Narrative:

While being vectored for a visual approach; we were cleared to follow a falcon three miles outside of the FAF. We established visual contact with the falcon and when spacing looked good we turned on base. I asked for flaps 15. Immediately after selecting flaps 15 the stabilizer miscompare and hydraulic press on annunciators illuminated.the hydraulic press on checklist calls for the hydraulic control circuit breaker to be pulled; but [it] must then be reset prior to approach; we elected not to touch it since we were on approach already and we did not want to worsen the situation or compromise other hydraulic sub-systems. The landing gear was extended using normal procedures; and the before landing checks were completed.we then ran the stabilizer miscompare checklist which states: - if landing 1. Flaps: check in desired position; 2. Use normal procedures; 3. Touch and go landings prohibited; procedure complete. So we did; we continued using normal procedures. At about 200 ft and approximately 120 KIAS the horizontal stabilizer started to move to its originally commanded position; causing the airplane to pitch up smoothly but unexpectedly. It felt like a runaway trim initially; but we realized what was happening after we noticed the stabilizer miscompare annunciator extinguish. The aircraft was under positive control at all times and it only required a relatively small change of power; a higher than normal forward pressure on the controls; and a pitch trim adjustment to maintain the desired flight path.

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Original NASA ASRS Text

Title: A C560XL flight crew overcame STAB MISCOMPARE and HYD PRESS ON annunciations and landed safely.

Narrative: While being vectored for a visual approach; we were cleared to follow a Falcon three miles outside of the FAF. We established visual contact with the Falcon and when spacing looked good we turned on base. I asked for Flaps 15. Immediately after selecting Flaps 15 the STAB MISCOMPARE and HYD PRESS ON annunciators illuminated.The HYD PRESS ON checklist calls for the hydraulic control circuit breaker to be pulled; but [it] must then be reset prior to approach; we elected not to touch it since we were on approach already and we did not want to worsen the situation or compromise other hydraulic sub-systems. The landing gear was extended using normal procedures; and the Before Landing Checks were completed.We then ran the STAB MISCOMPARE checklist which states: - IF LANDING 1. Flaps: Check in desired position; 2. Use normal procedures; 3. Touch and Go landings prohibited; PROCEDURE COMPLETE. So we did; we continued using normal procedures. At about 200 FT and approximately 120 KIAS the horizontal stabilizer started to move to its originally commanded position; causing the airplane to pitch up smoothly but unexpectedly. It felt like a runaway trim initially; but we realized what was happening after we noticed the STAB MISCOMPARE annunciator extinguish. The aircraft was under positive control at all times and it only required a relatively small change of power; a higher than normal forward pressure on the controls; and a pitch trim adjustment to maintain the desired flight path.

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.