What was found
FLIGHT CREW REPORTED, NR 2 ENGINE SURGED AT TOP OF DESCENT. *S/D* ENGINE SURGED AND RECOVERED. FLIGHT RECORDER DATA INDICATED DELAYED OPENING OF 2.9 STABILITY BLEED VALVE. REPLACED 2.9 BLEED SOLENOID (P/N: 04P23-8), PNEUMATIC RELAY VALVE AND 2.9 STABILITY BLEED VALVE. PNEUMATIC RELAY VALVE AND 2.9 STABILITY BLEED VALVE PASSED AS-RECEIVED TEST. FOUND 2.9 BLEED SOLENOID FAILED DROP-OUT VOLTAGE TEST, VALVE SEAT WORN.