Category: Security

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 3rd 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

Where’s the common sense?

It’s two whole years since the end of the UK’s Brexit transitional period. That’s since the day when the UK fully withdrew from the European Union (EU). Have we seen any, I mean any, Brexit benefits from the day of the Brexit referendum? The sad truth is – No. We are worse-off. Investments haven’t happened, political turmoil persists and bureaucratic barriers have grown.

Certainly, it’s right to say that British politicians have been busy. They have found lots of targets to blame for this continuing underperformance. You name it; Remainers, young people, environmentalists, protesters, strikers, human rights, overseas aid, COVID, flu, global economic downturn, energy prices, war in Europe, Biden’s administration, China, France, Germany, hot weather, cold weather, the list goes on and on and on. The Brexiter’s blame list is an exceptionally long one. Add to this the fact that Boris Johnson comes in for caustic blame. Often strongest from the people who trumpeted his ascendancy to power in 2019.

Although we should not dwell too much on the past, it’s as well to not let what has happened in this last year be swept under the carpet. Remember 2022, after 44 days, Conservative Liz Truss resigned as British Prime Minister (PM). She was the first choice of the members of the political party most entrenched in Brexit thinking. This extraordinary farce made the country look it was run by like a bunch of incompetent fools, of ill-disciplined fanatics, of preposterous comics.

The blatant dishonesty behind Brexit can not be denied. A recent example was the Government statement on having not attained a promised boost from new trade agreements. A ridiculous political line about not signing deals until they are right for the country is a brazen smoke screen to cover-up a significant lack of achievement[1].

We need some serious common sense injected into our politics. The UK is not going away. The EU is not going away. Both share an immense common interest. Both are faced with similar challenges and threats. Both share the same values.

Brexit has added to costs, adding to inflation, labour shortage and under performance. Most people[2] now accept this analysis and want to see serious change[3]. The more both Conservatives and the Labour Party cling on to the mythology of Brexit, the more damage will be done. Keir Starmer has confirmed that the Labour Party will not seek for Britain to re‑join the EU. What a reckless folly from a would be PM.

POST: referendum – latest news, breaking stories and comment – The Independent

[1] https://www.bbc.co.uk/news/uk-politics-63808657

[2] https://www.statista.com/statistics/987347/brexit-opinion-poll/

[3] https://yougov.co.uk/topics/politics/explore/issue/European_Union

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.

SPO 2

An instant reaction to Single Pilot Operations (SPO) is like the instant reaction to completely autonomous flight. “I’m not getting on an aircraft without a pilot!” Then to justify that reaction fatal accidents of the past are cited. Typically, this is to remind everyone of the tragic Germanwings accident[1]. It was 24 March 2015, that an Airbus A320 was crashed deliberately killing all onboard.  

However, it’s wise to remember that the likelihood of incapacitation[2] is much greater than that of the malicious behaviour of the pilot in command. Cases of malicious behaviour leading to a catastrophic outcome are truly shocking but extremely rare.

One fatal accident, that is still disputed is EgyptAir Flight 990[3] that killed 217 people in 1999. The possibility of inflight pilot suicide is unnerving, since on the face of it there is little any of the aircraft’s cabin crew or passengers can do to stop it.

This could be a future opportunity to use automation to prevent these scenarios occurring. Afterall the aircraft knows where it is and that a sustained high-speed dive towards the ground is not normally intended. A safety system exists to do this[4], but its outputs are not connected to the aircraft’s flight controls.

Humans being adaptable, extremely creative and capable of highly irrational actions, it’s unlikely that malicious behaviour resulting in aviation accidents will ever be reduced to zero. This is said regardless of the procedures or technology involved. The fate of flight MH 370 remains a mystery.

Thus, the prominent safety issue in respect of SPO is pilot incapacitation. Where the pilot in command is no longer able to perform as expected. That is, if the aircraft flown is not capable of safely landing itself. The objective always being safe continued flight and landing.

I’ve had the “1% Rule” rule explained to me by a notable aviation doctor, but I must admit I didn’t fully take it in. So far, the rule has stood the test of time. When the pilot in command of a Czech Airlines aircraft collapsed and died on route from Warsaw to Prague in 2012, the co-pilot took over and everyone got home safely.

Any automated co-pilot must be at least as capable as a human co-pilot in all aspects of operation of an aircraft. The key word here being “all”. It’s not enough to have the functions necessary to undertake safe continued flight and landing. Task such as communicating with the cabin crew and passengers must also be considered. Including preparation for an emergency landing.

[1] https://www.bbc.co.uk/news/world-europe-32072218

[2] http://www.avmed.in/2012/02/pilot-incapacitation-debate-on-assessment-1-rule-etc/

[3] https://www.theguardian.com/world/2002/mar/16/duncancampbell

[4] https://skybrary.aero/articles/terrain-avoidance-and-warning-system-taws

Single Pilot Operations

Single Pilot Operations is not new. What’s new is considering this way of working for everyday public transport operations of large aircraft

Research is of fundamental importance. It seems obvious to say so given the benefits it has given us. When proposals come forward to exploit new technologies there needs to be that moment when everyone steps back and takes a long hard look at the implications of its use.

In basic technical research it’s not the most important consideration is to focus on the drivers for change. They can be multifarious: economic, environmental, social, safety, security, political, and maybe just a matter of preference. Policy directions are taken by the industry and governments not constrained by what is happening now as much as what might happen tomorrow.

Research has delivered incredible safety improvements in aviation. This is not only in the basic design and construction of aircraft but all aspects of their operation. So, to see that the European Union Aviation Safety Agency (EASA) sponsoring research to study the implications of aircraft Single Pilot Operations[1] is a wholly good measure.

My history goes back to the early days of fly-by-wire aircraft systems. This is where the mechanical and physical connection between an aircraft pilot’s actions and the control surfaces that determine flight are replaced by digital computers. Back in the 1980s, a great deal of research and experimental flying proved the technology to make fly-by-wire work. It first found favour with the military. One reason being that an aircraft’s capability could be extended well beyond what was formerly reached. This change was introduced with caution, analysis, testing and much detailed risk assessment.

At the time, there was a significant body of professional pessimists who predicted a diminishment of aviation safety. Today, four decades on, studies show that even as air traffic has increased so civil aviation safety has improved. A momentous achievement. An achievement that has, in part, been because of the well-regulated adoption of advanced technologies. 

It is important to look at potential changes with an open mind. It’s easy to come to an instant opinion and dismiss proposals before a detailed study has been conducted. The detailed technical research can then be part of the challenge and response that is necessary to before approval of any major change. First difficult questions need to be tabled and thoroughly investigated.

[1] https://www.easa.europa.eu/en/research-projects/emco-sipo-extended-minimum-crew-operations-single-pilot-operations-safety-risk

Air Taxi 3

Urban mobility by air, had a flurry of success in the 1970s. However, it did not end well.

Canadian Joni Mitchell is one of the most celebrated singer-songwriters and my favourite. She has tapped into the social and environmental issues that have concerned a lot of us for decades. Of her large catalogue, I can’t tell you how much I love this song[1]. The shear beauty of the lyric.

Anyway, it’s another track on the album called “Hejira” that I want to refer. When I looked it up, I found out, I was wrong. The song I want to refer to is on the 1975 album “The Hissing of Summer Lawns”. The song “Harry’s House[2]” contains the line “a helicopter lands on the Pan Am roof like a dragon fly on a tomb.” Without going into what it’s all about, the lyrical image is that flying from a city skyscraper roof was seen as glamorous and the pinnacle of success.

In 1970, prominent aviation authorities were talking about the regulatory criteria needed for the city-centre VTOL[3] aircraft of the future. Then on the afternoon of 16 May 1977, New York Airways Flight 971, a Sikorsky S-61 helicopter, crashed[4] on Pan Am’s building rooftop heliport[5]. That ghastly fatal accident reset thinking about city centre operations air transport operations.

So, what’s different 50-year on? Proposals for city centre eVTOL operations are much in the News. City planners are imagining how they integrate an airborne dimension into public transport operations. Cars, busses, trains and eVTOL aircraft may all be connected in new multimodal terminals. That’s the city transport planners’ vision for less than a decade ahead.

For one, the vehicles are radically different. Yes, the physics of flight will not change but getting airborne is quite different between a conventional large helicopter and the plethora of different eVTOL developments that are underway across the world.

Another point, and that’s why I’m writing this piece, is the shear amount of safety data that can be made available to aircraft operators. Whereas in the 1970s, a 5-parameter flight recorder was thought to be neat, now the number of digital parameters that could be collected weighs in over thousands. In the 1970s, large helicopters didn’t even have the basic recording of minimal flight data as a consideration. The complexity in the future of eVTOL will be, not how or where to get data but what to do with all the data that is streamed off the new aircraft.

Interestingly, this changes the shape of the Heinrich and Bird “safety pyramid” model[6]. Even knowing about such a safety model is a bit nerdy. That said, it’s cited by specialist in countless aviation safety presentations.

Top level events, that’s the peak of the pyramid, remain the same, but the base of the pyramid becomes much larger. The amount of safety data that could be available on operational occurrences grows dramatically. Or at least it should.

POST: Growing consideration is being given to the eVTOL ecosystem. This will mean a growing need to share data Advanced Air Mobility Portal (nasa.gov)

[1] https://youtu.be/nyj5Be5ovas

[2] A nice cover https://youtu.be/bjvYgpm–tY

[3] VTOL = Vertical Take Off and Landing.

[4] https://www.nytimes.com/1977/05/17/archives/5-killed-as-copter-on-pan-am-building-throws-rotor-blade-one-victim.html

[5] https://www.thisdayinaviation.com/16-may-1977/

[6] https://skybrary.aero/articles/heinrich-pyramid

Social media is changing aviation safety

You may ask, how do I sustain that statement? Well, it’s not so difficult. My perspective that of one who spent years, decades in-fact, digging through accident, incident, and occurrence reports, following them up and trying to make sense of the direction aviation safety was taking.

In the 1990s, the growth of digital technology was seen as a huge boon that would help safety professionals in every way. It was difficult to see a downside. Really comprehensive databases, search capabilities and computational tools made generating safety analysis reports much faster and simpler. Getting better information to key decision-makers surely contributed to an improvement in global aviation safety. It started the ball rolling on a move to a more performance-based form of safety regulation. That ball continues to roll slowly forward but the subject has proved to be not without difficulties.

Digging through paper-based reports, that overfilled in-trays, no longer stresses-out technical specialist quite the same as it did. Answers are more accessible and can reflect the real world of daily aircraft operations. Well, that is the theory, at least. As is often the case with an expansion of a technical capability, this can lead to more questions and higher demands for accuracy, coverage, and veracity. It’s a dynamic situation.

Where data becomes public, media attention is always drawn to passenger aircraft accidents and incidents. The first questions are always about what and where it happened. A descriptive narrative. Not long after those questions comes: how and why it happened. The speed at which questions arise often depends on the severity of the event. Unlike road traffic accidents, fatal aviation accidents always command newsprint column inches, airtime, and internet flurries.

Anyone trying to answer such urgent public questions will look for context. Even in the heat of the hottest moments, perspective matters. This is because, thankfully, fatal aviation accidents remain rare. When rare events occur, there can be a reasonable unfamiliarity with their characteristic and implications. We know that knee-jerk reactions can create havoc and often not address real causes.

In the past, access to the safety data needed to construct a context was not immediately available to all commers. Yes, the media often has its “go-to” people that can provide a quick but reliable analysis, but they were few and far between.

This puts the finger on one of the biggest changes in aviation safety in the 2020s. Now, everyone is an expert. The immediacy and speed at which information flows is entirely new. That can be photography and video content from a live event. Because of the compelling nature of pictures, this fuels speculation and theorising. A lot of this is purely ephemeral but it does catch the eye of news makers, politicians, and decision-makers.

So, has anyone studied the impact of social media on developments in aviation safety? Now, there’s a good topic for a thesis.

Caught in the crossfire?

There’s no doubt the relative calm of the beginning of this century, yes, it seems extraordinary to say that has gone and a series of international events confront civil aviation’s way of working. It’s dramatic. In Europe, most countries, and their industries are shifting the way they operate.

Unfortunately, any reasonable observation shows that the situation for aviation is worse in the UK. Well, that is worse than the UK’s former partner States in the European Union (EU).

In times of difficulty partnerships, between counties and in industry help make the absolute most of economies of scale. It’s difficult to plan when constantly firefighting. It’s like that comic story about crocodiles and draining the swam. It’s difficult to think ahead when surrounded by crocodiles.

I agree with the article posted by David Learmount[1]. The massive efforts to achieve international harmonization in aviation regulation, over decades is of incalculable value. I have been lucky enough to work with exceptional people across the globe and played a small part in helping that move along.

In fact, I’d go further than David. I remember, quite a while ago, attending a lecture at the Brooklands Museum[2]. It was about the history of post-war UK Government involvement in aerospace manufacturing[3]. It wasn’t a happy story. It went a bit like a soap opera with technical excellence mixed with commercial incompetence and political interference. The overall lesson was that going it alone, piling on the world beating rhetoric and an inability to forge working alliances spells disaster. Whereas coming together, working cooperatively, and building multinational partnership pays dividends. Airbus being a prime example.

I joined the European Union Aviation Safety Organisation (EASA) as the start of its operation. It was a huge privilege. It was a rare opportunity. I mean, how many people get to set-up a new aviation authority, let alone one that works for so many States in Europe? I was proud that the UK took a leading role in making this venture happen. It was a progression that had been careful and thoughtfully developed and steered over decades.

What we built was a uniquely European solution. It isn’t a federal construction as we see in the United States (US). In Europe, National Aviation Authorities (NAAs) remain a key part of the system. The part that was new in September 2003 was to overcome a major deficiency of earlier cooperative working. That was the unfortunate habit nation States have for saying that’ll do the same thing but then not doing the same thing in practice.

David mentions the tricky subject of UK Additional Requirements for import. This is when the UK demanded a special difference between its aircraft and those of other countries. Often expensive and making it difficult to move aircraft around. I remember some UK Additional Requirements found their way into new European requirements and others were removed. That was a painful transition period. In aviation, technical requirements are often born of experience of accidents and incidents.

Today, the UK Civil Aviation Authority (CAA) works with a set of technical requirements that have been rolled over from the UK’s time as an EASA Member State (2003 – 2021). This presents opportunities to take a new path. Sounds tempting, if only you look at the subject superficially.

International technical standards never stand still. Big players invest resources influencing the direction that they take. Two of the biggest international players in respect of aerospace design and production are EASA and the Federal Aviation Administration (FAA).

So, UK CAA is caught on the horns of a dilemma. Unless it can significantly influence the big players the only practical way forward is to adopt what they produce (rules, regulations, standards, guidance material). Now, the UK CAA has considerable technical experience and maintains a high reputation, but it does not sit at all the tables where the major decisions are made.

This is the concern that David mentions in his article. The unnecessary ideological exit from EASA membership, that came with Brexit places the UK in a third-party arrangement. Not good.

It’s not like the world has suddenly become dull. Frantic development efforts and huge sums of money are being pumped into greening aviation. Part of this is the new Advanced Air Mobility (AAM). Part of this is known as Urban Air Mobility (UAM). Aviation folk love acronyms. It’s almost as if we are back at the beginning of the jet-age[4]. We know how that went.

Not surprisingly, the UK wants to achieve successes in this new field of “green” aviation.

Flying is a heavily regulated industry. So, national, regional, and international rulemaking processes matter. They matter a lot. Harmonisation matters a lot. That’s having common rules and regulations to maximise the size of the marketplace while ensuring levels of safety and security are high.

The bureaucratic burden of Brexit costs. It’s not free. The UK duplicates rulemaking activities because it must independently update its laws, all the secondary legislation and guidance material that comes with aviation. When there’s a significant difference between UK, Europe, US, and the rest of the world it makes business more complex. Often that added complexity comes with no discernible benefits (economic, social, safety, security, or environmental).

The UK should become an EASA Member State once again. Why not? Norway, Switzerland, Iceland, and Lichtenstein are not in the EU but are EASA Member States. Across the globe countries follow EASA rules as they are known to deliver the best results.

[1] https://davidlearmount.com/2022/06/17/uk-aviation-caught-in-the-crossfire/

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

[3] https://www.aerosociety.com/media/8257/government-and-british-civil-aerospace-1945-64.pdf

[4] https://www.smithsonianmag.com/history/comets-tale-63573615/

Emerging Safety Issues

Of the 3 approaches to aviation safety the one that depends on expert opinion the most is that of trying to anticipate what’s over the horizon. Reactive safety is strongly supported by the historic data from accidents and incidents. A pro-active approach to safety leans heavily on the data of everyday operations. When it comes to the question of what’s going to emerge as a significant safety issue in the next 10-years then past, or current data may not be the best guide.

Regrettably, several aviation safety issues are as if they were constants. Given the nature of flying, it’s difficult to imagine that the number of Controlled Flight into Terran (CFIT) events will ever reach zero. Similarly, with Loss of Control (LOC) events. These events should continue to diminish worldwide but their elimination is the stuff of dreams.

Flight is always a balance between benefit and risk. There’s no possibility of operation of an aircraft without safety risk. The benefits of flight are wide ranging but often liked to economy and utility. So, in the quest for Emerging Safety Issues (ESIs) we need to consider what new factors might tip the balance between benefit and risk in at least three cases: existing, planned or entirely new or novel aircraft flight operations.

There may be global aviation ESIs needing evaluation related to:

  • the use of aircraft in new ways[1];
  • a new understanding of known phenomena[2];
  • futurists speculations;[3]
  • shifting societal values[4];
  • accelerated adoptions of technology[5].

It’s possible to become overly hypothetical. That’s the point where a reasonable time horizon needs to be drawn. A decade is a good measure in terms of identifying and acting upon an issue. It’s a realistic way of keeping our feet on the ground. If we are considering the safety regulatory world, a decade is a short period of time.

With the above in mind, it’s possible to brainstorm a list of ESIs. Subjects like, urban air mobility, electric and hydrogen propulsion and new materials are good candidates. These could be called large-scale issues since they are wide ranging and self-evidently applicable to aviation. Additionally, there are more murky issues like cybersecurity, quantum computing and blockchain methods that are issues for every part of society. Take your pick.

[1] Example: Higher speeds or altitudes or greatly extended range or traffic density increases

[2] Example: Solar activity, climate change, shifting human factors

[3] Example: New materials, advanced artificial intelligence, new propulsion systems

[4] Example: Risk aversity, liability, service expectations, adventurous sports

[5] Example: Smart phones have changed far more than was envisaged

It can happen

Theories are nice. Having a way of explaining an event or failure, or both is a nice comfort blanket. It can give us a way of trying to look ahead. The common notion that; if it has happened once, it can happen again, is part of our mental hard wiring. We store up memories and are constantly ordering and re-ordering them in our minds. Looking for patterns.

What cuts across is a simple factual recollection of an event. Examples can be illustrative of a theory. Also, they can stand alone as evidence that anyone of us can fall foul of the unthinkable. One of my favourite events, which has the ingredients of the unthinkable happened in the 1990s. It’s about exploration and the space industry. That said, a story on this theme could be written about any part of the aerospace world.

Safety assessments are scoped to consider about anything that’s not extremely improbable. Let’s be clear that’s an approach that consciously asks people to discount some events as absurd or never going to happen, just beyond what we would ever do. The lesson is that when considering how things go wrong it’s as well to be open minded.

Let’s go back to December 1998. A spacecraft called the Mars Climate Orbiter (MCO) was intended to skim the upper atmosphere of the planet and return data to Earth. It had taken over 9 months to get to Mars. A journey like that one come with costs mounting in the tens of millions.

The spacecraft was about to go into orbit, it disappeared behind Mars but failed to re-emerge. Efforts to communicate with it were continued for a long-time but nothing came back. An investigation into the MCO’s loss concluded that it had crashed into the surface of the red planet. This was not the crux of the matter. Such projects have risks that can be unknown.

Investigation concluded that the MCO had been obliterated[1]. It was off course by 60 miles, so it plunged to destruction rather than entering orbit around Mars.

Now, I said that anyone of us can fall foul of the unthinkable. In this situation, that’s what happened. The managing organisation for spacecraft thruster data had been using imperial units. Thruster performance data was in “English” units. NASA’s navigation team had assumed the units used were metric. The trajectory modelers assumed the data was provided in metric units as per their requirements. Thus, the difference between miles and kilometres sealed the fate of the MCO.

Discovering that cause of the loss must have been excruciatingly embarrassing. One of the published recommendations; take steps to improve communication, seems modest. In addition to taking on-board all the investigations findings, my take on this event is two-fold.

  1. Think the unthinkable. Not all the time, but every so often it pays dividends and
  2. Question assumptions. Even the most cherished simple assumptions can be wrong.

These two are universally applicable.

[1] https://llis.nasa.gov/llis_lib/pdf/1009464main1_0641-mr.pdf