The newly proposed MOSAIC regulations state in § 61.316

(1) A maximum stalling speed or minimum steady flight speed without the use of lift-enhancing devices (V S1 ) of not more than 45 knots CAS, except for airplanes, which must have a V S1 speed of not more than 54 knots CAS at the aircraft's maximum certificated takeoff weight and most critical center of gravity.

I believe "most critical center of gravity" depends on context of flight condition: See: Under which condition is a forward CG most critical?

My question to the community: does the text "most critical center of gravity" in the context of the above Notice of proposed rulemaking (NPRM) have an accepted meaning?

Modernization of Special Airworthiness Certification

Am looking for educated answers and less commentary about interpretation. The (2) fold reason, is:

  1. This assists me in deciding if I should comment on the verbiage with the most informed data I can get.
  2. An example Cessna 182 > D model has a clean stall speed of 54 KCAS when CG is most rearward and 56 when most forward. Does the above proposed rule clearly indicate in this scenario if this particular Cessna 182 in fact meets the performance limits and design requirements for the aircraft that a sport pilot may operate?

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1 Answer 1


I can't think of anything "most critical center of gravity" could mean in this context except "the center of gravity that gives the highest Vs1." If that isn't your interpretation, then two reasonable people disagree on the meaning of that phrase, and commenting on the verbiage is entirely appropriate!

Under that reading, the Cessna 182 you've given the stall speeds of would not qualify.


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