Is Airworthiness Dead? 2/

Where I left the discussion there was a question mark. What does conformity mean when constant change is part of the way an aircraft system works?

It’s reasonable to say – that’s nothing new. Every time, I boot up this computer it will go through a series of states that can be different from any that it has been through before. Cumulative operating system updates are regularly installed. I depend on the configuration management practices of the Original Equipment Manufacturer (OEM). That’s the way it is with aviation too. The more safety critical the aircraft system the more rigorous the configuration management processes.

Here comes the – yes, but. Classical complex systems are open to verification and validation. They can be decomposed and reconstructed and shown to be in conformance with a specification.

Now, we are going beyond that situation where levels of complexity prohibit deconstruction. Often, we are stuck with viewing a system as a “black box[1]. This is because the internal workings of a system are opaque or “black.” This abstraction is not new. The treatment of engineered systems as black boxes dates from the 1960s. However, this has not been the approach used for safety critical systems. Conformity to an approved design remains at the core of our current safety processes. 

It’s as well to take an example to illustrate where a change in thinking is needed. In many ways the automotive industry is already wrestling with these issues. Hands free motoring means that a car takes over from a driver and act as a driver does. A vehicle may be semi or fully autonomous. Vehicles use image processing technologies that take vast amounts of data from multiple sensors and mix it up in a “black box” to arrive at the control outputs needed to safely drive.

Neural networking or heuristic algorithms may be the tools used to make sense of a vast amount of constantly changing real world data. The machine learns as it goes. As technology advances, particularly in machine learning ability, it becomes harder and harder to say that a vehicle system will always conform to an understandable set of rules. Although my example is automotive the same challenges are faced by aviation.

There’s a tendance to see such issues as over the horizon. They are not. Whereas the research, design and development communities are up to speed there are large parts of the aviation community that are not ready for a step beyond inspection and conformity checking in the time honoured way.

Yes, Airworthiness is alive and kicking. As a subject, it now must head into unfamiliar territory. Assumptions held and reinforced over decades must be revisited. Checking conformity to an approved design may no longer be sufficient to assure safety.

There are more questions than answers but a lot of smart people seeking answers.

POST 1: Explainability is going to be one of the answers – I’m sure. Explained: How to tell if artificial intelligence is working the way we want it to | MIT News | Massachusetts Institute of Technology

POST 2: Legislation, known as the Artificial Intelligence Act ‘Risks posed by AI are real’: EU moves to beat the algorithms that ruin lives | Artificial intelligence (AI) | The Guardian

POST 3: The world of the smart phone and the cockpit are here How HUE Shaped the Groundbreaking Honeywell Anthem Cockpit

[1] In science, computing, and engineering, a black box is a device, system, or object which produces useful information without revealing information about its internal workings.

Is Airworthiness dead?

Now, there’s a provocative proposition. Is Airworthiness dead? How you answer may depend somewhat on what you take to be the definition of airworthiness.

I think the place to start is the internationally agreed definition in the ICAO Annexes[1] and associated manuals[2]. Here “Airworthy” is defined as: The status of an aircraft, engine, propeller or part when it conforms to its approved design and is in a condition for safe operation.

Right away we start with a two-part definition. There’s a need for conformity and safety. Some might say that they are one and the same. That is, that conformity with an approved design equals safety. That statement always makes me uneasy given that, however hard we work, we know approved designs are not perfect, and can’t be perfect.

The connection between airworthiness and safety seems obvious. An aircraft deemed unsafe is unlikely to be considered airworthy. However, the caveat there is that centred around the degree of safety. Say, an aircraft maybe considered airworthy enough to make a ferry flight but not to carry passengers on that flight. Safety, that freedom from danger is a particular level of freedom.

At one end is that which is thought to be absolutely safe, and at the other end is a boundary beyond which an aircraft is unsafe. When evaluating what is designated as “unsafe” a whole set of detailed criteria are called into action[3].

Dictionaries often give a simpler definition of airworthiness as “fit to fly.” This is a common definition that is comforting and explainable. Anyone might ask: is a vehicle fit to make a journey through air or across sea[4] or land[5]? That is “fit” in the sense of providing an acceptable means of travel. Acceptable in terms of risk to the vehicle, and any person or cargo travelling or 3rd parties on route. In fact, “worthiness” itself is a question of suitability.

My provocative proposition isn’t aimed at the fundamental need for safety. The part of Airworthiness meaning in a condition for safe operation is universal and indisputable. The part that needs exploring is the part that equates of safety and conformity.

A great deal of my engineering career has been accepting the importance of configuration management[6]. Always ensuring that the intended configuration of systems, equipment or components is exactly what is need for a given activity or situation. Significant resources can be expended ensuing that the given configuration meets a defined specification.

The assumption has always been that once a marker has been set down and proven, then repeating a process will produce a good (safe) outcome. Reproducibility becomes fundamental. When dealing with physical products this works well. It’s the foundation of approved designs.

But what happens when the function and characteristics of a product change as it is used? For example, an expert system learns from experience. On day one, a given set of inputs may produce predicable outputs. On day one hundred, when subject to the same stimulus those outputs may have changed significantly. No longer do we experience steadfast repeatable.

So, what does conformity mean in such situations? There’s the crux of the matter.

[1] ICAO Annex 8, Airworthiness of Aircraft. ISBN 978-92-9231-518-4

[2] ICAO Doc 9760, Airworthiness Manual. ISBN 978-92-9265-135-0


[4] Seaworthiness: the fact that a ship is in a good enough condition to travel safely on the sea.

[5] Roadworthy: (of a vehicle) in good enough condition to be driven without danger.


Safety Research

I’ve always found Patrick Hudson’s[1] graphic, that maps safety improvements to factors, like technology, systems, and culture an engaging summary. Unfortunately, it’s wrong or at least that’s my experience. I mean not wholly wrong but the reality of achieving safety performance improvement doesn’t look like this graph. Figure 1[2].

Yes, aviation safety improvement has been as story of continuous improvement, at least if the numbers are aggregated. Yes, a great number of the earlier improvements (1950s-70s) were made by what might be called hard technology improvements. Technical requirements mandated systems and equipment that had to meet higher performance specifications.

For the last two decades, the growth in support for safety management, and the use of risk assessment has made a considerable contribution to aviation safety. Now, safety culture is seen as part of a safety management system. It’s undeniably important[3].

My argument is that aviation’s complex mix of technology, systems, and culture is not of one superseding the other. This is particularly relevant in respect of safety research. Looking at Figure 1, it could be concluded that there’s not much to be gained by spending on technological solutions to problems because most of the issues rest with the human actors in the system. Again, not diminishing the contribution human error makes to accidents and incidents, the physical context within which errors occur is changing dramatically.

Let’s imagine the role of a sponsor of safety related research who has funds to distribute. For one, there are few such entities because most of the available funds go into making something happen in the first place. New products, aircraft, components, propulsion, or control systems always get the lion’s share of funds. Safety related research is way down the order.

The big aviation safety risks haven’t changed much in recent years, namely: controlled flight into terrain (CFIT), loss of control in-flight (LOC-I), mid-air collision (MAC), runway excursion (RE) and runway incursion (RI)[4]. What’s worth noting is that the potential for reducing each one of them is changing as the setting within which aviation operates is changing. Rapid technological innovation is shaping flight and ground operations. The balance between reliance on human activities and automation is changing. Integrated systems are getting more integrated.

As the contribution of human activities reduces so an appeal to culture has less impact. Future errors may be more machine errors rather than human errors.

It’s best to get back to designing in hard safety from day one. Safety related research should focus more on questions like; what does hard safety look like for high levels of automation, including use of artificial intelligence? What does hard safety look like for autonomous flight? What does hard safety look like for dense airspace at low level?

Just a thought.


[2] Achieving a Safety Culture in Aviation (1999).



Red Tape

I know. Why explain? When people only hear what they want to hear? On the scale of right-wing political good or bad there are words that can make a slogan to suite any blank page. Shape any mood. Frame a slogan around “tax cuts” and you are at the happy end of the spectrum (blue). Frame a sentence around “red tape” and unhappy faces will appear (red).

My heart sinks when I see British newspaper headlines like: Truss pledges EU red tape bonfire[1]. It’s a celebration of ignorance and pessimism. The politics is crude. It’s kindergarten. Dam the past and paint a picture of gleaming utopia ahead. Comic book stuff. There’s never been a quicker way to appeal to the Conservative Grumpy[2] family.

In earlier articles, I’ve made it clear that 6-years of Brexit has meant more “red tape” rather than less. That is red tape that greatly impacts UK exports, imports, livelihoods, jobs, and prosperity.

For Leavers, the Brexit project was about cutting so called red tape in the belief that administration, laws and rights are the ultimate problems. However, the post-Brexit UK is presenting more complex bureaucracy, producing poorer results at a greater cost than before.

It’s always peculiar when legislators blame legislation for our ills.

When the UK was a member of the European Union (EU) countries worked together, removing trade barriers, and promoting free movement to create a better future. Now, the UK is determined to continue to reverse that good work much to its own detriment. Plainly, we are a country determined to sanction itself. All because it opens the political convenience of being able to blame others.

These years are the topsy-turvy years. A Government that tables a no-confidence vote and then cheers a discredited Prime Minister[3]. A zombie Government then limps on while a few thousand people mull over our future. Ministers boast of their achievements but then dam everything that has gone in the past.

It’s unfortunate but this generation of uncivilised minnows is in charge. At least for the moment.

POST 1: False words compound the problem of understanding. There is no EU “red tape”. The UK left the EU. What we have is UK law. Law made by the politicians that who are damming that law. Yes, parts of UK law have been derived from EU law. That is law that the UK helped make while in the EU.

POST 2: Concerns about the removal of consumer protection are being raised widely. Believe me, you will miss that red tape once it’s gone | Money | The Sunday Times (

POST 3: The list goes on and on UK chemicals sector hit by £2bn Brexit red tape bill | Financial Times (


[2] My coffee mug is from the Mr Men, Little Miss series (2017).



It’s a small Surrey village just off the A3. The Black Swan[1] in Ockham is a nice place to eat on a summer day. Although Surrey is a populous county there are many picturesque spots in its countryside. It’s best to describe the village as semi-rural as it’s an easy commute to Guildford.

It’s often a dictum used by politician, managers, and decision makers. Keep it Simple Stupid (KISS) appeals because it’s simple to remember as much as it implores simplicity.

Some sayings are plain folk-law and get repeated because they strike cord with everyday lived experience. Dig a bit and there’s little logic or foundation. KISS offers both a sense that it’s common sense and that there must be some underlying reasoning behind it. Surely, it must be more efficient to try to keep arrangements as simple as possible. That might be processes, procedures, training or even designs.

Although KISS is highly appealing it isn’t, by closer inspection, how we live our lives. Layers and layers of complexity underly everything we do. The issue is that most of the time we do not see the complexity that serves us. A case in point is my iPhone. Yes, its human interface has been designed with KISS in mind, but its functions are provided by levels of complex circuitry and software that go way beyond my understanding. So, we have an illusion of simplicity because complexity is hidden from our eyes. Quite frankly, I have no need to know how my iPhone works. It would only be curiously that would lead me to find out.

Now, I’m going to sound crazy. Because within the complexity, I have ignored there’s a simplicity. Deep in the complex circuitry and software of my iPhone is a design that has converged on the minimum needed to perform its functions. If that were not so then this handheld device would likely be the size of a house.

Ockham’s Razor[2] is a principle of simplicity. It asks us to believe that the simplest theory is more likely to be the true one. It’s like saying nature is lazy. It will not make its inner workings more complex than is needs to be. Even when those inner working can appear complex.

I remember one of my teachers saying that mathematicians are inherently lazy. What he meant was that they are always seeking the simplest way of explaining something. If there are two ways of getting from A to B why take the long one?

The popular expression of Ockham’s Razor is: “Entities should not be multiplied beyond necessity.”

Ockham did not invent the principle of simplicity, but his name is ever associated with it. He pushed the boundaries of thinking. Not bad for a 14th-century English philosopher. 



ITV Debate

For anyone interested in public affairs watching a debate of candidates for Prime Minister (PM) should be a pleasure #ITVdebate. It’s the summer heat. Pleasure it certainly wasn’t. It was a formulaic event that was enough to make milk curdle. The toxic blue-on-blue punch-up was uninspiring. A college debating society might have made better peak time TV.

The matter of who will be the British PM in only 7 weeks’ time is important. As the first question put it, we are at the start of an actual cost of living crisis. Unfortunately, Sunday night a lot of fairy tale economics were on show. Rubishing the past took front stage. All Conservative candidates said they would not have the caretaker PM Boris Johnson in a new cabinet.

All candidates vaguely rattled on about Brexit opportunities. When asked if the winner needed to call for a General Election to consolidate their mandate they all said – no.

Tom Tugendhat MP stood on a hill shouting “clean start,” but it was as if no one was listening. He said he was in mortal fear of the leader of the opposition. He shifted around in an uneasy manner.

Liz Truss MP wanted to emphasise that she was “honest” but admitted to not being “slick” as she sideswiped the other candidates. Here neo-Thatcher stance is thinning as quickly as it arrived. Word of the night was – bold.

“Time for a change” was Kemi Badenoch MP’s mantra. Being brave and asking for unity are all designed to create good vibes. The Twittersphere has dubbed her #badenough as if to mark that as the criteria for winning. To target the giveaway candidates Badenoch said there’s “no easy option”.

As the front running Rishi Sunak MP, former Chancellor, got the most kick backs from other candidates. “I want to be honest” and responsible were his themes. He put the stress on prudent conservatism, a phenomenon that may not exist anymore.

Penny Mordaunt MP was all about saying she’s a team player but not acting like one. Asking for an innovative approach and that the system is broken is appropriate. Sadly, filling the vacuum with nothing much hasn’t helped her case. She’s the spend, spend, spend candidate. She told a fib about the state of the polls too.

Robot like, Truss wanted it known that she has “served” and will stand up to Putin. She stressed her legacy of trade deals and getting things done. Her project fear was to mention the inflationary spiral of the 1970s. Truss and Mordaunt can across as arrogant and patronising by calling for change but being unclear what change is needed.

Badenoch was not ashamed of her role in Government. Strangely for a politician she hit out at the others by saying “talking is easy” Tugendhat is a fan of nuclear power and never misses an opportunity to mention his military service.

Sunak was the only one to come across as relaxed. Open shirts are his uniform. He was unshaken as he skilfully batted back all the balls bowled directly at him. If there was a winner – he was it.


There are echoes of the past in what’s happening now. One of these echoes is the exclamation that it’s getting more and more like the seventies. It’s a reaction to the turbulence and uncertainty that is all around. Especially when the spectre of inflation and recession is looming over us.

It’s easy to have mixed feelings about that decade. It can be said that the sixties were more revolutionary when it comes to the explosion of progressive attitudes and societal change.

The seventies weren’t a homogeneous period. In Britain, those turbulent 10-years culminated in a major political transformation as Thatcherism kicked-off in 1979. Romanising the seventies is foolish. That’s particularly the case when drawing comparisons between the here and now.

Life expectancy is one indicator[1]. The enormous improvement since the 70s is self-evident. What’s concerning about the situation is being put in jeopardy by a considerable slowing in these figures in recent years.

This chimes with lived experience. I remember pubs so full of smoke that the walls were stained, and a fog hung over the bar. Health and Safety legislation too. Car seatbelts and motorcycle crash helmets all helped reduce early fatalities. Workplaces have improved dramatically. Shivers run down my spin when I consider some of the toxic chemicals that were used in engineering and agriculture.

No way should anyone sane want to go back to the full 70s experience. That’s not to say there are cultural highlights that made a positive contribution to life in the UK. Punk rock coinciding with the Queen’s jubilee created a world of colour and vitality that has been lacking in the 202os.

Star Wars fans will no doubt cite Star Wars. There were some dam good movies made in the 70s. I’m seeing the mirror ball rotating, as the music from Saturday Night Fever rings in my ears.

On the technology side it was the time when the ground was broken. Microsoft and Apple own their success to the availability of early digital “chips”. A degree of that came from the strides made as the Apollo programme forced the advancement of digital technology. The Cold War played its part too.

On a personal note, motorcycles played a pivotal role in my decade. Growing up in a rural community the importance of mobility cannot be undenied. It was fun. It was freedom. It was exciting. I’d watch, and sometime marshal at road racing, grass track and motocross meetings[2]. I’m only here because a mate pulled me out of the path of an oncoming Laverda[3] side car outfit at a grass track meeting near Mere.

From 1970, to the day 1980 arrived much changed. Summing it up there were better times ahead.

POST: There were better cars ahead too. But I still have affection for my bright red Sunbeam Imp Not a Mini but a Sunbeam Imp | Articles | Classic Motorsports





Do you, like me get a bit fed-up with the constant stream of marketing speak in everyday life?

In this short article, I will explore new opportunities, showcase the state-of-the-art developments, and talk ground-breaking claptrap. Dynamic and comprehensive, this will rock your assumptions. Long-lasting valuable connection will be made tapping into a new global dimension. This is a chance of opening a window into an amazing array of innovative thinking. Unlock the immense range of possibilities for using super words used with passion to beef up drab and unsubstantial stuff. This is designed to deliver unprecedented levels of performance and power. Spearheading the drive to help everyone take bold decisions and make bold reforms.

I’ll stop before the page explodes. To be clear, I’m not making an argument for everyday communication to read like a legal textbook or a children’s annual but surely there’s a reasonable line to be drawn. Overselling anything has the habit of leading to disappointment. Regret creeps in after the realisation that accolades and exaggerations were only there to hook you like a fish. That’s the Brexit story in a nutshell.

Believe it or not, I’m not just talking about the on-going British Conservative party leadership elections.

Looking at my e-mail in-box there’s more than a few marketing e-mails that I should be unsubscribing. A quick review shows that the amount of useful information is likely to be less than tenth of what’s staring me in the face. The rule change from needing people to opt-in rather than opt-out of subscriptions hasn’t made a lot of difference to the stream of selling e-mails. I have a few bugbears that I’ll get off my chest. Bells ring whenever these words are used like confetti.

The overuse of the word “global” when often the context is far from global, is tedious. There’re about 200 countries, 1000s of languages and a huge range of cultural diversity in the world. Global is often used to signify a narrow band of technologically savvy suited and booted types. That’s far from the English dictionary meaning of the word. The term “world-class” is in the same league too.

Everything is “advanced,” it’s innovative and state-of-the-art. Pick up a 1970s car or computer brochure, and guess what? Everything is “advanced,” it’s innovative and state-of-the-art. These words are short cuts for the polish put on the new. Time being what it is, it never stands still. So, the cutting-edge of today becomes the amusing and “classic” of tomorrow. Wait long enough and it becomes “vintage”.

The word “bold” is doing the rounds too. It’s a dash of paint that gives the dull and boring the ability to stand out in public. Claim that something as bold and it doesn’t matter how many stupid things you do because they were bold. In many cases, the word means that the user was advised not to do something dangerously risky but they did it anyway. So take care when someones says they have: “taken bold decisions and made bold reforms.” Look at the small print. The word “grit” is in the same league too.

I admit that I’m one of the worst offenders when using the word “challenge.” It’s one of those convenient words that rolls off the tongue because its sounds more authoritative than saying “difficult”. Yes, it’s complex and nothing stays the same for long. For the sake of brevity, and not being bothered to say why change is hard, I’ll say it’s a challenge.

This blog has been curated just for you. For optimum impact in this ever-changing world, I’ll land a big full-stop here.

Fundamental schisms

Today, we have a UK Conservative Government running against a UK Conservative Government. Elections can be strange but this one is stranger than most. Even the rules for the election have been made-up as the process moves forward. Changing the rules is becoming a habit.  

Each candidate for British Prime Minister is pointing out the errors of the past and dire problems the country faces. With some, at the same time, sitting in a lame duck administration, these candidates are heralding how their personal qualities elevate them above the herd. How they are ready to lead. As if they had emerged from nowhere. As if a curtain can be drawn over Boris Johnson premiership.

When reporters ask about their record in the House of Commons, a quick sidestep is the most common approach. The general defence offered for our dire situation is that of quoting a list of global events. COVID, war and economic downturn. Yet we all know that these global events would have occurred whatever UK Government had been in power.

It’s like saying we have just travelled over an unmade-up road and then blaming the condition of the road for any damage done. That the driver, and political decision-makers in the country have no responsibility for the folly, harm, and pain of the last 7-years (2015-now). Yet, even as the road gets rougher those sitting next to the driver are trying to grab the steering wheel.

As bizarre as anything this Conservative Government limps on with a dominant parliamentary majority despite only commanding 44% of the votes cast back in 2019. As the turmoil continues under their watch, their national poll rating is sustaining a dip below 30% of the electorate.

This political whirlwind will not be stopped by shifting the political deckchairs. There are fundamental schisms within the Conservative party. It’s very evident from the camps being formed by the party candidates for Prime Minister. No new leader will be able to hold this fracture bunch together.

The Brexit Bolsheviks do not want to make peace. They see their roles are permanent revolution. They will always see the post-referendum era as work unfinished. It’s a partisan drive to a utopia of isolation. It’s the complete opposite to what the country needs. Confidence has truly been lost. In so many ways this Conservative Government has no legitimacy. The representatives in this British parliament have lost public confidence. It’s time for them to go.

Objects falling from the sky

In so far as I know, no person on the ground has been killed by an object falling from a commercial aircraft in flight. I’m happy to be corrected if that situation has changed. Strangely, in contrast there are plenty of reports of people falling from aircraft and being killed as a result[1]. Additionally, there are cases of parts shed by aircraft that subsequently contribute to an aircraft accident[2].

The most frequent reports of falling objects, in and around airports are not parts of an aircraft but that which is in the atmosphere all the time. Namely, ice. When it hits the ground in the form of a hailstorm it can be damaging. In flight, it can be seriously damaging to an aircraft.

What I’m writing about here are the third-party risks. That’s when an innocent individual finds themselves the target of an improbable event, some might call an act of God. Ice falls are rare. However, given the volume of worldwide air traffic there’s enough of them to be alert to the problem. As soon as ice accretes to create lumps bigger than a kilo there’s a real danger.

Can ice falls be prevented? Here again there’s no doubt some are because of poor maintenance or other preventable factors, but others are just nature doing its thing. Regulators are always keen to collect data on the phenomena[3]. It’s something that goes on in the background and where the resources allow there can even be follow-up investigations.

Near misses do make the newspaper headlines. The dramatic nature of the events, however rare, can be like a line from a horror movie[4]. Other cases are more a human-interest story than representing a great risk to those on the ground[5].

It’s worth noting that falling objects can be quite different from what they are first reported to be. That can be said about rare events in general.

I remember being told of one case where a sharp metal object fell into a homeowner’s garden. Not nice at all. The immediate reaction was to conclude it came from an aircraft flying overhead. Speculation then started a new story, and the fear of objects falling from aircraft was intensified.

Subsequently, an investigation found that this metal object had more humble terrestrial origins. In a nearby industrial estate a grinding wheel had shattered at highspeed sending debris flying into the air. Parts of which landed in the garden of the unfortunate near-by resident.

One lesson from this tale is that things may not always be as they first seem. Certainly, with falling objects, it’s as well to do an investigation before blaming an aircraft.  

POST 1: There’s a threat outside the atmosphere too. The space industries are ever busier. That old saying about “what goes up, must come down” is true of rockets and space junk. More a hazard to those on the ground, there is still the extreamly unlikly chance of an in-flight aircraft getting hit Unnecessary risks created by uncontrolled rocket reentries | Nature Astronomy

POST 2: EASA Safety Information Bulletin Operations SIB No.: 2022-07 Issued: 28 July 2022, Subject: Re-Entry into Earth’s Atmosphere of Space Debris of Rocket Long March 5B (CZ-5B). This SIB is issued to raise awareness on the expected re-entry into Earth’s atmosphere of the large space object.