AN ACR MD83 FLC FAILS TO CAPTURE AN OUTBOUND RADIAL WHILE OPERATING THE ACFT ON AUTOPLT. THE L SEAT PLT WAS AN IOE CAPT ON HIS FIRST LEG GETTING A LESSON FROM THE PIC CHK PLT ON THE USE OF THE WX RADAR.

Narrative

WHILE GIVING A NEW CAPT HIS IOE ON THE MD83 WE DEVIATED 8-10 NM W OF THE 159 DEG RADIAL FROM ROSEBURG; OR. THIS WAS THE CAPT'S FIRST IOE; AND I WAS IN THE R SEAT WHILE HE GETS HIS REQUIRED 25 HRS IN. WE WERE DISCUSSING THE WX RADAR (ITS USE); AND I BECAME INVOLVED IN MY EXPLANATION. WE STOPPED WHAT WE WERE DOING WHEN WE APCHED ROSEBURG; TO JOIN THE 159 DEG RADIAL AND TO DO A FINAL PROGRESS CHK. BOTH OF US SET THE OUTBOUND COURSE. THE CAPT (STUDENT) USED HEADING SELECT MODE TO TURN TO THE OUTBOUND COURSE AND ARMED THE VOR FOR AUTO TRACKING. OUR MISTAKE WAS TO RETURN TO OUR RADAR DISCUSSION PRIOR TO THE RADIAL ACTUALLY BEING CAPTURED. I FIRST NOTICED OUR DEV FROM COURSE BUT ESTIMATED US TO JUST BE ON THE BOUNDARY OF THE AIRWAY. I BROUGHT THIS TO THE CAPT'S (STUDENT'S) ATTN. HE PROMPTLY TURNED L 30 DEGS TO REINTERCEPT. ATC THEN SAID WE WERE APPROX 8-10 NM W OF COURSE. I SAID WE SHOULD WE WERE ONLY ABOUT 3 NM. HE SAID NO PROB. I THINK AS A CHK CAPT WE CAN GET OVERLOADED SOMETIMES BY TRYING TO DO TOO MUCH TEACHING AT ONE TIME. NEXT TIME I WON'T GO INTO THE TEACHING MODE SO QUICKLY; UNTIL I KNOW THE TASK AT HAND IS WELL IN HAND.