68-10-06 PILATUS: Amendment 39-599. Applies to Model PC-6 Series airplanes.
Compliance required within the next 200 hours' time in service after the effective date of this AD, unless already accomplished.
To prevent horizontal stabilizer stall, install fixed wing spoilers on the trailing edges of the wings in accordance with Pilatus Service Bulletin No. 76, dated November 1967, or later Swiss Federal Air Office approved revision or an equivalent approved by the Chief, Aircraft Certification Staff, FAA, Europe, Africa and Middle East Region.
This amendment becomes effective June 10, 1968.