An MD88 aircraft main landing gear would not retract. Aircraft returned to field.

Attributes
ACN	749765
Time
Date	200708
Local Time Of Day	0601 To 1200
Place
Locale Reference	airport : cvg.airport
State Reference	KY
Altitude	agl single value : 0
Aircraft 1
Controlling Facilities	tower : dab.tower
Operator	common carrier : air carrier
Make Model Name	MD-88
Operating Under FAR Part	Part 121
Flight Phase	ground : maintenance
Person 1
Affiliation	company : air carrier
Function	maintenance : technician
Qualification	technician : powerplant technician : airframe
ASRS Report	749765
Events
Anomaly	aircraft equipment problem : critical maintenance problem : improper maintenance non adherence : far non adherence : published procedure
Resolutory Action	other
Consequence	other
Factors
Maintenance	performance deficiency : fault isolation performance deficiency : non compliance with legal requirements
Supplementary
Problem Areas	Flight Crew Human Performance Maintenance Human Performance Aircraft
Primary Problem	Maintenance Human Performance

Narrative:

I worked maintenance manual service check items that require main landing gear open (door) and close using bypass lever. The next morning aircraft took off but landing gear would not retract. Air turn-back and found bypass lever in open position. I previously closed landing gear doors with bypass lever. I can only assume that latch for lever was not completely latched or came unlatched. Knowing the importance of that aircraft system; I should have doublechked the lever in the stow position. When working critical airworthy/safety system; I need to doublechk and triplechk my work. Also note that pilot reported that lever was not out on preflight walkaround. Callback conversation with reporter revealed the following information: reporter stated although the maintenance gear door handle was found in the open position upon return to field; the pilot doing the walkaround states the handle was in the closed position because that is one of the items he checks for on his preflight. The other possibility is the hydraulic system was shut off prior to full door-up closure after overnight maintenance work completed.

Original NASA ASRS Text

Title: AN MD88 ACFT MAIN LNDG GEAR WOULD NOT RETRACT. ACFT RETURNED TO FIELD.

Narrative: I WORKED MAINT MANUAL SVC CHK ITEMS THAT REQUIRE MAIN LNDG GEAR OPEN (DOOR) AND CLOSE USING BYPASS LEVER. THE NEXT MORNING ACFT TOOK OFF BUT LNDG GEAR WOULD NOT RETRACT. AIR TURN-BACK AND FOUND BYPASS LEVER IN OPEN POS. I PREVIOUSLY CLOSED LNDG GEAR DOORS WITH BYPASS LEVER. I CAN ONLY ASSUME THAT LATCH FOR LEVER WAS NOT COMPLETELY LATCHED OR CAME UNLATCHED. KNOWING THE IMPORTANCE OF THAT ACFT SYS; I SHOULD HAVE DOUBLECHKED THE LEVER IN THE STOW POS. WHEN WORKING CRITICAL AIRWORTHY/SAFETY SYS; I NEED TO DOUBLECHK AND TRIPLECHK MY WORK. ALSO NOTE THAT PLT RPTED THAT LEVER WAS NOT OUT ON PREFLT WALKAROUND. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: REPORTER STATED ALTHOUGH THE MAINT GEAR DOOR HANDLE WAS FOUND IN THE OPEN POSITION UPON RETURN TO FIELD; THE PILOT DOING THE WALKAROUND STATES THE HANDLE WAS IN THE CLOSED POSITION BECAUSE THAT IS ONE OF THE ITEMS HE CHECKS FOR ON HIS PREFLIGHT. THE OTHER POSSIBILITY IS THE HYD SYSTEM WAS SHUT OFF PRIOR TO FULL DOOR-UP CLOSURE AFTER OVERNIGHT MAINT WORK COMPLETED.

Data retrieved from NASA's ASRS site as of January 2009 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.