SEE & AVOID - A SOUND COLLISION AVOIDANCE STRATEGY?

ICAO standards and consequently most regulatory jurisdictions state that pilots have an obligation to be ‘vigilant’ so as to see and avoid other aircraft – here is an example:

US FAA Regulation 14 CFR Part 91.113 (b) states:

…vigilance shall be maintained by each person operating an aircraft so as to see and avoid other aircraft

In many ways this has come to be seen as the last line of defence in collision prevention but we know that it fails. We need to understand why this is – what are the limitations to see and avoid?

Firstly, there are significant physical obstructions to a pilot’s line of sight, in the shape of the aircraft’s own structure. In fact a pilot’s field of view as permitted by the size and shape of the cockpit windows, only constitutes a small portion of the total sphere of airspace around him or her. In some aircraft the wings may also present a further external obstruction to their view. Moving one’s head may help mitigate for things like window posts but nothing will permit observations below, above or behind the aircraft. Pilots must understand that these are effectively blind spots to any see and avoid strategy.

We are well aware from eyesight tests that human vision varies substantially from one person to another. It is also true that an individual’s own visual acuity can vary with time of day, fatigue, light conditions etc. Those of us of a certain age also know that our eyesight deteriorates with the passing years… The likelihood of actually seeing a conflicting aircraft, even if it is within the field of view, is highly dependent upon the visual acuity of the observer and there is no consistent means to predict that.

We also know that the sensitivity of the retina varies across its surface. The point at which the lens focuses the image, the Fovea, is the most sensitive to colour and definition but this diminishes as distance from the Fovea increases. Our peripheral vision, what we see ‘out of the corner of the eye’ is relatively insensitive and is actually best at detecting motion across the arc of vision. This is recognised in the design of road traffic signals, which use not only a change of colour but a change of light source position to attract our attention – rather like the wig-wag lights on taxiways.

Another inherent visual factor is empty field myopia. At rest or in the absence of something to focus on, our eyes focus at approximately half a metre distance. This means that when looking at an empty sky, we may inadvertently be focused much too close and thereby compromise the ability to see another aircraft in the distance. Other effects like dirt on the windscreen can ‘trap’ the focus of the eye. It may be necessary to deliberately choose objects in the distance to draw the focus out to where the targets might be.

Pilots will be familiar with the effects of glare from a low bright sun – it is quite simply impossible to look in that direction let alone search for aircraft. Fighter pilots have always taken advantage of this to attack ‘out of the sun’. To make it worse pilots may be tempted to use sun visors or even charts and newspapers to block out the glare, thereby increasing the area physically blocked from view. Glare may also interact with atmospheric effects like dust, haze, mist and precipitation to increase their effect on the prevailing visibility. Whilst we know that VFR includes 5 kilometres of visibility, this can vary dramatically in different directions with the atmosphere and the light. 

See and avoid may not be so hard if all we had to do was look out of the window. Unfortunately, or perhaps fortunately, pilots have many other things to do and cockpit workload often increases in the same places that traffic density increases. This allows less and less time for looking for aircraft precisely when there may be more to see. As with all cockpit activities pilots must be careful not to become so absorbed with one task as to forget to carry out another task, such as looking out.

There are a number of techniques recommended for more effective visual scanning. As well as moving the head, pilots can divide the field of view up into segments and scan each in turn in a systematic fashion. In the case of 2 pilots they might choose to search their ‘half’ of the sky. Focusing on objects in the distance may help avoid empty field myopia. Operators should research the various scan techniques and train the ones most suited to their operation and environment.

Finally let’s look at a couple of characteristics of distant visual targets. Firstly, the diagram on the left demonstrates that geometrically an aircraft on a collision course will maintain the same position in the field of view as it gets closer. This means that there will be no angular movement of the target across the field of view and therefore our peripheral vision will be less likely to detect it until it is very close. The aircraft that is going to hit you may be the hardest to see.

On the right is a diagram that shows the visual arc described by an aircraft closing head on. This model is based on a closing speed of 600 knots but even if we halve that, it indicates that a target may only describe an arc of half a degree in our vision, when only 6 seconds from impact. It is still only 1 degree at 3 seconds, when the ‘avoid’ part is out of the question.

PILOT TRAINING - ARE WE GETTING IT RIGHT?

The steering wheel of my old Reliant Scimitar motor car once came off in my hands while I was driving. That was certainly unexpected and the people who sold it to me would probably have said it couldn’t happen. But it did, and I had to figure out how to steer the vehicle while stopping in a safe (ish) place. I got lucky I suppose.

My thanks to Skybrary for https://bit.ly/2ImYXYY - a summary of the Preliminary Report on the investigation into the crash of B737 MAX 8 on 10 March 2019.

The way I read this summary (and I’m sure I’ll be corrected if I’m wrong), the aircraft was technically flyable, although not in a way the pilots had ever seen before and certainly not in a way they had trained for. In fact, they did manage to fly it for a while, overcoming the efforts of the automation to pitch the aircraft down into a suicidal dive, by nose-up elevator and electric stabiliser trim inputs. But eventually it won…

If we go back 10 years to AF447, the pilots were also presented with something they had never seen and had never trained for. The aircraft was technically flyable and operated to design but they couldn’t work out what was happening and correct it. The Air Asia A320 that crashed in 2014 was flyable, although the captain’s well-intentioned actions had caused the flight control systems to revert to ‘alternate law’. The pilots would have seen alternate law in the simulator but never with a sudden and unexpected onset.

I would be prepared to stake a substantial bet that each of these crews could have easily and competently managed an engine failure on the preceding take-off (and any other take-off). That’s what we have trained them for. But these other random, unexpected and potentially startling conditions are not trained and are therefore far more difficult to manage, just like my steering wheel incident.

So perhaps it is time be a bit more imaginative and a bit less optimistic when designing flight training profiles and show pilots some more extreme and unusual flight conditions.

WHY DO WE HAVE TO WAIT FOR A FATAL ACCIDENT?

The following bullet points are taken from the investigation report on a fatal turboprop accident in Nepal in 2017. The sad fact is that all of the listed operator deficiencies could easily have been identified and rectified in advance. No need for people to die and aircraft to be destroyed...

Think about getting a fresh and independent pair of eyes to review your operational safety performance.

My thanks to Skybrary for the text.

RISK & PROBABILITY

During audits and safety meetings I have often been asked ‘what are your top 5 risks?’ I have a problem with that question…

Let me start with a closer look at how the aviation industry historically quantifies ‘risk’. Once the system identifies a ‘hazard’ in the operating environment, we reach for a risk matrix of some kind – typically based on the 5 x 5 example described in ICAO Doc 9859, the Safety Management Manual. You know the one: ‘severity’ along one axis and ‘probability’ along the other.

I don’t really have a problem with the severity scale; it seems quite reasonable to imagine what the ‘worst case feasible outcome’ of the hazard could be and attach a severity in relation to the word pictures associated with the scale. But what about probability? Across the scale you will usually see 5 possible choices ranging from ‘very likely’ to ‘very unlikely’ or similar. What do they mean? If you look in the dictionary for ‘likely’ it will say something like ‘such as well might happen or be true; probable’ but that won’t mean a lot to a risk assessor. To help we tend to develop simpler word pictures to try and make the choice easier and more consistent or we might add a mathematical probability like ‘once in 10,000 flights’.

The trouble is that, once we have accepted that there is a probability of greater than zero, we need to be prepared for the outcome to happen at any time. Even if the probability is once in 10,000,000 flights, that accepts that it could occur on the next flight or the 10,000,000^th one, or anywhere in between. So for any activity that we propose to repeat indefinitely, like going flying, we must accept an inevitable occurrence whatever the probability.

Can I tell you what my ‘top 5’ risks are? No. While each of my identified hazards may have differing probabilities, they do have a probability and I don’t know which is going to happen next.

AIR CRASHES - 3 DIFFERENT THINGS – BUT ARE THEY CONNECTED?

The first of these three things I have mentioned in this blog before. I spend a lot of time taking apart fatal aviation accidents, looking for the influences and factors which came together in the unique combination that allowed each ‘accident’ to happen. In recent years one of the most common precursors to a crash is procedural non-compliance – deviation from standard operating procedures by one or more of those involved. The reasons that pilots and other professionals deviate in this way are many and often related to complex human behavioural conditions; it is worth looking at Abraham Maslow’s hierarchy of human needs for insight into some of them. Whatever the underlying reasons, prior to a crash the captain will frequently decide to do something contrary to their training and procedures, that will eventually lead to their own demise. Sadly their co-pilots often look on, aware that all is not well but saying nothing.

The second thing is ‘risk denial’; maybe I have raised it in earlier posts. This is a condition that arises when we are regularly exposed to a particular, perhaps severe, hazard but it never actually does us any harm. Over time we may subconsciously adopt a mind-set that whilst the severity could be very high, the probability or likelihood is so low that it can be disregarded. Imagine passing a heavy truck in the opposite direction on a narrow lane – the obvious action would be to slow down and pull in to the side of the road to let it pass safely but every time you have passed a truck no harm has come of it. So you are able to ‘deny’ the risk, despite its blatancy, and drive on as normal with a metre or less between you and death.

So here is the final thing and I wonder if there is a connection between the three? Modern movies, TV shows and most significantly computer games allow us to experience horrifically dangerous and deadly situations without suffering any (other than perhaps psychological) harm. Could that have led to a general conditioning of westernised humanity (including pilots) to be able to subconsciously ignore hazards and adopt risky behaviours on the assumption that we will come to no harm however bad things look? After all, passengers now routinely collect their baggage before evacuating an aircraft, despite the high risk of fire and explosion. I don’t know…

WHY NOT DEBRIEF?

After every mission military pilots and their crew will hold a debrief to discuss want went well and what could have been done better. This is an opportunity for those involved in the task to recognise superior performance and to learn by addressing any deficiencies – makes sense right?

However, post-flight debriefs in commercial aviation are quite rare, in spite of the obvious potential value. In many regulatory jurisdictions pilots and cabin crew are only considered to be ‘on duty’ until 30 minutes after ‘on-chocks’ time so there is a limited window of opportunity. Furthermore, the crew for the next scheduled flight will frequently be waiting to get on board to maximise preparation time during the short turnaround period. Perhaps most influential is the fact that it isn’t ‘the way we do things around here’ – it’s not part of the culture.

A pilot would think nothing of remarking on a colleague’s smooth landing in difficult crosswind conditions for example but there is unlikely to be much discussion about it if it went less well. The absence of a debrief effectively implies that the entire flight proceeded satisfactorily and in accordance with standard operating procedures: there were no errors, deviations, distractions and consequently no opportunities to learn. Any pilot knows that is never the case but without a professional conversation immediately afterwards, the implication becomes reinforced.

Pilots are well used to debriefs after training flights so why not after every flight?

HEALTH-CHECK YOUR SAFETY CULTURE

This is a bit of fun but it also has a serious side - give it a try and see how your organisation fares. We put it together to give you the opportunity for a bit of honest self-analysis of the culture with regard to safety and risk in your business. It doesn't purport to be a comprehensive analysis but it should give you an insight into how things are going.

If you come out with a score of 15 - 17 things are probably going pretty well but less than 10 could indicate that you have some systemic cultural and/or organisational safety issues which need to be addressed. At Gates Aviation we have a collaborative and realistic approach to resolving these issues without turning the business on its head. Give Sean Gates a call on +44 (0)207 4696437 or e-mail sgates@gatesaviation.com .

ORGANISATIONAL SAFETY CULTURE HEALTH CHECK Score 1 for ‘True’, 0.5 for ‘Part true’ and 0 for ‘False’
Statement	True	Part true	False	Score
The organisation has a clear safety policy: There is a policy statement with respect to safety and risk, that is written in simple and clear language, agreed by senior management and signed by the CEO/MD/Accountable Manager
The safety policy reflects reality: The terms of the policy reflect the genuine intent of the organisation’s management with regard to the safety of people, property and the environment
The organisation has clear safety objectives: There are a number of clearly stated and generally SMART safety objectives (2-6), which reflect the specific goals of the organisation with regard to safety and risk
The safety objectives directly support the safety policy: There is a recognisable link between the goals stated in the safety objectives and the intent implicit in the safety policy
Safety activities and initiatives directly support the objectives: The allocation of resources, the activities of the safety department and the safety initiatives of the organisation demonstrably support the objectives
The safety objectives are widely known and understood: Most personnel, especially those in front line safety critical roles, can articulate at least the intent of the safety objectives
The safety objectives have meaningful performance indicators: Each safety objective has one or more metric or performance indicator (SPI), which genuinely measures the organisation’s progress with respect to that objective
The performance indicators have valid targets: The organisation has defined realistic and achievable targets for each SPI, and there is a process to review the targets regularly
Performance in relation to targets is regularly reviewed: Senior management has a process to review safety performance as indicated by the SPIs and the achievement of targets
Failure to meet a performance target is examined at senior level: Failure to meet a performance target in the allocated time is analysed by senior management and the reasons for failure identified and addressed
Safety performance data is shared throughout the organisation: Safety performance as indicated by the SPIs and targets is disseminated to all personnel in an appropriate and understandable format
Reporting of safety incidents and accidents is a requirement: All personnel have an explicit and contractual obligation to report safety incidents and accidents via an established safety reporting programme
Reporting of hazards and near-misses is encouraged: Personnel understand what constitutes a hazard and a near-miss in safety terms and are positively encouraged to report them
Incidents, accidents, hazards and near-misses are investigated: There is a documented process to ensure that reported safety issues receive an appropriate level of investigation by trained safety investigators
Reporters are treated fairly: Originators of safety reports are treated in a fair and consistent manner, are assured of an appropriate degree of confidentiality, and always receive acknowledgement and feedback
Acceptable and unacceptable behaviours are clearly defined: There are documented definitions of what constitutes acceptable and unacceptable behaviour with regard to safety and risk
Disciplinary processes are clear and consistent: The consequences for an individual found to have behaved in an unacceptable manner with regard to safety and risk are clearly defined and always consistent
Total score:

SAFETY & SECURITY AUDIT IN A HIGH RISK LOCATION

The following is a 'guest post' from my Gates Aviation colleague John Edwards:

I have recently completed a risk assessment of the safety and security of an airline's crews, engineers and aircraft while operating in a high risk environment during the period of a proposed wet lease. The 'donor' airline was registered in a state that has, and the airline itself has embraced, a relatively high level of risk aversion.

 It is well known that there has been a longstanding history of terrorist attacks against commercial (and military) aviation in the location where the personnel and aircraft would be based and that numerous fatalities have resulted.

 The state authorities advise that that "all foreigners, may not move out of their city of residence without proper security and without prior coordination with the law enforcement agency". The approach taken to providing security in civilian life, especially in relation to what might be considered 'soft targets' e.g. selected public highways and shopping malls, was evident and likely to aid deterrence and detection (of terrorists and planned attacks). There was meaningful evidence to suggest efforts had been taken to harden these (previously soft) targets and protect the related communities.

 Security had been tightened at the state's international airports following a number of terrorist attacks in 2014 and further strengthened in 2015. A historic ban of locally registered airlines from operating into the EU for safety reasons had been lifted in 2015. ICAO and the USA consider that implementation of ICAO aviation safety standards in the state to exceed the global average. The airline with which the wet lease was proposed, is a member of IATA and therefore when last audited met the requirements of IOSA. Viewed in combination these facts provided evidence that the national aviation security and safety culture and infrastructure are widely considered to be sound. The main roads between the airports and hotels feature multiple manned checkpoints and the hotels where the crews and engineers were most likely to be staying, had robust security measures in place. The better quality shopping malls had entry search points operated by the military or other government agencies. It is known that places of worship and large public gatherings should be avoided and that periods leading-up to political elections can see increased civil tension and unrest. As in most business sectors and risk management environments, there was scope for continuous improvement to aviation security processes and procedures and implementation of best practices. But I considered existing measures to be relevant, adequate and sound. Accordingly, I concluded that subject to these measures being maintained, to the threat level not being raised to 'red' (the highest level) and to good situational awareness being exercised by operational personnel from the donor airline, when they are on site, the wet lease should not materially increase risk exposure. My assessment was that there are no substantive safety or security reasons why the proposed wet lease should not proceed as planned.