Date: 201709
Local time of day: 1801-2400
Location: APA.Airport, CO
Flight conditions: VMC
Weather elements / visibility: Turbulence
Light: Daylight
Aircraft: Challenger CL600
Operator: Corporate
Operating under: Part 91
Flight plan: IFR
Mission: Personal
Flight phase: Descent
Airspace: Class E D01
ATC / advisory: TRACON D01
Reporter organization: Corporate
Reporter function: Captain; Pilot Not Flying
Reporter qualification: Flight Crew Multiengine; Flight Crew Instrument; Flight Crew Flight Instructor; Flight Crew Flight Engineer; Flight Crew Air Transport Pilot (ATP)
Human factors: Situational Awareness
Anomaly: Aircraft Equipment Problem Less Severe; Deviation - Altitude Excursion From Assigned Altitude; Deviation / Discrepancy - Procedural Clearance
Detector: Person Flight Crew
When detected: In-flight
Result: Flight Crew Became Reoriented; Flight Crew Returned To Clearance
Contributing factors: Human Factors
Primary problem: Human Factors

Narrative: A bit of an odd report and I was a bit reluctant to file this; but I'm a bit old school and see a trend that I don't like. We were on the DUNNN2 RNAV Arrival into the Denver's Centennial (APA) airport and were provided with some shortcuts that actually simplified the procedure. The ATC Controller said to 'descend and maintain 14;000 FT and be level in 5 minutes.' The pilot flying started his clock and had the time/altitude restriction wired using the vertical speed mode of the autopilot. We entered some moderate turbulence at 14;300 FT during the descent and the autopilot disengaged but the pilot flying did not notice. I may not have noticed immediately because I was setting both heading bugs. Normal non-flying pilot duties.If I didn't see the disconnect right away; I'm sure within three to five five seconds I observed the autopilot disconnect annunciator light. I verbalized that the autopilot kicked off and to get the nose down. I saw the slight nose up tendency which was probably due to the stab trim condition and perhaps the effect of the bumpy air. The pilot flying saw the altitude increase and instead of manually flying (like I would have thought a jet pilot would do) and pushing the nose over slightly; he was using/manipulating the autopilot vertical speed wheel to arrest the climb.I was focused on his flight instruments and saw his right hand on the yoke (and trying to determine if we had a runaway trim or flight control malfunction) but didn't realize that his focus was on the darn now non-functioning (and slow to command even if it was working) vertical speed wheel. I said; 'I have it' and made a quick recovery but we topped out at almost 15;000 FT with a then expeditious return to our assigned altitude of 14;000 FT.I have stressed good hand flying skills to this aviator and have insisted that he practice honing those skills. He has good hand flying abilities but I'm sure that many aviators are reluctant to disengage and go down on the automation ladder when needed. I don't believe a loss of separation occurred because Denver TRACON gave us a turn just before this autopilot/pitch-up (that was why I was heads down setting both the independent HDG Bugs) occurrence happened.I would not be writing this if it wasn't for the 'be level in 5 minutes' clearance. Even with the altitude excursion we didn't miss the timing by much. Could I have done a better job? I'm sure; but I am fighting a culture of pilots that are too dependent on automation. If I [had] been the flying pilot; I have little doubt that ATC or anyone in the back of the airplane would have known of our issue. I would like to think that a near immediate transition to manual flight would have occurred; just like what you would see say on an ILS approach and disconnecting the autopilot on final. We don't disconnect and let the airplane do what it wants; we fly the darn thing. On a side note; I gave the airplane back to him after leveling and stabilizing and he re-engaged the autopilot.




Synopsis: CL60 Captain reported he noticed a deviation from assigned altitude when the autopilot disconnected; and observed that automation dependency was a factor in the excursion.