Gulfstream G200 (IAI 1126 Galaxy)
Flight Crew Multiengine; Flight Crew Air Transport Pilot (ATP)
Flight Crew Last 90 Days 65; Flight Crew Total 9000; Flight Crew Type 470
Workload; Distraction; Communication Breakdown
Aircraft Equipment Problem Less Severe; Deviation - Altitude Excursion From Assigned Altitude; Flight Deck / Cabin / Aircraft Event Other / Unknown
Flight Crew Returned To Clearance
Aircraft; Human Factors
I was PIC; and due to crew conflicts; a contracted Captain was SIC and was sitting in the left seat as the PF. I sat in the right seat as PNF. We taxied and took off from FXE and during our climb trough 3;500 FT we received a L BAT RED CAS message. The temperature was 170 degrees and RED ([requiring that we] land as soon as possible.) Operating under the Gulfstream SOPs I actioned to the QRH and the PF continued to aviate and had control of the radios. After performing the QRH actions the CAS message was cleared; and we decided to continue. Approximately two minutes later we received the same CAS message and requested a return to our departure airport. Center stopped our climb at 8;000 FT and we were given a vector back to the airport and a descent. I again performed the QRH procedure and; when I was finished; took the radios back and was cleared to maintain 1;500 FT. I looked at the Altimeter and called out to the PF that he was descending below 1;500 FT. He immediately pulled back and regained 1;500 FT. We landed without event and no emergency was declared. I asked the PF about his ALT deviation when we landed; he told me he was only 150 FT low when asked to maintain 1;500 FT by ATC. He apologized and said he was distracted in the moment dealing with the abnormality and an FMS that was intermittent. I was not able to confirm how great the deviation was; and wanted to report this incident in the event that it was indeed greater than 150 FT. ATC did not ask us to call or report to anyone yet I still wanted to report this event. I think the unfamiliar crew; and the maintenance issues were contributing factors.
While the flight crew of a GLF 200 was managing a battery overheat and a return to their departure airport the PF; a temporary contracted airman; descended 150 FT below their cleared altitude.