Sec. 135.369 - Large transport category airplanes:
Reciprocating engine powered: En route limitations: All engines operating.
(a) No person operating a reciprocating
engine powered large transport category airplane may take off that
airplane at a weight, allowing for normal consumption of fuel and oil,
that does not allow a rate of climb (in feet per minute), with all engines
operating, of at least 6.90 Vs
(b) This section does not apply to large transport category airplanes certificated under part 4a of the Civil Air Regulations.