diff --git a/retina_simulation/orchestrator.py b/retina_simulation/orchestrator.py
index 26ab0b2..7075d01 100644
--- a/retina_simulation/orchestrator.py
+++ b/retina_simulation/orchestrator.py
@@ -697,6 +697,37 @@ def build_ground_truth_payload(aircraft_summaries: list[dict]) -> list[dict]:
     return payload_aircraft
 
 
+def build_adsb_push_payload(aircraft_summaries: list[dict]) -> list[dict]:
+    """Remap world aircraft summaries to the server ADS-B push schema.
+
+    Transponder-equipped aircraft only.  This push IS the simulated ADS-B
+    broadcast, and a dark target by definition emits none — pushing it with
+    its object id standing in for the hex minted a fake transponder per dark
+    aircraft on the server, so every dark solve keyed mn-adsb-* and the dark
+    lane stayed permanently empty.  Dark aircraft still reach the server
+    through the ground-truth push, where the object id is the intended key
+    (build_ground_truth_payload above).
+    """
+    payload_aircraft = []
+    for ac in aircraft_summaries:
+        hex_code = ac.get("adsb_hex") or ""
+        if not hex_code:
+            continue
+        speed_ms = ac.get("speed_ms", 0)
+        payload_aircraft.append(
+            {
+                "hex": hex_code,
+                "flight": "",
+                "lat": round(ac["lat"], 5),
+                "lon": round(ac["lon"], 5),
+                "alt_baro": round(ac["alt_km"] * 1000 / 0.3048),
+                "gs": round(speed_ms * 1.94384, 1),
+                "track": round(ac.get("heading", 0), 1),
+            }
+        )
+    return payload_aircraft
+
+
 async def _push_ground_truth_live(
     orchestrator: FleetOrchestrator,
     base_url: str,
@@ -971,25 +1002,7 @@ async def _push_adsb_live(
 
         try:
             aircraft_raw = orchestrator.world.get_aircraft_summary()
-            payload_aircraft = []
-            for ac in aircraft_raw:
-                # Push ALL aircraft — ADS-B and dark/drone/anomalous alike.
-                # ADS-B aircraft use their transponder hex; others use object_id.
-                hex_code = ac.get("adsb_hex") or ac.get("id", "")
-                if not hex_code:
-                    continue
-                speed_ms = ac.get("speed_ms", 0)
-                payload_aircraft.append(
-                    {
-                        "hex": hex_code,
-                        "flight": "",
-                        "lat": round(ac["lat"], 5),
-                        "lon": round(ac["lon"], 5),
-                        "alt_baro": round(ac["alt_km"] * 1000 / 0.3048),
-                        "gs": round(speed_ms * 1.94384, 1),
-                        "track": round(ac.get("heading", 0), 1),
-                    }
-                )
+            payload_aircraft = build_adsb_push_payload(aircraft_raw)
 
             if not payload_aircraft:
                 continue
diff --git a/tests/test_adsb_push_payload.py b/tests/test_adsb_push_payload.py
new file mode 100644
index 0000000..2c081f4
--- /dev/null
+++ b/tests/test_adsb_push_payload.py
@@ -0,0 +1,56 @@
+"""ADS-B push payload schema (build_adsb_push_payload).
+
+The push is the simulated ADS-B broadcast, so it must carry transponder
+aircraft only.  The old inline loop substituted the object id for a missing
+hex, which minted a fake transponder per dark aircraft on the server — every
+dark solve then keyed mn-adsb-* and the server's dark lane stayed empty.
+"""
+
+from retina_simulation.orchestrator import build_adsb_push_payload
+
+
+def _summary(**overrides) -> dict:
+    base = {
+        "id": "obj-0001",
+        "lat": 34.85,
+        "lon": -82.4,
+        "alt_km": 9.5,
+        "heading": 270.0,
+        "speed_ms": 230.0,
+        "has_adsb": True,
+        "is_anomalous": False,
+        "object_type": "aircraft",
+        "adsb_hex": "a1b2c3",
+        "adsb_callsign": "ABC1234",
+        "anomaly_event": None,
+    }
+    base.update(overrides)
+    return base
+
+
+class TestBuildAdsbPushPayload:
+    def test_transponder_aircraft_pushed_under_its_hex(self):
+        out = build_adsb_push_payload([_summary()])
+        assert len(out) == 1
+        entry = out[0]
+        assert entry["hex"] == "a1b2c3"
+        assert entry["lat"] == 34.85
+        assert entry["alt_baro"] == round(9500 / 0.3048)
+        assert entry["gs"] == round(230.0 * 1.94384, 1)
+        assert entry["track"] == 270.0
+
+    def test_dark_aircraft_not_pushed(self):
+        """The regression: an aircraft with no adsb_hex must not appear at
+        all — above all not under its object id."""
+        out = build_adsb_push_payload([_summary(has_adsb=False, adsb_hex=None, adsb_callsign=None)])
+        assert out == []
+
+    def test_mixed_fleet_keeps_only_transponder_aircraft(self):
+        out = build_adsb_push_payload(
+            [
+                _summary(),
+                _summary(id="obj-0002", has_adsb=False, adsb_hex=None),
+                _summary(id="obj-0003", adsb_hex="d4e5f6"),
+            ]
+        )
+        assert [e["hex"] for e in out] == ["a1b2c3", "d4e5f6"]