A pilot's forum post raising a practical airspace communication question has surfaced a notable regional inconsistency in how general aviation pilots handle air-to-air position broadcasts outside of controlled airspace and away from ATC services. The original poster, trained and instructing in San Diego, describes a local convention of broadcasting position and maneuvering intentions on 122.75 MHz — a frequency the FAA's Aeronautical Information Manual (Table 4-1-3) does list as an air-to-air communications frequency for use by general aviation aircraft below 18,000 feet when not talking to ATC or operating in the vicinity of an airport. What makes the post noteworthy is the poster's discovery, through cross-country flying for Pilots N Paws transport missions and CFII training outside California, that this practice is essentially a San Diego-area idiosyncrasy rather than a nationwide norm. In most other regions the poster sampled, including the Bay Area and Bakersfield, 122.75 saw only sporadic or specialized use (formation flying coordination, aerial survey work) rather than serving as a de facto regional "party line" for traffic awareness.
For working pilots, this thread underscores a real gap between what the AIM formally sanctions and what actually happens in practice across different flying communities. The AIM's guidance on 122.75 is permissive rather than prescriptive — it's an available tool, not a mandated one — and pilots naturally converge on local norms that often aren't documented anywhere official. This matters operationally because pilots transiting into unfamiliar airspace, particularly those flying VFR without flight following (as the poster notes is often the case during their Pilots N Paws legs), may have a mental model of "who's talking on what frequency" that doesn't match local expectations. A pilot accustomed to broadcasting maneuvering intentions on 122.75 near San Diego could find themselves essentially transmitting into a vacuum in another region, while local traffic is coordinating on the nearest CTAF instead — creating a false sense of situational awareness on both sides. This is especially relevant for instructors, since the poster notes having taught the 122.75 habit to students for two years, effectively propagating a regional convention as if it were universal practice.
This ties into a broader and ongoing tension in the GA and Part 91/135 world around non-towered airspace communication discipline, especially as traffic density increases in busy VFR corridors and near non-towered fields. The FAA has periodically addressed CTAF misuse and self-announce procedures (including guidance discouraging blind "in the blind" calls on CTAF far from the airport environment, and reminders that 122.9 MUNICOM/122.75 air-to-air are not substitutes for proper CTAF use near airports). The rise of ADS-B In traffic displays has somewhat mitigated the risk of undetected conflicts, but radio communication remains a key layer of the see-and-avoid and situational-awareness stack, particularly for aircraft without ADS-B In or for traffic that isn't broadcasting reliably. Corporate and charter operators flying into unfamiliar non-towered strips, as well as flight schools training students who will eventually fly cross-country solo or as PIC, should treat this thread as a reminder to brief regional frequency conventions before a trip rather than assume home-base habits transfer nationally — a quick check of the Chart Supplement, local CTAF, and any regional air-to-air convention (via FBOs, local pilots, or online GA forums) can prevent the kind of communication mismatch the original poster stumbled into.
Finally, the discussion highlights a subtler professional development issue: regional aviation subcultures can quietly diverge from standardized practice without any formal feedback loop to correct it, since CFIs teach what they were taught, and that knowledge often doesn't get cross-checked against how other regions actually operate until a pilot happens to travel, change instructors, or (as here) fly missions that take them well outside their home training area. For check airmen, DPEs, and flight school chief instructors, it's a useful cue to periodically audit whether "the way we've always done it" locally still aligns with the AIM's actual intent and with what pilots elsewhere are doing, rather than assuming one region's convention is the default everywhere.