According to the US Federal Aviation Authority (FAA), ‘each certification project is unique, but the core requirements apply to all projects’. Global aviation authorities set the gold standard for aircraft certification, and reciprocally validate each other’s certifications under bilateral aviation safety agreements to ensure high standards and clarity. However, this requires international collaboration and standardization, which has not always proven easy.

Divining bodies

In 2016, Russia’s Federal Air Transport Authority (FATS) replaced its Interstate Aviation Committee with a new body, the Aviation Register of the Russian Federation. The USSR got off to a fast start at the dawn of the jet age, getting its Tupolev Tu-104 airliner off the ground around the same time as De Havilland’s Comet, and just ahead of the Boeing 707. For decades, Tupolev and Ilyushin jets were the workhorses of Aeroflot and the state airlines of the USSR’s satellites and allies. After the collapse of the USSR, once-ubiquitous Tupolevs and Ilyushins were scrapped in favour of Boeing and Airbus models that were already certified by the FAA and European Union Aviation Safety Agency (EASA).

Today, Russian civil aviation manufacturing is hoping for a renaissance. Last year, the latest model of the mid-sized Irkut MC21 became the first all-Russian civil aircraft to fly since the end of the Soviet era. In 2021, the IL96-400m, a souped-up version of the long-haul IL96-300 widebody, is expected to make its first test flight. Meanwhile, Soviet-era rotorcraft like the Mi-8 and its descendants have soldiered on in the SAR role in the former USSR and in Asia, Africa, and South America, alongside newer Russian-built helicopters like the Mi-38, type-certificated in 2016. Russia naturally wants foreign markets for its latest aircraft, and an overhaul of its certification body seems to have been partly intended to build trust in its products.

This kind of disruption is not strictly consigned to history. EASA has been responsible for primary certification of newly developed models in EU member states – including the UK – since 2003. Spurred by Brexit, the UK Civil Aviation Authority (CAA) has stated that the UK would continue to recognise EASA certificates for up to two years after the UK’s departure from the EU, while the EU would recognise UK-issued type certification ‘for a limited period’. Certificates provided by CAA-approved organizations should continue to be accepted globally as the regulations, systems, oversight, and approvals will continue to comply with International Civil Aviation Organisation standards and recommended practices, the CAA stated.

The worldwide aerospace industry is on the cusp of a new era of innovation that is comparable with the transformative 1950s, when the first civilian jet aircraft and helicopters came into service. New technologies and the global drive to cut carbon emissions are birthing revolutionary new flying machines in dramatic directions.
 

Certifying the revolution

Looking like nothing that has flown before, Australian company AMSL Aero plans for its first Vertiia tilt-rotor electric VTOL air ambulances to be flying for Sydney-based EMS operator CareFlight by 2023. Similarly, Israeli manufacturer Urban Aeronautics recently announced that US-based EMS operator Hatzolah Air will be the first customer for its CityHawk, a lightweight, compact jet-propelled VTOL aircraft going into production ‘within three to five years’, although it is yet to receive FAA certification for EMS use.

Attention grabbing vehicles like these that will keep the FAA’s Rotorcraft Directorate and international equivalents busy in coming years. However, for most designers and manufacturers aiming to meet the demands of airborne special missions buyers, though, evolution continues to be more important than revolution.

For example, Textron Aviation’s Cessna Citation Longitude, which received FAA certification in 2019, is a direct descendant of the Citation Latitude, which is already in service with EMS operators such as Babcock Scandinavian AirAmbulance, is similarly in direct line of descent from earlier Cessna models, albeit with several refinements. For such aircraft, type certification can normally be expected to be a quite seamless process. 

The FAA claims its flexible certification process enables the agency to address new and advanced materials and technologies when companies present them for certification, without the need for prolonged formal rulemaking. The route to certifying a new aircraft type isn’t always smooth, though. The Kopter Group’s experience with the development of its SH09 helicopter is a textbook example of how certification issues can become obstacles to bringing a ground-breaking product to market.

Kopter, now part of Leonardo, claims the SH09 will be the most versatile rotorcraft platform on the market, combining long range and five-hour endurance, with low running costs. Kopter aims to achieve that by taking use of new composite materials a step further, using the kind of monocoque composite airframe that has only been used in small two-seater rotorcraft. The SH09 was expected to enter service in 2021, and Kopter has previously attributed delays in rolling out the SH09 to the complexity of the certification process, saying this has highlighted the need to establish new certification guidelines for new hybrid materials. However, following Kopter’s acquisition by Leonardo and relocation of primary production to Leonardo’s Vergiate factory, the helicopter will not be market-ready until the latter of 2022 at the earliest.

Cecile Vion-Lanctuit, Kopter Group Marketing, said: “We’re not experiencing certification delays as such. We are boosting some activities and fine-tuning others to make sure the SH09 is a mature Leonardo Helicopters product when it gets into the market. We target an entry into service of the SH09 by end of 2022 or early 2023.” 

This is partly due to design tweaks aimed at future-proofing the SH09, including a new main rotor head design, a new main gear box with an extended mast, and installation of the state-of-the-art Garmin G3000H integrated flight deck that will be flown for the first time on a helicopter.

Leonardo has also faced delays in certification of its AW609 tilt-rotor craft. Leonardo expected FAA certification of the long-awaited civilian version of the US military’s V-22 Osprey in late 2019, but now says it expects operational activities to start ‘in around two years’, although the first two production aircraft are currently under assembly.

The Airbus angle

The Airbus H145 is the most recent iteration of a rotorcraft that was conceived almost 30 years ago, as the EC145, born from the merger that created Eurocopter. Since then, along with its sibling the H135, this model has become the most popular HEMS type in service, accounting for up the half of the world’s total HEMS fleet. Replacing the EC145’s conventional tail rotor with a shrouded rotor and the four-bladed main rotor with a five-bladed bearingless main rotor system, Airbus Innovations aimed at easing pilot workload and improving operational safety on HEMS missions range from synthetic vision systems to satellite communications and self-learning AI algorithms.

Airbus Helicopters spokesperson Jörg Michel, said: “Helicopters are serving more and more missions under difficult circumstances today compared with the past. This means more complex systems are onboard that need to be certified.” Despite this, the risk of a lengthier and more complex certification process and more demanding test pilot’s task should not be met. Michel continued: “When introducing new technologies into the design, we need to make sure that the certification regulations remain adapted.

“When we identify a gap in the regulation, we have to anticipate rulemaking activities with authorities as much as possible, to ensure that the certification requirements are frozen early enough to design provisions showing compliance at the earlier stage of the development activities.”

Failure to anticipate such challenges, Michel says, can lead to need for redesigns, additional testing activities, and a lengthier certification process.

“The continuous evolution is a clear benefit for the new H145 helicopter since we reuse proven design and improve the aircraft in the areas where we see additional benefit. The certification of an aircraft which is based on a former one is considered less demanding. There is no need to re-certify the full aircraft but only the modified systems and the associated affected areas. This reduces the scope compared to a full new aircraft. Compliance documents can be partly reused with adaptations.”

Advances in information technology have helped manufacturers keep pace with more demanding certification processes, Michel says: “IT provides our teams with additional data for evaluation and analysis. The focus on safety has grown and the requirements and substantiations of those requirements have become more stringent over the last 30 years.”

The test pilot is key

Where do test pilots fit into the certification process? In the early jet age, ace fliers like Chuck Yeager – the first man to fly faster than sound – were the glamour boys of aviation development. Today, the test pilot’s task is less risky, but no less central to the certification process.  

“Flight testing is often about verifying the modelling and analysis of the engineering work done in the design phase,” says Vion-Lanctuit. “The results are anticipated but still require flight testing to prove the data.”

However, she says, the introduction of ever more complex systems in modern cockpits has led to a change of emphasis within the testing process. “The handling qualities of the helicopter are and always will be a major area of the test pilot’s work but more and more it is the systems which require more attention. The success of these depends on good understanding of the role of the aircraft by the equipment manufacturer (OEM) and the test pilot is key to this understanding at all phases during development.”

Michel is similarly devoted to the role of the test pilot: “The test pilot is an essential part of the whole development cycle before certification.” Despite advances in computer modelling and automated data gathering, there is still no substitute for the human touch, says Alexander Heuhaus, Airbus Helicopters Test Pilot. “A test pilot needs to assess the aircraft, procedures, equipment regarding the associated workload, intuitivity, misleading indications, comfort level and so on.  These assessments are rather subjective and require lots of experience, so human test pilots will still be needed in future. Experience is required regarding operation, but also regarding a broad variety of different aircraft in order to be able to properly assess new aircraft, systems, procedures or equipment.”

“As a test pilot, you do not forget the operational roots of what a pilot is looking for. Test flying certainly requires a level of experience and skill,” says Mark Burnand, Chief Test Pilot at Leonardo Helicopters. “You need to be able to understand the helicopter’s role and the environments that it will be operated in, and have the capacity under some challenging conditions to assess how well the aircraft is performing, and also look at your own workload. You then decide whether the aircraft characteristics will allow a less experienced pilot to safely achieve the task.”

“Leonardo Helicopter test pilots come from a wide variety of applications. Many of us have engineering qualifications and certainly, the inquisitive nature of engineers brings additional interest value. Then comes the obvious pleasure of flying great aircraft around the world and the challenges and reward that that brings,” Burnard says.

Like Heuhaus, Burnard believes artificial intelligence is not yet capable of ousting human pilots. “Human beings have phenomenal sensors and processing powers that are hard to reproduce and come for free. When it comes to test flying, we already use a lot of technology to assist. For example, if the software has a glitch, or the aircraft decides to throw us a curve ball – we still have the option for the test pilot to deselect the systems and use experience and skill to recover the aircraft. We can then safely bring it back to base, and debrief and work with the engineers to embody modifications that ultimately ensure a safe and capable aircraft. So yes, seat of the pants flying is still required.”

Aircraft, not least fixed wing and rotorcraft designed for EMS missions, are becoming ever more complex creations. Certifying new types is also increasingly complex and sophisticated – but the human test pilot is still at the heart of that process.