Proponents of commercial operations with single-engine aircraft in instrument meteorological conditions (IMC) have been frustrated once again by seemingly interminable delays in prospective European approval for such flights. The European Joint Aviation Authorities had been scheduled to discuss a formal proposal last week, but that meeting has now been postponed until late in July.

It is almost 20 years since single-engine commercial IMC operations were first proposed in Europe, and more than three years since the date operators thought they might be able to start. A major stumbling block has been the reservations of conservative national aviation authorities about engine reliability.

They fear a public outcry against their judgment should an aircraft come down on a populous area following an engine failure. After long consideration, the JAA SEIMC working group is proposing an amendment to JAA operational requirements (JAR Ops), but senior industry and regulation officials still do not expect JAA unanimous agreement.

If unresolved, the document–JAR Ops notice of proposed amendment number 29 (NPA 29), now in its 13th draft–could be passed on to the new European Aviation Safety Agency that will inherit such responsibility in October. If NPA 29 is adopted, it could be implemented immediately.

SEIMC is prohibited except under special clearance, although some JAA countries permit cargo-only operations (under exemptions from basic rules) or passenger flights strictly within national airspace. Operators first proposed such European operations in 1986 and approval would permit SEIMC flights with Cessna 208 Caravan I, EADS/Socata TBM 700 and Pilatus PC-12 aircraft.