What was found
(CAN) THERE IS A POSSIBILITY THAT THE STATIC SWITCH VALVE AND STATIC VALVE HANDLE HAVE BEEN INSTALLED INCORRECTLY ON SOME ACFT. IF INSTALLED INCORRECTLY, THE VALVE WOULD OPERATE AS FOLLOWS: THE VALVE HANDLE WOULD INDICATE NORMAL SOURCE WHEN THE VALVE IS IN THE ALTERNATE SOURCE POSITION. THIS SITUATION IS NEGLIGIBLE FROM A SAFETY POINT OF VIEW FOR THE FOLLOWING REASONS: THE SOURCE IS ONLY USED TO SWITCH THE ESIS INPUT FROM THE UPPER STATIC PORTS TO THE LOWER STATIC PORTS. THE ESIS SHOULD SEE NO FUNCTIONAL DIFFERENCE IF THERE IS A PROBLEM WITH THE UPPER AND GOES TO LOWER OR VICE VERSA. THE ADAHRS IS SEPARATE AND SPLITS THE UPPER AND LOWER PORTS BETWEEN THE PARALLEL ADAHRS1/2. MFG WILL ISSUE ADDITIONAL INSTRUCTIONS FOR OPERATORS INSPECTION OF THE VALVE INSTALLATION AND RECTIFICATION.