Category: Aviation

Runway Incursions and Airline Safety

Firstly, condolences to the families and friends of those killed in the recent aviation accident at LaGuardia airport in New York. It’s incredibly sad that this destructive runway incident took place in the way that it did. At this stage there is a jumble of international News reports. As is often the case while attention is focused on what happened at a time when the facts have not been verified or data collected.

What is known is that Air Canada Express flight 8646 was where it was supposed to be on a runway and an airport-based fire truck was not. The resulting high-speed collision had disastrous consequences for both the aircraft and the fire truck.

The US National Transportation Safety Board (NTSB) has quickly engaged to start a detailed technical investigation. Their role is to independently piece together all the information that is available and determine a probable cause of the accident. With that to make formal safety recommendations aimed at preventing accidents and incidents.

What I can say is that the subject of Runway Incursion (RI)[1] is a long-standing aviation safety concern. So much so that it has its own accident category when it comes to aviation safety data analysis. Such tragic events are not isolated or extremely improbable.

Air Traffic Control (ATC) is tasked with separating aircraft from each other and any other vehicles. Accidents in this category have been the catalyst for advances in equipment and procedures. That said, there’s no getting away from the substantial number of human and operational factors that pervade this domain.

Unlike the design and construction of aircraft system whereby an onerous safety objective can be stamped on a technical specification. Managing air traffic on the ground is done with a high dependency on the actions of professionally trained staff.

In an internationally accepted code, a RI is defined as:

Any occurrence at an aerodrome involving the incorrect presence of an aircraft, vehicle, or person on the protected area of a surface designated for the landing and take-off of aircraft.

I don’t hesitate to say that’s what happened at LaGuardia. This says nothing about – why?

So, we have an indication of what happened. What’s a little unsettling is how quickly there is News reports speculation on why it happened. Initial references to someone having made a mistake or error are no helpful. This signalling tends to encourage a simplification of the circumstances of the accident into a matter of blame. That unfortunately leads to an impression that this is a rare event that can be attributed to one factor. All to often this is not the case.

The actions of professionally trained staff can be put under such work pressure as it comes to a situation where no normal person can perform adequately. It was the introduction of Safety Management Systems (SMS) that was intended to identify these scenarios and ensure that they were mitigated or eliminated.

The actions of everyone involved with this fatal aviation accident are now under investigation. Aviation is not a “a dangerous business”. However, it is a business that requires more care and attention than most. That includes the provision of adequate resources at all times.

[1] https://www.intlaviationstandards.org/Documents/OccurrenceCategoryDefinitions.pdf

Transitioning to Green Aviation

Put your hands over your ears if your mantra is – drill baby drill. If climate change is a myth, in your mind, or you take a devil may care attitude, then the mere mention of the word “green” may give you the jitters. This is not for you. Move out of the way.

For the rest of us, who live in the real world, on planet Earth, there’s a problem. A prickly, tricky, sticky, long-term global problem. One that has commanded a great deal of attention but sometimes almost to the point of boring the pants off. Transport is one of those sectors that needs attention. Progress toward the adoption of Electric Vehicles (EV) is underway. Now and then, there’s a push back, but the direction of travel is clear. An immediate reminder of the need to change is the volatility of fuel prices at the pump. An inability to control or foresee global events that push oil and gas prices one way and then the next.

Sustainable aviation is turning out to be a hard nut to crack. For ground-based vehicles the issue of power density is not as constraining as it is in aviation. Weight is one of the fundamental parameters in flight. So, current high energy batteries present a particular technical challenge.

Exploring new forms of flight propulsion is a god send for futurologists, researchers and adventurous innovators. None of the technical challenges are a quick win. The avenues for study are infinite. Well almost. Antigravity doesn’t seem to be on the cards – yet.

I guess one of the barriers is that we have a sophisticated global aviation system that we, almost entirely, take for granted. The technology involved in transporting 200 people from a cold, grey, dull, wet Britain to a sunny warm inviting holiday destination has matured to such a point that few look at it with astonishment. That so much is provided for so little outlay.

It wasn’t that the problems of providing such air transport services were easy to solve. It’s an inheritance that has stretched over many decades. Testament to the work of a vast number of smart entrepreneurs, engineers, scientists, officials and alike.

Hydrogen fuel, or some form of hybrid propulsion does seem to be a long-term prospect.

What I see now is the excitement created by past projections is being tempered by practical reality. Wonderful strategic plans, with outlandish charts, pointed the way to a fossil fuel free utopia. Those colourful documents did good in driving forward a level of thinking. Where they offered a lesser contribution is in predicting and enabling a practical transition.

This is the time when everyone does a double take. Where the aim is a workable business cases that provides a transition in a believable, sound and rational sense. Flirting with bankruptcy has been a habit of past adventurous aviation developments. Read the turbulent story of the jumbo jet. Most agree this is not a desirable state to wish for or be in. Maybe this is the tale of the tortoise and the hare. Methodical plodding through the difficulties, incremental change, ingenuity and sheer hard headedness are needed. A couple of points to round off.

One – don’t get stuck on the repetitive nonsense that new developments can’t takes place until the regulatory structure is in place.

Two – don’t build houses on all the small airfields and lesser-known airports that may, one day, become part of a new transport system[1].

[1] https://en.wikipedia.org/wiki/Plymouth_City_Airport

The Mystery of Flight MH370

It’s ridiculous and shocking. In the modern era of civil aviation, that a large passenger aircraft can go missing and never be found. This tragic disappearance that has had experts baffled.

Mysteries, in the early days of flying, were not commonplace. They were, however, sufficiently commonplace for pulp fiction writers and amateur investigators to fill their boots. Mysteries at sea, and in the air have been a fascination for as long as there has been maritime and air transport. As our scientific and technical capabilities have increased so has our expectation that these mysteries are of the past, not the present.

Without any cause for concern, Malaysia Airlines flight MH370[1] took off 12-years ago. The aircraft disappeared from radar and has never been seen since. Parts of the aircraft have been recovered. Unfortunately, those parts provided insufficient evidence as to where the whole aircraft crashed. With what is known, this Boeing 777-200ER[2] aircraft is somewhere in the depths of the ocean. How it got there, wherever there is, and why remain unknown.

The most recent sea search for the wreckage of the aircraft has yielded no findings. Systematically searching the Indian Ocean, an organisation known as Ocean Infinity, has not advanced our understanding of what happened to flight MH370. That might be unfair, since we now know that the aircraft wreckage is not likely to be at the locations they searched.

The vast area of the Indian Ocean has an average depth of over 12,000 feet. Locating an object on the seabed is a hard task even when there’s some idea where it’s resting. To make the task even more difficult, ocean seabeds have a wide variety of geological formations. Mountains, crevasse and flat expanses.

We spend most of our time living on dry land. The reality of planet Earth is that a larger part of its surface is covered with water. That we can be thankful for given what we see of other planets.

Thus, the importance of having the mechanism for location that works anywhere and everywhere. Airborne Communications, Navigation and Surveillance (CNS) is vital in all aspects of international flight. Flight MH370 was equipped with Boeing’s FANS-1 (Future Air Navigation System). This does have a surveillance function in that it provides aircraft position reports via satellite communication (SATCOM).

[In the late-1990s, I was involved in the standards setting and regulatory approval of the airborne components of both the Boeing FANS-1 and AIRBUS FANS-A systems].

Reports of the loss of MH-370 say this aircraft system was working at the point of take-off. Official reports also say that this aircraft system was “deliberately” disabled during the flight. A mystery remains as we may never get to understand the motivation for this action.

There’s no good reason for disabling such systems unless they are presenting a hazard to the aircraft in flight. Clearly the crew need to have the ability to isolate aircraft systems in the event of an avionics bay fire or other significant failure events. Circuit breakers are provided for that purpose. Procedures and training are too.

So many questions. Will the Indian Ocean search be revived again? Not for a while, I think.

[1] https://john-w-vincent.com/2024/12/20/mh370-and-mh17-a-decade-on/

[2] The ER stands for Extended Range.

Integrating for Success

It’s almost as if there’s two types of humans. Who often find it difficult to understand the other. In the field of pros and cons here’s a sketch.

One who takes a general overview that can be called the “big picture”. They shy away from dense information. Much in favour of short précis and a well-crafted pitch. Not so much interested in how an answer was derived as what it is an how it impacts their interests.

Another who specialises and focuses on precise detail. Deeply engrained in the working of a particular issue. Open to a continuous round of investigation and discovery. Not so much interested in an outcome as the interaction of the components that produced an outcome.

With the first, they are comfortable with ambiguity. A degree of vagueness. They can short-cut to decisions to provide a sense of certainty. On the downside this can lead to turning a blind eye to difficulties and failing.

With the second, they are obsessed with the pursuit of excellence almost to the exclusion of practicality. On the upside they may anticipate problems. Providing workable solutions before they become forced.

What am I talking about? Most people don’t fit in either camp. Or we have subjects where we dig deeply and others where we skim the surface. I’ve used the analogy of a basic comb on this one. The spine of the comb is the overview. The prongs of the comb are the deeper scrutiny.

My message is simple – both are needed. That is, both are needed to understand what’s going on. Where the subject is a complex aircraft systems design both are essential.

There’s another way of saying this too. Slightly different because this way assumes a hierarchic organisational structure. For the most part, despite fads and fashions to do differently, most large organisation still have a form of hierarchical arrangement. Directorates, departments, sections, teams and alike.

One view of a complex system can be taken “top-down”. Another view is taken “bottom-up”. Phrased like this (top and bottom) it’s not easy to appreciate that both are equally important.

As an illustration, I certainly remember working with highly professional engineers with incredibly detailed knowledge of their part of an aircraft. However, they had little idea of the implications of some functions in relation to the abnormal operations of an aircraft in service.

Equally, to be fair, those meetings with capable and highly experienced managers who were inclined to bypass or belittle difficulties to ensure that a promised date was met. Or an inability to appreciate the necessity to consider the long-term consequences of a finding.

My message is simple – the two perspectives must be drawn together for success. Bringing together the points of connection between the nitty gritty detail and a wider appreciation is a hard job. Fraught with misunderstanding the people who can do this are rare and precious.

The above is a reason to be concerned when the approach to efficiency is biased towards automation. To speed up design processes to get all the ducks in a row. To more quickly pile up the paperwork, or its digital equivalent, without time to think. Without the space to use our most valuable skills – experience, creativity, imagination, discussion and mutual respect.

Navigating Change

It’s all too easy to say – it was different in my time. How things have gone downhill. There’s a boring refrain from me, and my baby boom generation, which laments a lost era. What we forget is that all of history is a lost era. Becoming history is a discomforting feeling.

I remember walking around the transport museum at Brooklands in Surrey. Look to one side and there was an aircraft cockpit display that was the latest tech in my days as a young design engineer. It was slightly worse than that in that the retired equipment, covered in dust, was one I worked on in the late 1980s. Sophisticated at the time. Now an item of curiosity.

This weekend, I stood under the last flying Concorde at Aerospace Bristol. Looking up the supersonic aircraft, it remains stunning, impressive, and futuristic. It’s a real testament to the British and French engineers who were so adventurous, creative, and foresighted in its design.

That said, in the end that era came down to money and politics. Just goes to show what the implications are of having made a robust international commitment and finding it impossible to backout. As a purely business adventure, a project like Concorde is difficult to justify. As a cultural icon and industrial marker laid down for all of history to appreciate, it’s momentous. It’s reasonable to say that the success modern-day AIRBUS has roots in this tremendous European collaboration.

Anyway, back to war and more day-to-day concerns. There’s no doubt that having some form of industrial strategy is better than not having one. The trouble is that UK Governments come and go and are incredibly fickle. So, a nice policy document with sound ideas can either spur change or slowly gather dust with equal measure.

Reflecting over the last 40-years and more, the UK has taken a large peace dividend. Defence spending has declined steadily under every political flag. This has led to a focus on fewer engineering projects. A concentration on fewer prestige assets whether in the air, at sea or on land. A gradual cutting of cloth to fit a lesser role in the world.

How do I write is without the predicable lament? It’s a matter of highlighting the downsides of the current position without lapsing into an archaic wish for a return to a bygone era.

One observation I would make here. If I pick up a British aviation magazine of the 1960/70s it’s clear that there’s a huge diversity of small and medium sized enterprises (SMEs) making products that are as diverse as they are spread across the country. Yes, the large aerospace companies have consolidated so that there remains a handful of prominent names. A lot of the iconic British names have disappeared. Consigned to museums. Inward investment has meant that the titans of the past have been swallowed up by international businesses.

There’s a pattern here that is not uniquely British. I’d make the point that one of the most concerning weaknesses is the decline of the large ecosystem of SMEs. Or the precarious situation that is often their fate. These businesses are the smaller fish that swim around the bigger players. They have the capacity to be dynamic and innovative. Even if they are often under regarded and more vulnerable to economic shocks.

Central government can’t always solve problems. That said, they can, at least, take an interest and create an environment where such entrepreneurs can flourish. Reflecting over the last 40-years and more, governments have been immensely ineffective in this respect. Policy documents are great. Where the failing persists is going from words to effective actions.

From Daedalus to Artemis

Being in good company is always nice. That spirit of experimentation doesn’t suite everyone. Now, I find myself in company of a NASA astronaut and an 12th Century English Monk. All in one week.

I stumbled across the NASA App[1] last evening. I hadn’t reckoned at that being available on my smart Sony TV. There it was. So, it only seemed right to download it and check up on what’s going on with the current Artemis mission. Other News told of delays and troubles with the launch vehicle that’s to send astronauts to circle the Moon. Setbacks are common in space flight so that’s not an issue to be alarmed about.

[Whatever would we do without the Ancient Greeks. Artemis, Apollo, Mercury, Gemini[2]].

This is a fundamentally important space mission given that it’s the first-time humans will have ventured so far since the days of the Apollo missions. Sending four astronauts around Earth’s satellite is a hard task to undertake. It’s aimed at establishing a means to get to the Moon on a regular basis.

Apollo spacecraft did this journey when computers were relatively primitive machines. Artemis has the advantage of a technical capability that is many fold greater. The problem is that sheer complexity and society’s tolerance for safety risk has moved on since the 1960s.

Anyway, the tale told, in interview of one of the Artemis astronauts is one of jumping off a barn roof as a young lad. Constructing a homemade parachute and trying it out. Having that freedom of a life growing-up on a farm and that appetite for experimentation. I was thinking, been there, done that and lived to tell the tale. In my previous scribblings I’ve mentioned the large red Dutch hay barn that was part of my youth.

Back to the Greeks. It’s myth but there may have been an element of truth in it. A map of modern Greece makes it clear that the islands of Ikaria and Crete are separated by a great distance. So, suggesting that a father and son in ancient time flew from one to the other can’t be true. However, that doesn’t dismiss the possibility that the Greeks experimented with the possibility of human flight.

So, the myth goes, Daedalus was the design authority for a method of flying which does not come recommended. Strapping on wings made of wax and feathers is a 100% risky venture. Daedalus was, if a real person, an imaginative ancient inventor. An inspiration to others. In this century it’s best to interpret the famous myth of flight as one of experimentation in a way that is fully respectful of the risks involved.

Coincidentally, this week, more by accident than intention. It’s a long story. I visited the town of Malmsbury. Inspired by the story of Daedalus, Monk Eilmer of Malmesbury[3] has solid claim to be the first European to fly. It wasn’t an entirely successful flight, but it was a flight. In the 12th Century he leapt from a church tower with wings of his own invention and survived.

Monk Eilmer of Malmesbury did end up with broken legs and a place in history. It would be unwise to repeat his early experiment as an example of human flight. That is unless a crude glider was replaced by four rotors, electric motors, some electronics and a powerful battery.

I share the hazards of a technical ability. Luckily my youthful attempts at flying with a parachute made of black polythene sheeting from a red barn roof didn’t result in any broken bones. Good luck to all who fly. Especially those who travel the furthest.

[1] https://www.nasa.gov/nasa-app/

[2] https://www.greeknewsagenda.gr/from-olympus-to-the-universe-where-greek-mythology-meets-nasa-missions/

[3] https://en.wikipedia.org/wiki/Eilmer_of_Malmesbury

Determinism in Aviation Safety

The arrow of time. We fly from past, to live in the present and anticipate the future. Sir Isaac Newton would be proud of us. By unravelling laws, that where always there, the means to anticipate the future was illuminated.

In civil aviation, we have devised and grown a whole regulatory system that depends on learning from the past, doing calculations today and flying with a belief that we know what’s going to happen next. Flying is predicated on a reasonable degree of predictability. There’s clear logic in this way of thinking. Just imagine powering up a couple of massive jet engines and starting a take-off roll without being extremely confident that at a certain speed the laws of physics will do their part and the ground is left behind.

We don’t establish a reasonable degree of predictability by looking at a crystal ball or taking up alchemy. Yes, we do still depend on reasoned expert opinion in addition to doing calculations. The minute those expert opinions start to shift away from grounded reasoning and careful deliberation then danger is afoot. This is one of the arguments for treading carefully when political opinions start to come to the fore. The laws of physics are not established by a public opinion poll. Nevertheless, it’s equally polarising to say that there’s no political dimension in the aviation regulatory system.

Anyway, that’s not the subject that was on my mind. Conversations about Artificial Intelligence (AI) are more prolific than those about self-help books. Even the shelves of popular high street bookstores are starting to fill up. The non-fiction titles with AI, either as the main subject or as an adjunct are numerous. It’s the fashion to write something literate or purely speculative.

I’ve mentioned the word “determinism” before. It can be interpreted philosophically or in a more scientific and technical manner. Determinism is a belief in the inevitability of causation. That chain of cause and effect that is so familiar to anyone reading an aviation accident report.

Understanding what causes something to happen in a moment in time goes back to my initial subject of a reasonable degree of predictability. In aircraft certification, no matter how complex the system, when presented with a system safety assessment we expect a comprehensive and reasoned set of statement. Predictions about the “what ifs”. What if an aircraft part fails and what happens next? What happens in combination with other failures?

This is where AI is potentially problematic. All the reasoned arguments in the world go out of the window if a system, subject to the same conditions, behaves one way on a Monday and differently on a Friday. Not to mention the weekend. I could say, AI is remarkably human in that respect.

The subject that was on my mind is not the inner working of complex aircraft systems. Certification experts are on that one. It’s possible to put boundaries around the behaviour of some aircraft systems. What’s more fascinating is the evolution of AI interactions with us mere mortals.

Let’s say I have the responsibility for return to service of a transport aircraft that has been subject to maintenance. A pile of documentation will provide the evidence that the work conducted has been correctly completed. It conforms. Amongst that paperwork might be an output from an AI driven diagnostic system that flashes a green light to say everything is fine.

Now, playing with the “what ifs”. What if it’s not fine given that the conditions experienced were way outside the AI systems training and it does a creative hallucination. The person signing the release to service documentation would have no idea or facility to question the green light. But it’s their signature that matters in the process of return to service.

There is a point of concern.

POST: There’s a lot going on out there Enhancing aviation safety with artificial intelligence: A systematic literature review on recent advances, challenges and future perspectives – ScienceDirect

Aviation Insights

One shilling and seven pence, that’s what a copy of Flight magazine cost in 1960. Today, roughly that’s equivalent to £6. Which is not so far off the weekly cost of a typical printed magazine taken off-the-shelf in a newsagent. Now, Flight is a digital subscription[1] at £22 a month. We consume our News in a different way, but the overall price is not so different.

Spending money in charity shops always contributes to some good cause or another. Certainly, our British High Streets in 2026 are markedly transformed from that of 66 years ago. Fine, if I get hung up on that elegant number. It’s not a bingo call. It’s the number of times I’ve circled the Sun. Circled, that is, while safely attached to this rocky planet.

The young woman behind the counter was chatting to what must have been a regular when she looked up. I pointed an unregarded dusty box on the floor in the corner of the shop. “How much to you want for that box of old aviation magazines”. She looked slightly fazed. Nobody had even thought about pricing them let alone selling them. They had probably been donated as someone emptied the attic of their grandparents. Probably on the verge of going to the recycling bin.

Eventually, we settled on a modest price. She looked me up and down. I’m sure she thought that I was completely mad. That said, charity shop workers, volunteers, must face that colourful situation more than a couple of times a week. Even a day.

What struck me was the first inside page. The weekly editorial could have been written yesterday. It’s titled “Facing it” and reads thus:

“More than one great newspaper has given warning that our nation is living beyond its means – that our export prospects are poor, and that we are taking a commercial thrashing”.

“Bleak prospects for a people who have never had it so good, and one that promotes us to consider how the aircraft industry is facing up to cold reality.”

It went on to highlight that there had been few new aircraft at the Farnborough airshow of that year. It was an October publication[2]. There was a lot of talk about industry and Government cooperation but that this was not delivering.

“And now that the industry is needed, as it has never been needed before, it will not be found unready or unwilling.”

But the lament was about the failings of the Government of the time, and there being no room for complacency. This was 4-years after the Suez Crisis.

Today, we have an increased security threat, much as arose in the Cold War days. Industry and Government cooperation needs to be a lot more than fervent aspirations. We seem to be in the same phase of formulating strategies rather than implementing actions.

Don’t let me paint a picture of gloom and doom. What this Flight magazine had is great stories of British technical innovation. Electronics and control systems were advancing rapidly. Automatic landing systems were being pioneered. Technology applied improved aircraft performance and aviation safety significantly. In fact, in numerous areas Britain was not only leading, but guiding the world.

[1] https://www.flightglobal.com/subscribe

[2] Flight Number 2691 Volume 78.

The most important invention in your lifetime is…

A standout invention is one that is enduring. It’s celebrated. It shapes what comes next. It addresses an issue that’s been there for a long time. That just it – time.

I’m stretching the intent of the question a bit. Invitation doesn’t always have a single moment of realisation. Theory and experimentation come together to show promise. It’s latter that practical applications start to flow from that innovation. For me, the key invention is the beginnings of atomic time. The ability to measure time with precision.

Now, we know that past, present and future are the way we experience time. Not time itself. Having create clocks that gain or lose less no more than a second in billion years is an astonishing feat.

Today, a great deal of the infrastructure that surrounds us, and we hold in our hands, depends on precise time. Communication systems exploit it. We navigate using this asset. Society has been and will continue to be transformed.

Yet timekeeping systems have not reached their limit.

Mutuality in Aviation Safety

Back to the benefits of mutuality. That idea of working together for a common goal. It may seem bazar but instead I will start with the downsides of mutuality.

Parties who are in conflict often like to deny interdependency. It’s that instinctive feeling that we can go it alone. Highlighting that working with others turns out to be complicated, calculating and compromising. Surely much better to be that lone High Plains Drifter who lives day to day.

In the aircraft airworthiness discipline, I saw this happening during the lengthy process of the international harmonisation of technical requirements that took shape in the 1990s.

It’s not easy to say but a substantial number of aviation rules and regulations that are applied are written in blood. Ever since the first aircraft took to the skies there has been incidents and accidents. Each one presents an opportunity to gain experience. Tragic though they maybe, if there’s a positive outcome, it’s that measures are put in place to try to prevent similar occurrences happening again. This doesn’t aways work but it works often enough to make it the intelligent way forward. When that learning doesn’t take place, the result is condemnation and outcry[1].

So, imagine a situation where Party A has a rule that comes from a tragic aviation event and Party B does not have that rule, or see the need for that rule. Equally, where Party A is eliminating a rule that Party B views as a judicious measure for managing aviation safety risk.

Clearly, where safety is the goal, the harmonisation of technical requirements is not a trivial matter. Disagreements can put stress on relationship. It can from time-to-time cause people to walk off the playing field. To use an expression that became real at the 2025 Africa Cup of Nations football final. When the application of international rules doesn’t go the way people would like the results can be testing.

What I’m alluding to here is the early days of the technical harmonisation work that was done within what was then called the Joint Aviation Authorities (JAA) in Europe. And how that work interleaved with the work that was done to harmonise rules across the North Atlantic.

People did indeed walk off the playing field. One or two of them became ardent anti-Europeans. Maybe it was easier for younger technical staff to accommodate change. Nevertheless, each step that was taken to change or eliminate additional national technical requirements created tension. Maintaining sight of the greater goal of mutual benefit was demanding work. In fact, technical harmonisation is demanding work and always will be as such.

Across boundaries circumstances differ. My analogy is that of saying that it is no surprise that the Netherlands maybe concerned about bird strikes and overwater helicopter operations. At the same time Switzerland maybe more concerned about mountain waves and high-altitude helicopter operations. Each concern needs to be met. Priorities may vary.

Recent headlines saying: “Trump Says He Is ‘Decertifying’ Bombardier Aircraft In US[2]” has a sour ring about it. Political pressure should not be the driver of aviation safety technical rules. It’s perfectly reasonable for aviation entities to compete aggressively in the commercial world. It’s idiocy to compete on aviation safety grounds. This is not new learning. This has been the case for at least the last half a century.

POST: A view Gulfstream Confirms Delay over Canadian Type Certification of Business Jets | Aviation International News

[1] https://www.ntsb.gov/news/press-releases/Pages/NR20260127.aspx

[2] https://aviationweek.com/business-aviation/aircraft-propulsion/trump-says-he-decertifying-bombardier-aircraft-us