At the beginning of March, after two decades of wrangling, Europe finally approved commercial single-engine turbine operations at night and in instrument meteorological conditions (SET-IMC). The world now waits to see whether this will radically change business and commercial general aviation on the continent.

It may seem obvious that lower costs of acquisition, operation and maintenance associated with single-engine aircraft are bound to make business aviation and private charter more affordable, creating a new entry level – and as a result this will expand the activity in that sector.

On the other hand, single engine aircraft capable of meeting the full demands of EASA’s exacting SET-IMC rules are high-performance, usually pressurised machines with a flight management system and fully capable avionics suite. So the price advantage – if it exists – might be quite small. For example, a fully SET-IMC-equipped single-turboprop Pilatus PC-12 is a lot more expensive to buy than a Cessna Mustang twinjet, according to analyst WINGX – but the PC-12 beats the Mustang by a big margin on cabin capacity and range.

Cessna is one of the manufacturers that is optimistic about the opportunities. Says Tom Perry, vice president sales, Europe: “The CAT [commercial air transport] SET-IMC regulation change in Europe is fantastic news for the industry, and it’s great to see regulators putting through laws that are opening up opportunities. The early market reaction we’ve seen has been extremely positive. The Cessna Caravan and forthcoming Cessna Denali both have low operating costs and are ideally suited to operating in Europe.”

The General Aviation Manufacturers Association, while welcoming EASA’s rule changes, is slightly more cautious about how widely the beneficial effects will be felt, saying: “The new regulation is based on rigorous safety analysis, and contains all of the necessary safeguards to facilitate this form of passenger transport. It will greatly facilitate overnight cargo delivery and help provide connectivity to Europe’s most remote regions.”

But Ignaz Gretener, vice president general aviation at Pilatus, is much more confident. “CAT SET-IMC will make it possible to develop new routes in Europe," he says. "The decision by EASA provides an incentive for aircraft operators in Europe to replace older aircraft with new, safer, more environmentally-friendly single-engine turbine aircraft such as the PC-12. With its short take-off and landing capacities, the PC-12 will also fly closer to the desired destination. We are confident that we will soon see a large number of additional PC-12s providing good service in Europe.”

PC-12 over Florence


In fact it is difficult, right now, to find any Europeans eyeing commercial SET-IMC opportunities who are looking seriously at anything other than the PC-12. Its combination of large cabin size, range, an onboard toilet compartment, plus six million airborne hours of proven reliability statistics, is persuasive. Add to that cabin pressurisation that enables flight high above the weather, and thus also impressive gliding range that makes meeting the SET-IMC operations targets relatively easy, and there appear to be no serious competitors to it right now.

In due course Cessna’s promised Denali will undoubtedly compete, having remarkably similar size and performance, and it apes the PC-12 in sporting a large rear freight door. But it will take years to prove the in-service engine/airframe reliability to the standards required for European commercial SET-IMC clearance.

Meanwhile Daher’s pressurised TBM series has fantastic performance, adding nearly 50kt to the PC-12’s cruise speed and comparable range, but its smaller cabin is more suited to the private owner or the high-end air taxi market. A TBM 850, however, has been carrying out successful CAT-SET-IMC operations under an exemption for Voldirect in western France since 2013, and in the French Antilles St-Barth Executive plans to operate a TBM 900. The latter operator’s scheduled partner, St-Barth Commuter, won commercial SET-IMC approval back in 2012 for operation with a Cessna Grand Caravan. Nicolas Chabbert, senior vice-president of Daher’s business aircraft division, comments that the forward-looking attitude of French aviation authority DGAC has been a major influence on EASA’s progress toward commercial SET-IMC clearance. He adds: “We expect to see the TBM increasingly deployed on charters for on-demand transport, especially from community airports.”


To understand why EASA took so long to approve commercial SET-IMC operations, it is worth briefly reprising the European regulator’s objections to it – because in most other world regions the International Civil Aviation Organisation permitted it long ago. In fact certain commercial SET operations had always been permitted in Europe, but only in daylight visual meteorological conditions (VMC). In addition, a few European carriers operating in areas of relatively flat terrain and low population density were awarded SET-IMC exemptions for defined operations.

It all boils down to the simple fact that if a single-engine aircraft suffers engine failure the pilot’s only option is to glide to a forced landing. If this happens at night or when there is bad visibility, the argument says, a forced landing is likely to be fatal for the occupants and for anybody in the aircraft’s path.

But when, in the 1980s and 1990s, turbine engines increased markedly in reliability, other world regions decided the risk of power loss had reduced to an acceptably low level. Europe still refused, however, because the continent has nearly four times the population density of the USA, and an even greater multiple compared with Canada or Australia, so the risk of a blind forced landing to the population on the ground – as well as the aircraft occupants – was still judged unacceptable. This risk was seen as particularly significant in areas like England’s southeast with its many urban centres, and where even the countryside is well-populated.

The technical advances that have permitted EASA to approve SET-IMC in Europe’s airspace benefit operators everywhere, and make contenders like Daher’s TBM series and the PC-12NG credible competitors to turbine twins such as Textron Aviation’s Beechcraft King Air series, and even the lower-end jet twins.

Apart from increased engine reliability – boosted by engine/gearbox health monitoring systems – the CAT-SET-IMC-enabling technical improvements are many and varied. Advanced avionics and flight management systems play a major part. For example the Honeywell avionics suite in a SET-IMC-approved PC-12 can allow the pilot, in the event of engine failure, to select a diversion airport and runway-in-use within glide range, and the autopilot will fly the aircraft to arrive over the threshold at 50ft on its radar altimeter.

Rather patronisingly, the existing business aviation community suggests that the new industry sector created in Europe by EASA’s commercial SET-IMC clearance will become “the nursery end” of the business. PC-12 and TBM operators, on the other hand, argue that they are delivering a new and different product, not just a more affordable one. They can land and take-off at short and unprepared strips that the jets – and even some of the turboprop twins – can’t approach. That capability opens up an entirely new sector for high-end sport and leisure travellers, and promises to get business travellers closer to their ultimate destination, often incurring far lower airport charges. Lausanne, Switzerland-based Fly7 claims it can operate into “60% more” airfields in Europe with its PC-12s than the jets can.

So it seems business aviation is now able to cast its net wider in Europe. Simultaneously, other changes appear to be taking place. The gaps in the market between business aviation, the Part 135 charter sector, and even the regional airline sector are closing up. Aircraft like the Dornier 228 and 328, that were built for regional carriers, are increasingly being used by business or charter operators as well – and who can rule out the TBM or the PC-12 as a regional airliner for remote areas? If the Cessna Caravan series can do that, so can its pressurised counterparts.

The one commercial sector the industry generally agrees is dying a slow death is that served by ageing piston-powered twin-engine aircraft, and SET-IMC will accelerate this process in Europe. This trend started in the USA some time ago. The largest PC-12 operator in the world is US east coast-based PlaneSense, a fractional ownership and aircraft-management company that started up in 1995, assembling what is now a fleet of more than 30 of the machines. The company says most of its customers do not question the fact that the PC-12 is a single-engine aircraft – it does not seem to be an issue for them. More recently the company has added the compact twinjet Nextant 400XTi and will add the Pilatus PC-24 to its fleet.

Since it was only in early March that EASA finally granted clearance to SET-IMC operations, it may be too early to judge European market reaction to the news. But Edwin Brenninkmeyer, chief executive officer of Biggin Hill, UK-based Oriens Aviation, says that “it is already making a difference". Oriens, which distributes and supports Pilatus aircraft, says it has sold three PC-12NGs this year, and enquiries are up significantly. Customers, says Brenninkmeyer, are often individuals who want to own an aircraft but know they personally will use it for only 30 or 40 hours a year, and want it to work for a living with a full air operator’s certificate holder. What is more, for owners the PC-12 maintains its residual value astonishingly well. Brenninkmeyer quotes an example of a ten-year-old example selling for 80% of its new price.

Other potential competitors such as Piper’s M600 may be pressurised, but it has a smaller cabin and is not as fast. Cessna’s Caravan series and Quest’s Kodiak, both unpressurised, are highly cost-effective at utility and freight and are used in many countries on passenger routes, but they are much slower and less sophisticated.

Europe’s undisputed expert on the subject of SET-IMC, particularly using PC-12s, is Matti Auterinen, chairman of Vantaa, Finland-based Hendell Aviation. Since 2008 his company has had an AOC as a European Union commercial carrier, and was one of the first to be given SET-IMC exemptions for particular services.

Auterinen has been working with EASA for years to define the challenges of SET-IMC and find ways to overcome them. For that reason he has unparalleled experience in drawing up PC-12-specific operating procedures for approval by the European agency, and is much sought after by operators who want to set up similar operations. Two such operators are Fly7 in Lausanne, Switzerland, and newcomer GI Aviation in Abu Dhabi. Auterinen helped GI to prepare itself for approval by the United Arab Emirates General Civil Aviation Authority, and it won its air operator’s certificate in December 2016.

Auterinen says the arrival of EASA’s SET-IMC approval has not made much difference to his own operation because he was prepared for it, but it has increased his aircraft management business. Now he is particularly committed to the improvement of piloting skills in the highly specialist role of a fully capable SET-IMC pilot.

The EASA regulations acknowledge the fact that the position of a commander of a commercial SET-IMC flight demands much more than minimum commercial pilot licence experience in terms of total flying hours (minimum 700h), time in command (minimum 400h), and time flying under IFR (minimum 100h), so this is not an entry-level piloting job. For that reason commanders will have to be attractively paid or there will be a supply problem – and then there is the expense of the specialist training.

Airline pilots are not routinely trained to carry out a power-out glide approach from high altitude down to an airfield or a safe space for a forced landing. They just know there is a checklist page for the procedure. Single-engine aircraft pilots, however, have always had to bear in mind what they would do in the event of a power failure, but now that they have also been cleared to operate commercially at night and in IMC, they face a rather more complex eventuality than the ordinary GA leisure pilot who suddenly finds he has to scan the sunlit countryside for a friendly field.

What PC-12 operators need, says Auterinen, is a highly capable flight simulation training device (FSTD) with an excellent visual display. At the low-cost end of the market as it is today, however, no single operator could justify the cost of simulator ownership, he says. Pilot training economics in this sector are radically different from those for a large airline operating Airbus or Boeing jets. For the airline, base training in the aircraft is phenomenally expensive, but there is no shortage of third-party simulator training capacity if they choose not to provide their own. For an operator of single-engine turboprops, however, base training is more affordable than time in a high level FSTD.

The answer, according to Auterinen, is to share a simulator with other PC-12 CAT-SET-IMC operators. At the moment this is an idea that has yet to take shape. But if EASA’s rule change boosts this business aviation sector as much the early operators hope – and operators proliferate – it could be an idea that will become a reality soon.

Simulation is vital to enable SET-IMC pilots to hone their systems and procedural skills. However statistically unlikely an engine failure at night or in IMC is, providing pilots with the skills to deal calmly with it, using the aircraft’s sophisticated flight management tools to achieve a safe forced landing, is essential. This exercise is the single-engine commercial pilot’s equivalent to the airline pilot repeatedly having to face the notorious recurrent training “V1 cut” test in a multi-engine aircraft, or a rotary wing pilot having to face autorotation exercises.

As for crewing, Auterinen remarks that, although aircraft like the PC-12 or TBM series can be flown easily in daylight good weather by a single pilot, for night flying, IFR flights or in IMC a two-pilot crew is standard at Hendell. That is due not only to a cockpit workload issue, he says, pointing out that, on business aviation or charter trips, having two pilots provides the crew with greater flexibility to take care of customers and their needs.

There is no doubt at all that, under EASA’s new CAT-SET-IMC rules, flight in Europe will be much safer and more comfortable than in old piston twins – and a close operational equivalent to twin turboprops and some jets. But the European operating environment is demanding, and it will be challenging for operators to vault all the hurdles it brings and still offer a significantly cheaper product than existing services.

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