Narrative:

The event occurred on flight X, an IFR flight between sarasota and orlando. The WX was a mixture of VMC and IMC with scattered twring cumulus and thundershowers. Tpa approach had given us deviations as necessary to avoid the cells and to join the minee 3 arrival north of the lakeland VOR. The situation arose when the autoplt did not capture the assigned altitude of 11000 ft. Tpa approach assigned us 11000 ft, which I (the PNF) entered in the altitude preselector. We were climbing at about 1000 FPM when we approached a bank of cumulus clouds. In order to get on top of these clouds the captain utilized a toggle switch. (This switch allows the airplane to pitch up 1 degree for each click. You can pitch the aircraft up faster using the toggle switch than using the 'climb' button on the flight director.) this increased our climb rate to around 2000 FPM and a pitch attitude of 9 degrees. As we approached 11000 ft, I noticed that my 'altitude arm' light was not illuminated. I reprogrammed my flight director and the 'altitude arm' light appeared. I did not check the captain's flight director (I should have). When we reached 11000 ft, the autoplt did not capture altitude and we continued to climb. 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 captain and he took the airplane. We did not have a positive exchange of controls (we should have). Once he took control of the airplane he tried to reprogram his flight director and engage the autoplt. While he was trying to do this, we started climbing again due to several factors. First, the aircraft was still trimmed for climbing flight. Secondly, we were very light on that flight and the aircraft was accelerating quickly. Couple this with an out of trim aircraft and it still wanted to climb. Third, we were over some cumulus clouds and were getting updrafts from them. Finally, because we did not have a positive exchange of controls, the captain inherited all of these conditions while trying to figure out what went wrong and fix the situation. I noticed that we were climbing again and stated 'climbing' to the captain. At 11400 ft he pushed over and descended to 11000 ft. Upon discussing the situation with the captain, he stated that sometimes when you use the toggle switch aggressively it will click off the 'altitude arm' mode of the autoplt. I believe that this should be brought up in training and when the toggle switch is used the pilots should rechk their flight directors to make sure that they are still armed to capture their altitude.

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Original NASA ASRS Text

Title: 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.

Data retrieved from NASA's ASRS site as of July 2007 and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.