Narrative:

Cleared via ord 1 departure which is to climb to and maintain 5000 ft MSL. Climbing through 4500 ft MSL at 800-1000 FPM rate of climb, the first officer moved the landing gear lever to 'off' per the climb SOP's to comply with the climb checklist. He inadvertently hit the gear down position and the gear lowered causing a loud air noise and gear unsafe lights. I reached for the lever and raised the gear as I seemed to recognize the problem sooner. During this time, I exceeded the 5000 ft clearance by 300-400 ft. Descended immediately to 5000 ft with gear now back up. First officer was fairly new to airline operations and had never seen this problem -- training for this is not done. Since I was hand flying the aircraft (a B737-500) I should have ordered 'gear up' rather than to do it myself. We were below gear speeds and some delay would not have been a problem. At the time, quickness seemed important. The surprise and noise at that point in-flight was a factor. Departure control was notified immediately of our deviation and cleared us to 11000 ft. We then left 5000 ft for 11000 ft. No other aircraft were seen and I am not aware of a separation loss occurrence. Lesson learned was to solicit help from first officer rather than to try to do it all myself.

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Original NASA ASRS Text

Title: CAPT OF A B737-500 OVERSHOT INITIAL CLB LEVELOFF ALT DUE TO BEING DISTR BY THE LNDG GEAR EXTENDING WHEN THE FO MISSED THE GEAR LEVER POS OF 'OFF.'

Narrative: CLRED VIA ORD 1 DEP WHICH IS TO CLB TO AND MAINTAIN 5000 FT MSL. CLBING THROUGH 4500 FT MSL AT 800-1000 FPM RATE OF CLB, THE FO MOVED THE LNDG GEAR LEVER TO 'OFF' PER THE CLB SOP'S TO COMPLY WITH THE CLB CHKLIST. HE INADVERTENTLY HIT THE GEAR DOWN POS AND THE GEAR LOWERED CAUSING A LOUD AIR NOISE AND GEAR UNSAFE LIGHTS. I REACHED FOR THE LEVER AND RAISED THE GEAR AS I SEEMED TO RECOGNIZE THE PROB SOONER. DURING THIS TIME, I EXCEEDED THE 5000 FT CLRNC BY 300-400 FT. DSNDED IMMEDIATELY TO 5000 FT WITH GEAR NOW BACK UP. FO WAS FAIRLY NEW TO AIRLINE OPS AND HAD NEVER SEEN THIS PROB -- TRAINING FOR THIS IS NOT DONE. SINCE I WAS HAND FLYING THE ACFT (A B737-500) I SHOULD HAVE ORDERED 'GEAR UP' RATHER THAN TO DO IT MYSELF. WE WERE BELOW GEAR SPDS AND SOME DELAY WOULD NOT HAVE BEEN A PROB. AT THE TIME, QUICKNESS SEEMED IMPORTANT. THE SURPRISE AND NOISE AT THAT POINT INFLT WAS A FACTOR. DEP CTL WAS NOTIFIED IMMEDIATELY OF OUR DEV AND CLRED US TO 11000 FT. WE THEN LEFT 5000 FT FOR 11000 FT. NO OTHER ACFT WERE SEEN AND I AM NOT AWARE OF A SEPARATION LOSS OCCURRENCE. LESSON LEARNED WAS TO SOLICIT HELP FROM FO RATHER THAN TO TRY TO DO IT ALL MYSELF.

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.