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Proactive Safety Management Systemization in Aviation – An Overview

Aviation, as a mode of transportation, has revolutionized global connectivity and accelerated economic growth. It is also the source of the quality systems such as the ubiquitous ISO-9000. The inherent risks associated with flying necessitate stringent safety measures to ensure the well-being of passengers, crew and aircraft. A proactive Safety Management System (SMS) is crucial in mitigating these risks, fostering a culture of safety, and in the continuous improvement of operational standards.

Understanding Safety Management Systems

A Safety Management System (SMS) in aviation refers to a systematic approach to managing safety, integrating operational processes, policies and procedures to identify, to assess and mitigate risks effectively. Unlike traditional reactive safety approaches which respond to incidents after they occur, a proactive SMS focuses on preventing accidents and incidents before they happen. This shift from reactive to proactive safety management is pivotal in enhancing aviation safety standards globally. A living Safety Management System is the key.

The Evolution of Safety Management in Aviation

Historically, aviation safety initiatives primarily relied on post-incident investigations and subsequent regulatory oversight to enforce improved safety protocols. However, with the growing complexity of aviation operations and the increasing volume of air traffic, there emerged a need for a more comprehensive and forward-looking approach to safety. The concept of SMS gained prominence following recommendations from international aviation organizations such as the International Civil Aviation Organization (ICAO) and the Federal Aviation Administration (FAA). These bodies recognized the limitations of reactive safety measures and advocated for a proactive approach that incorporates risk management principles into daily operational practices. Surprisingly the troubled Boeing Company was a lead instigator of this policy and developed procedures which, as stated above, became the source catalyst of the ISO-9000 program

Components of a Proactive SMS

A proactive SMS comprises several key components essential to its effectiveness as follows:-

  • Safety Policy and Objectives:

The establishment of a clear safety policy endorsed by senior management within a company sets the foundation for an organization’s commitment to safety. This policy outlines safety objectives and defines roles and responsibilities across all levels in the organization.

  • Risk Management Processes:

Identifying hazards and assessing associated risks are fundamental to proactive safety management. Through risk assessment tools such as Safety Risk Management (SRM), aviation organizations can systematically analyze potential risks and implement measures to mitigate them.

  • Safety Assurance:

Continuous monitoring and evaluation of safety performance are critical in identifying trends, potential weaknesses and areas for improvement. Safety assurance processes ensure that safety standards are consistently met and provide insights for proactive intervention. Safety Managers are responsible for assuring the effectiveness of the System and need inspectors to implement it.

  • Safety Promotion:

Promoting a positive safety culture encourages open communication, proactive reporting of safety concerns and the ongoing training and education of aviation personnel. Safety promotion initiatives foster a collective commitment to safety excellence throughout an organization of which a principal tool is all company personal taking the initiative to seek and report potential hazards.

Benefits of a Proactive SMS

Implementing a proactive SMS yields numerous benefits that contribute not just to overall aviation safety but also operational efficiency:

  • Risk Reduction:

By identifying and mitigating risks proactively, aviation organizations can prevent accidents and incidents before they occur, thereby enhancing overall safety levels and reducing costs (not least through the reduction of insurance premiums).

  • Improved Decision-Making:

Data-driven insights from safety management processes also enable informed decision-making, optimizing operational efficiency and resource allocation.


  • Enhanced Safety Culture:

A proactive SMS fosters a culture where safety is prioritized at all levels of the organization, promoting accountability, collaboration, and continuous improvement

  • Regulatory Compliance:

Compliance with international Regulations and standards is facilitated through structured safety management processes and proactive risk mitigation measures. Although a robust SMS is now a Regulatory Requirement for most National Aviation Authorities, it does not guarantee full regulatory compliance and is only one of the many key components for an Company AOC to be granted.

Principal Challenges in Implementing a Proactive SMS

To achieve the full benefits, the implementation of a proactive SMS in aviation poses several challenges:

  • Resource Allocation:

Establishing and maintaining an effective SMS requires significant financial and human resources – a particular challenge for smaller aviation operators.

  • Organizational Culture:

Shifting towards a proactive safety culture may encounter resistance within organizations accustomed to reactive safety practices or overcoming cultural barriers to change.  In this regard, effective socialization is critical.

  • Data Management:

Effective safety management relies on accurate data collection, analysis, and reporting. Challenges may arise in integrating disparate data sources and ensuring data integrity.



Case Studies and Success Stories

Most major aviation organizations have now successfully implemented proactive SMS frameworks, demonstrating tangible improvements in safety performance and operational efficiency. For instance, aviation authorities and international airlines worldwide have achieved significant reductions in accident rates and enhanced safety records following the adoption of SMS principles. These success stories underscore the transformative impact of proactive safety management on the aviation industry’s overall safety landscape. Conversely, the correlation in Boeing’s recent troubles and a massive reduction in quality & safety personnel at production facilities is notable.

Similarly, it is notable that the most successful Air Service Providers in the Offshore Helicopter Market have greatly benefited from developing a robust and proactive SMS, shriveling overall accident statistics in recent years.


In conclusion, the realization of a proactive Safety Management System (SMS) in aviation has proven paramount in ensuring the highest standards of safety and operational excellence. By adopting a systematic approach to risk management, fostering a positive safety culture and continuously improving safety practices, aviation organizations can mitigate risks, prevent accidents, and uphold regulatory compliance. As aviation continues to evolve and expand globally, proactive SMS frameworks will play a pivotal role in safeguarding the industry’s future and maintaining public trust in air travel. Embracing a proactive approach to safety management is not merely a regulatory requirement but a moral imperative to protect human lives and uphold the integrity of aviation as a safe and reliable mode of transportation. All involved in realizing and regulating the next impending revolution engendered in eVtol UMAs would do well to remember that.




Wing in Ground Effect (WIG) is a niche type of transportation nominally offering significant increases in cost-efficiency over mainstream in-service types. The promise of rose-tinted revolution has thus far been dissipated by real-world practicalities. However, as advances in modern technologies mitigates known negativities, the WIG concept rears its pretty head again and  the dream cycle recommences. The aim of this text is to review its potential in the offshore logistic support service context and in comparison with existing core support vessel and helicopter service provision.


WIG development dates back to the early 1930s with the earliest designs originating in Sweden and Germany, then latterly, post war, in the USA. While effective over any flat surface, the need for a long take-off runs and surface skimming operating heights, has tended WIG designs to amphibian variants. With large internal seas and massive frozen, sparsely inhabited plains, it is not surprising that Soviet Russia became the centre for WIG development during the 60s/70s Cold War period (pun intended!), the focus being on fast surface attack craft of up to 600 tonnes – the so-called Caspian Sea Monster – primarily for use in the Black Sea and the Baltic. With a weakening economy and the fizzling-out of the Cold War, continued research has now almost ceased in Russia.

Seemed like a good idea at the time – 250 tonne, 300 kt. Lun class &  Beriev VVA-14 – then & now, a dream in decay

However, interest in commercial applications has continued in developed regions, particularly the USA and various countries in the Australasia locality, resulting in protypes with capacity for up to a dozen passengers. Principal players (as illustrated below) now include:-

  • Hoverwing – a late ‘90s development by Universal Hovercraft in Florida. A two-seat prototype for an 80 passenger production vehicle is flying, combining Hovercraft and WIG technologies.
  • Airfish – an 8 Pax amphibian WIG vessel now manufactured & operated by Wigetworks in Singapore first flew in 2011. It has a maximum speed of 100 kts and a 180 Nm range. Now on the Lloyd’s Register of Shipping.
  • Seaglider – a 12 Pax hydrofoil WIG vessel under design by Regent in the USA with eight electric engines providing a maximum speed of 150 kts and a 180 Nm range. Quarter-size prototype flew in 2022 with a production prototype is scheduled for 2025.
  • Liberty Lifter – a DARPA program launched in 2023 for a turbo-prop., amphibian WIG heavy lifter, also capable of operating as a normal aircraft up to 10,000 ft. with a target payload of 90 tonnes and 6000 Nm range (in WIG mode). Seen as a replacement for the C-17 Globemaster.

Good ideas for the future: small Pax. types – Hoverwing, Airfish, Seaglider & return of the heavies (Liberty Lifter)

Technology Overview

The concept is very simple and similar to the phenomenon of a helicopter hovering in ground effect and out of ground effect (IGE /OGE).  When air passes over any aerofoil with its axis at a positive angle with respect to that airflow, a pressure differential is generated with a higher pressure below the aerofoil (wing) than above: the faster the airflow, the higher that pressure differential which causes an upwards ‘Lift’ force. So when you catch a flight to go anywhere, the fixed-wing airliner trundles along a straight road (the runway) accelerating like a racing drag truck until after a couple of kilometres it reaches a reckless speed at which the pressure differential creates a lift force equal to the aircraft weight and one staggers into the air just before hitting the perimeter fence at the edge of the airfield. Helicopters have a more suave approach by rotating the aerofoil achieving the same effect in a much less risky and reckless fashion. A WIG aircraft (or vessel – after some 50 years, the regulatory jury is still out on whether they are slow aircraft or very fast ships) modifies the aerofoil so that, as it skims over a flat surface, air is trapped beneath it, thus substantially increasing that pressure differential. The good news is it reaches flight speed a lot quicker (ie at a lower speed): the bad news is, to maintain that IGE air cushion, it cannot go higher than a (very) few feet above the ground and so must operate from airfields without perimeter fences – hence, mostly they operate like amphibians, from marine bases.

The WIG concept – comparing the operation of a standard Aerofoil (left) with one ‘in ground effect’(right)
Note that for the same speed (V), the Lift (L) achieved is greatly increased while Induced Drag remains unchanged


As the above diagram shows, the principal advantage comes from the increase in lift for any given airspeed generated by the in-ground effect (IGE) and that, without any increase in induced drag (which is a rearwards vector caused by the lift force being at 90º to the aerofoil axis: hence the greater the aerofoil angle to the airflow, the more the induced drag).  More lift at less speed means less power required and also less body friction drag. All these combine to make the Wig aircraft significantly more fuel efficient than equivalent sized aeroplanes and nominally, with the potential to carry larger payloads.  


These are legion.

  • Firstly, like all seaplanes, the body needs to be structurally more robust to operate off water which thus results in some of the increased lift being lost due to an increase in aircraft weight

Mitigation – to maximise the use of composites.

  • Secondly, the increase in WIG vehicle efficiency only applies IGE. When OGE these vessels are significantly less efficient than an equivalent aircraft.

Note – IGE operations limit WIG vessels to less than 20ft above the sea surface: in moderate seas the ground effect is reduced by waves, both decreasing this platform’s efficiency and comfort due to vibration

  • Operation close to the sea surface results in salt ingestion into power plants requiring a significant increase in maintenance and additional corrosion protective measures.

Mitigation – none needed except giving more time for maintenance

  • Aero engines are designed to operate at altitude, so are less efficient at sea level thus negatively impacting the fuel efficiency element.

Mitigation – use electrical power plants (however, still early days)

  • Certification – still an open question whether this should be marine (cheaper) or aviation (more challenging): given that most WiG aircraft can operate OGE in hops (Class-B) or prolonged (Class-C), aviation standards are relevant.

Note – Class-A WIG platforms are limited to IGE operations: as such, the Singapore-based ‘Airfish’ has just been certified on the Lloyds register of Shipping

  • WIG craft are thus weather sensitive being limited to sea-state-4 (2.5m waves) which equates to Beaufort Force-5 winds (ie. up to 20 knots) and somewhat less than that for take-off/landing.

Mitigation – nil, but Hydrofoil types will fare better during take-off/landing in other than calm seas

  • IGE WIG vessels are not manoeuvrable with a large skidding turning circle. So at a typical 100-150kt cruising speed, they are a hazard to small, less visible vessels like fishing boats and recreational vessels.

Mitigation – improved digital radar processing and automated collision avoidance software should be able to overcome this issue in the near future (say in a 5-year timeframe).

  • Speed lanes – due to this lack of manoeuvrability and the associated risk of fatal collisions with small vessels, in the opinion of this author, as part of the certification process, specific designated routes marked with illuminated buoys with radar reflectors will be required. This is believed to be a ‘killer issue’ and so a separate section has been dedicated to this issue below.

The need for traffic lanes

As stated above, operating IGE just a few feet above the sea, these aircraft-like vehicles are more like surface vessels – but very fast and not very manoeuvrable. With radar, medium and large shipping are detectable at long range and thus easily avoided. Offshore fishing vessels in calm seas will similarly be detected at ranges allowing sufficient time for avoidance. But in less clement weather such detection ranges will be significantly reduced and to assure such detection will require a radar operator dedicated to that task (ie. an additional crew member). Smaller recreational vessels and wooden coastal fishing boats do not show up on radar until very close, if at all, so cannot be avoided. As such, in terms of Risk Management, WIG operations represent an unacceptable hazard. To mitigate this, routes from onshore bases to offshore platforms would need specific designation. Because such small vessels are not in receipt of NOTAMs (Notices to Mariners), such routes will have to be physically designated with illuminated buoy markers equipped with radar reflectors perhaps at some 500m separation. In addition, since any collision between a WIG craft at 100kts and a small surface craft will surely be fatal, at least for those on the latter, such designated ‘Speed Lanes’ will likely require national legislation and perhaps, will have to be patrolled to ensure enforcement. Such additional infrastructure costs will more than eliminate any of the anticipated operating cost benefits.


The final nail in the coffin of WIG OGP sector service provision is their weather sensitivity due to the limiting sea-state (SS) for take-off (ie. getting into ground effect) and landing (ie. returning to normal displacement operations) of SS.4-5 – such ‘moderate’ seas are a very common, even normal,  condition in an offshore environment. The resulting high frequency of cancellations due to weather will surely be unacceptable.


Summary & Conclusion

WIG vehicles have long been hyped as a more cost-effective replacement for the helicopters and supply vessels typically used in offshore support operations. The potential is surely there. To support an average production platform requires at least two offshore supply vessels (one in the field, one loading – exchanging (say) fortnightly) and two medium helicopters doing some 10 trips per week (two are required to guarantee a 24/7 emergency response capability). A single 50-tonne payload WIG craft nominally could replace all of these, requiring only a single medium helicopter on standby for medevac, the cost of which can be kept low by farming into an existing operation. At typical 100+kt cruising speeds, a turn-round (outbound-offload-reload-inshore) should be achievable in a single long day. The ability of such a vessel to also carry some 50+ Pax. means such trips would only be required, say, every 3-days. Such would offer less flexibility and redundancy, but by amending SOPs is eminently doable. The cost savings potentially would be significant.

A Sea State 4 limitation kills this potential. However, this applies to the exiting small (<12 seat) craft. Larger, heavier craft, also using hydrofoil types like the Seaglider, can cope with higher sea states thus reducing this limitation . But, as vessels get larger the collision risk remains and may even grow. So nominally, this concept warrants further investigation, except for one thing – such a platform does not yet exist! While all the technologies to create one are available now and well understood, it will take a lot of money and time to develop. The DARPA Sea-Lifter program is gobbling up some $30m p.a. just pushing paper. Designing, building and certifying such craft will thus surely need a few billion dollars. The commercial market is likely too small to amortise such cost. However, if such a vessel is developed under military funding, then the development cost in the commercial sector would, in principle,  become more manageable. At that time, one of the players identified above will surely run with it at which point the offshore industries in particular, would be wise to study this application again in more depth.

Meanwhile, the existing 12 seater craft are not fit-for-purpose in the OGP sector. While the procurement cost is about one-third of an equivalent medium helicopter, operating costs, while nominally significantly less, will be increased by corrosion control requirements and additional operating infrastructure requirements and particularly the suggested speed lanes. The increased safety offered by these craft is a risky claim, not only because of the collision risk which still has to be properly addressed, but also the fact that every trial / demonstration in the OGP sector has ended ‘in tears’ with the craft incurring serious damage. That these accidents were a function, in the main, of a lack of familiarity with that environment, if nothing else, this shows that an extensive (and expensive) sea trials are still required to move this forward. But, even if successful, there remains the issue of weather sensitivity. That these existing craft are limited to sea-state 4, an approximately a 50 percentile weather condition, is likely the final nail in the current WIG operational coffin!

Notwithstanding, the use of WIG craft is an interesting concept with some potential. Accordingly, the recommendation of this paper is for the OGP sector to sit on their hands and let the US Government spend the necessary billions to bring a high payload, therefore high potential, craft into service.

The next ‘Big-Thing’ in Aviation

The next ‘Big-Thing’ in Aviation

Commercial aviation is at its centennial. One hundred years ago it was mostly used for freighting or, more particularly, as couriers on behalf of national post offices. Mail then, as emails now, required expeditious transmission. So, in those days, rickety piston engine aircraft criss-crossed the globe generally successfully fulfilling that requirement. Their pilots had a bravado and mystique similar to that of an astronaut today. The true nature of that unique operating environment is well captured by Sainte Exubery in his biography ‘Sand, Sea & Stars’ – now more famed as the author of the ubiquitous ‘The Little Prince’, which itself was devised while he was awaiting uncertain rescue when his plane came down on a remote, high plateau in Morocco. Commercial passenger flights then were more akin to extreme sports than normal travel. That said, at that time, long haul Zeppelins carried almost 100,000 well-heeled passengers across the Atlantic in lavish style, and reasonably safely – until the Hindenburg’s (possibly terrorist instigated) Hydrogen-fuelled flaming destruction in 1936 which bought that era of commercial aviation to a close.

In the hundred years since, aviation technology and safety have steadily improved in incremental steps with revolutionary changes being very rare. In the early 50’s, the jet airliner was likely the first such ’Revolution’ along with the subsequent wide-body jet airliners making cheap (in every sense of that word) air travel available to all. The helicopter in general aviation is surely another. The (almost unequalled) speed of the Mach 2.2 Concorde had too small an impact to be considered revolutionary. Now, the development of AAM (Advance Air Mobility) electrically powered, city-hopping, autonomous flying vehicles has the potential to be the next such revolution. That these air vehicles are to be electrically powered is under the incremental category as is the fact that there will be no pilot which, technically, if not emotionally, is also but an incremental change – this author flew in a fully automatic helicopter in 1968 (a measure of both his maturity and that of automated flight!).

The revolutionary element here is not so much the vehicle but more in how it will be used. Until now commercial flights have, in the main, been over distances of many hundreds of miles in aeroplanes and dozens of miles in helicopters. These flights, in the main, are scheduled and over fixed routes. Even for helicopters in an emergency response context, flight plans are submitted and fixed routes in an (air) traffic controlled environment are generally followed. The AAM environment however, will be over very short distances – typically of less than a dozen miles – be unplanned and ad-hoc and, if the dream is realised, not much above roof-top height and from any door to any door – in short AAM holds the promise of low level bedlam! S o, the revolutionary element here is less one of vehicle technology and more one of the huge levels of anticipated production of these small flying craft and how they will be used, with the associated automated control software – IF such can be satisfactorily developed and certified. This article will give an overview of each of these elements.

First the vehicles themselves. This article will be limited to the passenger carrying, so-called ‘Air-Taxis’. This is because the freighting variants have lower certification thresholds (Aerial Work rather than Transport Category) and will anyway merge into the already established Drone market. As one would expect, all the prospective Air Taxis use VTOL (Vertical take-off/landing) technologies. While largely based on rotary wing principals, there is one significant difference. In place of the very large main rotor(s) of the helicopter, powered by a couple of engines through a large reduction gearbox, the eVTOLs use multiple small rotors each individually and directly powered by an electric motor – much lighter and with a higher level of failure redundancy. Forward flight will be either by tilting the overall rotor disc (à la helicopter) or with a separate pusher propeller. Like the smallest light helicopter types, the power-to-weight ratio of current eVtol types is low. This negatively impacts hover precision and also make them susceptible to gusting winds, thus predicating fairly substantial landing pads – currently referred to as Vertiports (more on which below) – and probably, with low certified weather thresholds.

In product development terms we are exactly where we were in aviation a hundred years ago, with scores of start-ups proposing a myriad of different iterations. Aviation authorities (which did not exist 100 years ago) are struggling to keep things under control and have yet to develop a standard. Developers, being entrepreneurial by definition, are promising in-service dates a year-after-next. Given the absence of a formalised standard and the lack of experienced personnel within aviation authorities to produce it, such dates are surely fictional. This author was involved in the commercialisation of modern airships, so has had first-hand experience of this challenge which, in the lighter-than-air case, was resolved by running the development of platforms and regulations in parallel over several years with the OEM typically preparing the regulatory drafts. The same is unlikely to occur in the AAM context due to the high level of competition between protagonists reducing cooperation, and the massive envisaged number of  air vehicles in end-use complicating regulatory controls. That said, the Big Boys in main-line aviation are now becoming deeply involved including DARPA and some defence ministries, some large airlines, Boeing and Airbus and uniquely, two major car manufacturers, Stellatis and Toyota. Also, among the large helicopter operators, Bristow is dipping its toe in the pond with regard to off-shore applications. So buckets of money are being thrown at the problem with investments now measured in billions of dollars (in one’s Airship days, we only ever enjoyed investments in units of millions!). This will likely both speed up certification and reduce numbers of Newco OEMs on the playing field.

Some Leaders of the ‘Air-Taxi’ pack (top left, clockwise) Lilium(Germany), Archer-Midnight (USA), BetaTech.(USA), Joby(USA), Volocopter (Germany), Ehang (China)

Being based on investment pressures rather than technical requirements, all information in the certification context needs to be taken with ‘a bucket of salt’, but there are clear indicators of progress in the ‘real world’ as summarized in the table that follows. This AAM (Advanced Air Mobility) Reality Index (ARI) has been put together by SMG Consulting, a US based business management consultancy working in conjunction with the Vertical Flight Society and Aviation Week. The top half-dozen players are shown in order of their assessed ARI, which generally reflects their level of investment capital. Stated EIS (Entry into Service) dates here are likely based more on financial imperatives than technological fact so, as discussed below, there is little risk of an air-taxi buzzing in your neighbourhood any time soon……

* ARI –
AAM Reliability Index.           **  EIS – Entry Into Service.          *** PP – Production Prototype flying

The Chinese Ehang was one of the first iterations in this field. With capability limited to a single Pax. over 30 km range – a 12 minute flight – it is more reflective of the Wright Brothers’ initial creation than a commercial prospect! That it aspires to claim CAAC certification is surely a factor of not-too-subtle CCP (Chinese Communist Part) influence. Besides anything else, those knee-capping rotors would not pass any serious risk analysis! It is anyway understood that the initial certification is limited to Cavok (ie. perfect weather), within sight of its ground staff and not over built-up areas – thus somewhat limiting its utility as a taxi even if the planned EIS is achieved! The current 1000 unit sales projection, being almost entirely within China, is possibly also a function of gentle arm-twisting.

Volocopter’s ‘Volocity’, also a two-seater and an early iteration, is little better. But at least one has to reach up for an amputation by one of the 18 rotors (although, in fairness, a new 4 seat iteration has one third the number of the rotors and lifts them out of reach). But capacity and capability are marginally less than the Ehang. So, even if a restricted EIS capability was certified by next summer as advertised, in time for the Paris Olympics, the nature of the transportation service it will provide for a single passenger over the spread-out Olympic events, defies imagination. The series has achieved some 2000 test flights in total which, while more than any of its peers, still only equates to a total of only some 350 flight hours. A lot more will surely be required even to achieve a minimum Aerial Work certification to allow it to fly with a (non-paying) passenger over Paris next summer.

Archer & Joby aspire to reasonable aircraft flight parameters. This is largely because their rotors partially / completely tilt (respectively). While  the two early iterations described above achieve forward flight through a marginal tilt of the overall rotor disc – hence their low forward speed (unlike helicopters their rotors have a fixed angle of attack, increasing lift by increasing rpm so limiting said ‘tilt’). These latter tilt rotor types aspire to light helicopter performance (hence the USAF interest) but, due to current battery limitations, not the range.  Based on what the USAF has agreed to pay to acquire a half-dozen test units, the AAM cost-efficiency appears considerably less than light helicopter types, being some 4 times the cost with half the gross disposable load. Of course this is not representative of the envisaged production run which, unlike aircraft, is intended to be more akin to that of the ground vehicles (taxis) it is nominally intended to replace, hence in the hundreds of thousands. But is such a taxi replacement concept feasible?

To judge that one needs to consider AAM operating parameters and particularly landing sites and ‘refuelling’ (ie. recharging) requirements. The latter first. A wheeled taxi, if used 24/7, typically will refuel once a day. A light chopper shuttling, maybe after every 2½ hours of flight. But even the most capable AAM birds will need to recharge every half-hour and likely, sooner. While to recharge car fuel takes a minute and a light chopper maybe 5 minutes, a full AAM recharge will be more than five times that. As we all know from our computers and cell phones, constant topping up destroys battery life. So a regular half-hour full charging is likely an essential requirement. OEMs suggest a typical transit distance for an AAM of some 50km, which at typical stated cruise speeds will take approximately 15 minutes. On landing, the stated battery recharging time is about 12 minutes. So it appears that, in general, flight times and recharging times will be similar – while not an impossible situation, it would seem to be a less-than-optimum state of affairs.

Then there is the small matter of parking. From this diagram it is clear that this air taxi will not be able to pick up passengers in the same way as a standard (4.5x2x1.9m (l-w-h)) London Cab. So the door-to-door ethos of taxis will be inapplicable to the so-called air-taxi.  And, in aviation safety terms, the low power-to-weight ratio of AAMs will predicate a fairly substantial landing pad. And indeed, from glossies provided by prospective, so-called, Vertiport service providers, it would appear that CAP-437 heliport criteria will remain generally relevant for AAMs (see overleaf). So hailing an air taxi will be less like hailing a Cab or ‘Apping’ an Uber and more like hailing a helicopter – so not done on a whim! And then there is the likely weather limitations to consider. Since the developed AAM end-product will be fully automated, low visibility should not be an issue, but wind will. Low power-to-weight ratios and lack of inertia will make AAMs sensitive to updrafts & general turbulence caused by wind – and in the city-scape environment, there are plenty of sources of both in high winds. One would therefore expect a (say) 25knot wind limitation to be imposed – hence, essentially limiting AAMs to fair weather flying. So it would appear that, just when a taxi is most required, these air taxis will be unavailable – not a good prospect!

Costs similarly reflect this. The London Cab illustrated above can be bought for 150-160,000 pounds – say $200k. The USAF has just agreed to purchase a half dozen each Archer and Joby AAMs at a unit cost just short of $25m. United Airlines are expecting a unit cost of an early production AAMs of $2m. Let us assume an established production run is half that. Given the thrill and high transit speeds, a factor of 5 in unit cost seems not unreasonable but again, unlike taxis, one would not use it on a whim. This is made the more so because, to ride in said AAM ‘Taxi’, one will need to first hail a cab to get to the nearest Vertiport atop a multi-level parking lot, take the lift to the upper level (in such salubrious areas, with risk of a mugging) and at the destination Vertiport reverse the process again – in short, such seems low in convenience and high in cost!

Vertiports will likely be of similar dimensions as existing Heliports

And then there is operating cost. The USAF is budgeting AAMs at $1500 per flight hour – roughly twice that of a 4-seat helicopter (which has twice the payload). This is similarly reflected in the Volocity’s suggested seat price for a 10 minute transit (jaunt?) during the Paris Olympics next year which is currently pitched at $385.  Again, for the well-heeled, paying five times the normal taxi fare to cover a distance in one fifth of the time is not unreasonable – but again, for us normal folk, not on a whim! (…..and then one needs to also take into account the cost of that ground taxi (and the time lost) to get to/from the Vertiports at each end…..).

Finally there is the issue of control. Based on outline specifications, AAMs will be buzzing around between 1000-3000ft. So interfacing will national ATC systems should not be a significant issue. But given the high numbers of AAMs envisaged in any city, and the very large number of destination Vertiports required, to operate reliably and safety will require an automated control system of enormous complexity (and cost), the more so because it will also need to cater for massive inter-vehicle 4D positional/vector communication and with passenger reservations in time-frames measured in minutes rather than a day or two as now with existing commercial aircraft types.

Since, given the envisaged nature of the service, pilots will be in insufficient numbers and anyway, too expensive, this massively complex system will have to operate fully autonomously with no ‘human in loop’. Such appears to be a mind-boggling challenge but likely, not beyond the capabilities of Artificial Intelligence. That currently, all are piloted, is in order to simplify the certification process. All proposed types have built-in autonomous capability which, it is expected, will be introduced some years downstream once the flight infrastructure / software is in place. This reflects the anticipated reality that AAM will evolve from the existing low level airspace helicopter management infrastructure which, initially, it will use and from which an Urban Air Mobility (UAM) system is expected to evolve.

Swishing quickly and quietly around the world’s megacities in air-taxis is a worthy dream but, from this elemental overview, it is clear that there are a range of killer issues that may prevent its realization. That said, AAMs will almost certainly come into service albeit in timeframes more likely stretching into the next decade and with only a very few of the dozen’s of current OEM players surviving. In this stretched timeframe, Battery technologies will surely improve, thus resolving the currently ridiculous situation of requiring the same charging times as flight times, and also correcting the present low endurance flight hazard. Green electricity will also surely soon be the norm as Nuclear Fusion becomes a reality (given present trends by 2050). So UAM transportation has good environmental credentials, which however, will apply equally to electric ground vehicles (EVs).  Both AAM and EVs are intended to be fully autonomous with similar risk of systems’ failure leading to accidents. The difference here is that, accidents involving the flying vehicles will likely be very much more serious in terms of damage to both human life & infrastructure. Hence, the associated autonomous UAM management software will need to be very much more demanding and byzantine which, one suspects, is at the limit of human capability, so likely be a productive job for Artificial Intelligence. So, in short, notwithstanding all these challenges, with respect to technologies, this next aviation revolution could happen.

However, the EV ground vehicle revolution which is running in parallel, may prove to be the ‘killer threat’ to the UAM concept. It is lower risk, significantly lower cost and far more advanced. Within the same suggested ten-year AAM certification timeframe all production cars will become electrically powered and (likely) autonomously controlled. Already there are autonomous taxi services in the USA and the use of Apps world-wide to rapidly book a lift through a small number of very large ground vehicle service providers such as Uber, is now a routine matter. As such car ownership in cities is already inessential. In addition, the software systems allowing inter-vehicle communication for effective traffic management are already in service with Google Maps and Waze to name but two.  Once ground vehicles are fully autonomous, vehicle ownership will likely become an anachronism.

It is thus very probable that, using adaptations of existing Apps., within the next decade, vehicle sharing will likely replace vehicle ownership. It is a simple fact that privately-owned vehicles spend some 90% of their life parked. But the new generation of autonomous EVs will run 24/7 and never be idly parked except when recharging. Accordingly, within AAM certification timeframes, individual vehicle ownership will have become an anachronism for rich eccentrics and hence, the numbers of vehicles on the road may be expected to reduce dramatically (by something approaching that 90% of previously parked units) thus eliminating traffic jams and hence, the need for those airborne taxis.

Another threat to AAM is a new generation flying cars. Ground-vehicle-to-fixed-wing conversion types have been around for a couple of generations, but the need for an airstrip at each end has limited their use to that of an eccentric plaything rather than serious transportation. However, a new generation of e-VTOL type cars, now in the early stages of certification, will surely negatively impact the current larger AAM market. While their range and payload limitations /control issues are the same as for AAMs, the fact that flying cars are of the same size as road cars, and are to be offered at the same price as an expensive car, and its ability in principal to go door-to-door, will drive nails into the coffins & demise of AAM. The 2 person-on-board limitation will obviate their use as air-taxis but as a play-thing of the rich, it is in every respect most attractive.

Subaru motor company (1/2) & Alef Aeronautics (3) will lift Flying cars form affluent dream to certified Reality

For these reasons Advanced Air Mobility, while a certain future prospect, may not be revolutionary but, similar to Concorde, more likely will be just another plaything for the rich and famous.  So while these small AAM air vehicles, produced a few small niche manufacturers, will surely soon be swishing over cities quietly, smoothly and safely in the sunshine, the currently booming, multi-billion dollar, prospective AAM industry will most likely ‘crash and burn’!

Aladdin’s Chopper – Brand-New Helicopters vs. As-New

Aladdin’s Chopper – Brand-New Helicopters vs. As-New

Folk typically do not fantasize over buying second-hand used vehicles, least of all a chopper. However, sometimes needs must. Such will be the case in any situation where limiting cash-flow or cost-efficiency are driving parameters. In the mineral resource recovery sector, such is likely to be the case in exploration projects.

In highly profitable production situations, aircraft services, as part of a logistic support framework, are effectively a tax-deductible accessory. In exploration they are not – they are a ‘lost’ expense that could be better spent on the main aim of the project they are supporting. So, for the former, the newest and best, with all bells & whistles, can be considered: for the latter cost-efficiency should be a main driver.  

Also, in production situations, demand for air support is typically high due to the need to move large numbers of personnel and support equipment. In Exploration, personnel numbers are usually lower and the operations more self-contained. The former thus tends to high flight hours predicating the best equipment: for the latter, flight hours are generally low with air support mostly on immediate standby for emergency response, again predicating cost-efficiency as the main driver.  So, for the former ‘brand-new’ is a feasible option but the latter necessitates older, cheaper, aircraft. But ‘old’ need not mean ‘clapped-out’: as explained below, old helicopters can readily (i.e., over a few months) be refurbished to an ‘as-new’ condition.

Ball Park costings (per. Chopper) for the two options are along the lines indicated in the table below – in this regard, an ‘as-new’ aircraft is assumed to be more than 10 years old (as such, typically fully amortised and depreciated). The table shows that, while the operating costs of an older chopper may be some 35% higher than its new counterpart, the fixed financial charges – the more significant element – are some 60+% lower. As a result, overall, an ‘As-new’ aircraft has the capability to achieve the required project air support function with equal safety & equal reliability (as explained hereafter) but at some half the overall cost.


Cost Line Item


As-New (10+ y/o)

Aircraft Book Value



Typical Fixed Monthly Charter Cost  (FMC)*



Assumed Monthly Utilization (flt.hrs)



Cost per flight hour (including fuel)



Typical Monthly Flight-hour Charge  (FHC)



  Total Monthly Cost per Helicopter



Cost (pfh) for normal operations (100/50 hrs p.m. respectively)



* Amortization/Depreciation + Insurance + Air & Ground Crews + Operator overhead & profit

That said, bottom line (literally in the above table), while in monthly cashflow terms the Brand-new Chopper represents a very much higher financial outlay, in production situations, the total operational cost makes this fully justifiable as, with the utilization typically being twice that in an exploration environment, the total cost per flight hour (pfh) in each case is similar. If then, in addition, tax due on highly profitable production operations are taken into account, at least a third of the cost of the brand-new production chopper cost can be offset against tax that would otherwise be paid on said profits, thus making the net cost significantly less than that of the exploration team’s ‘As-new’ chopper. So, the highly profitable production world can treat themselves to the best which, in terms of net value, is still highly cost-effective.

But in the exploration environment, where profits are less certain, this argument does not hold, and cash-flow becomes the driving consideration. But does lower cost predicate lower quality & safety? We all know that in life, generally one gets what one pays for – as such, it is typically expected that expensive vehicles will not only be more luxurious but also more reliable and safer. The thesis of this article is to demonstrate that for helicopters, while high expenditure will buy (marginally) more comfort in brand-new types, with regard to reliability and safety there is no difference – indeed, as explained below, the older aircraft may even have an edge in this regard.

Helicopters (indeed, any unpressurised aircraft) over a period of a ‘couple’ of weeks, can be stripped down to a bare skeleton so that every frame can be readily inspected for corrosion or damage and replaced as necessary – effectively making its refurbishment more-or-less the same process by which a brand-new unit is built. Hull sections displaying weakness can be strengthened or replaced and any showing corrosion can not just be replaced but provided with additional corrosion protection to prevent reoccurrence. External panelling is taken down to bare metal (in older choppers with several layers of paintwork being removed, based on previous experience, weighing as much as 80kg!). Any badly corroded panelling is replaced with brand-new units from the OEM and the entire hull is covered with several layers anti-corrosion paint.

New lamps from old – how aging helicopters can be reborn ‘As-new’ with analogue cockpits digitized

New lamps from old – how aging helicopters can be reborn ‘As-new’ with analogue cockpits digitized

With the helicopter thus stripped down to bare frames, ageing wiring looms, anyway, made by specialist companies not by the aircraft OEM, can now be readily replaced. At the same time, the installation of the automated wonders of digital early warning of critical systems’ failure, can be easily installed. Similar to HUMS in brand-new helicopter types, these systems comprise a couple of dozen sensors feeding data into a similar AVMS (Automatic Vibration Monitoring System) computer. At the same time analogue cockpit instrumentation (as shown above) can be readily upgraded to a digital computerised ‘Glass Cockpit’ standard.

The helicopter ‘Roteables’ – principally the engines, gearbox and landing gear (the rotors are a (very expensive) lifed consumable) – are actually not integral to the aircraft, each being designed and built by separate OEMs and each with its own maintenance schedules and documentation. If nearing their TBOs (time before overhaul) they too can be sent back to their respective OEMs (not the aircraft manufacturer) to be zero-houred (ie. also, to be rebuilt to an ‘as-new’ condition) – in passing, it is worth noting that all these items, if properly maintained, can have very long lives measured in dozens of years.

So, after some six months of work and an expenditure typically of some $3m, any aging helicopter, however poor its initial condition, can be bought back to an ‘as-new’ condition, typically with similar technical guarantees as a brand new one. In addition, there are a couple of big (and positive) differences between as new and Brand-new types.

  • The first is the quality of engineering on each of these aircraft types. Brand-new aircraft are built on factory production lines, partially robotically, supported by ‘lightly’ qualified personnel essentially taken off the street and given a ‘couple’ of months training to do a single specific task. On each factory shift, typically, there are only a couple of licensed engineers (LAME) with quality control oversight over a score of aircraft.

An As-new unit, however, is hand-crafted with the same number of LAMEs on EACH aircraft overseeing technicians each normally with many years engineering experience. It is worth noting that a LAME is rather more qualified than a doctor in that it takes some 10 years to be awarded the generic licence (a doctor is 8 years). They then have to attend certificated courses on each aircraft type on which they wish to work (another 3+ months).

THEN they need to work on the type (if new to them) for a further 6 months, effectively as an unlicenced technician, in order to be awarded certification approval by the national Aviation Authority and subsequently by the AOC company for which they work. So, unlike OEM factory personnel, they know the aircraft inside-out, its strengths, weaknesses and piquilloes. In short, an As-new helicopter is a hand-crafted product, not ‘spat-out’ from a production line. I will let you draw your own subjective conclusion as to which is likely to be the ‘better’ quality product…….

  • The second difference is an ‘As-new’ aircraft is a known quantity – a specification supported by some million hours flight time globally with each unit itself will have flown many thousands of hours. So, an ‘As-new’ product has no secrets. A brand-new production build however, while benefiting from the same proven specification, will only have flown a very few hours flight test before being put to work. As a very complex piece of electro-mechanical engineering, typically there will typically be teething troubles galore as the systems bed themselves in.

Worse still, a newly developed, brand-new helicopter type will add to these teething issues, the surprises inherent in an unproven specification – unproven because during the new type certification process, each prototype only flies a few hundred hours. As such, no one knows what the future holds as early in-service units rack-up a few thousand hours (in case you missed it, you can get a lot of additional information on this in PFT-7 ‘Aircraft Certification – an uncertain compromise’).

So, not only is an ‘As-new’ helicopter type easier on cashflow, but typically, it will also be more reliable (if a bit less capable) than Brand-new and, in that there are no ‘known unknowns’, arguably a little bit safer than its glossy counterpart. OK, with respect to a corporate image and individual passenger appeal, a glossy, brand-new aircraft has its attractions. And there is merit in the argument that in a high-utilization environment, brand-new is better. But, similarly, for all the reasons stated, in a low utilization environment, ‘as new’ is certainly optimum. As such, taken overall, if you want to get a job done predictably, cost-effiently and in a trouble-free fashion, an ‘as-new’, proven work horse, is still likely the better bet.

SAF for the Savvy

SAF for the Savvy

Sustainable Aviation Fuels (SAF) is about as dull a subject as one can imagine writing about and for you, my one reader, to read. But the hype and quality of the ‘BS’ generated over it is more interesting. In elucidating on that subject, the scope of the discussion inevitably must expand into a wider environmental context and risk ecological excommunication. So here we go………

The Tropopause (the bit we breathe and fly in) is just 12 miles thick – the distance of a healthy walk. So, to keep this fearfully thin, life-giving gas veneer of the planet ‘clean’ is just simply good husbandry. So how bad is pollution today? The short answer is, that 99% of the atmosphere comprises good clean, largely inert Nitrogen (78%) and live-giving Oxygen (21%) – the other 1% is all other gases and pollutants most of which is harmless hydrogen: the greenhouse gas cocktail (CO2 / Methane / Nitrous Oxide) is less than 0.04% of that 1% comprises 25% Methane, a trace of poisonous nitrates (<0.5%) with a smidgeon of trace gases: most of that 0.04% of the 1% is the harmless human-generated exhaust gas CO2 – rather less than 400 parts per million (or 0.004% – statistically speaking not a significant number). So, in short, the air we breathe (taken overall) appears to be in good shape.

So, what are the environmentalists screaming about? Based on the above, it would appear that they live in a self-inflating bubble, apparently headed in social media by an articulate teenage Jeanne d’Ark battling the Barons of industry knowing little of the messey realities of this world. From within the security of an upper-middle class Nordic family, this environmental heroine rallies her virtual green army of well-meaning lap-top environmentalists – a vociferous media-friendly amateur among hard-bitten but no less shrill professionals – all creating a lot of noise signifying nothing that holds deductive reason. But like during the Covid pandemic, the multi-media cacophony makes it hard for politicians to think straight. That one is an environmental cynic is a function of the apparent self-serving nature of these practitioners. Their cultivation of the concept of ‘Global Warming’ – that element due to mankind’s impact – appears to be more of a carefully nurtured hypothesis, now not so different to a religion – developed by men of faith, stating fiction as fact, and making a good living from it.  

That said, climate change is an indisputable fact: there is absolutely no doubt that planet earth is warming.  It is a singular and undisputed FACT that there is a 100,000-year sun-cycle due to the elliptic path of the planet’s solar orbit. Today we are some 15,000 years into the warming phase after the last Ice Age – the so-called Inter-Glacial period – as the planet slowly gets closer to the sun. This makes it very likely that the principal cause of this planet’s warming is astronomical not chemical. The graphic below on the right shows the change in concentration of CO2 in atmospheric air bubbles over the last million years taken from ice cores in the Artic and Antarctic regions: this is clearly cyclical and sinusoid. The changing concentration is a function of Dalton’s Law of partial pressures. In this, the concentration of the cocktail of gasses that make up the 1% of the atmosphere that is not Nitrogen or Oxygen, increases with temperature – the graphic below is just the CO2 element.

The figures showing the CO2 concentration in the left margin of the graphic appear enormous until you read the small print and see they are parts per million: so that massive spike right at the end on the right-hand side, that is causing such angst in the environmentalist community, represents an increase of 200 parts per million or 0.002% – so don’t panic!!! And, with a 100,000-year spacing on the horizontal axis of this graphic being barely one centimeter, inevitably a 50–100-year timeframe will appear vertical and, possibly (ok, not surely), might be an aberration that would, in such circumstances, disappear when smoothed-out over the 100,000-year cycle.

The Environmental lobby talks in billions of tonnes of CO2 pollution in the atmosphere which sounds terrifyingly impressive, until one realizes that all those billions represent less than 0.004% – a statistical non-entity. And, as explained in the next paragraph, there is surprisingly little science to demonstrate that a trace substance in such a minute quantity (in percentage terms), can have any impact on anything.

That greenhouse gases warm the atmosphere by absorbing Infrared energy is not in dispute – recent experimentation at the Max Plank Institute has clearly shown that, as does the above graphic of the CO2 density cycle. What is more doubtful is the impact of CO2 as an atmospheric trace gas at 0.004%. Making an AI-BOT research on the experimental evidence for this, produced information on observations made with respect to the Pliocene era (3-5 million years ago) when CO2 was at similar or greater concentrations. A further input into the AI-BOT that his was an observation, not experimental, the AI-BOT ‘agreed’ and could only find a single experiment, recently conducted at Harvard in 2015 which showed that even at that low concentration, ‘significant’ quantities of IR radiation are indeed absorbed causing the gaseous mix to warm. The experiment does not appear to have specified or quantified the degree, merely confirming the common experience that in sunny climes, IR radiation warms anything in its path. As to the former observation, with the Pliocene predating mankind altogether, this simply demonstrates the wholly natural character of the increase in CO2 density in the atmosphere that is being experienced right now.

But I disagree: all this is only the background to the argument here, namely the environmental impact of the polluting gases from the efflux of aircraft jet engines. How bad is it?

The graph to the right shows the environmental impact of the whole hydrocarbon sector, now producing some 10 billion tonnes of CO2 pa. Of that, only one third appears to be from ‘engines’ (the blue petroleum line), and of those engines, the few hundred jets touring the globe each day are, but a relatively small element compared to the tens of millions of cars clogging up metropolitan streets around the globe. And if the other two-thirds of hydrocarbon gas and coal elements are also considered – in the main used in the production of ‘clean’ electrical power – the aircraft emissions become even less significant.

Yet, 10 billion is a very large number and in tonnes of anything such is huge but let us put that in perspective. Each of us, through respiration, on average produces about 1kg of CO2 per day. There are now 8 billion of us. So that equates to some 3 billion tonnes of gas each year – almost the same as all the powered motion machinery on the planet, of which the high-profile aviation element is, in truth, only a relatively small part. But, in bowing to multi-media pressure, would the use of SAF in place of Kerosene have any impact on the issue of limiting greenhouse gases or the pragmatics of atmospheric husbandry.?  The short answer is ‘No’.

It is claimed by the environmental clerics (…. sorry, lobbyists) that SAF offers – and here I am quoting BP – an 80% reduction in ‘lifecycle’ carbon emissions as compared to jet fuel (which I reiterate is but a small element of a minute portion of the greenhouse gas problem).  The important word here is “lifecycle”.  Being drawn from the green of pleasant lands and human waste, SAF is still a hydrocarbon so, like kerosene, its exhaust will still flood the atmosphere with CO2, water, and noxious nitrates – that is by the very nature of the natural components from which it originates. It’s just a question of vintage. Those in kerosene are of a several million-year-old vintage – that in SAF is ‘benzene nouveau’. They are essentially the same, the younger vintage perhaps being cleaner and ‘fresher’ (like Beaujolais Nouveau wine, a question of taste if you will) in that, as stated, it is produced from current environmentally friendly vegetation and human waste (admittedly the latter element being particularly good news).

The energy-heavy processes that get SAF from ‘waste to wingtip’ (a great marketing lyric that!) and the associated energy outlay, are similar to those pertaining from ‘crude to kerosene’ (my factual lyric!). So, the science supporting said 80% reduction is likely more related to the math of carbon credit calculations (with electrical production from sustainable sources) than the nature of the polluting chemicals released in the jet efflux from the useful generation of energy from SAF. In short it appears to be little more than a clever, if harmless, ploy to keep the crusading hordes of the environmentalist army at bay until hydrocarbon power sources in aircraft can be replaced with hydrogen and (maybe) electricity. This is reflected in the aviation industry itself in that no serious R&D has been allocated to optimize the production of SAF or its conversion to energy in engines. This is in part evidenced by a recent report in the Air transport Digest (an Aviation Week magazine) that the US government Audit Office (GAO) has discretely recovered some $200m set aside by the Pentagon to assist in the general development of SAF production facilities.

Instead, the industry R&D focus is on the more worthy zero-emission hydrogen and electrical propulsion systems in the next generation aircraft.  And this will happen, likely in a 15-year timeframe. ‘Green’ Hydrogen, electrolyzed from water or other sources, is designated thus because the electricity to extract it, is sourced naturally from Hydro, solar/wind, or geothermal power.  In that, unlike SAF, the fuel efflux comprises only clean water, this will, in an environmental context, truly be a fundamental game-changer and therefore worthy of such focus.  One challenge with hydrogen is its high volatility – storage is mildly challenging but the crash case in the aircraft that it is powering, is more thought-provoking. Counter-intuitively, initial studies show that hydrogen fuel is less dangerous than kerosene. For while very much more volatile, being the lightest of elements (Atomic Weight – 2) it is also very much less dense. Being stored at high pressure, in the event of tank rupture, the massive jet of the gas that will shoot out will always be in the vertical. It has been shown that this vertical sheet of flame, while very hot, immediately dissipates. As such, its impact is very much less than that of a pool of burning viscous liquid fuel typically emanating from the ruptured wing tanks of a conventional aircraft accident – be it kerosene or SAF. For all these reasons, the environmental impact of using SAF in place of kerosene is negligeable while that of ‘green’ Hydrogen will be considerable.

Returning to a more general environmental context, the negative raving in this piece is not to say that climate change should be ignored. Of course not! It is rapidly topping and tailing the planetary ice caps which, whatever else, will raise global sea levels by a meter or more, which is an existential threat to, maybe, a billion people. What has changed in this, our current sun cycle, is that, the last time around, mankind was numbered in millions and, like every other species with which they shared the planet, they were nomadic, hence upwardly mobile.  So, as water levels slowly rose over a few generations in some areas and desertification occurred due to drought in others, all could easily migrate to greener pastures. Today the issue is that, as a function of numbers and our technological advances, the fixtures of our metropolitan civilization and the associated agrarian infrastructure has made us all – man and beast alike – more or less immobile. Hence, faced with the fact of climate change, the emphasis should logically be on protection from its effects rather than futile ‘Canuteian’ attempts at its prevention.

But, given the current latter focus, what can be done to prevent the snail-paced inevitability of this environmental tsunami? Sustainable energy from renewable sources, while largely an irrelevance in this specific context, in the perspective of good husbandry with respect to the thin veneer of the planet’s atmosphere, it is surely worth pursuing. Of more significance is Nuclear Fusion which is now expected to start powering the grid by 2050 thus providing a perfect, sustainable, and unlimited power resource. Taken together, the imminence of these two, deeply green sources of energy, reduces global warming from an existential matter to one of a serious short-term safety issue. Given the imminence of a truly effective fusion solution, like all safety matters, controls and mitigation should meet ALARP (as low as reasonably practical) criteria.  The commercialization of renewables surely meets that criterion: but tinkering with aviation fuels, while a harmless distraction, is essentially a wasted effort and anyway, a total irrelevance.

In passing it is worth highlighting the imminence of fusion power. For more than a generation such has been 10 years away – this may now finally be the case. An outfit in California (Tri Alpha Energy – TAE) expects to have a prototype system capable of producing net electrical power in 2025, with a production prototype in 2035 and OEM supply connected to the grid five years later producing unlimited, (eventually) inexpensive, emission-free (truly green) power source to drive the planet. Such will solve the whole greenhouse gas issue, clean up the planet’s atmospheric veneer and finally put my environmental lobbyist nemeses out of work.

Tinkering with greenhouse gases (should such, at a density of 0.004%, actually be a problem at all!) won’t change that. A measure of the futility of such ventures has been demonstrated by the Shell petroleum company (hence possibly not without some bias) which has shown that carbon capture through current methods of sequestration of the CO2 produced by the hydrocarbon sector alone each year would require some 66 exajoules (that’s 18 zeros!) of energy – or enough to heat/cool all the world’s homes). While such a comparison lacks indisputable clarity, it clearly shows the futility of such politically correct ventures and, unless this associated electrical power is sourced solely from green energy, it will anyway only be exacerbating the problem!

Aircraft Certification – an Uncertain Compromise

Aircraft Certification – an Uncertain Compromise

Stifle your initial yawn – our lives depend on a technical oxymoron of innovation & certitude.

You have surely wondered at the checks & balances, the machinations & controls that go into realising the approvals on the aircraft in which you fly. Fear not – they are extensive, but fear(!) – inevitably there is an element of compromise.

First and foremost, aircraft certification is not given in the belief that it will prevent accidents. Anything that defies gravity and leaves terra-firma, is certain, now-and-again, to come down unexpectedly and with a big bump. The aim of regulatory authorities is to seek to minimize design and human error as a cause, and to put controls in place by exacting technical and operational systemization. But as is now common in any risk analysis, acceptable risk is not zero risk.  In aviation it is 0.002%. In other words, when you fly you have a 99.998% of reaching your desired destination (albeit, not always in a timely manner !!). As a measure of overall safety, this far exceeds that of ground transportation that you use most days. But, notwithstanding this elevated targeting, the process is not without surprising discrepancies.

The world of aviation is based on a baseline set of regulations (in massive tomes) drawn up by the International Civil Aviation Authority (ICAO), now effectively the aviation arm of UNO (the United Nations). Dull as puddle water, its origins were a riveting bit of history, dating back to 1944 during the still uncertain and intense hostilities in the latter years of WW-II.  

Recognizing that aircraft now transporting bombloads of destruction, would one day carry passengers and freight in similar quantities, all parties to the war gathered in Montreal, Canada to agree a set of baseline regulations for the conduct of commercial aviation once the war was over – whoever won it. The logistics of getting everyone to that meeting and the underlying diplomacy which produced the final declaration (below), is as extraordinary as the regulatory document is dull – and it is very dull! Also, to this day, ICAO remains based in Montreal.

On that foundation three main aviation genus have evolved, inevitably based aviation hubs of design, innovation, and manufacture – the American FAA, the European EASA, and the Russian ‘WhatevA’!  Roughly 90% of aviation is controlled by the first two and that in most of the former Russian empire (the USSR) by the latter. As is true for most things Russian, the devil is in the (lack of) detail. That doesn’t make Russian designs bad – indeed they build robust aircraft, particularly helicopters. But historically lower levels of control and verification have led to higher levels of risk**, albeit matched by significantly lower cost of purchase (an 18 Pax. helicopter in ‘the West’ costs more than 5 times that of an equivalent manufactured in Russia).  Fortunately, now (or at least until the invasion of Ukraine), with most commercial aircraft operated by Russian airlines being of western manufacture, there is a better alignment in accident statistics.

(**By way of example, there are similar numbers of aircraft on the Russian and UK registers but, over the last 50 years, with more than five times the accident rate in Russia)

Not surprisingly there is a high level of commonality between the two western systems which themselves form the basis of most other global national regulatory practices (even in China) – with nations’ choice of US or EU alignment typically being based on countries’ historical alignments.

So, the regulatory big picture is multi-tiered. ICAO approves a country to operate the aircraft on its register internationally but has no control, only influence, in what goes on within each country’s internal airspace. There, the National Civil Aviation Authority, going under many different names, but to which here we will refer as ‘the NCAA’, certifies each air operator by periodic award of an AOC (Air Operator’s Certificate) and each registered aircraft by issue of an annual CofA (Certificate of Airworthiness). You’ve guessed it – the potential for corruption is rife!!  And there is another issue, the dual hatted nature of NCAAs – to both promote and to regulate their national aviation industries. These two roles are, in the main, incompatible and is an issue that remans largely unresolved as exemplified, in part, by the Boeing Max-saga discussed in an earlier article on this site. As such, while the regulations are based on the ICAO baseline with FAA or EASA alignment, the quality of the detail and consistency of its implementation by NCAAs varies enormously.

The principal control in this regard is ICAO through a single sanction – the right to deny corrupt nations’ aircraft the right to use international airspace. Of course, they don’t shoot down a sanctioned nation’s aircraft if they stray outside their national airspace, but ICAO can decertify any international airport which allows them to land – a fully effective commercial sanction. Unfortunately, such NCAA declassification by ICAO is only used in extremis, with less than a dozen (mostly small and backward) countries thus black-listed.

The certification process, like everything in life, is subject to financial limitation. In all aspects of regulation, there is just not enough money available to do things ‘properly’ across the board. So, under ICAO rules, the regulatory focus is on the carriage of passengers. Hence, as a general principal, the less the passengers on an aircraft type or mission profile, the less the regulation. This is reflected in the ICAO specified levels of certification, with increasing degrees of monitoring at each level along these lines: –

  • Experimental – this is what all aircraft fly under during the certification process under FAA/EASA. Aircraft are limited as to when and where they can fly, what flight profiles are followed and with whom on board. Each series of test flights is endorsed by the National Authority with approvals of subsequent steps being subject to the reporting of the previous series. Some wild things can go on within this category and it is here that most aviation technical development occurs.
  • Aerial Work – this is the lowest level of certification under which aircraft can fly ‘for hire & reward’ basically only for freighting or specialist missions. Pax. on board are limited to crew members. This includes such things such as cargo carriage, heavy-lifting, forest firefighting, logging, aerial advertising, aerobatics, paramilitary agency marine surveillance and pilot training. Transport Category aircraft (see below) can recertify themselves at this lower level to do specific jobs. So, if you want to do something ‘extra-ordinary’ with an aircraft, this is the way to go.
  • Transport Category – this is for the carriage of fare-paying passengers (Pax.) and under ICAO regulations is evidently the most highly controlled. However, within a national context, this again is to various levels.
    • Part-91: is for private aircraft servicing a restricted & specified range of Pax. such as corporate business jets, flying clubs and the like. Controls & limitations are kept to a minimum, it being very similar to Aerial Work. Even more lofty service providers such as Airforce-One in the USA and the Queen’s (now King’s) Flight in the UK, nominally are also likely to be operated under this category.
    • Part-135: is for General Aviation (GA) including all charter operations. So if a business jet is offered for charter, it must upgrade to this level. On the technical side, the level of service provider surveillance and controls is essentially the same as Part-121 (below) but with less stringency on operating criteria and passenger controls.
    • Part-121: is for Commercial Aviation. As such, any Airline accepting ad-hoc, fare-paying Pax., must operate to these most stringent criteria where everything is done to the highest standard, in accordance with a proscribed and documented methodology from which no deviation is permitted.

Not surprisingly, the US-FAA and the European EASA use the same certification benchmarks, but separately developed.  But with their respective aircraft designs now only differing in the detail, the two set of regulations have steadily become more aligned to the point of being almost identical. Only the Russians hold out to their own (lack of) rules and for that reason, while designing robust and relatively inexpensive aircraft, they can only use them for carriage of Pax. within their (albeit massive) national borders. As yet, and not for want of trying, none of the established Russian-built airliners have achieved EASA/FAA certification standards. However, a new generation of Russian (and Chinese) aircraft designs are stumbling uncertainly towards that goal.

The big difference between EASA and the FAA is in the method of certification of new aircraft types.  The US-FAA is a tortuously labyrinthine bureaucracy, while the Europeans, while still ever the bureaucrat, the style is more corporate than governmental. So, while in the US certification is at fixed rates based on the nature of the task, in Europe it is man-hour related. So, while this makes European certification more expensive (which, since the OEMs there have access to low-cost government loans, to the fury of their US competitors, the European counterparts can afford), it is also quicker and more adaptive, as the Authority is as much a Service Provider as a Government Agent.

The Brits (as is their eccentric way) have taken this to an extreme. In the 1930s, as aviation became a mainstream service and the government sought to legislate, the industry kicked back and formed a self-regulating body – as such the UK-CAA fulfils the same regulatory role but, as a Non-governmental Organisation (NGO), it is largely funded by the industry it regulates. As such, in the UK, certification is a contractual task with obligations on both sides and the ability to sue if the Regulator fails to provide the agreed certification within the contracted timeframe.

As a result, while with EASA and the FAA, the onus is on the OEM to demonstrate that a product is safe, in the UK it is the other way round, with the onus is on the CAA to substantiate that a product is unsafe to require its modification. The path to certification in the UK is thus surer, but a lot more expensive. The one bonus of FAA certification is that the experimental category which, being a domain dominated by DARPA (the Defence Advanced Project Agency), extremes are acceptable. The European experimental counterparts are typically more conservative. It is for this reason that the USA now leads in most aspects of aeronautical development.

Underlying the above systemisation and controls are financial realities – money still talks! In truth, no electro-mechanical device testing and certification is fool proof. But at least in cars it reflects the vehicles’ guarantee period. With aircraft, as a function of operating costs and development timeframes, the level of testing during the certification process gets nowhere near to this. Typically, the process from first flight to type certification takes some 3-5 years and with barely a couple of a thousand hours of test flying – and with the latter flight hours typically spread over several test aircraft (hence, with only a few hundred hours on each unit).

This is driven purely by commercial pressures and ALARP principals.  So, notwithstanding certified airworthiness by the FAA/EASA, the parties in the sale any new aircraft type, will have little idea of what will happen in the latter part of the 5 year or 5000 flight-hours typically covered in an aircraft guarantee period, and not an inkling of what might occur thereafter (a typical aircraft life being some 30 years and/or more than 40,000 flight hours – choppas rather less). So, even the best and most exacting of aircraft designs can have awful incidents.  

An example of this occurred in one of the most powerful, hence safest, of helicopters. Having passed the normal certification process with flying colours and taken the market by storm, as a function of its very high-power output, after 3000+ hours of flying a few individual aircraft experienced serious tail-rotor problems with a few of them dropping-off in flight!!  With the half-dozen test vehicles each having only flown less than 1000 hours under test, there was no way such failure could have been reasonably predicted.

A detailed design review immediately imposed by the OEM Regulatory Authority quickly produced an effective solution, and there have been no problems since.  But sometimes, driven by commercial pressures, technical solutions can be fudged. There is an example of a much-used Part-121 Airliner flying to this day with such an egregious compromise. Like any cell phone its lithium battery at the core of the electrical system risks severe overheating and associated fire-risk. The Authorities of course suggested a different battery be used.  However, there was none on the market with the required capability and output. Such predicated a restructuring of the aircraft electronic design which at such a late stage in the certification process was commercially unthinkable. The fudge therefore was to accept the risk but to mitigate it by locating the battery in a specially designed fireproof compartment. So, to this day, hundreds of these airliners are flying with a potential fire-bomb encased in its technical core.  While such has been shown to meet acceptable ALARP and Risk Management criteria, subjectively it is somewhat unnerving and clearly shows the financial constraints on the certification process.  

Unfortunately, almost every new aircraft type experience something similar. Regulatory Authorities therefore oblige and formalize the end-user community reporting of all failures and, where deemed a risk to flight safety, aircraft by type or batch can be immediately grounded by issue of an ASB – Alert Service Bulletin (ASB) – by the manufacturer. This is then rapidly endorsed by the OEM Regulatory Authority by issue of an ASR (Aircraft Servicing Requirement) or an AD (Aircraft Directive). These remain in force until the failure is corrected or mitigated. Typically, this will be measured in days or weeks, but in the case of the B737-Max, it took almost two years.

And talking of the Max., one of the aspects of this sorry tale that the scandalising multi-media made a feast of, was that the OEM Quality department did many of the FAA certification tasks in-house. This was seen as corporate duplicity. It is, in fact, a norm throughout the aviation industry.  The FAA annual budget, along with every other NCAA in the world, is insufficient for the task.  So, there are never enough inspectors not least because, anyone qualified for that role, can earn a lot more money in the commercial sector that is being inspected – so there is no waiting list of applicants. As a result, QA (Quality Assurance) managers world-wide are twin-hatted, reporting both to the CEO of the Airline and the Technical Directorate of the NCAA. 

This works because it takes a lot of graft to get an engineering license – at some 10 years, it is significantly longer than, say, a doctor: and a QA license is only awarded to folk having many years experience in engineering management.  As such, it is effectively the top of the technical tree, and no-one there will allow an ‘amateur’ CEO/CFO to put his valuable and hard-earned license at risk by demanding he cover-up any incident that may occur within an air operator! The Boeing Max saga was a very rare exception to this rule.

In summary, the only way to guarantee safety in aviation, is not to fly. So, while the process of aircraft certification is far from flawless, the systematic and frequent checks and balances of every process, and every electro-mechanical part of an aircraft, ensures that the level of risk is significantly less than that relating to an outing in your car. But systems are only as good as the humans that implement them so, as on the road, one should keep a beady eye out for folk who do not look after their vehicles properly!