Narrative:

Ferry flight from ZZZ1 to ZZZ at FL400. On descent into ZZZ approximately 2 hours into the flight; selected flaps to 15 degrees at approximately 195 KTS. While flaps were in transit; we selected gear down. Stabilizer miscompare light illuminated along with hydraulic pressure light. Additionally; the nose; the right main landing gear down and the unlock lights illuminated. Left main gear down light did not illuminate. Gear warning horn sounded when throttles were retarded. Approach indexers did not illuminate. We completed the quick reference handbook procedures for stabilizer miscompare while circling overhead ZZZ at 16;000 ft; but the condition persisted. The flaps were selected to 35 degrees. After discussing divert with the first officer; we made the decision to go to ZZZ2. Enroute; we finished the checklist for landing gear failure to extend including blowing the gear down. The left main landing gear remained up. We declared an emergency; and made the decision to go to ZZZ3 because the airport has a long runway; a tower and fire-fighting capabilities. The plan was to do a fly-by of the tower to confirm the position of the left main landing gear before landing. During the 50-mile transit; at 13;000 ft; the stabilizer moved to its proper; commanded position and the associated caution lights went out. For a period of approximately 2 minutes; the right low hydraulic flow light illuminated. We completed the left or right low hydraulic flow procedures. The right low hydraulic flow light went out. At about the same time; we received indications that the left main landing gear went safe. We shot a visual approach to runway at ZZZ3 and landed normally. Supplemental information from acn 821950: I am not sure if selecting the gear while the flaps were in transit put added workload on the hydraulics system; but maybe waiting until the flaps and stabilizer stopped moving before selecting the gear down would have avoided this whole situation.

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Original NASA ASRS Text

Title: A CE560XLS flight crew experienced STAB MISCOMPARE; HYD PRESS; and L MLG UNLOCK lights after selecting gear down while flaps were in transit. They blew the gear down; declared an emergency; and diverted to a more suitable airport.

Narrative: Ferry flight from ZZZ1 to ZZZ at FL400. On descent into ZZZ approximately 2 hours into the flight; selected flaps to 15 degrees at approximately 195 KTS. While flaps were in transit; we selected gear down. STAB Miscompare light illuminated along with Hydraulic Pressure light. Additionally; the Nose; the Right Main Landing Gear Down and the Unlock lights illuminated. Left Main Gear Down light did not illuminate. Gear warning horn sounded when throttles were retarded. Approach indexers did not illuminate. We completed the Quick Reference Handbook procedures for STAB Miscompare while circling overhead ZZZ at 16;000 FT; but the condition persisted. The flaps were selected to 35 degrees. After discussing divert with the First Officer; we made the decision to go to ZZZ2. Enroute; we finished the checklist for landing gear failure to extend including blowing the gear down. The left main landing gear remained up. We declared an emergency; and made the decision to go to ZZZ3 because the airport has a long runway; a Tower and fire-fighting capabilities. The plan was to do a fly-by of the Tower to confirm the position of the left main landing gear before landing. During the 50-mile transit; at 13;000 FT; the STAB moved to its proper; commanded position and the associated caution lights went out. For a period of approximately 2 minutes; the Right Low Hydraulic Flow light illuminated. We completed the Left or Right Low Hydraulic Flow procedures. The Right Low Hydraulic Flow light went out. At about the same time; we received indications that the left main landing gear went safe. We shot a visual approach to runway at ZZZ3 and landed normally. Supplemental information from ACN 821950: I am not sure if selecting the gear while the flaps were in transit put added workload on the hydraulics system; but maybe waiting until the flaps and STAB stopped moving before selecting the gear down would have avoided this whole situation.

Data retrieved from NASA's ASRS site as of April 2012 and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.