LSA flight into IMC to be prohibited

September 3, 2010

Proposals under consideration by ASTM committees for light sport aircraft (LSAs) could ban flight in instrument meteorological conditions (IMC) for future special light sport aircraft (S-LSAs) until such time as ASTM reaches a consensus on standards for IFR aircraft. The prohibition could come by the end of the year. However, it is important to note that the aircraft could still be used in VMC for IFR flight training.

The ASTM committee for LSA will require consumer notification that the aircraft does not comply with any design standards for operation in IMC. It is the FAA that requires the LSA to comply with such standards. The required notification highlights that no design standards have ever been developed for LSA operations in instrument conditions.

Pilots will still be able to train for an instrument rating in appropriately equipped S-LSAs and file IFR flight plans, as long as they remain in VMC.

ASTM’s IFR subcommittee members have been unable to agree on design standards for LSAs used in actual instrument weather, so the placarding would not be required if the aircraft complied with, and the manufacturer declared agreement to, any FAA or future ASTM design standards for aircraft to be operated in IMC.

Until that day comes, LSAs would carry a placard saying flight into IMC is prohibited. Again, the placard could be removed if the manufacturer of the aircraft declared that the aircraft was in compliance with design standards, once consensus is found, for aircraft approved to operate in IMC. Regardless, no flight under IFR is allowed—before or after the placard—if the manufacturer does not permit it.

“None of this affects night flying,” said Dan Johnson of bydanjohnson.com. Johnson is a pioneer in the promotion of the light sport category.

Any LSA now approved for IFR flight will continue to be capable of entering instrument conditions, as long as the pilot is also instrument rated and the airplane is suitably equipped, including instrumentation and powerplant. Such aircraft can also be used for IFR training.

“This is an effort to ensure that the consumer and operators of these aircraft are aware of what meteorological conditions were considered in the design of the LSA,” Johnson said. “If there is no [IFR] standard, then selling an LSA as IMC capable is foolhardy, because how are you going to defend that later? Until an IFR standard is done, ASTM wants to issue a placard that says ‘no IMC.’”

Additionally, any manufacturer can ban IMC flight regardless of the ASTM standards. If the manufacturer wants to sell an IFR-capable airplane that uses a Rotax engine, then a certified Rotax engine must be used. That will increase the cost of the aircraft by approximately $10,000. At the current time, there is a lack of agreement within both the FAA and ASTM as to whether LSAs should be allowed into IMC weather. Although ASTM sets standards for LSAs, the FAA must still accept them.