A fokker 100 was dispatched and operated with the alternate landing gear handle lock solenoid replac...

Narrative:

On my shift, I was assigned an engineering order (eo) prepared by air carrier to replace an electrical solenoid on the landing gear handle in the cockpit. The engineering order was a draft engineering order and a minor alteration to the airframe. The title of the engineering order didn't clearly state the handle requiring the modification. The aircraft, xyz, was in heavy maintenance for a 'Q check.' the subject for the engineering order was a landing gear-anti-retract solenoid replacement. The engineering order replaces the current solenoid with a more reliable solenoid. I was familiar with a solenoid on the alternate landing gear which was known to fail, located on the rear of the pedestal in the cockpit. I had replaced that solenoid in the past to repair other aircraft. I didn't know there was another solenoid on the normal landing gear handle located on the main instrument panel. The engineering order asked to identify the part number of solenoid (-1), which was done. A new and improved (-2) solenoid was installed. The polarity of the wires was determined and wires connected to the solenoid. No testing of the system was required. No inspection of workmanship was required. Aircraft landing gear was tested in hangar, test flown before entering service, and returned to service on dec/xb/98. The next aircraft was brought into the hangar, and the 'Q check' started. Another fellow worker was assigned the same engineering order on dec/xa/98. I observed he was changing a solenoid on a different handle than what I had done on the previous aircraft. I was puzzled and asked to read the engineering order again. I discovered I had changed the wrong solenoid. I self- disclosed the error to my lead mechanic, the foreman, and another foreman that same shift. The aircraft was routed back to the maintenance hangar that same day. The engineering order was correctly completed and released for service by someone other than myself. A request for engineering services at air carrier has been submitted to revise the engineering order to modify both landing gear handles and purge all (-1) solenoids from stock.

Original NASA ASRS Text

Title: A FOKKER 100 WAS DISPATCHED AND OPERATED WITH THE ALTERNATE LNDG GEAR HANDLE LOCK SOLENOID REPLACED. ENGINEERING ORDER REQUIRED REPLACEMENT OF THE NORMAL LNDG GEAR HANDLE LOCK SOLENOID. ERROR WAS CAUSED BY A PUB DEFICIENCY.

Narrative: ON MY SHIFT, I WAS ASSIGNED AN ENGINEERING ORDER (EO) PREPARED BY ACR TO REPLACE AN ELECTRICAL SOLENOID ON THE LNDG GEAR HANDLE IN THE COCKPIT. THE ENGINEERING ORDER WAS A DRAFT ENGINEERING ORDER AND A MINOR ALTERATION TO THE AIRFRAME. THE TITLE OF THE ENGINEERING ORDER DIDN'T CLRLY STATE THE HANDLE REQUIRING THE MODIFICATION. THE ACFT, XYZ, WAS IN HVY MAINT FOR A 'Q CHK.' THE SUBJECT FOR THE ENGINEERING ORDER WAS A LNDG GEAR-ANTI-RETRACT SOLENOID REPLACEMENT. THE ENGINEERING ORDER REPLACES THE CURRENT SOLENOID WITH A MORE RELIABLE SOLENOID. I WAS FAMILIAR WITH A SOLENOID ON THE ALTERNATE LNDG GEAR WHICH WAS KNOWN TO FAIL, LOCATED ON THE REAR OF THE PEDESTAL IN THE COCKPIT. I HAD REPLACED THAT SOLENOID IN THE PAST TO REPAIR OTHER ACFT. I DIDN'T KNOW THERE WAS ANOTHER SOLENOID ON THE NORMAL LNDG GEAR HANDLE LOCATED ON THE MAIN INST PANEL. THE ENGINEERING ORDER ASKED TO IDENT THE PART NUMBER OF SOLENOID (-1), WHICH WAS DONE. A NEW AND IMPROVED (-2) SOLENOID WAS INSTALLED. THE POLARITY OF THE WIRES WAS DETERMINED AND WIRES CONNECTED TO THE SOLENOID. NO TESTING OF THE SYS WAS REQUIRED. NO INSPECTION OF WORKMANSHIP WAS REQUIRED. ACFT LNDG GEAR WAS TESTED IN HANGAR, TEST FLOWN BEFORE ENTERING SVC, AND RETURNED TO SVC ON DEC/XB/98. THE NEXT ACFT WAS BROUGHT INTO THE HANGAR, AND THE 'Q CHK' STARTED. ANOTHER FELLOW WORKER WAS ASSIGNED THE SAME ENGINEERING ORDER ON DEC/XA/98. I OBSERVED HE WAS CHANGING A SOLENOID ON A DIFFERENT HANDLE THAN WHAT I HAD DONE ON THE PREVIOUS ACFT. I WAS PUZZLED AND ASKED TO READ THE ENGINEERING ORDER AGAIN. I DISCOVERED I HAD CHANGED THE WRONG SOLENOID. I SELF- DISCLOSED THE ERROR TO MY LEAD MECH, THE FOREMAN, AND ANOTHER FOREMAN THAT SAME SHIFT. THE ACFT WAS ROUTED BACK TO THE MAINT HANGAR THAT SAME DAY. THE ENGINEERING ORDER WAS CORRECTLY COMPLETED AND RELEASED FOR SVC BY SOMEONE OTHER THAN MYSELF. A REQUEST FOR ENGINEERING SVCS AT ACR HAS BEEN SUBMITTED TO REVISE THE ENGINEERING ORDER TO MODIFY BOTH LNDG GEAR HANDLES AND PURGE ALL (-1) SOLENOIDS FROM STOCK.

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.

Attributes
ACN	422618
Time
Date	199812
Day	Wed
Local Time Of Day	0001 To 0600
Place
Locale Reference	airport : zzz
State Reference	US
Altitude	agl bound lower : 0 agl bound upper : 0
Environment
Light	Night
Aircraft 1
Operator	common carrier : air carrier
Make Model Name	Fokker 100
Operating Under FAR Part	Part 121
Flight Phase	ground : parked other
Flight Plan	None
Person 1
Affiliation	company : air carrier
Function	other personnel other
Qualification	other other : other
ASRS Report	422618
Person 2
Affiliation	company : air carrier
Function	other personnel other
Qualification	other other : other
Events
Anomaly	aircraft equipment problem : less severe non adherence : published procedure non adherence : far
Independent Detector	other other : unspecified
Resolutory Action	none taken : detected after the fact
Consequence	Other
Supplementary
Air Traffic Incident	other

A fokker 100 was dispatched and operated with the alternate landing gear handle lock solenoid replaced. Engineering order required replacement of the normal landing gear handle lock solenoid. Error was caused by a publication deficiency.