In this special episode, we celebrate 50 years of Mandatory Occurrence Reporting (MOR) and reflect on the vital role it has played in improving aviation safety.

Jon Round, Head of Airspace, ATM and Aerodromes at the UK CAA, and Phil Sleight, Deputy Chief Inspector at the Air Accidents Investigation Branch (AAIB), discuss how a strong reporting culture, combined with a just culture approach, has enabled the aviation industry to learn from events, identify trends, and continuously enhance safety standards.

The episode also explores how these principles will remain essential as aviation evolves through new technologies and emerging challenges.

For more information on Mandatory Occurrence Reports visit:

Occurrence reporting | UK Civil Aviation Authority

Welcome to the CAA Safety Files podcast.

Hello and welcome to the Safety Files, the UK Civil Aviation Authority podcast that looks at occurrence, incident or accident reports that have been published throughout the different areas of the UK aviation industry.

I'm Danielle Anto-Kawahkwah from the communications team.

And in this episode, we're looking at mandatory occurrence reporting, more commonly known as MOR.

Since its beginning in '76, MORs have formed a crucial part of the UK's aviation operations, with reporting of safety-related occurrences involving UK airspace users required under UK regulations.

Today, we'll be looking at the MOR system, which is marking its 50th anniversary this year.

Today we are joined by John Round, Head of Airspace, Air Traffic Management and Aerodromes at the CAA, and Phil Slight, the Deputy Chief Inspector at the Air Accidents Investigations Branch.

John and Phil, welcome.

Thank you for joining us today.

Could you tell us a bit about what an MOR is and the benefits of the system?

So an MOR, as you've said it's a mandatory occurrence report.

It's a report that gets filled in after a significant event.

There is a list of qualifying criteria for

the requirement, expectation to fill one in.

And we've, over the years, and we'll talk about the start of this in a moment, over the years, we've seen the actual numbers increase at the outset, some 50 years ago, there were about 5 thousand a year, where at the moment up to about 50 thousand reports.

It gives data de-identified from the individuals, but it gives data that is helpful for specific events, but also helpful to create trend analysis on certain events.

And that allows certainly the parent company, but then also the Civil Aviation Authority to look across the whole industry within the UK to work out trends, locations and work out whether any interventions need to be made.

And over the years we've made many such interventions on the basis of the power of this evidence.

I think mandatory occurrence reporting been around for a very long time.

And certainly when I first started in aviation, which is some 30 odd years now, MORs were very much embedded in the way of working and the way of understanding what happened and learning those lessons from those and making those improvements.

And where it sits with what we do at the Air Accidents Investigation Branch, which is to investigate aircraft accidents and serious incidents,

If you imagine a triangle and you put the accidents and serious incidents at the top of that triangle, that's events that have either happened as in an accident or with a serious incident, something that was very close to being an accident.

But underneath that, you then have a whole layer of events that are not serious enough to be a serious incident or accident, but in themselves would enable learning and in some cases to actually put in place changes

So you never get to that situation of a serious incident or an accident.

And in my experience in the 24 years I've been with the AIB, the whole culture within certainly the UK in relation to occurrence reporting is very much part of anyone who's involved in the system.

If they see something that requires reporting that they will do that, even though it is mandatory, it's almost a feeling as if it's just part of the norm.

It's part of of what's going on.

I think a real testimony to the types of people that we have within the aviation industry and that need to learn and keep it as safe as we can.

It's at the heart of the safety culture, which I think is pretty unique for aviation amongst other transport sectors and other industries.

It is reliant on an open reporting culture and just culture.

And I know we'll cover that a bit later on, but for me, it is a crucial bedrock of that.

My background was as a pilot for many years, and certainly over those years, I've filled in many MORs.

And now as a regulator, I can see the value of it.

So it plays both ways.

To add to Phil's point about the AAIB being at the top of his triangle, MORs being one step down, the more significant events, but short of that,

I think most airlines then have, if you like, the iceberg sitting underneath the surface of enormous amounts of data that they don't necessarily give to the CAA because it's specific to them, of which a subset is normally an MOR.

So you've got three categories.

You've got that huge mass of data, a certain amount the CAA asks for that is internationally recognised is the MOR, and then hopefully we fall short of any accident.

Thank you very much.

Why is the reporting process so important?

Is it the case that one single report can highlight something more critical?

Certainly what we've seen with the AAIB, we get to see these mandatory occurrence reports that potentially could fall into a serious incident or accident category.

And there have been occasions where we've actually seen these reports come in and decided to actually do an investigation.

Again, the whole idea of an investigation that the AAIB carries out is not to portion blame and liability, it's to learn the lessons and then put in place actions to prevent recurrence, which in most cases is a safety recommendation, although we do work with those involved to encourage them to do safety action prior to us issuing the safety recommendations.

So we've certainly done that.

We also use the MORs as a way of looking at whether something we're looking at has been reported previously and what sort of actions were taken as a result of those.

So a sort of reverse trend analysis, I suppose, in that an event has occurred and we're now looking back to see whether there were some precursors that could have identified that.

So it's important to have that data set.

And indeed, we've also carried out full investigation from an MOR.

One that was quite significant a few years ago was a Sikorsky helicopter which suffered an issue with its tail rotor bearing.

We were identified about that event through the MOR system and then we started an investigation.

And our highest level of reporting is what we call a formal report, which is a larger report that follows the international standards on how you present that.

And indeed, in this case, that investigation was so serious in the fact that it was very close to being an accident that it was actually one of our formal reports.

Had there been no MOR, we may not have even been made aware of it.

So in answer to your question, can a single report be on its own a significant yes, clearly, and most accidents would have in the end an MOR associated with them.

Conversely, as we've said earlier on, the trend analysis, the themes is a hugely important part for the regulator in assessing where we need to spend our time.

I'll give you an example.

I look at a all possible forms of airborne conflict where different sorts of aircraft might come into interaction with each other and or potentially are getting a bit closer than we'd like them to.

Air traffic keepers apart, but occasionally we have what's known as a level bust where someone goes through the cleared level.

That can be for all sorts of understandable reasons.

Anyone who's flown would understand that if you're climbing too fast or if you're given a late clearance or if the radio traffic was interfered with and you didn't hear correctly,

or if the clearance was changed.

There's multiple reasons why people technically level bust.

But what we do is analyse the data and look for trends outside specific boundaries that we've set ourselves as being a normalised volume.

And then last year or the year before, I think it was, we saw a big spike, relatively speaking, managed to associate that with some very unusual low pressure days when we're all seeing variations in weather as climate change occurs and low pressure days are becoming more common.

Very low pressure, again for those who are familiar with altimetry, leads to some unusual rapid altimetry resetting as you go from the altitude to a flight level and those are causing level busts.

What we were able to anticipate looking at that data was, well if we warned people and got them to think about it in advance and we now put out a warning as a NOTAM on those days in advance for people to be thinking and briefing and carefully managing it.

We've seen those spikes disappearing and we're monitoring it against low pressure days to check that our intervention has had the desired effect.

So it's an example of quite large data sets helping us to improve safety in the UK and we share that around the world as we talk to people.

I think one thing we should sort of talk about is the genesis of the mandatory occurrence reporting process.

As you say, it's been around for 50 years.

And what really started this off was a tragic accident in '72, where a Trident aircraft shortly after takeoff from Heathrow stalled and then crashed shortly after the takeoff.

That accident investigation has triggered quite a few things.

One, which is the mandating of copy voice recorders.

in aircraft as we know now.

But one of the things it did also highlight was there have been a couple of previous events that had occurred prior to this accident which had very similar circumstances to them in the way that the aircraft was being handled out of those departures.

And although in one case a report was raised internally within the airline,

it never really found its way into the right places where it would be looked into.

So it was very much internal within the airline.

And then the second event really wasn't reported at all in some respects.

And again, didn't find its way into where it could be looked at and engaged.

Now, there were a lot of other changes at the time.

There wasn't a Civil Aviation Authority as we know it today.

They were split functions between other parts of government and agencies.

So there were several recommendations that were raised as a result of that public inquiry into that tragic accident.

And one of which was to actually look at how there is a way of learning from these events and then putting those changes in.

And that was sort of really the genesis towards having this joined up system where events like that would have to be reported.

They would come into a central location, which is as we know now is the CAA, in order to review those and then learn from them.

But importantly in a way of just culture as we will come on to again around trying to prevent recurrence or trying to prevent an occurrence to the extent of in that respect and to hopefully save lives at the end of the day.

I think I'd go back to the fact that was the genesis, that was 50 years ago.

It is the crown jewels of what this building exists in order to achieve, which is to try to make aviation safer for everybody.

It's our job not to take that for granted as much as perhaps the travelling public quite rightly do.

But we need all of the reporting across all of aviation in order to make that happen.

And the aviation professionals creating those reports, describing what's happened, I think is at the heart of that.

There's no one in aviation goes to work in order to make or have an event have what they might view as something going wrong.

And that on a human level can make people resistant to wanting to file a report.

And that's, I think, what other sectors suffer from.

And sometimes it's with a slightly heavy heart that you fill in a report.

But the truth is you're doing the right thing by doing it because you're helping everybody else.

That in itself is a powerful act.

So I think it's come from a very tragic event, but aviation keeps learning to try and avoid any such event in the future.

And on the whole, touch wood, we are a very safe way to travel.

So with the MOR process, can you tell us a bit more about just culture and how it feeds into MORs and how it has informed safety guidance?

So just culture is about a fair and a correct outcome. I think there's sometimes a confusion with what used to be, it used to be called a no blame culture, which was a sort of get out of jail free card if you had done something careless or reckless or the like.

Just culture is about getting to the heart of what's happened, reporting it honestly, openly, and then quite reasonably expected to be well treated, perhaps retrained, because often errors are made because of a lack of training.

So it's perfectly reasonable to expect to be retrained to the required standards.

A just culture says that everyone, all parties, the individual and their parent company and the regulator treat people fairly

But it doesn't come if in the event of something reckless, it doesn't come with no jeopardy at all.

It's a slightly nuanced build on no blame into a what we've described as just culture.

It requires reporting and for everyone to be honest and fair with each other and to celebrate learning and to celebrate the report, even if it's a difficult report to have written and to thank people for it.

That for me is an industry, a system.

At the moment that behaviour by any one of those three parties is breached, then you will drive people not to file reports and you will get to a place where you haven't got openness, honesty, and no one has got a just culture and we're all the losers for it.

So it's a very fragile but important ecosystem that we've created where we trust each other.

We trust each other to be honest and then we treat each other respectfully and seek to build a common understanding.

So I certainly agree with that.

And it is that ability to get behind what's going on without those people you're discussing it with, fearing that what they're going to tell you is then going to be used against them in whatever investigation is being looked at.

And certainly when we're doing our investigations at the AIB,

We're not looking to apportion blame or liability. What we're doing is we're looking forward. We're going, okay, this event has happened.

What is it we can learn from that to prevent the next one?

Whereas if you're a prosecuting authority, it's more looking backwards and it's not so much learning, it's about who did what and why.

So just culture is saying, okay, well, let's get this information.

Well, what are we going to do with it?

And what we're going to do with it is to learn and stop something happening again, rather than pinning it on someone.

And, you know, as you see in other industries, almost trying to find a scapegoat in some respects.

And that's one thing that within a just culture, you're not looking to pin it on somebody.

It's learning and as a system with everyone in there.

And I certainly agree with Jon, if you breach that trust at any point if people are then fearful. You're not going to get the information that you need and you're not going to get that learning as you go forward.

And I think that's what we're seeing in some other industries that are trying to introduce just culture into their areas.

But there is still this fear factor, I suppose.

So I think the other industries, I think the just culture is under some strain.

If you look at any media commentary about any accident in any industry, and there have been notable ones recently.

The media are very quick to seek to blame in how the language used.

Individuals are quick to seek retribution, financial retribution.

There is a litigiousness of society, which actually flies in the face of the aviation system just culture.

So it's a fragile and precious thing that we're holding onto here that I think we must fight for collectively. Thankfully, that litigious element tends to only come out when Phil's team is involved.

Hopefully at the MOR stage, which stops short of an event, we can all learn and there shouldn't be anything litigious about it.

But I'm very conscious that in the event of a high profile or even low profile accident, lawyers will get involved.

And then I think it's a difficult dance to be doing with each other.

I think it's also fair to say when you're dealing with certainly a fatal accident, there are relatives that are involved in that as well.

And of course, they've got a vested interest in understanding what happened.

And of course, they're looking at it from the perspective of their loved one has suffered as a result of this accident.

And they want to know why. And in some cases, who.

And again, it's working, walking that really fine tightrope between understanding and learning and that sort of blameworthiness that you were mentioning there, Jon.

So it's making sure that we do get that right and we work with those people and we work very closely with families, informing them of what our process is and what we're trying to do.

And what we're trying to do is to avoid other families having to suffer the same fate as they do.

And that provides comfort to some, for others it doesn't.

And part of what we do is assisting them in that understanding.

I think I was just reflecting on where we see this and why we don't.

And I think it's fairly true to say that where we have licensed or approved parts of the system, so pilots, certainly commercial pilots, air traffic controllers, engineering, and airport or aerodrome approvals and certifications, those are the areas where we get the lion's share of the mandatory occurrence reports because they have a sort of professional requirement to have a system that does so.

They have a safety management system and a big part of that is their reporting culture and they're measured on it.

So it is part of a sort of quite joined up system.

And kind of with that, from both the CAA and AAIB point of views, have you seen changes in common behaviours from guidance, whether that be from pilots, airports, airlines?

I think there's more reporting.

I think things are differently reported.

A lot of airlines are developing their own systems.

So I think it's been made easier for people, less paperwork, more filling it in online.

So hopefully the rise in numbers is because it's been made more straightforward. So that's a positive. I still come across pockets of resistance.

We occasionally hear of an event, look for the MOR, can't find it and have to go back to the organisation and ask for it. And it hasn't been filed.

So I think there's that reluctance still sits with some individuals.

And I recognise the human element of this and why that's something they just want it all to go away. But I do think we owe it to each other to air that for the common good.

Certainly, if we see that resistance, sometimes when we're doing investigations, we will use our reports as a way of reminding what are the requirements, what needs to be reported and when.

I suppose one of the questions that we sometimes ask is, why are we getting a lot of reports from UK operators say, but we're not getting a similar level of reports from operators coming into the UK.

And in some cases, is it a cultural thing as in the other states, for example, the country doesn't have the same reporting culture and is that then impacting on their reporting in some respects?

And as you say, there are certain pockets that either it's because of awareness or lack of awareness or not actually fully understanding what needs to be done.

But I think there is already a lot of guidance out there.

And I think you're right, Jon, in that the ease in which to report has obviously improved what we get both in the MORs and also then at our level as well with when we're looking at those as sort of borderline between incident and serious incident.

One of the more interesting elements that I'm just thinking as you're talking there is some people are very sparing with their words and you can sometimes read into what's not written down.

if you are used to reading MORs on the receiving end, which we are.

And sometimes we will go out and reach out and seek more information.

And then conversely, we can get a very, very comprehensive war and peace report, which gives us absolutely everything.

But that in itself tells us something because it can be, perhaps was written soon after the event when emotions were high and every detail seemed vital at the time.

So it's an interesting, you can read quite a lot into how things are written as well.

I think that's again human nature.

So looking into the future with innovations and technology coming up, are we seeing MORs in this area?

So we are. Not as many as we perhaps would like, but it's growing and I think there's a positive trend.

I open a lot of reports that come across my electronic desk.

Most days there's new things to look at and it always pleases me when I see UAV RPAS drone events being reported, normally by those with operational approvals who I think are at the more professional end of the half million users of drones in the UK.

But that's as it should be. They're the people with approvals who are taking the flying of them very seriously.

I think it's absolutely fantastic and that trend I'd like to see grow.

I'd like to see more people feel it's in their interest to collectively understand what's going wrong.

It may well be that the CAA could, if they had enough reports, they'd know which common parts were failing.

They'd know which failures, training issues were prevalent, and we'd be able to help point that out to people. So we are seeing a growth.

It's fairly early. This is a pretty embryonic sector, albeit it's quite large numbers.

We'd like to see the numbers of reports going up. And I think that would be indication of slight perversities here. Sometimes people think the number of reports equals a failure.

If you see it going up, in this instance, we'd like to see this number increasing.

Any analysis of reporting based on sheer numbers is a flawed statistical approach because it may well just be that you've encouraged that group to report more. They're reporting more equals better data.

I think you have to be very cautious about sheer numbers meaning anything.

But in this instance, because it's a new sector, we'd like to see some more because we know there's more events and more activity.

And the other two areas, whilst I'm speaking, that I think is worthy of comment about that perhaps one we have regulated with a relatively light touch for many years, that's general aviation.

And we probably would like to see more reporting from the general aviation community who tend to be on the whole, by definition, not professional in their licensing and requirements.

It's more of a leisure activity for most of that sector, and they perhaps don't have the systems for the ease of processing, but I'd like to encourage any such event to be reported.

And then finally, there's a group that will soon have some relatively, some new but light touch regulation, that's ground handling.

The number of significant, both fatal and life-changing events that happen amongst ground handlers seems to have sort of remained at a fairly regular event, regularity across the big airports in the UK.

Sorry to say people do lose their lives fairly regularly. It's a dangerous place. We'd like to have the same data source and the same analysis that we could do in that space.

I think there will be a requirement more formally for that to become a uniform feature. We'd like to make sure they have a just culture.

Again, historically, perhaps not always been the case.

It's moving that way and many of the bigger companies are already in that space.

So ground handling, general aviation and the RPAS sectors would very much like those areas to join the other areas that are established well with their reporting so that we have a collective system.

Certainly ground handling was one of the areas that I was going to mention as an area where perhaps reporting is not as strong as other areas of aviation.

And of course, we're talking about remotely piloted air systems and that area, but of course, that's a growing area.

And although it's in its sort of embryonic stages in some respects, that could start to increase.

And then when you start moving towards urban air mobility, that inevitably will then lead to and also operations beyond visual line of sight.

Again, how is that risk being managed?

In some cases, the only way of doing that is to actually understand where things may not have gone as well as they should.

And that's where through this reporting is a way of identifying those trends and hopefully putting things in place long before we have to then actually get involved.

Phil and John, can you just explain when and how to report an MOR?

So there is a list of qualifying criteria.

There's one at the bottom of that long list that says if in doubt or if you think it's serious enough, also fill in a mandatory occurrence report.

So I think if you've had an event that you think is seriously noteworthy, there's no harm in filling one in.

So better to do one than to err on the side of not doing one.

How to do it, I think, will depend on who you work for.

I think if you work for a big airline, there will be an established system.

If you work for an air traffic organisation and application service provider, there'll be an established system.

So I think there won't be a one-size-fits-all.

Certainly if you were unsure, you'd be able to log on to the CAA website and you'd be directed to mandatory occurrence reports.

So to add to that, reporting of an aircraft accident or serious incident is separate to the mandatory occurrence reporting scheme.

So there are two different ways.

However, if something is reported to us on our accident line, and if you go onto www.aaib.gov.uk, you will find how to report an accident to us and there's a 24-hour accident reporting line.

And like the MORs, if anyone has any doubt that it's an aircraft accident or serious incident to report it to us and we will make that determination.

But we do inform the CAA that we've been notified of something.

It won't contain all of the details and we will encourage the reporter to then report an MOR through their systems.

And as Jon says, there's various different mechanisms in which to do that reporting.

I think that's an important point that an accident goes to the AAIB, MOR takes sometimes a day or two to get into the system before we're notified about it.

So there's lots of them, 50 thousand a year.

We don't instantly respond.

It was a comment I was going to make earlier, but forgot to, which is I think one of the frailties of the system is that you might put quite a lot of work and effort into filling out a form and actually you'd like to hear back what happened.

Now that's not always going to be possible and or administratively it may fall through the cracks.

I guess my plea to everyone listening to this is it is still hugely valuable so please make the effort because it will be helping long-term trend analysis and safety management.

But also I think it behoves both the organisation and the CAA to do its best to respond to the more significant events.

So just one question I want to ask Jon.

The whole MOR system is looking at something that's gone wrong and then looking at what can be done to put it right.

There's a thought process about, well, how do we know what went right?

So there's sort of safety 2 aspect.

So I'm just interested in your thoughts around safety 2 versus safety 1, which is what we're talking about.

I've had this debate many times. I think it would be quite a shift in people's thinking. I've had a very long career, longer than yours. I think I would struggle to do both. I think if you always talked about the things that went well, you could be completely drowning in data.

I know it would be a way to build best practice.

And there are theories, and I've seen academic papers that say that is the road to nirvana.

I don't know is the real honest truth. I don't know whether that's the answer.

Certainly, knowing the things that have gone wrong has proved to be a pretty good system for us.

But maybe we need to be thinking in addition to doing that.

Yeah, I certainly agree with you.

I mean, we're probably the ultimate part of safety one, which is obviously a tragic event has happened and looking at that.

But sometimes we even question ourselves as to how can we learn from something that actually went right and why did it go right?

And I suspect that's a whole series of podcasts from which we would need to do a bit of thinking and get some expertise in the room.

But I don't think that is the answer for the MOR system.

But I do think there's probably a positive way to conclude in that safety is not neat and tidy. We're always learning.

And I always think it's worth thinking of different angles of attack to look at how we might approach safety in a fresh way that adds a different focus, a different lens.

And it may be that doing that as well, we might be able to scope it down and limit it and to see its value, could be a thing that helps us.

There's no absolute safety other than keeping everything on the ground and not going flying.

So everything has something of a risk associated with it.

We're part of this industry because we love that.

And we've made it remarkably safe in large part due to the MOR and the reporting culture and that safety culture, the just culture, has made aviation what it is today.

Thank you both very much.

That's it for this episode.

Thanks again to John and Phil for joining us today.

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