A United Airlines 737-800 on approach to Santa Ana. A California National Guard UH-60M Black Hawk crossing its path. Five hundred feet of vertical separation between them. That geometry is alarming. But the investigation that follows shouldn't stop at the cockpits. **The gap isn't airspace. It's procedure.** SNA sits inside Class C airspace — a 10-nautical-mile radius shelf designed to manage the density of commercial and general aviation traffic around busy metro airports. Class C requires two-way radio contact and ATC advisories. What it does not require, for VFR military traffic, is a full IFR clearance with its associated sequencing obligations. That distinction is the structural problem. The 737 crew was flying an IFR approach under precise ATC sequencing. The Black Hawk crew was operating under a fundamentally different communication framework — advisory-based, not clearance-based. Both were legal. Neither was fully visible to the other in the way the system implies they should be. **ATC cannot bridge a gap it wasn't designed to close.** Controllers managing Class C airspace around mixed-use metro corridors are coordinating across two parallel information streams. IFR commercial traffic flows through a tightly choreographed sequence. Military VFR traffic flows through a looser advisory channel. The coordination protocols between those streams — especially when military missions operate on short notice — were not built for the traffic density that corridors like SNA now carry. The FAA has opened a formal investigation into the incident. What that investigation can fix through procedure is limited: tighter coordination requirements, revised military VFR notification timelines. What it cannot fix through procedure alone is the underlying visibility gap — military VFR aircraft are not universally subject to the ADS-B equipage mandates that give IFR controllers a complete traffic picture. Closing that gap requires a technology mandate, not a memo. DCA in January. SNA now. The pattern is established. The seam stays open.