DFW Controller providing OJT experienced near loss of separation event when approving patrol operation during seldom used East flow operations; reporter noting; given the circumstances; the patrol approval was inappropriate.

Narrative

While conducting OJT on Local East 3; my developmental and myself worked a patrol aircraft through DFW's Bravo Airspace from the South to the North. I performed the necessary coordinations and point-outs as the aircraft approached DFW Airport; which was in a NORTH flow. As the aircraft neared the airport; jet arrivals on the parallel final approach courses on both sides of patrol aircraft were being executed. Eventually; I was forced to instruct the patrol aircraft to make right 360 degree turns between DFW's East and West Complexes and provide my own visual separation until the pilot could do so. Recommendation; DFW Airport operates in a south flow 75-80% of the calendar year; and pipeline patrols are very common. My willingness to conduct this operation; and my very fallible level of confidence in the whole matter was related to my mindset of being in a SOUTH flow. The problem; DFW Airport had been in a NORTH flow during the preceeding several hours of my shift!! The combination of conducting a patrol operation in close proximity to the approach ends of ILS runways in MVFR conditions was a terrible decision on my part; and I shared this philosophy with my developmental afterwards. Luckily; I was able to provide the necessary visual separation between aircraft and all were able to see each other; but I was 'betting on the come' without even realizing it until it would have been too late if *every* facet of this operation hadn't gone perfectly. In the future; I will do exactly as I recommended to my trainee; just say 'unable' when you're not able to provide a safe service with numerous secondary options should they become necessary.