Citation Excel (C560XL)
Maintenance Airframe; Maintenance Powerplant
Maintenance Technician 14
Situational Awareness; Training / Qualification; Confusion
Aircraft Equipment Problem Less Severe; Deviation / Discrepancy - Procedural Maintenance; Deviation / Discrepancy - Procedural Published Material / Policy
General Maintenance Action
Human Factors; Manuals
I replaced an airspeed switch for a stab mis-compare squawk. I performed an ops check of the two position horizontal stab system I/A/W CE560XL m/m chap. 27-40-00 and believed the system checked ok per the maintenance manual. [Seven weeks later] I was contacted by my supervisor and advised that the aircraft was in inspection and during the operational check of the horizontal stab system it was discovered that the airspeed switch failed the operational check and was installed incorrectly. After being made aware of this instance I was counseled on paying attention to the proper installation of components and indications during the operational checks. The company made a training PowerPoint for its employees to bring awareness to this issue and other components that can be installed incorrectly. Also a technical publication change request was submitted by Cessna from a request made by QAC to note/warn of the possibility of this switch being able to be installed incorrectly.When I installed the switch and performed the ops check I believed it to check good IAW the MM and would not have released the aircraft otherwise. I have learned to pay closer attention to the components before and after install to try and assure this does not happen again.
A Maintenance Technician was advised that the part he replaced several months earlier had been installed incorrectly. The fault was identified by the failure of the horizontal stabilizer operational check during routine inspection.