diff --git a/src/main/kotlin/com/gzzn/omms/msgexchange/codec/JacksonXmlCodec.kt b/src/main/kotlin/com/gzzn/omms/msgexchange/codec/JacksonXmlCodec.kt
index d6af86b..bcfb631 100644
--- a/src/main/kotlin/com/gzzn/omms/msgexchange/codec/JacksonXmlCodec.kt
+++ b/src/main/kotlin/com/gzzn/omms/msgexchange/codec/JacksonXmlCodec.kt
@@ -88,6 +88,8 @@ class JacksonXmlCodec : XmlCodec {
      * 子类型分派必须是**白名单**：未知的 SCHD 子类型不能静默当成全量日计划（DNLD）——
      * 那会让一条本该"暂不支持、等人工处置"的报文走最重的整包合并写入路径。
      * 空 STYP 按 legacy 约定视为 DNLD（该约定待与 SIS 逐类对拍确认，见 Q3）。
+     * FLOP 同样按白名单：仅现行七类（`implementation.md`「动态运行事件」`US-05` AC1）
+     * 走合并路径，其余 STYP 是 `Q3` 闭合目标，落 `Unsupported`（`FDEL` 单独成类，不参与白名单）。
      * 静态参考数据类别码（`implementation.md`「静态参考数据」`SIS:3.1`～`3.14`）单列成
      * [MsgKind.RefData]：它们必须走参考数据处理（US-13），不得混入"不支持"跳过。
      */
@@ -98,11 +100,18 @@ class JacksonXmlCodec : XmlCodec {
             "DNLD", "" -> MsgKind.Schd(MsgKind.SchdSubtype.DNLD)
             else -> MsgKind.Unsupported("SCHD-$styp")
         }
-        "FLOP" -> if (styp == "FDEL") MsgKind.Fdel else MsgKind.Flop(styp)
+        "FLOP" -> when {
+            styp == "FDEL" -> MsgKind.Fdel
+            styp in FLOP_SUBTYPES -> MsgKind.Flop(styp)
+            else -> MsgKind.Unsupported("FLOP-$styp")
+        }
         in REF_DATA_TYPES -> MsgKind.RefData(type)
         else -> MsgKind.Unsupported("$type-$styp")
     }
 
+    /** 现行 FLOP 白名单 7 类（`US-05` AC1）；表内其余行是 `Q3` 闭合目标，不是现行白名单。 */
+    private val FLOP_SUBTYPES = setOf("ABTM", "DELY", "PSDT", "CKDT", "CLDT", "CHDT", "GTDT")
+
     private val REF_DATA_TYPES = setOf(
         "COUL", "ARPT", "AIRL", "AIRC", "REGN", "ORGN", "FLTL",
         "TLST", "GLST", "SLST", "CLST", "BLST", "CHLT", "RSTA",
diff --git a/src/test/kotlin/com/gzzn/omms/msgexchange/codec/JacksonXmlCodecTest.kt b/src/test/kotlin/com/gzzn/omms/msgexchange/codec/JacksonXmlCodecTest.kt
index 8f71ec3..6cc77f3 100644
--- a/src/test/kotlin/com/gzzn/omms/msgexchange/codec/JacksonXmlCodecTest.kt
+++ b/src/test/kotlin/com/gzzn/omms/msgexchange/codec/JacksonXmlCodecTest.kt
@@ -250,4 +250,25 @@ class JacksonXmlCodecTest {
         val unknown = (codec.decode(raw("XYZZ", "TEST")) as DecodeResult.Ok).message
         assertEquals(MsgKind.Unsupported("XYZZ-TEST"), unknown.kind)
     }
+
+    @Test
+    fun `FLOP subtype whitelist sends only the seven current types to FlopProcessor`() {
+        fun raw(styp: String) = """
+            <MSG><META><SNDR>AODB</SNDR><SEQN>9</SEQN><DTTM>20021010090311</DTTM>
+            <TYPE>FLOP</TYPE><STYP>$styp</STYP></META></MSG>
+        """.trimIndent()
+
+        // 现行白名单 7 类（US-05 AC1）
+        for (styp in listOf("ABTM", "DELY", "PSDT", "CKDT", "CLDT", "CHDT", "GTDT")) {
+            assertEquals(MsgKind.Flop(styp), (codec.decode(raw(styp)) as DecodeResult.Ok).message.kind)
+        }
+
+        // FDEL 独立分派，不参与白名单判定
+        assertEquals(MsgKind.Fdel, (codec.decode(raw("FDEL")) as DecodeResult.Ok).message.kind)
+
+        // 白名单外子类型（ACTT/CNCL 是 Q3 闭合目标）与空 STYP 都落 Unsupported，不走合并路径
+        assertEquals(MsgKind.Unsupported("FLOP-ACTT"), (codec.decode(raw("ACTT")) as DecodeResult.Ok).message.kind)
+        assertEquals(MsgKind.Unsupported("FLOP-CNCL"), (codec.decode(raw("CNCL")) as DecodeResult.Ok).message.kind)
+        assertEquals(MsgKind.Unsupported("FLOP-"), (codec.decode(raw("")) as DecodeResult.Ok).message.kind)
+    }
 }
diff --git a/src/test/kotlin/com/gzzn/omms/msgexchange/processing/IgnoreBranchTest.kt b/src/test/kotlin/com/gzzn/omms/msgexchange/processing/IgnoreBranchTest.kt
index d356de6..2f5e285 100644
--- a/src/test/kotlin/com/gzzn/omms/msgexchange/processing/IgnoreBranchTest.kt
+++ b/src/test/kotlin/com/gzzn/omms/msgexchange/processing/IgnoreBranchTest.kt
@@ -24,6 +24,7 @@ import com.gzzn.omms.msgexchange.infra.stub.StubSnapshotLog
 import com.fasterxml.jackson.databind.ObjectMapper
 import org.junit.jupiter.api.Assertions.assertEquals
 import org.junit.jupiter.api.Assertions.assertNotNull
+import org.junit.jupiter.api.Assertions.assertTrue
 import org.junit.jupiter.api.Test
 import java.time.Clock
 import java.time.Instant
@@ -212,6 +213,28 @@ class IgnoreBranchTest {
         assertEquals("refdata-pending:ARPT", row.lastError)
     }
 
+    @Test
+    fun `flop subtype outside whitelist is skipped without touching flights`() {
+        val proc = StubProcState()
+        proc.insertIfAbsent(msgId, null)
+        val inbox = StubInbox()
+        inbox.raws[msgId] = "<RAW/>"
+        val msg = DecodedMessage(
+            meta = MetaFields("AODB", "FLOP", "ACTT", 500L, 1L),
+            kind = MsgKind.Unsupported("FLOP-ACTT"),
+            rawXml = "<RAW/>",
+        )
+        val flights = StubFlightState()
+        val p = processor(proc = proc, inbox = inbox, codec = codecReturning(msg))
+
+        p.processOne(head())
+
+        val row = proc.find(msgId)!!
+        assertEquals(ProcStatus.SKIPPED, row.state)
+        assertEquals("unsupported:FLOP-ACTT", row.lastError)
+        assertTrue(flights.snapshots.isEmpty())   // 白名单外子类型不改航班（US-05 AC1）
+    }
+
     @Test
     fun `ignore increments counter`() {
         val proc = StubProcState()