On February 14, 2017, Honeywell released the SIL (Service Information Letter) D201702000027, Revision 0, applicable to the AS907-3-1E (HTF7500E) model engine.
This SIL announces the 1st and 4th Stage Compressor Stator Vane Seal Inspection Program.
This program is a result of isolated instances of individual rivets separating from the 1st and/or 4th stage high pressure compressor stator vane assemblies on engines with more than 850 hours. This is not a safety issue and no operational issues have been reported.
The details of the program, including borescope inspection intervals, will be further explained in the Service Bulletin AS907-72-9072 scheduled to be published in March 2017. No action needs to be taken at this time.