A CANADAIR CL-65 IN CLB AT FL270 EXPERIENCED A PARTIAL ROLLBACK ON #1 ENG THRUST TO 50 PERCENT CAUSED BY A FAILED AUTOMATIC POWER RESERVE INPUT TO THE ELECTRONIC ENG CTL UNIT.

Narrative

DURING A CLB TO FL290 WE EXPERIENCED A PARTIAL ROLL BACK ON THE NUMBER ONE ENG. WITH THE THRUST LEVERS SET FOR CLB POWER THE ENG WAS DEVELOPING 50 PERCENT THRUST. WE IMMEDIATELY REQUESTED TO LEVEL AT OUR PRESENT ALTITUDE. ALL ENG PARAMETERS WERE NORMAL EXCEPT THE THRUST. WE INFORMED ATC THAT OUR NUMBER ONE ENGINE WAS DEVELOPING PARTIAL THRUST. AT THAT TIME WE DID NOT DECLARE AN EMER. THE QRH WAS CONSULTED AND WE DID NOT FIND AN APPLICABLE CHKLIST. WE WERE UNABLE TO MAINTAIN OUR ALTITUDE ON ONE ENG. THE MANUAL WAS CONSULTED FOR THE APPROPRIATE DRIFT DOWN DATA. WE DETERMINED THAT WE WOULD BE ABLE TO MAINTAIN FL220. A DSCNT TO FL220 WAS MADE. COMPANY DISPATCH AND MAINT WERE CONTACTED FOR DIVERSION INFO AND ANY ADDITIONAL INFO THEY COULD GIVE US. DURING A CONVERSATION WITH MAINT THE ENG BEGAN TO DEVELOP NORMAL THRUST. ALL ENG PARAMETERS WERE NORMAL. DISPATCH AND MAINT ADVISED TO CONTINUE TO OUR DESTINATION. AFTER DISCUSSING OUR OPTIONS AS A CREW WE DECIDED THAT WAS THE BEST OPTION AND THE FLT CONTINUED ON TO OUR DEST. THERE WERE NO FURTHER PROBS WITH THE ENG DURING THE FLT. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: THE RPTR STATED THE ACFT IS POWERED WITH TWO GENERAL ELECTRIC CF34-3A1 ENGS WITH ELECTRONIC ENG CTL. THE RPTR SAID MAINT RPTED THE CAUSE OF THE ROLL BACK WAS FAILURE IN THE LOSS OF THE AUTOMATIC PERFORMANCE RESERVE SYS INPUT TO THE ELECTRONIC ENG CTL UNIT. THE RPTR STATED THE ROLL BACK LASTED ONLY A SHORT PERIOD OF TIME AND POWER WAS RECOVERED AND ENG OP WAS NORMAL.