Flight Crew Flight Engineer; Flight Crew Multiengine; Flight Crew Air Transport Pilot (ATP)
Flight Crew Last 90 Days 90; Flight Crew Total 28700; Flight Crew Type 505
Distraction; Workload
Aircraft Equipment Problem Less Severe; Deviation - Altitude Overshoot; Deviation - Altitude Crossing Restriction Not Met; Deviation / Discrepancy - Procedural Published Material / Policy; Inflight Event / Encounter CFTT / CFIT
Flight Crew Took Evasive Action; Flight Crew Returned To Clearance
Human Factors; Weather; Aircraft
Captain was on an intercept heading to join the ILS XXR. We were assigned 2;400 feet to join the ILS XXR. I was making a First Officer instrument sub panel change and was head down and noticed the jet at 1;750 feet when it should have been 2;400. At the same Approach noticed it and repeated the assigned altitude. That was my first time in the right seat on the Citation V. Previous limited in training with the company was left seat only. It was also my first revenue flight with the company. I did fly both seats in the CE500 in the early 1980's. We landed without further incident but we did not have the terrain separation desired while at that altitude. There was no other traffic that time of night fortunately. Later that night when I flew 2 legs I did notice that that the autopilot would not always capture altitudes while descending with altitude select annunciated. Possible contributing factor was the short notice flight assignment on a late night mission.
A CE560 First Officer reported the aircraft did not capture 2;400 feet on approach and while he was heads down the Captain allowed a descent to 1;750 feet before both he and ATC alerted about the deviation.