77-02-03 GENERAL ELECTRIC COMPANY: Amendment 39-2809. Applies to all General Electric Company CT64-820-4 model turboprop engines.
Compliance required within the next 100 hours time in service after the effective date of this AD, unless already accomplished.
To prevent the possibility of overstressing the Stage 4 turbine buckets, the engine output shaft overspeed limit is reduced from 1512 rpm to 1450 rpm. The original limit is given in Note 2 of Type Certificate Data Sheet E13EA-10, dated February 15, 1976.
This amendment becomes effective February 9, 1977.