Narrative:

Incident of aircraft X rtf due to main landing gear proximity sensor targets installed backwards (also resulted in overweight landing). Required maintenance action on jul/xa/07 was to remove and replace both #1 main landing gear torque links. Both torque links were replaced in accordance with CRJ700 amm task: install the weight on wheels 'wow' target (4) on the upper torque link (1) as follows:...install the bolts (8); the washers (7); and the nuts (6) with the note! 'To make sure that you install the targets in the correct position. When the landing gear is extended; the sensor will be above the larger notch; aft of the sensor face.' this statement was very unclr (without a drawing) at this point in the installation; illustrating the above statement; which was a factor in a mechanic installing the targets backwards and other steps being missed or done incorrectly. Other unclr statements in the amm are as follows: 1) landing gear extended? Sitting on the ground or aircraft on jacks? At this point in the installation no statement to jack up the aircraft. 2) targets not clearly marked l-hand; r-hand; inboard/outboard. 3) landing gear extended statement; should read with landing gear strut extended...also I asked inspection if we should swing the landing gear and was told; 'only if required by the maintenance manual or gmm' which they didn't. Other factors were many distrs; pressure perceived or actual to meet a set etr; lack of experience on this job; at the same time working with a new hire and a non line mechanic (both good mechanics); still all of this is no excuse for the events that followed. Human factors idented: lack of knowledge; distrs; operation pressure. Will be more assertive when pressured. Not to be pushed to complete a job. Submitting a technical publication change request to correct some unclr procedures. Seek out other help.

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Original NASA ASRS Text

Title: A CRJ700 ACFT RETURNED TO FIELD DUE TO PROXIMITY SENSOR TARGETS INSTALLED BACKWARDS. ACFT LANDED IN OVERWEIGHT CONDITION.

Narrative: INCIDENT OF ACFT X RTF DUE TO MAIN LNDG GEAR PROX SENSOR TARGETS INSTALLED BACKWARDS (ALSO RESULTED IN OVERWT LNDG). REQUIRED MAINT ACTION ON JUL/XA/07 WAS TO REMOVE AND REPLACE BOTH #1 MAIN LNDG GEAR TORQUE LINKS. BOTH TORQUE LINKS WERE REPLACED IN ACCORDANCE WITH CRJ700 AMM TASK: INSTALL THE WT ON WHEELS 'WOW' TARGET (4) ON THE UPPER TORQUE LINK (1) AS FOLLOWS:...INSTALL THE BOLTS (8); THE WASHERS (7); AND THE NUTS (6) WITH THE NOTE! 'TO MAKE SURE THAT YOU INSTALL THE TARGETS IN THE CORRECT POS. WHEN THE LNDG GEAR IS EXTENDED; THE SENSOR WILL BE ABOVE THE LARGER NOTCH; AFT OF THE SENSOR FACE.' THIS STATEMENT WAS VERY UNCLR (WITHOUT A DRAWING) AT THIS POINT IN THE INSTALLATION; ILLUSTRATING THE ABOVE STATEMENT; WHICH WAS A FACTOR IN A MECH INSTALLING THE TARGETS BACKWARDS AND OTHER STEPS BEING MISSED OR DONE INCORRECTLY. OTHER UNCLR STATEMENTS IN THE AMM ARE AS FOLLOWS: 1) LNDG GEAR EXTENDED? SITTING ON THE GND OR ACFT ON JACKS? AT THIS POINT IN THE INSTALLATION NO STATEMENT TO JACK UP THE ACFT. 2) TARGETS NOT CLRLY MARKED L-HAND; R-HAND; INBOARD/OUTBOARD. 3) LNDG GEAR EXTENDED STATEMENT; SHOULD READ WITH LNDG GEAR STRUT EXTENDED...ALSO I ASKED INSPECTION IF WE SHOULD SWING THE LNDG GEAR AND WAS TOLD; 'ONLY IF REQUIRED BY THE MAINT MANUAL OR GMM' WHICH THEY DIDN'T. OTHER FACTORS WERE MANY DISTRS; PRESSURE PERCEIVED OR ACTUAL TO MEET A SET ETR; LACK OF EXPERIENCE ON THIS JOB; AT THE SAME TIME WORKING WITH A NEW HIRE AND A NON LINE MECH (BOTH GOOD MECHS); STILL ALL OF THIS IS NO EXCUSE FOR THE EVENTS THAT FOLLOWED. HUMAN FACTORS IDENTED: LACK OF KNOWLEDGE; DISTRS; OP PRESSURE. WILL BE MORE ASSERTIVE WHEN PRESSURED. NOT TO BE PUSHED TO COMPLETE A JOB. SUBMITTING A TECHNICAL PUB CHANGE REQUEST TO CORRECT SOME UNCLR PROCS. SEEK OUT OTHER HELP.

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.