The rotorcraft must be able to be flown, without undue pilot fatigue or strain, in any normal maneuver for a period of time as long as that expected in normal operation. At least three landings and takeoffs must be made during this demonstration.
source: Docket No. 5084, 29 FR 16150, Dec. 3, 1964, unless otherwise noted.
cite as: 14 CFR 29.171