NPRM Offers New Part 23 Airplane Lexicon

By Scott Spangler on March 14th, 2016

If the recently released Part 23 Notice of Proposed Rulemaking survives the comment and review period and makes it to a final rule, old, new, and prospective pilots will have to learn a new airplane lexicon. But don’t hyperventilate, like the NPRM itself, it is simple and straightforward.

Based on aircraft weight and propulsion, the existing Part 23 divisions are Normal, Utility, Acrobatic, and Commuter. As proposed, say good-bye to the last three. All new Part 23 airplanes will be certificated as Normal, in one of four Airplane Certification Levels (ACL) determined by the maximum number of seats:

Level 1 – for airplanes with a maximum seating configuration of 0 to 1
Level 2 – for airplanes with a maximum seating configuration of 2 to 6
Level 3 – for airplanes with a maximum seating configuration of 7 to 9
Level 4 – for airplanes with a maximum seating configuration of 10 to 19 passengers.

This works in concert with the Airplane Performance Level (APL).  It replaces the existing propulsion-based divisions, which were established with piston-powered airplanes were traditionally slower than those with turboprops. To quote the NPRM, “These assumptions are no longer valid. Airplane certification based on performance levels would apply regulatory standards appropriate to airplane’s performance and complexity.” So the Normal Part 23 airplane will be either:

Low Speed – for airplanes with a design cruising speed (VC) or maximum operating limit speed (VMO) ≤ 250 KCAS (or MMO ≤ 0.6).
High Speed – for airplanes with a VC or VMO > 250 KCAS (or MMO > 0.6).

A subset of Normal Level 1 is the “simple airplane,” a low-speed airplane with a stalling speed (VSO) ≤ 45 Knots Calibrated Airspeed (KCAS) approved only for VFR operations. This is akin to Europe’s Very Light Aircraft, and the FAA “believes that creating the simple certification level would encourage manufacturers of light-sport and experimental aircraft kits to pursue type certificates for their airplane designs without encountering the administrative, procedural or regulatory barriers existing in current part 23, while allowing innovative technology in those designs.”

Speaking of light-sport aircraft, the FAA considered including them in the Part 23 NPRM. “However, the FAA decided that this would not be in the best interest of the GA community because it could result in the elimination of the special light-sport aircraft category. There are advantages in the certification of special light-sport aircraft, such as self-certification, that would not be available if the aircraft were type certificated under part 23. This proposal would instead enable a simpler path to part 23 certification for airplanes that meet the definition of a light-sport aircraft and wish to pursue a type of certificate for business reasons.”

Nicely done.

To this foundation of aircraft certification airplane makers would employ the consensus standards, which will address every aspect of certification, the Normal Airplane’s capabilities, such as VFR and IFR operations, a structure stressed for Acrobatics, pressurization, and so on. And in its continuing effort to stem the consistency of loss of control accidents, the FAA also proposed new enhanced standards for resistance to departure from controlled flight.

The FAA started work on Part 23 and published it Small Airplane Certification Process Study, which is the foundation for the forward-looking changes embodied by the 283-page NPRM. I’m about halfway through it, and so far my overall feeling is that it will finally usher small aircraft certification into the 21st century. –Scott Spangler, Editor


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