Flying – John Vincent

Comms

The long history of data communications between air and ground has had numerous stops and starts. It’s not new to use digital communications while flying around the globe. That said, it has not been cheap, and traditional systems have evolved only slowly. If we think Controller Pilot Data Link Communications (CPDLC)[1] is quite whizzy. It’s not. It belongs to a Windows 95 generation. Clunky messages and limited applications.

The sluggishness of adoption of digital communications in commercial aviation has been for several reasons. For one, standardised, certified, and maintainable systems and equipment have been expensive. It’s not just the purchase and installation but the connection charges that mount-up.

Unsurprisingly, aircraft operators have moved cautiously unless they can identify an income stream to be developed from airborne communication. That’s one reason why the passengers accessing the internet from their seats can have better connections than the two-crew in the cockpit.

Larger nations’ military flyers don’t have a problem spending money on airborne networking. For them it’s an integral part of being able to operate effectively. In the civil world, each part of the aviation system must make an economic contribution or be essential to safety to make the cut.

The regulatory material applicable to Airborne Communications, Navigation and Surveillance (CS-ACNS)[2] can be found in publications coming from the aviation authorities. This material has the purpose of ensuring a high level of safety and aircraft interoperability. Much of this generally applicable material has evolved slowly over the last 30-years.

Now, it’s good to ask – is this collection of legacy aviation system going to be changed by the new technologies that are rapidly coming on-stream this year? Or are the current mandatory equipage requirements likely to stay the same but be greatly enhanced by cheaper, faster, and lower latency digital connections?

This year, Starlink[3] is offering high-speed, in-flight internet connections with global connectivity. This company is not the only one developing Low Earth Orbit (LEO)[4] satellite communications. There are technical questions to be asked in respect of safety, performance, and interoperability but it’s a good bet that these new services will very capable and what’s more, not so expensive[5].

It’s time for airborne communications to step into the internet age.

NOTE: The author was a part of the EUROCAE/RTCA Special Committee 169 that created Minimum Operational Performance Standards for ATC Two-Way Data Link Communications back in the 1990s.

POST 1: Elon Musk’s Starlink Internet Service Coming to US Airlines; Free WiFi (businessinsider.com)

POST 2: With the mandate of VDLM2 we evolve at the pace of a snail. Internet Protocol (IP) Data Link may not be suitable for all uses but there’s a lot more that can be done.

[1] https://skybrary.aero/articles/controller-pilot-data-link-communications-cpdlc

[2] https://www.easa.europa.eu/en/document-library/easy-access-rules/easy-access-rules-airborne-communications-navigation-and

[3] https://www.starlink.com/

[4] https://www.esa.int/ESA_Multimedia/Images/2020/03/Low_Earth_orbit

[5] https://arstechnica.com/information-technology/2022/10/starlink-unveils-airplane-service-musk-says-its-like-using-internet-at-home/

Just H

What is the future of Hydrogen in Aviation? Good question. Every futurologist has a place for Hydrogen (H) in their predictions. However, the range of optimistic projections is almost matched by the number of pessimistic ones.

There’s no doubt that aircraft propulsion generated using H as a fuel can be done. There’s a variety of way of doing it but, the fact is, that it can be done. What’s less clear is a whole mass of factors related to economics, safety and security and desirability of having a hydrogen-based society.

H can be a clean form of energy[1], as in its purest form the process of combustion produces only water. We need to note that combustion processes are rarely completely pure.

It’s an abundant element but it prefers to be in company of other elements. Afterall, the planet is awash with H₂O. When H is on its own it has no colour, odour, or taste. In low concentrations, we humans could be oblivious to it even though there’s a lot of it in the compounds that make us up.

Number one on the periodic table, it’s a tiny lightweight element that can find all sorts of ways of migrating from A to B. Ironically, that makes it an expensive element to move around in commercially useable quantities. H is often produced far away from where it’s used. For users like aviation, this makes the subject of distribution a fundamental one.

Part of the challenge of moving H around is finding ways of increasing its energy density. So, making it liquid or pumping it as a high-pressure gas are the most economic ways of using it. If this is to be done with a high level of safety and security, then this is not going to come cheap.

There are a lot of pictures of what happens when this goes wrong. Looking back at the airships of the past there are numerous catastrophic events to reference. More relevantly, there’s the space industry to look at for spectacular failures[2]. A flammable hydrogen–air mixture doesn’t take much to set it off[3]. The upside is that H doesn’t hang around. Compared to other fuels H is likely to disperse quickly. It will not pool on the ground like Kerosene does.

In aviation super strict control procedure and maintenance requirements will certainly be needed. Every joint and connectors will need scrupulous attention. Every physical space where gas can accumulate will need a detection system and/or a fail proof vent.

This is a big new challenge to aircraft airworthiness. The trick is to learn from other industries.

NOTE: The picture. At 13:45 on 1 December 1783, Professor Jacques Charles and the Robert brothers launched a manned balloon in Paris. First manned hydrogen balloon flight was 240 years ago.

[1] https://knowledge.energyinst.org/collections/hydrogen

[2] https://appel.nasa.gov/2011/02/02/explosive-lessons-in-hydrogen-safety/

To provoke

Social media provocateurs are on the rise. Say something that’s a bit on the edge and wait for the avalanche of responses. It’s a way of getting traffic to a site. The scientific and technical sphere has these digital provocateurs less than the glossy magazine brigade, but the phenomena is growing.

Take a method or technique that is commonly used, challenge people to say why it’s good while branding it rubbish. It’s not a bad way to get clicks. This approach to the on-line world stimulates several typical responses.

One: Jump on-board. I agree the method is rubbish. Two: I’m a believer. You’re wrong and here’s why. Three: So, what? I’m going to argue for the sake of arguing. Four: Classical fence sitting. On the one hand you maybe right on the other hand you may be wrong.

Here’s one I saw recently about safety management[1]. You know those five-by-five risk matrices we use – they’re rubbish. They are subjective and unscientific. They give consultants the opportunity to escalate risks to make new work or they give managers the opportunity to deescalate risk to avoid doing more work. Now, that’s not a bad provocation.

If the author starts by alleging all consultants and managers of being manipulative bad actors that sure is going to provoke a response. In safety management there are four pillars and one of them is safety culture. So, if there are manipulative bad actors applying the process there’s surely a poor safety culture which makes everything else moot.

This plays into the discomfort some people have with the inevitable subjectivity of risk classification. It’s true that safety risk classification uses quantitative and qualitative methods. However, most typically quantitative methods are used to support qualitative decisions.

There’s an in-built complication with any risk classification scheme. It’s one reason why three-by-three risk matrices are often inadequate. When boundaries are set there’s always the cases to decide for items that are marginally one side or other side of a prescribed line.

An assessment of safety risk is just that – an assessment. When we use the word “analysis” it’s the supporting work that is being referenced. Even an analysis contains estimations of the risk. This is particularly the case in calculations involving any kind of human action.

To say that this approach is not “scientific” is again a provocation. Science is far more than measuring phenomena. Far more than crunching numbers. It includes the judgement of experts. Yes, that judgement must be open to question. Testing and challenging is a good way of giving increased the credibility of conclusions drawn from risk assessment.

[1] https://publicapps.caa.co.uk/docs/33/CAP795_SMS_guidance_to_organisations.pdf

High ALT

Normal commercial air traffic control doesn’t go beyond 60,000 ft in altitude. That makes sense since civil flying activities have been limited to lower altitudes. In fact, modern commercial airliners are not designed to fly above about 45,000 feet. This is a compromise based on what works commercially as much as what’s works best. Aircraft instruments are calibrated making standard assumption about the atmosphere.

For some of its flight, Concorde cruised at a height of 60,000 feet. More like a military jet, with its speed it had the capability to make use of higher altitudes.

It’s even possible to fly above 50,000 feet without an engine. The world record glider flight by AIRBUS shows it’s possible.

The Earth’s atmosphere is not uniform. It changes its characteristics with altitude. The atmosphere can be divided into five layers, as the temperature and density change. They are named: Troposphere, Stratosphere Mesosphere, Ionosphere and Exosphere.

The Troposphere is a layer that goes from 8 kms (26,247 ft) on the poles to about 18 kms (59,055 ft) on the equator. This is the layer where weather is experienced.

On average, the Stratosphere goes up to about 40 kms (131,234 ft). The winds blows fast but they tend to be more consistent as they wrap around the globe. The lower portion of the Stratosphere is virtually isothermal (layer of constant temperature).

A medieval English philosopher and Franciscan friar, Roger Bacon[1] figured out that the air might support a ship in the same way that water supports ships. In the 13^th Century that was a nice academic conclusion but little more.

With all the current controversy surrounding high altitude balloons, that the road to flight started with balloons, could be said to be a bit ironic. It’s long been known about that balloons fly well at high altitudes but it’s a new frontier as far as commercial activity is concerned. For science, weather balloons may go up to 40 km to measure the high level winds.

Some experimental work has been done on trying to commercially use the airspace above normally civil flying. The Google Loon trials[2] are an example of an attempt to float a telecommunications platform high in the sky. These balloon trials were abandoned as difficulties proved greater than anticipated.

It’s not so easy to keep a high altitue balloon on-station.

Now, considering the news in North America, maybe high-altitude operations ought to be a matter of regulatory concern. This is not a subject that any one country can address alone.

There is some legal, regulatory and technical work[3] underway in Europe[4] but it needs to make progress. This is a subject for international collaboration.

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

[2] https://blog.x.company/loons-final-flight-e9d699123a96

[3] https://www.eurocontrol.int/article/echo-making-space-new-high-altitude-entrants

[4] https://www.eurocontrol.int/events/european-higher-airspace-operations-symposium

UFO

It’s intriguing. Reports of unidentified flying objects being shot down over Alaska, Canada, and Michigan prompts a lot of questions.

The Earth’s atmosphere eventually becomes space at 100 km up. The Kármán line[1] is one way to define the boundary. All aeronautic activities are deemed to take place below that imaginary line. Theodore Karman[2] did his best to determine a height at which the Earth’s atmosphere is too thin to support flight. Now, there’s an international discussion about bringing that boundary down to 80 km. That is the hight above which a person in a space vehicle is said to become an astronaut.

I guess my point is that there’s a lot of the Earth’s atmosphere to continuously monitor, if the task is to know about everything that is flying everywhere. So, it’s perfectly reasonable that reports of unidentified flying objects will crop up, now and then.

It doesn’t mean that there are alien probes popping in to keep an eye on us earthlings. No, in so far as is commonly known there’s no evidence that stands up to scrutiny to definitively prove the existence of sustained airborne craft that are not of this Earth. However, extra-terrestrial objects fall to Earth all the time. Mostly ice and rocks. I wrote about objects falling from the sky in an earlier article.

It’s worth recalling the first article of the Chicago Convention on Sovereignty:

The contracting States recognize that every State has complete and exclusive sovereignty over the airspace above its territory.

For those monitoring what’s in the air, the primary concern remains about flights over land and populated areas. This is the case where hazards can exist to those below.

All said and done, it’s no time to become alarmed. It may well be the case that these unidentified flying objects were previously ignored. Only now has the militaries in North America been galvanised into action and being more vigilant. The more people look, the more people see.

What do I know? Spy balloon, craft and drones may be much more common than has been generally reported.

Claims and counter claims that everyone is doing it shouldn’t be dismissed out of hand. The technology involved in flying above normal air traffic has a multitude of potential applications. A framework for higher altitude operations is now being written[1].

POST: Diplomatic tensions between the US and China continue to escalate as the US explains its shooting down of high altitude flying objects over North America. Much is still to be uncovered.

[1] https://www.eurocontrol.int/article/echo-making-space-new-high-altitude-entrants

[1] https://www.fai.org/news/statement-about-karman-line

[2] A Hungarian American physicist and engineer who was born 11 May 1881.

Fatal accident in Nepal 3

The air transport year started badly. A Yeti Airlines twin-engine ATR 72-500[1] aircraft plunged into a gorge as it was approaching Pokhara International Airport (PKR) in Nepal.

Singapore’s Ministry of Transport (MOT) is supporting Nepalese authorities.

The latest news is that the aircraft’s Flight Data Recorder (FDR) and Cockpit Voice Recorder (CVR) have been replayed. It is reported that the analysis of the FDR and CVR data shows that the propellers of both engines were feathered during approach.

It is not known if this was due to the actions of the crew or a technical fault.

The investigation continues.

The propellers on this aircraft type have pitch control of their blades. The pitch of the blades can be changed to the “feather” position (approximately 90 degrees). Feathered blades reduces the drag that would occur in the event of an engine shutdown.

This event occurring while the aircraft is slowing on approach will have an impact on the aircraft’s air speed. Monitoring air speed on approach is vital.

The suspicion that the aircraft may have stalled remains one theory.

The normal actions required on an approach are called up on a checklist.

Example: Here is a video of an ATR 72-500 landing.

Notice the pilots’ hands at 4:57 minutes in.

An incident involving an aircraft of the ATR 72 type on the way from Stockholm to Visby[2] is interesting but may not be relevant in the Yeti Airlines case.

[1] https://skybrary.aero/aircraft/at75

[2] https://www.havkom.se/en/investigations/civil-luftfart/tillbud-med-ett-luftfartyg-av-typen-atr-72-pa-vaeg-fran-bromma-till-visby

Apprenticeships

What do you think are the reasons behind the overall decline in engineering apprenticeship starts in recent years? We are particularly interested in understanding more about supply and demand.

Image. It persists even now. In fact, the paper[1] that asks these questions has images of spanner turning. It’s so easy to pick royalty free pictures that pop-up from search engines searches. These images show mechanics in blue overalls. Don’t get me wrong, this is not the least bit disrespectful of spanner turning.

A deep cultural memory persists. It has multiple elements. You could say, in part, industrialisation, still conjures up images of dark satanic mills contrasted with grand country homes of a class of business owners. Basically, dirty, and clean as two key words.

The Victorians did a great deal to both elevate engineering personalities, like Brunel[2], but to hold them as different or apart from the upper middle-class society that the fortunate aspired to join. Those who forged the prosperity of the age had to work hard to be accepted in “society”.

Today, it makes no difference that’s it’s American, popular comedies like “The Big Bang Theory[3]” entertain us immensely but pocket the “nerd” as eccentric, peculiar and unfathomable. I admit this is attractive to a proportion of young people but maybe such shows create exclusivity rather than opening people’s eyes to possibilities.

Having Government Ministers standing=up can calling for Britan to become a version of Silicon Valley doesn’t help. Immediately, that signal is heard from those in authority, young people switch “off”. To boot, the image conquered up is a whole generation out of date. We have the Windows 95 generation telling the iPhone generation what’s the best direction to get to the 2030s.

Here’s a proposition – you must see yourself as an “engineer” to become an engineer. That can be said of a whole myriad of different professions. Each with a common stereotype. Look at it the other way. If you cant’t see yourself as a person who can shape the future, it isn’t likely you will choose engineering.

My observation is that we need to get away from too many images of activities. In other words, this is an engineer at work. This is what they do. This is what they look like. What we need to address is the touchy-feely stuff. Let’s consider how young people feel about the world they have inherited from my generation.

A high level of motivation comes from the wish to make changes and the feeling that it’s possible to make changes. That the skills picked-up as an apprentice will help you shape the future. Engineering is part of making a better world.

[My history is that of an Engineering Industry Training Board (EITB) apprentice who started work in 1976.]

[1] https://www.engineeringuk.com/media/318763/fit_for_the_future_knight_and_willetts_apprenticeship_inquiry_euk_call_for_evidence.pdf

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

[3] https://www.imdb.com/title/tt0898266/

AI2

There’s not just one form of Artificial Intelligence (AI). This group term hides a great panoply of different configurations, shapes, and forms of applications.

One of the most impactful applications is that of machine learning or expert systems. It’s where we go beyond a conventional computer’s ability to store and manipulate information against set rules. It’s where the machine has the capability to learn new ways of interpreting information and thus becomes different every day of operation from the day it was switched on. That’s a bit vague but it captures the essence of moving from deterministic to non-deterministic systems.

In all this we do presuppose that such complex systems are in the hands of able and highly illiterate users who understand what they are doing in training that learning machine. There’s debate about how bias in algorithms can produce unintended consequences. In addition, a reliable and trustworthy machine can be trained in a way that embeds errors and biases too[1].

Just as a child picks up the bad habits of a parent, so “intelligent” machines can learn from pilots, controllers and engineers who may have less than optimal ways of undertaking tasks. This Human-AI interplay is likely to become a major area of study. As the topic of Human Factors is itself a large body of material.

Already with the debate on social media it is all too obvious that the aviation community has a wide range of views on the use of AI. All the way from utter rejection, or scepticism deeming such systems as “unsafe” to advocates who profess only the benefits and merits of such systems.

Clearly, both extreme ends of the spectrum of professional views don’t help much. I don’t think that the promoters of AI want to see blind overreliance on it. Equally, surly even ardent sceptics can see virtue in making the best use of the accumulated knowledge that is available.

I can foresee a system of systems approach. With my parent and child analogy, from time to time a child will ask a question that is blunt and to the point. A question that demands a straightforward answer. This can be uncomfortable but hits out at biases and bad habits.

In aircraft systems there are boundaries that must be respected. The physics of flight dictate that going beyond those boundaries is generally not good for life and limb. So, a system programmed to question an expert system, one AI questioning another AI, or even question its trainer, is not beyond the realms of possibility. It might even be a good idea.

[1] https://www.nature.com/articles/s41746-022-00737-z

Poor law making

If you thought the Truss era was an aberration, and that the UK’s Conservative Party had learned a lesson, then please think again. Wheels set in motion by the ideologue Jacob Rees-Mogg MP are still spinning.

The Retained European Union Law (Revocation and Reform) Bill is trundling its way through the UK Parliament. The Government Bill will next be prepared for its 3^rd reading in the House of Commons[1]. The Conservative Government has brought forward this Bill to revoke, reform or revise all the remaining law in the UK that was formerly derived from the UK’s membership of the EU. This turns on its head the normal approach to changing UK legislation. Revocation is automatic unless there’s an intervention by a Minister.

UK civil aviation depends on several thousand pages of legislation derived from EU law[2]. Much of this law was created with considerable contributions from the UK. There’s hardly any if any advocates for automatic revocation of current aviation legislation. Even the thought of this action sends a shiver down the spin of aviation professionals. Generations of them have worked to harmonise rules and regulations to ensure that this most international of industries works efficiently.

Unless amended, the Government’s EU Retained Law (Revocation and Reform) Bill[3] could turn out to be an absolute disaster. Even those who have an irrational wish to eliminate any and every past, present, or future link to Europe must come up with a practical alternative and do this in an incredibly short time. Without a consistent, stable, and effective framework civil aviation in the UK will grind to a halt. Again, even those who have an unsound need to change for change’s sake will be hitting a vital industry hard, as it is only just getting back on its feet after the COVID pandemic and now setting out to meet tough environmental standards.

It’s going to be interesting to see what happens when this poor Bill reaches the House of Lords. Once again, the country will be relying on the upper house to add some common sense to this draft law.

POST 1: The 3rd reading debate makes it clear that the Government is unsure which laws are covered by the Bill. If the Ministers responsible for this legislation do not themselves know its extent, how can anyone expect civil servants working on this legislation to know the full extent of change? A most strange state of affairs Retained EU Law (Revocation and Reform) Bill (Third si – Hansard – UK Parliament

POST 2: Retained EU law lays down rules for the airworthiness and environmental certification of aircraft and related products, parts and appliances, as well as for the certification of design and production organisations in the UK Commission Regulation (EU) No 748/2012 of 3 August 2012 laying down implementing rules for the airworthiness and environmental certification of aircraft and related products, parts and appliances, as well as for the certification of design and production organisations (recast) (Text with EEA relevance) (legislation.gov.uk)

POST 3: Retained EU Law Bill is being debated in the House of Lords on Monday, 6 February.

[1] https://bills.parliament.uk/bills/3340

[2] https://www.eiag.org.uk/paper/future-retained-eu-law/

[3] https://www.gov.uk/government/news/the-retained-eu-law-revocation-and-reform-bill-2022

SPO 3

Now, there’s an activity with two humans in the loop. Given the physics involved the goalkeeper should be beaten every time. Well, I’m saying that assuming a high level of expected performance on the part of the footballer taking the penalty. I guess that’s why we are often critical when they miss. In the last few weeks there have been more than a few examples to watch.

What we know is that football penalties are much more than mechanical actions and reactions. However, there’s a degree of mythology about the inevitability of human factors taking control of the outcome: goal or no goal. I’d like to think that there’s an ever-shifting blend of what physics does to the ball and what the human does. Is it always possible to predict the slipperiness of a spinning ball traveling at speed that is then touched by the fingertip of a goalkeeper?

What if the footballer taking the penalty, was an “intelligent” machine. That is a machine with a sensor array and computational capability that far exceeded normal human performance. Such advance automation could calculate the most probable reaction of a goalkeeper based on history and the immediate movements they make right up to the last millisecond before the ball is struck.

Assuming the machine was limited in term of the force it can apply to the ball, it could still adjust its actions as soon as any new information was available. I’m not saying the outcome will always be better for the machine football striker. However, it could reduce the scope for error and randomness to dictate what finally happens.

So, with that argument, in aviation, I’m saying it’s not right to say that Single Pilot Operation will always be worse than two crew operations. Don’t get me wrong, those people aggressively advancing the idea that the intelligent machine will always be better than a human are missing something too.

One thing that highly capable automation could have to bring to the party is not only early detection and diagnosis of problems but a massive library of stored experience. How we embed and constantly update that flight experience is an almighty challenge.

Afterall, the dread in aviation is knowledge with hindsight. It takes the form: “You should have known. Why did you let this incident happen?”

I’m now tempted to think of a Star Trek analogy. Every second an aircraft of a type is flying, experience of its operation is being accumulated. If there are hundreds of a type flying at any moment across the globe, that’s a lot of data to collect and absorb and think about before acting.

The fictional and scarry Borg are cybernetic creatures linked by a hive mind and they know a thing or two about assimilation. Granted that’s farfetched as analogies go but my point is that I believe we are generations away from that kind of capability. Not only that, just as humans fail so any such “intelligence” designed by humans will fail to.