Companies that have long been awaiting European approval for commercial single-engine operations under instrument meteorological conditions (SE-IMC), or at night, clearly face a longer wait. Despite continuing optimism voiced by some operators, it will be almost three more years before such flights can be approved across the region.

At best, European approval for commercial SE-IMC (roughly equivalent to U.S. single-engine instrument flight rules) could be in place by early 2010, which will be almost 25 years after initial requests were made for such operations. A recently commissioned European Aviation Safety Agency (EASA) study, which will take into account “all the risks,” is being conducted by UK contractor Qinetiq and should be complete by October. This may open the way for the formulation of new rules later this year or next year.

If EASA is happy with the study’s conclusions about any inherent dangers in commercial SE-IMC operations, it then would consult the industry through a notice of proposed amendment to its implementing rules on operations. In turn, that could lead to submission of an “opinion” to the European Commission by the end of 2009. [Opinions are draft legislation sent to the European Commission for further process, by the Commission–or the Council of Ministers and the European Parliament–before enactment. Any resulting new legislation would be an amendment to the EASA Basic Regulation and its implementing rules.–Ed.]

Qinetiq successfully proposed the safety assessment contract about six months ago and the study was launched in February. The results could be published on the EASA Web site, the agency told EBACE Convention News. Previous efforts by the European Joint Aviation Authorities (JAA), which preceded EASA, failed to reach a necessary consensus in support of commercial SE-IMC approval and their deliberations were passed on to EASA last year.

Under the earlier procedures, national aviation authorities (NAAs) in member countries could choose whether to adopt JAA regulations, which were not mandatory, or apply their own rules to operations with locally registered aircraft in their own airspace. In the case of commercial SE-IMC, the innate conservatism of safety officials in a few countries–particularly Germany, Italy and the UK–ultimately stymied the proposed regulation that would have permitted cross-border flights.

Previously dissenting NAAs may now gain consolation from EASA’s rejection of many arguments previously raised in support of commercial SE-IMC clearance. Protagonists, including aircraft and engine manufacturers, as well as potential operators, argued that experience with single-engine operations in other geographic regions provided sufficient data to assure European rulemakers about safety.

The lobby hoped to persuade safety officials to approve commercial SE-IMC services that included so-called “risk periods,” up to a cumulative 15 minutes in any flight. During this time, operators would be permitted to expose passengers to a possible loss of engine thrust while outside still-air gliding range of suitable landing strips.

Among European NAAs, the UK Civil Aviation Authority has steadfastly said it does “not accept the concept of an in-flight ‘risk period.’” When challenged by an operator about how much better single-engine safety needed to be to gain its approval, the CAA reportedly said it was not tied to “any particular fatal-accident rate” as being an acceptable minimum.

In documents inviting tenders to perform the current study, EASA pointed out that several countries had introduced rules permitting commercial SE-IMC operations under specified conditions. These include some with advanced regulations, such as those in effect in Australia, Canada and the U.S. and EU member states such as Denmark, Finland and Norway.

Two successive JAA working groups previously were tasked with preparing a draft NPA to European JAR-Ops 1 regulations to replace varying national rules with a joint requirement. A string of proposals were circulated for member states’ comment, but their governing body, the JAA committee, could not reach a consensus on a draft final rule.

The JAA suspended SE-IMC activity with the prospective transfer of European operational requirements’ responsibility to EASA, which had been closely monitoring JAA developments. Similar discussions in the International Civil Aviation Organization led, in 2005, to the establishment of requirements covering SE-IMC operations.

EASA’s Concerns
EASA had expected to use a JAA draft final rule in drawing up its own proposal, but the lack of JAA consensus and arguments against both a draft final rule and a supporting regulatory impact assessment (RIA) have led it to propose further research. The safety agency cites several negative arguments and its reasons for reviewing commercial SE-IMC proposals:

• the concept of “risk periods” on departure and during cruise where there is no available landing site provides insufficient safety;

• specifications for a landing site and requirements for its availability and physical inspections are insufficient and do not provide enough safety;

• operations over densely populated regions may be unacceptable;

• reliability data on accidents/incidents involving SE-IMC operations are based on non-European (that is, U.S.) data, are considered unbalanced and incomplete, and reflect a prevailing percentage of operations with a single airplane type (the Cessna 208 Caravan I) not representative of potential European operations;

• U.S. data do not reflect specific European conditions, such as population density and lack of suitable landing sites in certain European regions; and

• composition of the JAA working groups preparing the commercial SE-IMC NPA did not balance supporters and opponents.

Accordingly, EASA has concluded that “at least some” of the objections, particularly against the RIA, “might be valid” and has stopped planned rulemaking. Instead, it will review proposals, based on a “full and objective” risk assessment for each phase of commercial SE-IMC operations. “It is necessary to identify all the risks and to identify possible mitigating factors assuring that SE-IMC operations do not involve more risks than multi-engine IMC operations,” the agency concluded.

In completing its SE-IMC research, Qinetiq is specifically required to review existing reliability data using results of previous JAA work and particularly to verify that data is “statistically valid, balanced, applicable to the aeroplanes [sic] expected to be used in [European] SE-IMC operations and reflects the specifics of the European region.”

Where data does not meet these criteria, EASA permits Qinetiq to identify additional sources to complement and/or update existing information with new data. The contractor also must consider reliability of modern engines, including risk periods and their impact on safety, and the new ICAO requirements adopted into Annex 6.