Aviation – Page 6 – John Vincent

Challenges of Hydrogen Fuel in Civil Aviation

This week has been a Hydrogen week. It’s great to learn more of the projects that are out there and the ambitions of those developing systems. Hydrogen is a live subject. Looking at the possible pathways for civil aviation to take there’s a myriad of choices. However, when it comes to the fuel for propulsion there are not so many potentials.

It’s surely the case that at some time in the future the use of fossil fuels to propel us across the skies will no longer be acceptable. Even if I’m talking to climate change sceptics the point must be made that fossil fuels are a limited resource. Not only that but the air quality around airports is a matter of concern.

It’s there in our basic education. Water is H₂O. It’s that combination of Hydrogen and Oxygen that is essential to life on Earth. So, if we have a process that provides aircraft propulsion by using Hydrogen it should be a whole lot better for the environment than using Jet A1.

The problem is, and there’s always a problem, to carry enough Hydrogen it will need to be pressurised and in liquid form. That means extremely low temperatures, robust storage containers and extensive leak free plumbing.

Today, we have cars on the road that run on liquefied petroleum gas (LPG). It’s a novelty. It’s less harmful to the environment and can cost less. However, LPG systems need regular servicing. The point of mentioning this pressured gas in a transport system is that it has been integrated into regular everyday usage. That’s knowing that escape of even small quantities of the liquefied gas can give rise to large volumes of gas / air mixture and thus a considerable hazard[1].

Any analogy between the car and the aircraft can be forgotten. That said, one or two of the issues are similar. Yes, what happens when an escaped volume of gas / air mixture is ignited?

What scenarios would bring about conditions whereby a destructive explosion is possible?

Let’s start with the situations where aircraft accidents most often occur. Take-off and landing are those phases of flight. A surprising number of accident scenarios are survivable. The important part being to get an aircraft in trouble on the ground in such a way that an evacuation is possible. That can mean hitting the ground with a great deal of force[2].

Here’s the matter of concern. An aircraft with large cryogenic tanks and associated complex plumbing hits the ground at a force of many “g”. What then happens? Certainly, pressurised liquefied gas would escape. Being a very light gas, the uncontained Hydrogen would rise rapidly. However, trapped amounts of gas / air mixture would remain a hazard. Would that be ignited?

There are a lot of unknowns in my questions. Although there are unknowns, any post impact situation is likely to be very different from a situation with a conventionally fuelled aircraft.

Today’s, burn through requirements ensure that an external fuel fire is held back. Thereby ensuring enough time to evacuate. For a hydrogen aircraft ventilation may be essential to stop build-up of a gas / air mixture inside a fuselage. That means a whole different approach.

[1] https://youtu.be/AG4JwbK3-q0

[2] https://skybrary.aero/accidents-and-incidents/b772-london-heathrow-uk-2008

1930s Aerodrome Architecture

We talk of optimism and pessimism as if one presides while the other sleeps. It’s not quite like that in consideration of the legacy around us. There’s no doubt that the 1920s and 1930s were years of austerity and depression. The Great War had an overwhelming impact on all sections of society. The buildings that remain from that era, including the house that I once lived in, do record a simpler style. Material chosen for their functional value rather than decorative.

Victorian’s built with flair and every mechanical contrivance that their technology could provide. Value in longevity was integral in their thinking. Who could imagine the sun setting on British empire?

The brief inter-war period was one of concrete and steel. A bit of classicism retained an influence. Form, fit and function played a bigger part. Modernism meant reflecting the advances in technology that were making great pace. Construction was fast.

Aviation was one of the most notable advances. Post-war flying moved from the military to sport, the recreation of the rich and the wonder of the onlooking public. It went together with the race for speed on land. Everything had to be faster and go further.

Maybe it was the Bauhaus in Germany, that set down some much-copied rules. Symmetry and square lines were on the drawing boards of a lot of public architects. It’s the case that some ornamentation was thrown in where the patrons were wealthy. Even that was relatively muted.

What lasted is no abomination of a poverty of ambition. It’s not utopian. It’s not brutalist. There’s instead a simplicity that was authoritative enough but not too ostentatious.

Pictured above is the 1932 Aero Clubhouse at Brooklands[1] in Surrey. It was designed by Graham Dawbarn[2] in what was a typical 1930s style. It set a trend for aerodrome buildings. Buildings like this one added grandeur to aerodromes where sheet metal hangers and small wooden huts were more often to be seen.

I like these enduring, straightforward, practical buildings. Yes, they are a form of British colonial architecture. One that could be easily reproduced anywhere on the globe. In today’s terms not the least bit environmentally friendly or efficient. Nevertheless, there’s an appeal that marks them out particularly when compared to the sheets of glass and skeleton frames of steel of modern aviation facilities.

[1] https://www.brooklandsmuseum.com/

[2] https://www.ribapix.com/graham-dawbarn_riba47117

Brazilian Air Crash

Two weeks have elapsed since the tragic loss of VoePass Linhas Aéreas flight PTB2283[1].

Reports are that the Brazilian air accident investigators[2] have successfully downloaded recordings from the aircraft Cockpit Voice Recorder (CVR) and Flight Data Recorder (FDR).

A detailed analysis of both recordings should provide a replay of the flight events on the fateful day. This means that any flight anomalies can be interpreted. Both actions of the crew and the response of the aircraft can be used to understand the sequence of events.

Those conducting the analysis will need to verify the past serviceability[3] of both recorders. It’s easy to assume that what’s presented in the recovered replay is what happened. However, that depends on the calibration of sensors and the correct functioning of the aircraft’s audio system.

CVRs and FDRs are primarily tools for the investigation of accidents and serious incidents by investigating authorities. Accident recordings can be a rich source of information. It’s not just the obvious contribution technical records make to an investigation. The CVR, via a cockpit area microphone picks up much more than just the speech of the crew and their communications with air traffic. Engines, propellers, aircraft warning systems, aerodynamic noise and the impact of structural failures all produce audio signatures.

I assume that the aircraft operator has a Flight Data Monitoring Program. Such a program can support continuing airworthiness and operational safety of an aircraft. It can be a vital part of a Safety Management System (SMS). Also, the regular analysis of flight data is one way of ensuring that the serviceability of the data acquisition system for an FDR is known.

A preliminary report on this fatal accident is expected in early September. It is up to CENIPA if the publish any transcript of the accident recordings.

VoePass, the airline in question, operates a regional network in Brazil. Not surprisingly it has now come under greater scrutiny by the Brazilian aviation regulator, Agência Nacional de Aviação Civil (ANAC).

It’s worth noting that the Brazilian civil aircraft fleet is one of the largest in the world. It’s a sizable country. Both ANAC and CENIPA are well experienced in addressing the aftermath of a major aviation accident. Expectations are high that the causes of this fatal accident will be fully understood. Appropriately then corrective action will be taken.

[1] https://asn.flightsafety.org/wikibase/409335

[2] Brazilian Aeronautical Accidents Investigation and Prevention Center (CENIPA)

[3] https://www.caa.co.uk/publication/download/12811

Navigating Speculation in the Age of Abundant Information

Speculation is a natural human response. When faced with a paucity of information we often put together what we know and then make a best guess as to what happened or what might happen. However, wise or unwise it’s not possible to stop speculation. Well, that is assuming that autocratic power doesn’t use force to crush the free exchange of ideas.

Since the rise of the INTERNET, with a proliferation of all kinds of material, it becomes less and less possible to quell speculation. A sprinkling of information can grow into a monstrous conspiracy but equally it can grow into a stepping stone to greater understanding. Living with this two-edged sword is our modern dilemma.

In a more deferential society, that we may have been immediately post WWII, officialdom was accustomed to restricting information. The principal of “need to know” and statements like – wait for the official report – were enough to quell Press intrusion and intense public curiosity. On occasions this deference turned out to be tragic and been an enabler for authorities to cover up dreadful errors and failings. My mind goes to the Hillsborough disaster[1] when I think of tragedies made worse by the manipulation of information.

What’s all this about – you might say. I’m giving a thought to the post- accident scenarios that become more common. When major fatal transport accidents happen to planes, boats and trains there’s an instant demand for detailed information.

This is happening in relation to the recent Brazilian ATR aircraft accident and, this morning, to the sinking of a large modern yacht off the coast of Sicily. Both tragedies seem astonishing in their own way. So much of our technological world works so perfectly, a great deal of the time, that we get accustomed to reliability, safety and security. Almost taking it for granted.

Basic technical information, like registration numbers, type and age of the vehicle all surface quickly after an event. Even numbers of fatalities are verified within a couple of days. What gets the speculators going is the answers to the question – why?

A list of circumstantial factors can soon emerge. The time, the weather, the location and the organisations involved. All of this creates a mix that feeds both intelligent and unintelligent speculation. I’m not saying this is de-facto bad. It’s reality.

What’s all this about? There are reports across the media of the “last words of Brazil plane crash pilots.” This speculation surrounds the words spoken in the cockpit and seem to come from someone’s knowledge of a transcript. How can that be? Through international agreement the independent aviation investigation organisations across the globe are committed to a protection of this type of recorded information (Cockpit Voice Reporter (CVR)[2]). Accident flight recorders are there for the purposes of the investigation of an accident or incident.

Back to our modern dilemma. Is it good or bad that sensitive protected information leaks into the public domain before it’s been thoroughly analysed and properly understood? There is a cost to a dilution of the protection of information. For one, it may discourage the voluntary application of safety enhancements, like fitting a recorder to a plane, boat or train.

[1] https://www.bbc.co.uk/news/topics/c8m8v3p0yygt

[2] https://skybrary.aero/articles/cockpit-voice-recorder-cvr

Spectacular Sighting

There’s steep hills. Some more interesting than others, you might say. In my youth this one was known for the road that climbed the hill. That’s the B3081, if you want the detail. It’s an opportunity to journey through wonderful English countryside. The area being Cranborne Chase, a protected landscape.

Zigzag hill was great fun for us as children. Probably not so much fun for my parents as our jet black Wolseley16/60 strained to get around the corners and climb to the top. The car packed with the six of us. This was a route we’d take to get from home to Bournemouth, and the seaside.

On the way, I remember the finger post signs to Compton Abbas Airfield[1]. My thought being what an interesting place for an airfield, right up here high on the chalk hills. Looking down on the surrounding Dorset countryside and the town of Shaftsbury.

Normally, I have to go to flying displays to see historic aircraft fly. This Sunday afternoon, I travelled no further than my back door. Sitting outback in the steaming 30C-degree summer weather all I had to do was look-up. Not that I’d planned to look skyward.

That doesn’t happen every day. First there was a distant rumbling sound. Then it developed into the hum of multiple piston engines. It’s only when the distinctive sight of a Lancaster bomber appeared over the roof of my house did all become clear what was happening.

As soon as I fixed my eyes on the aircraft it was already off over the garden and out across the neighbouring field. This was Avro Lancaster PA474 passing right overhead[2]. It was heading off in a north easterly direction at a notably low altitude. Quote a spectacular sight.

I had to do a little research once the aircraft had disappeared over the horizon. Looking at what was happening on Sunday, I assume it was flying back from Compton Abbas Airshow[3] to its home in Lincolnshire. Given the high summer weather, this was a great day for flying.

This Second World War heavy bomber first flew in 1941. It’s part of the Battle of Britain Memorial Flight (BBMF), based at RAF Coningsby. It’s the only Avro Lancaster that remains airworthy and flying in the UK. It’s only recently returned to the air after a tragic accident involving the BBMF.

Later in the day, off in the distance, looking north, three other historic aircraft trundled across the sky. After dark, with the heavens clear, I caught the Perseid meteor shower. So, for watchers of the skies, 11^th August was a noteworthy day.

[1] https://www.comptonairfield.com/

[2] https://www.bbc.co.uk/news/articles/clyg7e7x319o

[3] https://comptonabbasairshow.co.uk/participants/

Tragic VoePass ATR72 Crash

2024 was going so well. Looking at the indicator of worldwide fatalities in commercial aviation for the first six-months of this year, and it is exceptionally low. The time between major fatal accidents across the globe is another indicator that my team once looked at on a regular basis. Aviation is an extremely safe mode of transport but when accidents happen, they can be devastating.

Yesterday, the situation changed in Brazil. A VoePass ATR72-500 aircraft[1], registration PS-VPB, flight number PTB2283 crashed in the Brazilian state of São Paulo. The twin-engine aircraft crashed in a residential location.

Yet unknown events resulted in a loss of control in-flight. On-line videos of the aircraft flying show a dive and then a spiralling decent to the ground. The aircraft was destroyed on impact, and it is reported that all lives were lost.

The publicly available flight data shows a sudden decent from a stable altitude[2]. The aircraft was about and hour and twenty minutes into its flight.

Looking at the video information it might appear that local weather may not have been a factor in the accident. However, there was known to be severe icing conditions at the altitude that the aircraft was flying.

It’s speculation on my part but unrecognised severe icing is one of the conditions that can bring about a catastrophic outcome for such an aircraft. It is sad to have to say that there is a record of a major accident to an ATR-72 that has some of the characteristics of this new accident.

In fact, it is one fatal accident that is etched on my mind given that it happened in late 1994, when I was still fresh in my job with the UK Civil Aviation Authority as an airworthiness surveyor. It’s known as much by its location as by the name of the aircraft, namely Roselawn[3]. The accident was extremely controversial at the time.

Crews are told that they may be operating in severe icing conditions but there is no specific regulatory requirement for on-board advisory or warning system on this generation of turboprop aircraft. An ice detection system can serve as a final warning to alert a crew that ice protection is needed.

Work to update the technical document; In-Flight Ice Detection System (FIDS) Minimum Operational Specification EUROCAE ED-103 is completed. Issued in April 2022, ED-103B – MOPS for In-Flight Icing Detection Systems is available[4].

In the case of the current accident, it is a matter for Brazil’s highly capable independent accident investigators to determine what happened. Anything I have written here is purely speculative.

POST 1: Reports of statements made by Agência Nacional de Aviação Civil (Anac) say that the aircraft was in good condition.

POST 2: Accident flight recorders have been recovered from the accident site. Flight recorders retrieved from crashed Voepass ATR 72-500 | Flight Global

[1] https://asn.flightsafety.org/wikibase/409335

[2] https://www.flightaware.com/live/flight/PSVPB/history/20240809/1450Z/SBCA/SBGR/tracklog

[3] https://www.faa.gov/lessons_learned/transport_airplane/accidents/N401AM

[4] https://eshop.eurocae.net/eurocae-documents-and-reports/ed-103b/

Electric Aviation: The Promise of Clean Flight

Electric aviation is not new. Not new at all. The engineers of the past struggled with two factors. Power and weight. A French electrically powered airship was the first aircraft to make a controlled circuit. On 9 August 1884, it flew a circular course of 8 km at a max speed of 14.5 mph. Its electric motor weighed 100 kilograms and its battery weighed 263 kilograms.

It’s not a problem to be able to distribute or use electrical power on-board an aircraft. The problem come in generating enough of it from a reliable source. Today’s “conventional” civil aircraft generate and use large amounts of electrical power. For example, the Boeing 787 has two starter/generators per engine[1]. Electrical power from the generators goes to four alternating current (AC) electrical distribution buses, where it is either sent for use as is (235 V AC) or converted for use by the aircraft systems that need it.

A revolution is taking place in electric aviation. It offers the opportunity to fly cleanly. That said, the traditional technical challenges remain the same. Power and weight. In 140-years battery technology has advanced considerably. But is that enough?

A difficulty that battery powered flying is stuck with is that at the start and at the end of a flight the batteries weigh, more or less, the same as they did from the day of their manufacture. Today’s “conventional” civil aircraft consume fuel. Thus, they are significantly lighter at the end of a flight than they are at the start. Airframes can be designed to take advantage of this fact.

One of the up sides is that a good electric motor can get to an efficiency of 80% whereas a turbo fan engine comes in at around 35%. That sound great until we look at the amount of energy we can store within a given volume. Jet fuel packs a punch. To get the same punch from an electrical battery it would likely be 15 times the size. That’s not good for a practical design. The low battery energy density coupled with the high weight of batteries means that this strategy for large aircraft needs to be put to one side for now.

A modern aircraft engine like the CFM International LEAP, can develop a max take-off thrust of over 30,000 lbf. Two of those engines can safely accelerate a Boeing 737 or Airbus A320 with ease and cruise with good economy. Thus, electrification of the propulsion of this class of aircraft is a long way off. The nearest possible future for propulsion of a B737 and A320 sized aircraft may be hydrogen based.

This explains why the drawing boards are full of small electric aircraft designs where performance demands are more modest. There’s a hope that the continuous development of battery technology will provide year on year gains. Much more than aviation alone demands that battery technology advances.

Developments in hydrogen-electric aviation are catching the headlines. Much of what has been achieved is experimental. I look forward to the day when hydrogen is not used to fill airship gas bags but becomes the life blood of transport aviation. It’s conceivable that will happen in my lifetime.

[1] http://787updates.newairplane.com/787-Electrical-Systems/787-Electrical-System

Just Culture

My thought is that we’ve forgotten the discussion of more than a decade ago. There was a time when the thoughtful reflections on responsibility and accountability were much discussed.

Without focusing on specific examples, there are plenty to choose from, there’s the propensity of our institutions and politicians to reach for “blame” as a first response. When situations go bad the instinctive inclination to hunt out someone to blame. This is an all too prevalent habit.

Naturally, in cases, there’s the strong need to identify who is accountable for bad decisions. Society does not like it when the powerful protect, cocoon themselves and grab for immunity. Certainly, some people and organisations are genuinely blameworthy. However, if we scrutinise and point the finger of blame, it doesn’t help if that finger is pointed at a person’s honest errors. There isn’t a human on this planet who hasn’t made an error.

The finger of blame is easily pointed. Judgment so often falls after an event. The time when more is known, and hindsight comes into play. This tips the balance. It’s so much easier to say: why on Earth did you do that? I would never have done that.

For people to come forward and be fairly heard in an open and fair inquiry or investigation they need to have the confidence that they are not stepping into a public blame-fest. Without trust between those on all sides of it’s less likely that the truth will come out.

“Just Culture” is a concept written into aviation legislation and followed by others. The overriding aim is to learn from mistakes. It’s the surest way of not repeating the same mistakes time and time again. It’s beneficial to have that long-term learning objective. Why suffer the pain of a bad event when the means to avoid it are known and understood?

Now, I’m going back 20-years. I remember being part of an international working group[1] called GAIN. The group compiled guidance about organisational culture. At the time, the group was considering the subject in the context of the air traffic profession. Guidance like the one referenced, emphasise that a Just Culture is not simply a no-blame culture. It’s not, and never has been a way of circumventing accountability.

Determining culpability can be complex. There’s often a test to consider the wilfulness of the participants in a bad event. In other words, did they carelessly, intentionally, maliciously or negligently make decisions that resulted in the bad event? In these cases, the “they” could be an individual or an organisation.

Gross negligence, wilful abuses and destructive acts should be addressed by the enforcement of laws. If we say the criminalisation of honest people involved in bad events has a negative impact. That is not to negate the need for enforcement. Regulators in all sorts of walks of life have a duty to apply enforcement where and when it’s appropriate. Maybe we ought to have applied that to the UK water industry.

My plea here is to first consider the nature of the events in question. Was there an element of genuine honest human error? Is the right balance being struck between the need to learn and the need to ensure accountability?

NOTE: Just Culture is defined in EU law as “A culture in which operational staff or others are not held accountable for actions, acts, omissions or decisions commensurate with their experience and training, but gross negligence, intentional violations and destructive actions are not tolerated” EC 376/2014 Art. 2 Para. 12.

[1] A Roadmap to a Just Culture https://flightsafety.org/files/just_culture.pdf

Turbulence

Turbulence is the result of atmospheric or environmental effects. Afterall, aircraft are craft that fly in the air. This is a hazard that is inherent in flying. Clear air turbulence (CAT) is common. However, extreme examples experienced in commercial aviation are rare. For one, aircraft operators and their crews do their best to avoid known potential atmospheric or environmental upsets, namely bad weather.

En-route turbulence accounts for a substantial number of cabin crew members injuries, and can occur at any time and at any altitude[1]. As far as I know, the UK Civil Aviation Authority (CAA) does not hold detailed data on turbulence injuries occurring on foreign registered aircraft. Numbers of injuries to passengers and flight crew on UK registered aircraft resulting from turbulence are recorded. However, it is not always known whether those injured in turbulence encounters were wearing seat belts.

Nevertheless, I can confidently say that the more passengers that are wearing seat belts during turbulence encounters the less the number of injuries. Deaths in these circumstances are rare. As might be expected fatalities are more likely to results from a combination of multiple causes and factors.

This subject is not immune from airline economics and competition. International flight routes can often be highly competitive. Fought over. So, the route taken, and associated fuel costs, can have an impact on the likelihood of a hazardous weather encounter. In fact, choosing to take routes for the benefit of picking-up specific winds is a common practice.

A high percentage of cases of turbulence events come about by flying too close to active storms[2]. Here there is often visual cues, reports, forecasts and feedback from turbulence encountered by other flights. This all helps crews avoid the worst weather encounters.

With very few exceptions, flight turbulence does not result in fatalities, permanent injure, or structurally damage commercial aircraft. However, turbulence is recognised as both an aviation safety and an economic issue, and it has been steadily increasing. Speculation and some research cites climate change as a reason for this increase. Also, there is the international growth in air traffic and development of new long-range routes.

One thing to say is that until recently, with INTERNET connections now in both in the cockpit and cabin, it could be the case that a passenger could access better real-time weather information than a flight crew. Now, SATCOM connections providing up-to-date weather information are more common on modern civil aircraft types.

There is still more that can be done to reduce crew and passenger injuries during turbulence encounters. There will inevitably happen despite any policy to avoid hazardous weather. The greatest threat to life exists to cabin crew. The cabin is their place of work.

There is potential to develop and employ better airborne detection systems to assist crews. That maybe by enhancing existing weather radar systems. It maybe by new means of turbulence detection using LIDAR, and possibly AI/ML. There is research and innovation that could be done to develop algorithms to better predict turbulence hazards.

Avoidance remains the best strategy.

[1] NASDAC Turbulence Study, August 2004

[2] US CAST briefing in 2004.

Harmonisation

There’s an example in of itself. I’ve used the British English spelling. Perhaps I should have standardised on the American spelling, namely Harmonization. Or does it matter at all given that the definition of the word remains the same, whatever. Oh, I can’t resist the temptation to say; you say Tomato, I say Tomato.

“You say tomato, I say tomato.

You eat potato and I eat potato,

Tomato, tomato, potato, potato,

Let’s call the whole thing off.”

Naturally, in the voice of Fred Astaire[1]. Nice though this is, my subject is not pronunciation.

Aviation is a highly regulated business. It’s been that since its potential for transporting huge numbers of people around the globe was recognised. Safety must be number one. Although, it’s not if you read the first few words of the all-important Chicago convention.

Article 1: Every state has complete and exclusive sovereignty over airspace above its territory.

In the minds of those who signed the convention it was sovereignty that took first place. That didn’t mean abusing the word “sovereignty” as has to often been done. Afterall, the whole basis of the Convention on International Civil Aviation was international cooperation. It still is.

Let’s put that to one side for a moment. One of the challenges of international aviation has been the different rules and regulations in place in each country. There’s a level of harmony in the standards of the International Civil Aviation Organization (ICAO). But ICAO is not a regulator and it’s for each country to interpret agreed standards within their domestic law.

Europe, or at least the European Union (EU) is different in this respect. Since there’s European law and an active European regulator then there’s common rules and regulation set for a regional grouping of countries. So far, Europe is the only region to go this far.

When it comes to aircraft airworthiness this has been a topic of a lot of discussion in the last four decades. In the 1990s, that discussion centred around the idea that a single worldwide code was a desirable achievement. That the time the two major entities engaged in the business of aviation rulemaking, and the maintenance of rules were the FAA (US) and the JAA (Europe).

A single worldwide code could greatly facilitate the movement of aviation produces around the globe. That done to ensure that common safety standards were maintained on every occasion. It proved hard to get to this utopian condition. That said, a great deal was achieved in the harmonisation of existing civil aviation codes. Today, we benefit from that work. I’d say we even take it for granted.

In around 2000, after much study, countries concluded that it was fine to seek some form of equivalence between respective rules rather than having to write done one single set of rules. Mutual recognition has flourished in the form of agreements between countries that has smoothed the path for the aviation industries.

That last major study of the pros and cons of harmonisation is now nearly a generation old. A lot has moved on. For one, in Europe the JAA transition to the EASA.

At the same time the manufacturing countries worked closely together to agree on measures to ensure that there was no great divergence in rules and regulations. Now subjects, like Safety Management Systems (SMS) became codified. However, sovereign countries continued to develop and maintain their own aviation rules and regulations.

International working groups often achieve remarkable commonality and convergence on detailed technical topics. Often because the few people who were deeply embedded in a technical subjects all knew each other and shared information relatively freely.

Discussion as to the viability of a single worldwide code has not completely faded into the past. In fact, there’s some good reason to breath life back into this historic debate. Here’s what’s added to the dynamics of the situation:

Ongoing moves from prescriptive rules to more performance-based rules,
Entirely new products in development, like eVTOL aircraft,
Interdependency, interconnection, and integration all increased since 2000,
Security and safety are becoming inseparable,
Digitisation is changing the ways that we ensure that an aircraft is airworthy.

If you have knowledge of, and thoughts on this subject, I’d be happy to hear from you.

[1] https://youtu.be/LOILZ_D3aRg