Bird Strike 2

What makes a bird strike different is that it’s an unpredictable collision. If we talk about aircraft collisions with terrain the outcome is predicable bad. All that kinetic energy must go somewhere. So, a high-speed vehicle hitting something that is immovable is not going to end well.

Now, it must be said that some hunting birds can dive at incredible speeds. More typically, a large bird in flight between feeding sites isn’t going to be traveling fast. In fact, it may as well be viewed as a static object relative to an aircraft in flight. A bird in-flight is unlikely to be able to take avoiding action. For a pilot the action of “see and avoid” may work in respect of other aircraft but a bird ahead is no more than a pinprick in the sky.

These factors make aircraft bird strikes inevitable. That said, the range of outcome because of impacts are rarely at the severe end of the scale. One reason for this is the effort made at design certification to ensure an aircraft is sufficiently robust. Damage can occur but if the aircraft design and test processes have been rigorous everyone should get home safely.

I remember paying particular attention to the zonal analysis done by several major manufacturers. In my experience the most difficult designs are for those of business jets and large helicopters. One of the design challenges in both cases is the limited physical real estate within the aircraft structure. Weight is another big consideration. This leads to cramming essential avionics and electrical systems and their interconnections into confined spaces.

Zonal analysis is about ensuring there’s segregation between different systems. Afterall what’s the point of having two Attitude & Heading Reference Systems (AHRSs)[1] and putting them next to each other in the nose cone of an aircraft. That’s not a good design strategy. One damaging impact must not take out two essential independent aircraft systems.

It’s just as important to ensure an aircraft’s wiring isn’t all bundled togther and taken through one connector. That may save money on electrical parts but it’s not going to work after being hit hard by a 5kg goose.

These issues will need particular care in the new electric vertical take-off and landing (eVTOL) aircraft that are on the drawing boards. Choosing a safe architecture, manufacturers must balance the use of creative design solutions, to produce a competitive product, with limited physical space.

A couple of key words in the certification requirements concern hazards that are anticipated. Bird Strike is hazardous and aircraft systems and equipment must “perform their intended function” should it occur. See EASA Special Condition for small-category VTOL aircraft, Subpart F[2].

POST: Good to see the bird strike criteria Joby’s airworthiness criteria: A blueprint for the nascent eVTOL industry – Vertical Mag


[1] https://helicoptermaintenancemagazine.com/article/layman%E2%80%99s-guide-attitude-heading-reference-systems-ahrs

[2] https://www.easa.europa.eu/sites/default/files/dfu/SC-VTOL-01.pdf

Bird Strikes

Birds and aircraft share the same airspace. This is not a beneficial relationship for either.

I watched two rather aloof Branta canadensis in our local park the other day. They seemed oblivious to all the other birds on the priory pond. I’d certainly describe these two birds as being well fed. Given their stature and size, they looked formidable. These resident North American visitors are not to be messed with and are only eclipsed by the Swans on Reigate’s pond.

This species of bird has adapted well to living in urban and suburban areas and are frequently found on lakes, ponds, and rivers. I used to see large flocks of them gather on the river Thames. That was only a couple of miles from London Heathrow.

Even though they are numerous in the UK these birds are protected by law (Wildlife and Countryside Act 1981[1]). Today, the population numbers may be as high as 62,000 breeding pairs[2]. Although these birds have the capability to fly great distances they tend to hang around where there’s a reliable source of food. Bird populations are changing their behaviours as a result of climate change.

Geese fly in the typical V-formation which is called a “wedge” or skein. From time to time, I see them fly over my house at a few hundred feet as they move between local lakes and ponds. They are easy to spot and often noisy as they elegantly traverse the sky.

Birds and aircraft share the same airspace. This is not a beneficial relationship for either. Strikes occur around the world every day. In the history of aviation, there have been hundreds of aircraft accidents and more than 47 fatal aircraft accidents caused by bird strikes[3].

It must be said that most bird strikes cause little damage to aircraft but that is highly dependent upon the size of the unfortunate bird and their habits. The story can be very different when an impact is with a Canada goose. Their large size and tendency to fly in flocks can have a devastating impact. On 15 January 2009, a US Airways Airbus A320 aircraft[4] ended up in Hudson River as the result of an encounter with such birds.

The risk of collision between birds and aircraft have always been part of aircraft operations. As a result, measures are taken to certify aircraft to be robust in the event of such collisions. Additionally, there’s a great deal of effort made at major airports to keep birds away from active runways.

Most of the bird threat to aviation safety exists when travelling at speed at relatively low altitudes. Bird strikes happen most often during take-off or landing. This makes me think that bird strikes are going to be a regular feature of the operations of Urban Air Mobility (UAM) / Advanced Air Mobility (AAM). The use of use highly automated aircraft may offer the opportunity to provide sophisticated bird avoidance features. However, so far, I’ve detected no talk of such features.

POST 1: A useful safety booklet Large Flocking Birds (skybrary.aero)

POST 2: A recent Boeing 737-800 serious incident LinkedIn

POST 3: An example of what can happen from 2019 Ural Airlines Flight 178 – Wikipedia

POST 4: Another useful safety booklet Bird strike, a European risk with local specificities, Edition 1 – Germany | SKYbrary Aviation Safety


[1] https://www.legislation.gov.uk/ukpga/1981/69

[2] https://www.wildlifetrusts.org/wildlife-explorer/birds/waterfowl/canada-goose

[3] https://www.skybrary.aero/sites/default/files/bookshelf/615.pdf

[4] https://en.wikipedia.org/wiki/US_Airways_Flight_1549

Walk the line

Aeronautical products must be certified before entering transport services. Is certification too complex? Is it too expensive and thus a barrier to innovation? Hasn’t deregulation delivered successes since the 1970s? More choice and more aviation services across the globe.

These are perfectly reasonable questions. They are asked frequently. Especially during economically tough times and when new products are pushing to get operational. In answering, it’s all too often a butting of heads that results. Industry puts its point. Authorities put theirs. Commercial reality and public interests settle at some point which leaves the debate on the table for next time.

Walking that line between satisfying the demand of the new and protecting the good safety performance of the aviation system is a perpetual challenge. It goes without saying that we all know what happens when the line is crossed. Textbooks will continue to chew over stories like that of the Boeing 737 MAX development. In fact, the stories of safety lapses are an important part of the learning process that led to aviation’s admirable safety record.

The counter argument is that we are in a new situation and that technology has significantly changed. This argument of the “new” is not new. Every major new step encountered significant hurdles to overcome. Pick-up the story of the development of the Boeing 747[1][2] and it’s a real dramatic page turner. However, the problem remains the same but as much innovative thinking needs to go into certification as the products that are certified. There’s a reason that’s difficult and its called legacy.

On the public’s behalf, how big is the risk appetite of the certification authorities? At the same time how far do the innovators want to push the envelope knowing that liability rest on their shoulders?

What I find inadequate is that when reading reports like “Funding Growth in Aerospace[3]” I find little, or no consideration is given to funding regulatory improvement. Arguments are for product development and little else. It’s as if certification activities are to be blamed for holding up innovations introduction to service but forget any thought of increasing the resources for certification activities.

It’s short-sighted. Believe it or not there is money to be made in testing and validation. There’s money to be made in education and training. These go hand in hand with efforts to exploit innovative products.


[1] https://www.bbc.co.uk/news/business-37231980

[2] https://www.theguardian.com/science/2016/sep/07/joe-sutter-obituary

[3] https://www.ati.org.uk/publications/

Practicable

I am in two minds. When I see the words: “in so far as practicable” I can think; great, a degree of flexibility. On another occasions when I see the self-same words I think; that’s too vague and indistinct. It can easily circumvent more strict language.

Practicable is a perfectly useful word. The idea that it’s practical to do something and likely to succeed can be a matter of reasoned judgement. However, there lies the crux of the problem. It’s the subjective of that judgement, as to what’s practical and will it succeed, that becomes the possible difficulty.

If there’s a clause in a group’s constitution or working arrangements that says: “in so far as practicable” then it can become open season for someone to avoid a commitment or go their own way. That can be to shoot a big hole in a set of agreed expectations.

A lot depends on where the burden of proof sits. In other words, I may assert that something is not practicable but is it then for someone else to prove me wrong? Or do I have to provide the necessary proof?

There are elements of degree here too. If the assumption is that a judgement can be a snap judgement that’s one thing. However, there may be an assumption that a judgment is based on a rigorous level of analysis and reasoning.

The term “in so far as practicable” is most useful when applied thoughtfully and with honest intent. That the person applying this caveat would work hard to undertake whatever obligation was written and only as a fall back, having been unable to meet an obligation, revert to the use of these words.

Context and circumstances weigh heavily on what is practicable. An easy task on a sunny day can be a nightmare in a thunderstorm. Some legal clauses go as far as “insofar as is reasonably practicable in the circumstances”.

I guess I’m coming around to the wish that the “ALARP” concept (short for “as low as reasonably practicable”) would be sparingly used. ALARP weighs risk mitigation, elimination or reduction against time, trouble, and money. That’s a balancing act where there’s no perfect answer.

ALARP is a basic concept in health and safety law, but it hasn’t caught on in aviation or at least safety of flight. It’s not that aviation is blind to the fact that flight safety can be a priority, but it will never receive infinite time, trouble, and money.

It’s more that with flight there’s always a choice. It’s a “go – no go” choice. If adequate risk mitigation, elimination or reduction is not available the reasonable choice is to stay on the ground.

Luggage

It’s a space we have control over. Not a house or a room but, most often, a volume of space no greater than what we take up in our human frame. It’s not organic. It’s far from that because its role is security, storage and logistical. That’s the humble suitcase, and a great array of bags and backpacks that help us get from A to B with enough possessions to make life comfortable.

The choice of a suitcase or bag is not a trivial matter. Lessons from experience range from bursting zips to leaking contents that turn favourite clothes into damp rags. The challenge of replacing a cabin bag or case takes research and careful weighing of multiple options.

If traveling by air, there are numerous constraints on size and weight. A completely free choice as far as colour is concerned but that’s about the only characteristic that’s an open book. That said, it’s astonishing how many black cases look like other black cases in the array of black cases.

More than a decade ago airlines started charging extra for hold luggage on top of their basic fares. Since then, flying with hand luggage only has become popular. This trend can be troubling. Watching passengers squeeze unreasonably sized bags into overhead bins is not an entertainment. The expectation that an aircraft overhead bin can take a massive bag is not a reasonable one.

My latest purchase has been made from recycled plastic bottles. Naturally, that conveys a fell good factor. It’s a great way to give new life to the huge numbers of discarded single use plastic bottles that somehow we’ve become dependent upon. In my childhood, I don’t remember any plastic bottles. Plenty of glass but no plastics.

For short journeys, the faff of checking-in a suitcase, waiting to collect at a baggage belt and paying additional fees is a burden that is sometimes not worth carrying. There’s always the delightful experience of never seeing the case and its contents again as it wanders off into the maze of lost objects airports accumulate. Etched into my memory, even after more years than I care to think about, is arriving at a small airport after a tortuous journey of connections and having nothing but the clothes I stood up in. On a Sunday, in 35C degrees of bright summer sun that’s not an experience I want to ever repeat. Especially with a tough meeting planned for early the next day. A free airline toothbrush was no compensation.

So, I now have a new Cabin Max Metz 20 litre RPET backpack. This is an experiment on my part. Can I live out of this tiny space for 4-days? To do so is going to require some innovative thinking. In theory, it ticks all the boxes that I was considering essential. This backpack is lightweight but offers the maximum amount of packing space given an airline’s cabin bag restriction.

The plastic material the bag is made of doesn’t feel nice, but it’s flexible and hopefully durable. The zippers look substantial and should have a long life. Now, the task is mine. How to choose exactly the necessities of life to enjoy the journey ahead. To pack as smartly as smart can be.

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

Talent

This coming week an international tradeshow takes place in London. It’s easier to get to than it’s ever been, at least for me. The wonderful new Elizabeth line[1] goes directly to the ExCeL London.

The organisers describe the event as for the commercial aviation aftermarket. Personally, I don’t like those terms, but I guess it’s a way of grouping together all the activities that happen after an aircraft has been delivered by an airframe manufacturer. That’s maintenance, repair, overhaul and a good deal of other activities. It might be sophisticated test equipment or spanners. It might be hanger facilities or complete aero engine overhauls.

MRO Europe[2] is a major European event. Along with the exhibition there’s a conference highlighting some of the challenges aviation faces. There are a whole lot of uncertainties that are rippling through the industry. Recovery from the impact of the COVID pandemic is happening but it has taken its toll. 

The conference subject that caught my eye is that concerning the shortage of qualified people. Civil aviation must compete with every other international technology-based industry. Long gone are the days of the 1960s and 70s when aviation was associated with glamour and a kind of post-war kudos. Now, those with the right abilities, attitude and experience can command excellent reward packages in a wide variety of digital high-tech industries.

The MRO industry is aging. Offering an attractive pathway to young people is proving to be difficult. It’s a two-sided problem. On the one side the industry is inherently conservative. Afterall it’s in the safety business where reputation for quality matters. On the other side the attitudes, beliefs and expectations of younger people are markedly different from those of their potential mentors and teachers. Bridging this divide isn’t easy.

Apprenticeship schemes do help[3]. However, they are often picking up the people who already know they want a career in aviation.

The challenge is not just recruitment but retention. The aviation industry must make it attractive to retain talent. Working in an aircraft hanger, or on the ramp in the middle of a cold winter isn’t everyone’s cup of tea. Especially when comparing stories with a colleague in a nice warm office of a telecoms or social media company.

Building community, professionalism and a love of aviation is a priority. I’ve seen this done in the US. Next April at MRO Americas at the Georgia World Congress Center in Atlanta a competition[4] takes place. It’s an excellent example of how to create excitement in this field. Check it out.


[1] https://tfl.gov.uk/modes/elizabeth-line/

[2] https://mroeurope.aviationweek.com/en/home.html

[3] https://www.stsaviationgroup.com/sts-aviation-services-launches-newly-formed-apprenticeship-scheme-united-kingdom-1/

[4] Aerospace Maintenance Council – YouTube

Air Taxi 2

As a quick effort at simple research, I looked at several local government websites searching for Air Taxi or Urban Air Mobility (UAM) or Advanced Air Mobility (AAM). The result was lots of blanks with one or two exceptions[1][2]

There’s numerous articles about e-scooters and how they might be integrated into cityscapes.

Addressing local governments, much of what has been published to date concerns the use of drones. Yes, the use of drones is happening here and now, so this is not such a surprise. However, to me, this was a reminder that the frenetic world of aviation often discussed the future in rooms full of like-minded people. Embracing a wider audience is overdue.

In the case of UAM/AAM, innovations in civil aviation are move beyond airports, upper airspace, and specialist technical interest. If the electrification of flight is to take hold it will touch the lives of many more people than conventional commercial aviation.

These new aviation developments will generate new business models and offer new services. This is challenging stuff. It’s clear to me that, without the agreement of local authorities such enterprises will be dead before they start.

National governments may take a regulatory approach that imposes on local governments. That would be ill advised and ultimately unsustainable. A cooperative partnership would open a smooth transition from transport novelty to accepted everyday part of mobility.

Local authorities will need to adapt their formal local plans to include planning considerations of zoning, land-use, multi-modal matters, environmental impact, construction, utilities/support infrastructure, public privacy and much more.

Local government is a partner in risk management too. Just as highway authorities wrestle with improving road safety so, no doubt, UAM/AAM accidents and incidents will be on their agenda.

Fostering public-private partnerships is talked about but few examples have moved beyond theory and into practice.

POST 1: These issues have been highlighted at ICAO this year Urban Air Mobility and the Role of Air Transport – ICAO 2022 Innovation Fair – ICAO TV

POST 2: The organisation is looking at possible future operations https://varon.aero/

POST 3: People taking a holistic view http://www.supernal.aero


[1] https://www.civataglobal.org/

[2] https://www.urbanairmobilitynews.com/global-map/

Air Taxi

My daily routine once comprised of walking across a bridge over the Rhine to an office in Ottoplatz in Köln-Deutz[1]. That’s in Cologne, Germany on the eastern side of the river.

In the square outside the railway station is a small monument to a man called Otto. A small monument marking a massive transformation that took place in the way transport has been powered for well over than a century. This monument honours Nicolaus August Otto who created the world’s first viable four-stroke engine in 1876.

Today, the internal combustion engine hasn’t been banished. At least, not yet and Otto could never have known the contribution his invention would make to our current climate crisis. But now, rapid change is underway in all aspect of transport. It’s just as radical as the impact of Otto’s engine.

As the electrification of road transport gathers apace so does the electrification of flying. That transformation opens new opportunities. Ideas that have been much explored in SiFi movies now become practically achievable[2]. This is not the 23rd Century. This is the 21st Century. Fascinating as it is that in The Fifth Element the flying taxi that is a key part of the story, has a driver. So, will all flying cars of the future have drivers?

I think we know the answer to that already. No, they will not. Well, initially most of the electric vehicles that are under design and development propose that a pilot (driver) will be present. Some have been adventurous enough to suggest skipping that part of the transition into operational service. Certainly, the computing capability exists to make fully autonomous vehicles.

The bigger question is: will the travelling public accept to fly on a pilotless vehicle? Two concerns come up in recent studies[3][4]. Neither should be a surprise. One concerns passengers and the other concerns the communities that will see flying taxies every day of the week.

Public and passenger safety is the number one concern. I know that’s easy to say and seems so obvious, but studies have show that people tend to take safety for granted. As if this will happen de-facto because people assume the authorities will not let air taxies fly if they are unsafe.

The other major factor is noise. This historically has prevented commercial public transport helicopter businesses taking-off. Strong objections come from neighbourhoods effected by aircraft constantly flying overhead. Occasional noise maybe acceptable but everyday operations, unless below strict thresholds, can provoke strong objections.

So, would you step into an air taxi with no pilot? People I have asked this question often react quickly with a firm – No. Then, after a conversation the answer softens to a – Maybe.


[1] https://www.ksta.de/koeln/innenstadt/ottoplatz-in-koeln-deutz-eroeffnet–das-muss-nicht-gruen-sein–2253900?cb=1665388649599&

[2] https://www.imdb.com/title/tt0119116/

[3] https://www.easa.europa.eu/en/newsroom-and-events/press-releases/easa-publishes-results-first-eu-study-citizens-acceptance-urban

[4] https://verticalmag.com/news/nasa-public-awareness-acceptance-of-aam-is-a-big-challenge/

Out of Step

If ever a political party has misjudged the public mood more in the last few decades, it’s the British Conservative Party, here and now. Without going into the cavalcade of reasons why they are incompetent, the overriding fact is that they are completely out of step with the British people.

After years of turbulent instability and pressures caused by the banking crisis, the pandemic, conflict and Brexit they have a mad idea that we have a big appetite for chaotic change with blind sheeplike obedience. It’s difficult to say that in “normal times” this Government’s irresponsible behaviour would be totally unacceptable to the point of civil disobedience and mass protest. But it’s true and the later may indeed happen. Winter is coming.

Running the British economy as if it were a poorly thought-out student project is beyond contempt. The childishness of the UK Prime Minister and Chancellor of the Exchequer is off the scale. There is’nt a scale made for this bunch of idealogical fanatics.

This week there maybe a week of back peddling, without seeming to back peddle but the damage is done. Reputational damage is easy to achieve but mighty difficult to recover from in the short-term.

The classic British example is that of Ratners in 1991/92. Now, instead of the “Ratner effect[1]” we will have to speak of the “Truss effect” in 2022. Certainly, in the rank and order of economic disasters the Truss Government must rank well above Ratner. Afterall, he only lost 330 jewellery stores, 2500 employees and over £122 million in a few seconds.

Interestingly, the fall of Troy is on the list of all time disasters brought on by human folly. Even I wouldn’t draw a comparison with the Truss effect and a tragic story from classical literature. Or would I?

In breaking my own rule, I can just see the Chancellor of the Exchequer Kwasi Kwarteng as a wooden horse entering the His Majesty’s Treasury ready to burn it down. He’s jumped out of the horse and what comes next is writen. He may be serving at His Majesty’s pleasure but I’m sure that’s just formal terminology and, there’s a whole bucket load of displeasure behind the scenes. Whatever his eccentricities, it’s likely His Majesty is far more in-touch with the British people than this appalling British Government. They have sat too long. It’s time for them to go. And go soon.

POST 1: At conference, it is reported that the Conservative Party chairman is telling their MPs they will lose the party whip if they vote against the fatal mini-budget of last week. Shirts are being printed with the slogan – I’m with stupid.

POST 2: Conservatives now plan to scrap the scrapping of the 45p top rate of tax. It’s a big poltical u-turn only days after the UK PM publically defended the policy.


[1] https://www.businessblogshub.com/2012/09/the-man-who-destroyed-his-multi-million-dollar-company-in-10-seconds/