diff --git a/cmd/server/loadchunk_observer_iata_test.go b/cmd/server/loadchunk_observer_iata_test.go
new file mode 100644
index 00000000..715518ca
--- /dev/null
+++ b/cmd/server/loadchunk_observer_iata_test.go
@@ -0,0 +1,54 @@
+package main
+
+import (
+	"database/sql"
+	"os"
+	"path/filepath"
+	"testing"
+	"time"
+)
+
+// The background loader (loadChunk) fills in days 2-7 of the retention
+// window after the hot startup window. Its query left out the observer's
+// IATA code, so packets older than the hot window lost observer_iata in the
+// packets API and the iata filter (#1188), while Load and ingest kept it.
+func TestLoadChunkKeepsObserverIATA(t *testing.T) {
+	dir := t.TempDir()
+	dbPath := filepath.Join(dir, "iata.db")
+	createTestDBAt(t, dbPath, 20)
+	t.Cleanup(func() { os.RemoveAll(dir) })
+	conn, err := sql.Open("sqlite3", dbPath)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if _, err := conn.Exec(`INSERT INTO observers (id, name, iata) VALUES ('obs1', 'Obs1', 'SJC')`); err != nil {
+		t.Fatal(err)
+	}
+	conn.Close()
+
+	db, err := OpenDB(dbPath)
+	if err != nil {
+		t.Fatalf("OpenDB: %v", err)
+	}
+	t.Cleanup(func() { db.Close() })
+	store := NewPacketStore(db, &PacketStoreConfig{})
+	from := time.Date(2025, 12, 31, 0, 0, 0, 0, time.UTC)
+	if err := store.loadChunk(from, from.Add(72*time.Hour)); err != nil {
+		t.Fatal(err)
+	}
+	store.mu.RLock()
+	defer store.mu.RUnlock()
+	if len(store.packets) == 0 {
+		t.Fatal("loadChunk loaded nothing")
+	}
+	for _, tx := range store.packets {
+		for _, o := range tx.Observations {
+			if o.ObserverIATA != "SJC" {
+				t.Fatalf("tx %d: observation IATA = %q, want SJC", tx.ID, o.ObserverIATA)
+			}
+		}
+		if tx.ObserverIATA != "SJC" {
+			t.Fatalf("tx %d: IATA = %q, want SJC", tx.ID, tx.ObserverIATA)
+		}
+	}
+}
diff --git a/cmd/server/store.go b/cmd/server/store.go
index b6b3d898..d0f2fae5 100644
--- a/cmd/server/store.go
+++ b/cmd/server/store.go
@@ -1203,7 +1203,7 @@ func (s *PacketStore) loadChunk(from, to time.Time) error {
 	if s.db.isV3 {
 		chunkSQL = `SELECT t.id, t.raw_hex, t.hash, t.first_seen, t.route_type,
 				t.payload_type, t.payload_version, t.decoded_json,
-				o.id, obs.id, obs.name, o.direction,
+				o.id, obs.id, obs.name, COALESCE(obs.iata, ''), o.direction,
 				o.snr, o.rssi, o.score, o.path_json, strftime('%Y-%m-%dT%H:%M:%fZ', o.timestamp, 'unixepoch')` + obsRawHexCol + rpCol + scopeNameCol + `
 			FROM transmissions t
 			LEFT JOIN observations o ON o.transmission_id = t.id
@@ -1212,10 +1212,11 @@ func (s *PacketStore) loadChunk(from, to time.Time) error {
 	} else {
 		chunkSQL = `SELECT t.id, t.raw_hex, t.hash, t.first_seen, t.route_type,
 				t.payload_type, t.payload_version, t.decoded_json,
-				o.id, o.observer_id, o.observer_name, o.direction,
+				o.id, o.observer_id, o.observer_name, COALESCE(obs.iata, ''), o.direction,
 				o.snr, o.rssi, o.score, o.path_json, o.timestamp` + obsRawHexCol + rpCol + scopeNameCol + `
 			FROM transmissions t
-			LEFT JOIN observations o ON o.transmission_id = t.id` + filterClause + `
+			LEFT JOIN observations o ON o.transmission_id = t.id
+			LEFT JOIN observers obs ON obs.id = o.observer_id` + filterClause + `
 			ORDER BY t.first_seen ASC, o.timestamp DESC`
 	}
 
@@ -1268,7 +1269,7 @@ func (s *PacketStore) loadChunk(from, to time.Time) error {
 		var rawHex, hash, firstSeen, decodedJSON sql.NullString
 		var routeType, payloadType, payloadVersion sql.NullInt64
 		var obsID sql.NullInt64
-		var observerID, observerName, direction, pathJSON, obsTimestamp sql.NullString
+		var observerID, observerName, observerIATA, direction, pathJSON, obsTimestamp sql.NullString
 		var snr, rssi sql.NullFloat64
 		var score sql.NullInt64
 		var obsRawHex sql.NullString
@@ -1277,7 +1278,7 @@ func (s *PacketStore) loadChunk(from, to time.Time) error {
 
 		scanArgs := []interface{}{&txID, &rawHex, &hash, &firstSeen, &routeType, &payloadType,
 			&payloadVersion, &decodedJSON,
-			&obsID, &observerID, &observerName, &direction,
+			&obsID, &observerID, &observerName, &observerIATA, &direction,
 			&snr, &rssi, &score, &pathJSON, &obsTimestamp}
 		if s.db.hasObsRawHex {
 			scanArgs = append(scanArgs, &obsRawHex)
@@ -1330,6 +1331,7 @@ func (s *PacketStore) loadChunk(from, to time.Time) error {
 				TransmissionID: txID,
 				ObserverID:     obsIDStr,
 				ObserverName:   nullStrVal(observerName),
+				ObserverIATA:   nullStrVal(observerIATA),
 				Direction:      nullStrVal(direction),
 				SNR:            nullFloatPtr(snr),
 				RSSI:           nullFloatPtr(rssi),