ASTM’s F37 committee is composed of people with technical knowledge who achieved a challenging task: Start with a blank sheet of paper and create aircraft standards for the Light-Sport Aircraft (LSA) sector.
That this group did so in just a few years on the leanest of budgets is a credit to their dedication.
These volunteers from many countries created a series of standards, one of which is the Design and Performance Standard. Following a positive ballot by committee members, all such standards have been accepted by the FAA.
For several years a subcommittee has worked to create an IFR standard that has yet to find agreement.
Until consensus can be found and to provide an interim defensive position for the committee and for manufacturers, F37 added a point to the Design and Performance Standard prohibiting use of a Special LSA for flight into IMC — that is, into clouds or no-visibility situations.
This does not prevent flight in the IFR system — filing and flying IFR into controlled airspace by qualified pilots with a current medical, assuming the LSA is properly equipped with the correct instrumentation, lighting, and powerplant.
Regardless of the ASTM committee’s decision, FAA regulations governing LSA do not prevent IMC operations. This is a complex topic that will continue to stimulate debate.
For those who enjoy reading FARs, here is additional info: IFR training in visual meteorological conditions (VMC) may be conducted by qualified pilots in a Special LSA that meets the equipment requirements of 91.109, 91.205, and — for an airplane operated in controlled airspace under the IFR system — 91.411 and 91.413.
Unlike in the world of FAA Type Certified aircraft, an LSA manufacturer has ultimate authority over how their airplanes (or engines) may be used.
Before or after the ASTM committee’s prohibition of flight into IMC, if a manufacturer states that it does not want its airplanes flown IFR, that’s the end of it… no IFR for that brand as an SLSA.
However, any manufacturer can change its mind, amend the Pilot Operating Handbooks (and other related documents), and begin offering IFR aircraft.