77-10-09 PIPER: Amendment 39-2899. Applies to PA-31-325.
To prevent possible adverse airplane vibration effects at higher altitudes, accomplish the following within the next 25 hours in service after the effective date of this Airworthiness Directive unless already accomplished:
Attach the following operating limitation placard on the pilot's instrument panel between the clock and airspeed indicator in full view of the pilot: "Above 21,000 feet reduce Vno speed 3 m.p.h. per 1000 feet"
(Piper Service Bulletin No. 544 refers to this subject.)
This amendment becomes effective May 17, 1977.