years of operations. Parts being more valuable than the aircraft.

Generally, flight-time lives in operational service are getting shorter. The pace of technology is such that advances offer commercial and environmental advantages that cannot be resisted. Operating conditions change, business models change and innovation speeds forward.

My earlier proposition was that our traditional aviation regulatory structure is out of date. Well, the detail is ever evolving – it’s true. Some of the fundamentals remain. The arrow of time, however fast the wheels spin, mixing my metaphors, remains an immobile reality.

In airworthiness terms an aircraft life cycle is divided into two halves. Initial airworthiness and continuing airworthiness. This provides for a gate keeper. A design does not advance into operational service, along the aircraft life cycle, until specified standards have been demonstrated as met. An authority has deemed that acceptable standards are met.

I’m arguing, this part of the aviation regulatory structure is far from out of date. However much there’s talk of so called “self-regulation” by industry it has not come into being for commercial aviation. I think there’s good reason for retaining the role that a capable independent authority plays in the system. A gate keeper is there to ensure that the public interest is served. That means safety, security and environmental considerations are given appropriate priority.

To fulfil these basic objectives there’s a need for oversight. That is the transparency needed to ensure confidence is maintained not just for a day but for the whole aircraft life cycle. And so, the case for both design and production approvals remain solid. The devil being in the detail.

Aviation Regulations Outdated?

Machines, like aircraft started life in craft workshops. Fabric and wood put together by skilful artisans. Experimentation being a key part of early aviation. It’s easy to see that development by touring a museum that I’d recommend a visit. At Patchway in Bristol there’s a corner of what was once a huge factory. In fact, somewhere where I worked in the early 1980s. Aerospace Bristol[1] is a story of heritage. A testament to the thousands who have worked there over decades.

Fabric and wood played part in the early days. The factory at Filton in Bristol started life making trams. An integral part of turn of the century city life. Carriage work brought together skilled workers in wood, metal and fabrics. It was soon recognised that these were just the skills needed for the new and emerging aircraft industry. The Bristol Aeroplane Company (BAC) was born.

It’s war that industrialised aviation. Demonstration of the value of air power led to ever more technical developments. Lots of the lessons of Henry Ford were applied to aircraft production. Factories grew in importance, employing a large workforce.

My time at the Filton site was in a building next to a hanger where the Bristol Bulldog[2] was originally produced. This was a single engine fighter, designed in the 1920s, in-service with the Royal Air Force (RAF).

Right from the start orderly processes and regulatory oversight formed part of aircraft design and production. The management of production quality started as a highly prescriptive process. As aviation grew into a global industry, the risks associated with poor design or faulty production became all too apparent.

In the civil industry, regulatory systems developed to address the control of design and production as two different worlds. Airworthiness, or fitness to fly, depended on having a good design that was produced in a consistent and reliable manner. So, now we have a regulatory framework with two pivotal concepts: DOA (Design Organisation Approval) and POA (Production Organisation Approval). It took about a century to get here. Now, these concepts are codified within EASA Part 21, FAA regulations, and other national aviation authorities’ frameworks.

Here’s my more controversial point. Is this internationally accepted regulatory model, that has evolved, conditioned by circumstances, the right one for the future? Are the airworthiness concepts of DOA and POA out of date?

This is a question that nobody wants to hear. Evolution has proved to be a successful strategy. At least, to date. What I’m wondering is, now the world of traditional factories and large administrative workforces is passing, how will regulation adjust to meet future needs?

Maybe I’ll explore that subject next.

[1] https://aerospacebristol.org/

[2] https://en.wikipedia.org/wiki/Bristol_Bulldog

Why ‘Artificial’ in AI May Be Misleading: A Deeper Look

On reflection it seems strange to me that the biggest commercial push in technology should be called Artificial Intelligence (AI). Universally, this term has seeped into the daily media as being the only form of shorthand for the coming transformation in our lives.

Generally, the word “artificial” isn’t associated with desirable qualities. If I say that it’s opposite is “natural” then there is a wide gulf between the two. It couldn’t be clearer. Place a plastic garden chair next to an antique wooden chair – case proven.

Imagine a marketing campaign for artificial cosmetics as opposed to natural cosmetics. Which one do you think would be the more successful? It’s honest to say that a product is artificial given that it’s manufactured but it’s much more appealing to talk about its natural roots.

A desire to elevate natural content has a historical context. It’s the industrial revolution that provided society with a rich wealth of choice. Trouble is that a legacy image of dark satanic mills[1] and grim-faces of exploited workers is written deep into our culture. The natural world was assaulted and abused by the unstoppable steam roller of the industrial revolution.

It’s reasonable to refer to a complex digital system as an artifact. Not in the way of an archaeological discovery. More like a popular game, chess, checkers or go, in that it’s extant and associated with a set of practices and rules.

Today, AI doesn’t exist in nature. It may be inspired by nature, in terms of analogies with the workings of our brains. Neural networks and memory. Interconnections of circuits and wires and their arrangements are a human creation.

Having written the above, it does make me think; what will happen in 1000 years? A long time for our social structures and organisation but no time at all for any inhabitants of the Earth. Will someone be writing academic tones on the natural history of computers? Humans will be looking at them, and their evolution wondering how and why they got to do what they do. Much as we might now study ravens, rats and rabbits.

Surely AI will evolve. A natural process. Current systems will inevitably have deficiencies and flaws that get corrected in future generations. Experimentation is a human domain. Give it several decades and machines will be doing it for themselves.

The word “artificial” has a big downside. Although I’m having a lot of difficulty in thinking of a better general word. In my long-term scenario, what’s coming is a new branch of evolution. We know, the complexity of human behaviour is largely conditioned by our environment. We adapt. What AI may become, continuity dependent, will likely follow a similar path.

Whenever I visit the Natural History Museum[2] in London I like to look in on our ancestors. Today, our species, Homo sapiens, is the only human living. We once lived amongst our other human ancestors. Homo is the Latin word for “human” and sapiens is derived from a Latin word meaning “wise”.

There’s a story for you. Will AI eventually become Machina sapiens?

[1] “Dark Satanic Mills” is a phrase from William Blake’s poem.

[2] https://www.nhm.ac.uk/discover/the-origin-of-our-species.html

Guilt: Double-Edged

Guilty as charged. At the end of a crime drama that’s what I want to hear. There’s been a resolution. Justice has been done. The baddies have been locked up and the aggrieved are vindicated. Oh, for the simplicity of the simple story. I guess that’s why they are liked so much.

What I want to spin a couple of lines about here is that whole subject of guilt. In reality, that multi-layered feeling is more complex than the two sides of the coin of my crime drama example. A world of purely nothing but good and bad does not exist.

There cannot be a single modern human who has never experienced a form of guilt. Even those who are on the edge of sanity or living as a total hermit will at one moment or another experience remorse, regret, or shame. A lingering uneasiness about what has happened, what’s happening or what might happen.

It’s built into our brains in a fundamental way. Because we can reflect on thoughts and events and learn from them, so we can analysis, even at a superficial level, poor decisions, failures, mistakes or tragedies.

Then comes the internalising thought that – I should do better or have done better. Surely, I should have seen that coming. How did that happen to me? Why me? What did I do? In the answer to those questions a feeling responsible permeates. For past events this can be compounded by knowledge that comes from hindsight.

These emotions can be entirely illogical. For example, feeling guilty about a random event that I have absolutely no responsibility for. An occurrence where, whatever I did, it would still have happened in one shape or form.

On the positive side, a feeling of responsible born of guilt can be a powerful motivator. Moments that tip people from a bad course of action to a good one. A true moment of learning.

On the negative side, guilty feelings can be destructive. They create resentment and even suffering. Especially when associated with any kind of injustice, intolerance or manipulation.

That gets to the point that I had in mind. It’s when people use of guilt as part of the general management toolbox. I’ve experienced that one often enough at work and elsewhere. Putting in those extra unpaid hours because if I didn’t the outcome will reflect badly on me. Doing that job, that I didn’t want to do, because someone was insistent that my saying “no” would result in failure. Not competing would let the side down.

My point. Don’t do it. For anyone who has authority over another, moral or actual, this is a foolish way to get things done. It can work in the short term. The problem is that such emotional blackmail has a lingering tail. That tail can kick-back and so it should.

What’s in a box?

I didn’t have a jack-in-the-box as a toy. Springing into life at the flick of a catch. For the larger part frightening the living daylights out of a young child. Or is it play, and thus basic training that surprising events can be scary and fun? Early days of leaning to handle risks.

In this case my boxes are square. Although they don’t need to be square. They are square or rectangular on a ballot paper (usually). These boxes are a boundary within which a mark is put to say “yes” this applies or “no” this is does not apply. Naturally, that can be the other way around too. For that matter they can indicate all sorts of conditions or views.

Here’s my beef. Back in March, this year, me and the Sun developed our relationship. There’s the giveaway – year. My number of years on Earth clocked up to sixty-five. At the time, I didn’t think of this as any more significant than past birthdays as a man of mature years. Then I got to completing numerous questionaries. Yes, I have moved the subject to more stuff to do with data and its use. Collecting data has never been so popular.

Never in the whole of human history have we, you and me, been faced with so many questionnaires. Almost every time I buy a coffee, and use a card of App to collect points, next day my in-box has an e-mail with a survey. Most of these I just ignore. Now and then, I fill one in with the ridiculous idea that the insignificant draw prize they offer could come my way.

Please offer your feedback in this short survey. The number of minutes they say that are needed are never right. Then they, the collectors of my data, get greedy. Asking for “as much detail as possible”. At this point I want to say – get real. What’s even worse is clicking on the “Next” button and then an error message comes up saying “This is required”. What audacity. Checky. Pushing my good will to its limits. If there were questionnaires about questionnaires, when it asked: “please tell us how your experience was on this occasion” they would get more than 100 creative words.

All this said, my real beef is to do with the collection of personal data. There’s no obligation to provide such data, when it comes to marketing surveys. This is when the incentivising possibility of a prize comes in. Afterall this data is valuable to the collectors with little incentive for a respondent to offer it. Surveys with prizes must have published terms and conditions. I wonder if anyone ever reads these legal niceties.

To the point. One question that often gets asked is – tick the box appropriate to my age. What I’ve noticed is that several of these unsolicited surveys have a box marked sixty-five and over. It’s like a whole section of the population is piled into one big bucket. Like we all fall off the end of the bell curve. Over 11 million people in England and Wales are like one.

I’m part of a growing cohort. That maybe good or bad but it is the case. It’s the case too that my cohort spends. Again, for good or bad, we are the beneficiaries of some good fortune. However, marketing surveys continue to sit in the stone age. At both ends of the demographic bell curve, toddlers and more mature folk, we are viewed as the same, one big bucket. I imagine data collectors and the designers of surveys have wrestled with this one. Whatever, the results don’t sit well with me.

Data Interpretation

More on that subject of number crunching. I’m not so much concerned about the numerous ways and means to produce reliable statistics as the ethical factors involved in their production.

Two things. One is the importance of saying truth to power and the other the importance of seeing things as they really are rather than how you or I would like them to be.

Starting with the first. If ever it was a hard day to say this but asserting truth is not one of several options, it’s the best option.

Whatever any short-term gains there are in distorting a description of a current situation, in the longer term the truth will out. Now, that may not have always been so. It’s often said that the victors write history. That famous view had some validity when literacy was not universal or when texts were chained in church libraries. Now, information speeds through the INTERNET (and whatever its successor will be). Controlling or supressing information has become like trying to build a castle out of sugar on a rainy day.

The second factor is more troublesome and, for that matter, more difficult. It could be the tug of war between subjectivity and objectivity. What we see is so much dependent upon the observer. What we hear is conditioned by what we’ve heard in the past.

I saw this often in the interpretation of a written narrative. Aviation accidents and incidents are reported. Databases full of multivarious reports of different origins siting there waiting to be read. This is a good thing.

It’s the choice of language that shapes our understanding of past events. That can be voluminous and contradictory. It can be minimalist and ambiguous. It can have peculiar expressions or fuzzy translations. Even if reporters are asked to codify their observations, with a tick box, there remains wide margins.

The writer of a story often knows what they want to say. It might be obvious to them what happened at the time of writing. Then it’s the reader who takes that up. A text could be read years later. Read by many others. Similar stories may exist, all written up differently. Hopefully, slight variations.

Seeing things as they really are, rather than how you would like them to be, without bias, requires more than a degree of care. A great deal of care.

It’s hard enough for an enlightened and skilled analysist to take a sentence and say “yes” I know exactly what happened. Not just what but all six of these – who, what, were, when, how and why. In future, the artificial intelligence tools that get used by authorities will have the same challenge.

For all our technological wonders, it’s the writers of reports that shapes our understanding. From a couple of sentences to a massive dissertation.

Try telling that to a maintenance engineer whose last job of the day, before going home, is to file an occurrence report after a terrible day at work. In a damp hanger with a job only half done. Tomorrow’s troubles looming.

POST: Rt Rev Nick Baines and his Thought for the Day on BBC Radio 4 is thinking the same this morning. Truth is truth. In his case it’s Christian truth that he has in mind. There lies another discussion.

The Power of Numbers

If I was to give advice to a politician in power, it would go like this: numbers matter but don’t let them dictate the right course of action. Of course that’s fully loaded advice. The right course of action is subjective. That can mean expert or non-expert judgement of such a great wide range of felicity that it doesn’t bear thinking about.

For a long time, there was a mantra that organisational policy should be data driven. There’s quite a bit of wisdom in this statement as an alternative to arbitrary opinion and volatile reactivity. There’s no doubt an organisation is better off if it has a few able number crunchers.

I can recollect times when I’ve been advised to look favourably upon one way of presenting information as opposed to another way. Not that either was in error but that one way would reflect better on the management of an organisation. This is a perfect example of Lies, Damned Lies and Statistics[1]. Which is often nothing to do with lies but rather the presentation of information. Some would say manipulation.

Sacking a head of a Bureau of Statistics because the numbers their technical people produce are not favourable, well that’s one way to go. It’s the sort of action that’s take in devoutly authoritarian countries. Better not be embarrassing the higher ups at any cost.

Suddenly, I’m taken back to my “O” level history lessons. Our enthusiastic secondary school teacher who wanted us to love the Russian revolution as much as she did. It’s a fascinating but brutal period for Europe. Here I’m thinking of Stalin’s Five-Year Plans. A Russian official, in the late 1920s, would have been very unwise indeed to produce anything other than favourable statistics. However, for all the cruelty and suffering Russia did archive a rapid industrialisation.

Numbers matter. My dictum. If they are wildly inaccurate or manipulate numbers, they are worthless. Even presentational they are worthless because few will believe. Credibility is key but that’s often the issue. Who do you trust?

My domain has been aviation safety numbers. The analysis of these numbers can be of significant consequence. Going back to that data driven philosophy, if the numbers are wrong the direction of travel will be wrong. When policy making has an objective basis then it’s much easier to justify to a wide audience. There are advantages in having trustworthy numbers.

In the ideal world, a degree of independence is essential. This is so that the producers of statistics and associate information can endeavour to be accurate and unbiased. Doing this without fear or favour to any interested party can take some resolve. It’s only possible in an environment that is both inquisitive and respectful.

I say “degree of” as an observation. Just as investigators often follow the money trail, it’s as well to consider who is paying the bills. The analyst’s salaries must come from somewhere. Again, in an idea cultural environment where integrity and trust are valued, it’s not those who are funding the number crunching work that should determine (dictate) the results. Let the numbers speak.

The ideal world doesn’t exist but it’s clearly unwise to swerve away from it at speed.

[1] https://www.york.ac.uk/depts/maths/histstat/lies.htm

Why 12,500 Pounds?

Regulation is a strange business. It often means drawing lines between A and B. Bit like map making. Those lines on a map that mark out where you are and the features of the landscape. You could say that’s when all our troubles start but it’s been proven unavoidable. As soon as our vocabulary extends to words like “big” and “small” someone somewhere is going to ask for a definition. What do you mean? Explain.

For a while you may be able to get away with saying; well, it’s obvious. That works when it is obvious for all to see. An alpine mountain is bigger than a molehill. When you get to the region where it’s not clear if a large hill is a small mountain, or not then discussion gets interesting. Some say 1000 ft (about 300 m) others say much more. There’s no one universal definition.

[This week, I drove through the Brecon Beacons. Not big mountains but treeless mountains, nevertheless. Fine on a clear day but when it rains that’s a different story. This week Wales looked at its best].

Aviation progressed by both evolution and revolution. Undeniably because of the risks involved it’s a highly regulated sector of activity. Not only that but people are rightly sensitive about objects flying over their heads.

For reasons that I will not go into, I’ve been looking at one of these lines on a regulatory map. One that’s been around for a long time.

I cannot tell you how many discussions about what’s “minor” and what’s “major” that have taken place. That’s in terms of an aircraft modification. However, these terms are well documented. Digging out and crewing over the background material and rationale is not too difficult, if you are deeply interested in the subject.

The subject I’m thinking about is that difference between what is considered in the rules to be a “large” aeroplane and a “small” aeroplane. Or for any American readers – airplane. So, I set off to do some quick research about where the figure of weight limit: maximum take-off weight of 12,500 pounds or less originated for small airplanes (aeroplanes).

I expected someone to comment; that’s obvious. The figure came from this or that historic document and has stuck ever since. It seems to work, most of the time. A confirmation or dismissal that I wanted addressed the question, is the longstanding folklore story is true. That the airplane weight limit was chosen in the early 1950s because it’s half the weight of one of the most popular commercial transport aircraft of that time.

There is no doubt that the Douglas DC-3[1] is an astonishing airplane. It started flying in 1935 and there are versions of it still flying. Rugged and reliable, this elegant metal monoplane is the star of Hollywood movies as well as having been the mainstay of the early air transport system is the US. Celebrations are in order. This year is the 90th anniversary of the Douglas DC-3[2].

What I’ve discovered, so far, is that the simple story may be true. Interestingly the rational for the weight figure has more to do with economic regulation than it has with airplane airworthiness. The early commercial air transport system was highly regulated by the State in matters both economic and safety. Managing competition was a bureaucratic process.  Routes needed approval. Thus, a distinction established between what was commercial air transport and what was not.

POST 1: There is no mention of 12,500 pounds in the excellent reference on the early days of civil aviation in the US. Commercial Air Transportation. John H. Frederick PhD. 1947 Revised Edition. Published by Richard D. Irwin Inc. Chicago.

POST 2: The small aircraft definition of 12,500 pounds max certificated take-off weight first appears in US CAB SPECIAL CIVIL AIR REGULATION. Effective February 20, 1952. AUTHORIZATION FOR AIR TAXI OPERATORS TO CONDUCT OPERATIONS UNDER THE PROVISIONS OF PART 42 OF THE CIVIL AIR REGULATIONS. This was a subject of economic regulation in the creation of the air taxi class of operations.

[1] https://airandspace.si.edu/collection-objects/douglas-dc-3/nasm_A19530075000

[2] https://www.eaa.org/airventure/eaa-airventure-news-and-multimedia/eaa-airventure-news/2025-07-17_dc3_society_celebrate_90_years_douglas_dc3_airventure25

Aircraft Safety and Fuel Starvation

Unsafe. In common language it’s the opposite to being safe. So, take a definition of “safe” and reverse it. Let’s say to be safe is to be free from harm (not a good definition). That would lead to “unsafe” being subject to harm or potentially being subject to harm. The probabilistic element always creeps in since it’s the future that is of concern. Absolute safety is as mercurial or unreal as absolute certainty.

Let’s apply this to an aircraft. The ultimate harm is that of a catastrophic event from which there is no escape. Surprisingly, taking a high-level view, there are few of these situations that can occur.

Flying, and continuing to fly, involves four forces. Lift, Weight, Thrust and Drag. It’s that simple. An aircraft moves through the air with these in balance. Flying straight and level, lift opposes weight and thrust opposes drag.

Yes, there are other safety considerations. If there are people on-board. For example, it’s important to maintain a habitable environment. At higher altitudes that requirement can be demanding. Structural integrity is important too. Otherwise flying is a short-lived experience.

In the recent Air India fatal accident, the four forces of flight were not maintained so as to make a continued safe flight possible. The wings provided lift but the force that was deficient was thrust.

Two large powerful engines, either of which could have provided enough thrust, were unable to do so. The trouble being fuel starvation. Fuel starvation occurs when the fuel supply to the engine(s) is interrupted. This can happen even when there is useable fuel on board an aircraft[1].

Sadly, in the records there are numerous aircraft incidents and accidents where this has happened. Quite a few fuel starvation incidents and accidents occur because of fuel mismanagement. This can result from a pilot selecting an incorrect, or empty, fuel tank during a flight.

Now and then, it is the aircraft systems that are at fault. The pilot(s) can be misled by a faulty fuel indication system[2]. In one notable case, a major fuel leak drained the aircraft’s fuel supply[3].

When there is useable fuel on-board an aircraft, the imperative is to restart and recover. It is not uncommon or unreasonable for there to be a delay in restarting engine(s), especially when a fuel starvation event is entirely unexpected. Diagnosis takes time given the numerous potential causes of a starvation event.

In cruise flight there is time available to perform a diagnosis and take appropriate corrective action. Both take-off and landing have their hazards. Both are busy times in the cockpit. When looking at the worldwide safety numbers, less fatal accidents occur on take-off than landing. The numbers Boeing provide put take-off at 6% and landing at 24% of fatal accidents. Each one only occupies about 1% of the total flight time.

Although these are the numbers, my view is that, even though take-offs are optional and landings are mandatory, the requirements for adequate thrust are most critical during take-off. This is arguable and it reminds me that safety assessment is never simple.

[1] https://www.faa.gov/lessons_learned/transport_airplane/accidents/G-YMMM

[2] https://asn.flightsafety.org/asndb/322358

[3] https://asn.flightsafety.org/asndb/323244

Understanding Boeing 787 Avionics

In what I’ve written so far, I’ve taken the humancentric view much as most commentators. The focus of interest being on what the two Air India crew members were doing during the critical moments of this tragic flight. Let’s shift perspective. It’s time to take an aircraft level view.

On the Boeing 787-8 “Dreamliner”, the flight deck has two crew seats and two observer seats. One observer seat is directly behind and between the two crew seats. Since these observer seats are not mentioned in the preliminary report, it’s responsible to assume that they were unoccupied.

In my days working on civil aircraft certification, it was often as a part of a multidisciplinary team. I suppose one of the privileges of working on aircraft avionic systems is that they touch every part of a modern civil aircraft. That meant working with highly experienced specialist in every technical field, including flight test pilots and engineers.

When it came to reviewing aircraft system safety assessments, we’d often put it like this, you look at the aircraft from the inside out and well look at the aircraft from the outside in. Meaning that the flight test team looked at how the aircraft flew and performed. Systems engineering specialists focused on how the aircraft functioned. What was the detailed design, the means and mechanisms. It was by putting these differing perspectives together that a comprehensive review of an aircraft could be established.

Here’s where I need to be careful. Although, I worked on the technical standards1 for complex aircraft systems, I did not work on the Boeing 787 at initial certification.

If I go back 25-years, a major change that was happening with respect to aircraft systems. It was the move to apply Integrated Modular Avionics (IMA). This was a move away from federated systems, where just about every aircraft function had its own box (autopilot, autothrottles, instruments, etc.) There was a fundamental architectural difference between federated and IMA systems.

The Boeing 787 has what is called a Common Core System (CCS). As an analogy let’s think of a time before the smart phone became universal. I had a Nokia mobile phone, a Canon camera, a HP calculator, a Dell lap-top, lots of connectors and pen and paper. Now, the only one that has survived the passage of time is the pen and paper.

So, it is with modern civil aircraft. An Integrated Modular Avionics (IMA) hosts the applications that are necessary for safe flight and landing. The IMA hosts functions that provide, Environmental Control, Electrical, Mechanical, Hydraulic, Auxiliary Power Unit (APU), Cabin Services, Flight Controls, Health Management, Fuel, Payloads, and Propulsion systems.

Information is digitised (sensors, switches and alike), processed and then acted upon. General Processing Modules (GPM) inside the aircraft CCS perform the functions needed. There’s an array of these GPMs and redundancy to provide a high integrity aircraft system.

An aircraft’s Fuel Shutoff Valve Actuator depend on the above working as intended in all foreseeable circumstances. No doubt the accident investigators are undertaking an analysis of the Boeing 787 avionics architecture to gain assurance that it worked as intended.

  1. Standards: EUROCAE started a working group (Number 60) in September 2001, which was tasked to define guidance. Later, in November 2002, there was a merge with an RTCA steering committee (Number 200). ↩︎