FLC OF AN EMBRAER 120 OVERSHOT ASSIGNED ALT DURING CLB DUE TO NOT RESETTING THE MODE CTL SELECTOR AFTER CHANGING THE PROGRAMMING OF THE FLT DIRECTOR FOR A HIGHER RATE OF CLB.

Narrative

THE EVENT OCCURRED ON FLT X; AN IFR FLT BTWN SARASOTA AND ORLANDO. THE WX WAS A MIXTURE OF VMC AND IMC WITH SCATTERED TWRING CUMULUS AND THUNDERSHOWERS. TPA APCH HAD GIVEN US DEVS AS NECESSARY TO AVOID THE CELLS AND TO JOIN THE MINEE 3 ARR N OF THE LAKELAND VOR. THE SIT AROSE WHEN THE AUTOPLT DID NOT CAPTURE THE ASSIGNED ALT OF 11000 FT. TPA APCH ASSIGNED US 11000 FT; WHICH I (THE PNF) ENTERED IN THE ALT PRESELECTOR. WE WERE CLBING AT ABOUT 1000 FPM WHEN WE APCHED A BANK OF CUMULUS CLOUDS. IN ORDER TO GET ON TOP OF THESE CLOUDS THE CAPT UTILIZED A TOGGLE SWITCH. (THIS SWITCH ALLOWS THE AIRPLANE TO PITCH UP 1 DEG FOR EACH CLICK. YOU CAN PITCH THE ACFT UP FASTER USING THE TOGGLE SWITCH THAN USING THE 'CLB' BUTTON ON THE FLT DIRECTOR.) THIS INCREASED OUR CLB RATE TO AROUND 2000 FPM AND A PITCH ATTITUDE OF 9 DEGS. AS WE APCHED 11000 FT; I NOTICED THAT MY 'ALT ARM' LIGHT WAS NOT ILLUMINATED. I REPROGRAMMED MY FLT DIRECTOR AND THE 'ALT ARM' LIGHT APPEARED. I DID NOT CHK THE CAPT'S FLT DIRECTOR (I SHOULD HAVE). WHEN WE REACHED 11000 FT; THE AUTOPLT DID NOT CAPTURE ALT AND WE CONTINUED TO CLB. I NOTICED THIS AND CLICKED OFF THE AUTOPLT AT 11200 FT AND STARTED TO MANUALLY LEVEL OFF THE PLANE. I STATED 'IT DIDN'T CAPTURE' TO THE CAPT AND HE TOOK THE AIRPLANE. WE DID NOT HAVE A POSITIVE EXCHANGE OF CTLS (WE SHOULD HAVE). ONCE HE TOOK CTL OF THE AIRPLANE HE TRIED TO REPROGRAM HIS FLT DIRECTOR AND ENGAGE THE AUTOPLT. WHILE HE WAS TRYING TO DO THIS; WE STARTED CLBING AGAIN DUE TO SEVERAL FACTORS. FIRST; THE ACFT WAS STILL TRIMMED FOR CLBING FLT. SECONDLY; WE WERE VERY LIGHT ON THAT FLT AND THE ACFT WAS ACCELERATING QUICKLY. COUPLE THIS WITH AN OUT OF TRIM ACFT AND IT STILL WANTED TO CLB. THIRD; WE WERE OVER SOME CUMULUS CLOUDS AND WERE GETTING UPDRAFTS FROM THEM. FINALLY; BECAUSE WE DID NOT HAVE A POSITIVE EXCHANGE OF CTLS; THE CAPT INHERITED ALL OF THESE CONDITIONS WHILE TRYING TO FIGURE OUT WHAT WENT WRONG AND FIX THE SIT. I NOTICED THAT WE WERE CLBING AGAIN AND STATED 'CLBING' TO THE CAPT. AT 11400 FT HE PUSHED OVER AND DSNDED TO 11000 FT. UPON DISCUSSING THE SIT WITH THE CAPT; HE STATED THAT SOMETIMES WHEN YOU USE THE TOGGLE SWITCH AGGRESSIVELY IT WILL CLICK OFF THE 'ALT ARM' MODE OF THE AUTOPLT. I BELIEVE THAT THIS SHOULD BE BROUGHT UP IN TRAINING AND WHEN THE TOGGLE SWITCH IS USED THE PLTS SHOULD RECHK THEIR FLT DIRECTORS TO MAKE SURE THAT THEY ARE STILL ARMED TO CAPTURE THEIR ALT.