Narrative:

I was the captain and the PF a visual approach. I was hand flying with the gear down and locked with flaps set at 42 degrees. At approximately 1200 ft AGL we received a level 1 alert. I glanced at the MFDU and told the first officer to comply with the checklist. I expected this to be a relatively simple fix due to the nature of the alert (level 1). I proceeded with the approach, being mindful not to be distracted by the event. I was surprised when the first officer started reading from the MFDU that neither reversers nor nosewheel steering would be available on rollout, that the gear could not be raised and that flaps must be raised using alternate procedure. I advised the first officer that we would go around. The first officer immediately recommended that I land since we were in landing confign and that gear and flap retraction would be issues. There was not much time left to hesitate, so I concurred and asked the first officer to declare an emergency and landed uneventfully. I steered the aircraft clear of the runway using rudder input, set the brakes and requested tow-in to the gate. The hydraulic system 2 quantity indicated 62 degrees, possibly triggering the level 1 alert. The mystery was why were system 1 components unavailable. The first officer realized that he had inadvertently selected system 1 pumps off instead of system 2 pumps in attempting to comply with the checklist. I should have gone around when my initial instinct told me to, despite the well-intentioned advice from the first officer to the contrary. If we had gone around, we would have been able to eventually detect the self-induced problem and make a safer approach with more critical system operating. Additionally, hypothetically, I would rather make a go around from 800 ft AGL with our drag problem than from 80 ft. Given that we were less than 2 mins from touchdown when the alert occurred, the safest solution would have been to go around first and then to have addressed the system problem. This would have avoided the problem of the first officer having to rush the checklist. When in doubt, go around.

Related reports:

Google
 

Original NASA ASRS Text

Title: F100 FLC HAS HYD MALFUNCTION ON FINAL APCH, DECLARES EMER.

Narrative: I WAS THE CAPT AND THE PF A VISUAL APCH. I WAS HAND FLYING WITH THE GEAR DOWN AND LOCKED WITH FLAPS SET AT 42 DEGS. AT APPROX 1200 FT AGL WE RECEIVED A LEVEL 1 ALERT. I GLANCED AT THE MFDU AND TOLD THE FO TO COMPLY WITH THE CHKLIST. I EXPECTED THIS TO BE A RELATIVELY SIMPLE FIX DUE TO THE NATURE OF THE ALERT (LEVEL 1). I PROCEEDED WITH THE APCH, BEING MINDFUL NOT TO BE DISTRACTED BY THE EVENT. I WAS SURPRISED WHEN THE FO STARTED READING FROM THE MFDU THAT NEITHER REVERSERS NOR NOSEWHEEL STEERING WOULD BE AVAILABLE ON ROLLOUT, THAT THE GEAR COULD NOT BE RAISED AND THAT FLAPS MUST BE RAISED USING ALTERNATE PROC. I ADVISED THE FO THAT WE WOULD GAR. THE FO IMMEDIATELY RECOMMENDED THAT I LAND SINCE WE WERE IN LNDG CONFIGN AND THAT GEAR AND FLAP RETRACTION WOULD BE ISSUES. THERE WAS NOT MUCH TIME LEFT TO HESITATE, SO I CONCURRED AND ASKED THE FO TO DECLARE AN EMER AND LANDED UNEVENTFULLY. I STEERED THE ACFT CLR OF THE RWY USING RUDDER INPUT, SET THE BRAKES AND REQUESTED TOW-IN TO THE GATE. THE HYD SYS 2 QUANTITY INDICATED 62 DEGS, POSSIBLY TRIGGERING THE LEVEL 1 ALERT. THE MYSTERY WAS WHY WERE SYS 1 COMPONENTS UNAVAILABLE. THE FO REALIZED THAT HE HAD INADVERTENTLY SELECTED SYS 1 PUMPS OFF INSTEAD OF SYS 2 PUMPS IN ATTEMPTING TO COMPLY WITH THE CHKLIST. I SHOULD HAVE GONE AROUND WHEN MY INITIAL INSTINCT TOLD ME TO, DESPITE THE WELL-INTENTIONED ADVICE FROM THE FO TO THE CONTRARY. IF WE HAD GONE AROUND, WE WOULD HAVE BEEN ABLE TO EVENTUALLY DETECT THE SELF-INDUCED PROB AND MAKE A SAFER APCH WITH MORE CRITICAL SYS OPERATING. ADDITIONALLY, HYPOTHETICALLY, I WOULD RATHER MAKE A GAR FROM 800 FT AGL WITH OUR DRAG PROB THAN FROM 80 FT. GIVEN THAT WE WERE LESS THAN 2 MINS FROM TOUCHDOWN WHEN THE ALERT OCCURRED, THE SAFEST SOLUTION WOULD HAVE BEEN TO GAR FIRST AND THEN TO HAVE ADDRESSED THE SYS PROB. THIS WOULD HAVE AVOIDED THE PROB OF THE FO HAVING TO RUSH THE CHKLIST. WHEN IN DOUBT, GAR.

Data retrieved from NASA's ASRS site as of July 2007 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.