FLC OF AN MD88 NOTED THAT THE 'WX ON' AND RADAR DISPLAYED PREDICTIVE WINDSHEAR ON AFTER PUSHBACK AND ENG START RESULTING IN IRRADIATING THE PUSH BACK GND CREW. THE XPONDER SWITCH WAS FOUND TO BE IN THE 'ALT OFF POS' INSTEAD OF 'STANDBY.'

Narrative

AFTER PUSHBACK AND ENG START WE NOTICED OUR PRIMARY FLT DISPLAYS INDICATED 'WX ON;' AND THE RADAR DISPLAY INDICATED 'PREDICTIVE WINDSHEAR ON.' THIS INDICATED THAT THE PREDICTIVE WINDSHEAR SYS WAS ACTIVE AND THE WX RADAR WAS ON; LOOKING FOR WINDSHEAR AND IRRADIATING THE PUSHBACK CREW. I PULLED THE WX RADAR CIRCUIT BREAKER AND INVESTIGATED. OUR PLT'S REF MANUAL SAYS THE PREDICTIVE WINDSHEAR SYS IS ON WHEN BOTH ENGS ARE RUNNING AND THE XPONDER IS ON. IN THIS CASE THE XPONDER WAS SET TO 'ALT OFF.' THIS SWITCH POS IS ONE CLICK FROM 'STANDBY' WHICH IS WHERE THE SWITCH SHOULD HAVE BEEN. THE INBOUND CREW MUST HAVE LEFT IT IN 'ALT OFF' AND WE DID NOT NOTICE; DESPITE A THOROUGH PREFLT CHK. THE SWITCH IS SMALL AND HAS 6 POS MAKING IT EASY TO MISSET. THE PREDICTIVE WINDSHEAR SYS IS NEW TO THE FLEET AND OUR TRAINING FOR ITS USE INCLUDED ONLY A CHANGE TO THE PLT'S REF MANUAL. NO CHANGES WERE MADE TO OUR NORMAL PROCS OR CHKLISTS. THERE NEEDS TO BE A 'WARNING' IN OUR NORMAL PROCS THAT SAYS 'WARNING; IF THE XPONDER IS ON AND BOTH ENGS ARE RUNNING; THE WX RADAR IS ON.' THERE NEEDS TO BE BULLETIN ISSUED TO INSURE EVERY CREW UNDERSTANDS THAT THE XPONDER SWITCH IS VERY IMPORTANT AND IF LEFT IN THE WRONG POS CAN HURT PEOPLE. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: RPTR STATED THAT HE HAD RPTED AND DISCUSSED THIS PROB WITH HIS COMPANY WITH REGARD TO THE POSSIBILITY OF THE FLC'S NOT UNDERSTANDING THAT THE WX RADAR AUTOMATICALLY COMES ON WHEN THE ENGS ARE STARTED AND THE XPONDER SWITCH IS NOT SET ON OFF; OR STANDBY POS. HE WAS ADVISED THAT THE COMPANY WAS DISSEMINATING AN ALERT NOTICE VIA THEIR FLC BULLETIN. HE ALSO ADVISED THAT THE FULL OP PROC IS COVERED IN THEIR ACFT OPS MANUAL BUT THE SUBJECT IS NOT COVERED IN THE ACFT PREFLT CHKLIST DUE TO THE ABBREVIATED FORM OF THE CHKLIST FORMAT.