FAR 135 single-engine IFR rule published

November 11, 2009

FAR 135 single-engine IFR rule published

The FAA published a final rule in the August 6, 1997, Federal Register titled “Commercial Passenger-Carrying Operations in Single-Engine Aircraft Under Instrument Flight Rules.” The new regulations will take effect on May 3, 1998, to allow operators to transition from the limited IFR provisions of the existing rules to the new full IFR regulations. The existing limited IFR rules will be eliminated. (The final rule is available here.)

AOPA has supported the concept of single-engine IFR commercial operations for years based on improved safety and enhanced utility. Most recently, AOPA filed comments supporting the NPRM issued on December 3, 1996. The NPRM proposed to permit passenger-carrying Part 135 operations in single-engine aircraft under certain conditions. The final rule largely reflects the conditions outlined in the NPRM. After preliminary review, AOPA supports the final rule as written.

An operator conducting single-engine IFR operations in either turbine- or piston-engine aircraft must meet all of the existing requirements for IFR flight including those for equipment (e.g., vertical speed indicator, free-air temperature indicator, heated pitot tube, marker beacon receiver, etc.), crew (a second pilot or autopilot), pilot training and testing (proficiency check every six months), and pilot experience (1,200 hours).

The new requirements will require operators to have an engine trend monitoring program (such as oil analysis), as well as approved maintenance instructions. In addition, the rule requires that aircraft have redundant systems to provide needed power to maintain critical flight instruments (gyroscopic), as well as the necessary navigation and communications capability. This means independent vacuum systems (electrical/engine-driven) and back-up electrical system (dual generators/generator and battery combination).

The new rule takes effect on May 3, 1998, to allow operators using the existing limited IFR provisions time to obtain the required equipment, retrofit aircraft, and revise their operations authority (certificates) and manuals. The FAA is planning to publish a Special FAR (SFAR No. 81) in the next 60 days to permit single-engine operators who already meet the new requirements to begin operating under IFR prior to the effective date of the rule.

August 8, 1997