AN ACR WDB OVERSHOT ITS ALT ON A SID CLBOUT.

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FLT DFW-NRT ISSUED WORTH 5 TO 10000 FT. SET UP GLARESHIELD CTL PANEL WITH ASSIGNED ALT IN ALT SELECTOR WINDOW. BOTH CAPT AND I REMEMBER SEEING 10000 FT IN WINDOW IN BEFORE STARTING ENGS CHKLIST AND BEFORE TKOF CHKLIST. AFTER TKOF; PLANE WAS FLOWN TO ALT BY 'HAND' AND FLT DIRECTOR WAS IN USE. PASSING 10200 FT; ATC ADVISED 'YOU'RE SUPPOSED TO BE AT 10000 FT' AND WE SAW THAT 11000 FT WAS IN ALT SELECTOR WINDOW AND THE FMA ON SCREEN. WE LEVELED AT ABOUT 10400-10500 FT AND STARTED BACK DOWN TO 10000 FT AT WHICH TIME DEP SAID 'WELL; YOU'RE ALREADY THROUGH 10000 FT; CLB TO 17000 FT' AND SWITCHED US TO FTW ARTCC. THIS ACFT'S WDB PARTICULAR ALT SELECTOR ALLOWS YOU TO SET A DIFFERENT ALT BY MERELY 'BUMPING' THE KNOB AS OPPOSED TO SELECTING THEN PULLING/PUSHING KNOB. AS PRONE AS WE ARE TO JUST FLY THE FLT DIRECTOR AND GIVEN THE DIFFERENT SCAN OF THIS TYPE OF INSTRUMENTATION; IT IS EASY TO SEE HOW YOU COULD MISS AN OBVIOUS MISTAKE LIKE THIS OCCURRENCE. OBVIOUSLY; IN REACHING FOR ALL THE BUTTONS AND KNOBS ON THE GLARESHIELD CTL PANEL; THE ALT SELECTOR WAS BUMPED. INCIDENTALLY; THE ALT SELECTOR GOES IN 500 FT INCREMENTS ABOVE 10000 FT WHICH COULD IN PART EXPLAIN WHY WE DIDN'T HAVE SOME ODD BALL ALT (LIKE 10300 FT) IN THE WINDOW WHEN WE FINALLY SAW THE 11000 FT IN THE ALT SELECTOR WINDOW. SUPPLEMENTAL INFO FROM ACN 228224: THE GLARESHIELD CTL PANEL ON THE WDB IS A VERY BUSY AREA DURING TKOF; CLB; APCH AND LNDG. THERE ARE APPROX 60 BUTTONS; KNOBS; WHEELS; ETC ON THIS PANEL AND SEVERAL ARE USED TO CTL THE ACFT DURING THE BUSY PHASES OF FLT. THE ALT CTL WINDOW IS SET BY TURNING THE ALT KNOB TO THE DESIRED SETTING AND THIS ALSO PLACES THE ALT IN THE ALT WINDOW OF THE FLT DIRECTOR AND AUTOMATICALLY ARMS THAT ALT. THE ALT SETTING KNOB DOES NOT HAVE TO BE PULLED TO ARM. THEREFORE; ANY UNINTENTIONAL MOVEMENT OF THE KNOB ARMS ANOTHER ALT. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: THE RPTING CAPT DOES NOT KNOW WHAT ACTUALLY CAUSED THE WRONG ALT TO BE SET IN THE WINDOW. IT IS POSSIBLE THAT A 'JOLT' OR 'BRUSH' OF THE HAND MIGHT HAVE CHANGED THE SETTING; OR THAT THE WRONG ALT WAS INADVERTENTLY INSERTED AND ALL 4 CREWMEN FAILED TO NOTICE THAT THE ALT REQUESTED WAS 1000 FT HIGH. THE CAPT HAS NOT EXPERIMENTED TO SEE IF ONE CAN 'BUMP' THE ALT SELECT KNOB OUT OF ITS SELECTED POS. THE RPTING CAPT NOTES THAT MANY OF THE CREWMEN THAT TRANSITION FROM ANOTHER WDB FROM THE SAME MANUFACTURER TRY TO 'ARM' THE ALT SELECT BY PULLING THE KNOB AS THEY HAD TO DO IN THE PREVIOUS ACFT. SOMEONE MAY HAVE INADVERTENTLY TWISTED THE KNOB 2 CLICKS WHEN TRYING TO ARM THE ALT SELECT.