WESTWIND II FLT CREW OVERSHOOTS ALT IN ZOB AIRSPACE.

Narrative

ALTHOUGH I HAD FILED THE FLT PLANS; MY BOSS; AND CHIEF PLT FOR THE COMPANY; WAS IN THE L SEAT AND FLYING AT THE TIME. WE HAD BEEN CLRED FROM FL330 TO FL350 AND WERE ON AN ASSIGNED HDG AT THE TIME. WHILE CLBING TO FL350; CTR RECLRED US TO VHP; I WAS CHANGING THE INFO IN THE GPS FOR VHP WHEN I NOTICED OUT OF THE CORNER OF MY FIELD OF VIEW; THAT WE WERE JUST PASSING THROUGH FL350. BY THE TIME I FOCUSED ON THE ALTIMETER; THE 200 FT ALT LIGHT AND CHIME WENT OFF. I CALLED 'ALT' TO THE CHIEF PLT AND HE ARRESTED THE CLB BUT NOT BEFORE WE REACHED FL354. CTR NOTICED AND INQUIRED. I TOLD THEM WE WERE AWARE AND WERE CORRECTING BACK TO ASSIGNED ALT AND THAT THE AUTOPLT HAD NOT CAPTURED THE SELECTED ALT; WHICH WAS VERY TRUE SINCE THE CHIEF PLT HAD NEGLECTED TO ENGAGE THE ALT SELECT IN THE CLB. ALSO; AT SOME POINT HE TURNED OFF OUR MODE C BECAUSE CTR CALLED BACK AND SAID 'YOU CAN TURN YOUR MODE C BACK ON NOW.' CTR DID NOT SEEM PARTICULARLY UPSET BY ANY OF THIS AND FORTUNATELY THERE WERE NO TFC CONFLICTS. I AM QUITE SURE THIS WOULD NOT HAVE OCCURRED AT ALL HAD THE CHIEF PLT NOT BEEN DISTR BY TRYING TO READ UNRELATED MATERIAL AT THE TIME. MY LESSON: DOUBLECHK EVERYONE; EVEN YOUR CHIEF PLT. THE OMISSION OF PUSHING EVEN 1 BUTTON (ALT SELECT) COULD HAVE DISASTROUS CONSEQUENCES.