diff --git a/B07_DesignDetail/B07_DesignDetail_Api_Fetch.ts b/B07_DesignDetail/B07_DesignDetail_Api_Fetch.ts
index 69fc10e89..bbce8b861 100644
--- a/B07_DesignDetail/B07_DesignDetail_Api_Fetch.ts
+++ b/B07_DesignDetail/B07_DesignDetail_Api_Fetch.ts
@@ -243,12 +243,15 @@ export function saveCrossLayout(projectId: string, layout: CrossLayout): Promise
 
 /** 도면 축척 종류(485) — 표준 횡단 · 평면도 · 구조물은 뺌. */
 export type DrawingScaleKind = "longitudinal" | "cross" | "mass_haul" | "development";
-/** 축척 분모 — null = 자동(토적 가로 · 전개도) · 범위 = [최소, 최대]. */
-export type DrawingScaleAxes = { x: number | null; y: number | null };
+/** 축척 분모 — null = 자동(토적 가로 · 전개도 · 종단 평면 위치도) · 범위 = [최소, 최대]. */
+export type DrawingScaleAxes = { x: number | null; y: number | null; plan?: number | null };
 export interface DrawingScales {
   scales: Record<DrawingScaleKind, DrawingScaleAxes>;
   defaults: Record<DrawingScaleKind, DrawingScaleAxes>;
-  ranges: Record<DrawingScaleKind, { x: [number, number]; y: [number, number] }>;
+  ranges: Record<
+    DrawingScaleKind,
+    { x: [number, number]; y: [number, number]; plan?: [number, number] }
+  >;
   /** 종류마다 저장본(확정) 장 수 — 바꾸면 풀리므로 화면이 먼저 물음. */
   saved: Record<DrawingScaleKind, number>;
   /** PUT 응답만 — 이번에 풀린 저장본 장 수. */
diff --git a/B07_DesignDetail/B07_DesignDetail_Engine_Cad_Long.py b/B07_DesignDetail/B07_DesignDetail_Engine_Cad_Long.py
index 1a889d09a..7b5b33e76 100644
--- a/B07_DesignDetail/B07_DesignDetail_Engine_Cad_Long.py
+++ b/B07_DesignDetail/B07_DesignDetail_Engine_Cad_Long.py
@@ -42,6 +42,11 @@ from B07_DesignDetail.B07_DesignDetail_Engine_Cad import (
     polyline_entity,
     station_no_label,
 )
+from B07_DesignDetail.B07_DesignDetail_Engine_Cad_LongPlan import (
+    LONG_PLAN_LAYER_ID,
+    long_plan_entities,
+    plan_box_overlaps,
+)
 from B07_DesignDetail.B07_DesignDetail_Engine_Template import (
     drawing_scale,
     entities_bbox,
@@ -93,12 +98,14 @@ def _span(stations: list[dict[str, Any]], index: int, take: int) -> dict[str, fl
 
 
 def _fits_sheet(longitudinal: dict[str, Any], span: dict[str, float]) -> bool:
-    """이 구간을 고정 축척으로 그렸을 때 A1 작도 영역에 드는가."""
-    bbox = entities_bbox(_long_content(longitudinal, "probe", span))
+    """이 구간을 고정 축척으로 그렸을 때 A1 작도 영역에 들고 평면 위치도 칸을 안 덮는가."""
+    content = _long_content(longitudinal, "probe", span)
+    bbox = entities_bbox(content)
     if bbox is None:
         return True
     usable_w, usable_h = usable_area()
-    return bbox[2] - bbox[0] <= usable_w + 1e-6 and bbox[3] - bbox[1] <= usable_h + 1e-6
+    fits = bbox[2] - bbox[0] <= usable_w + 1e-6 and bbox[3] - bbox[1] <= usable_h + 1e-6
+    return fits and not plan_box_overlaps(longitudinal, content, bbox)
 
 
 def longitudinal_chunks(longitudinal: dict[str, Any]) -> list[dict[str, Any]]:
@@ -124,9 +131,10 @@ def longitudinal_chunks(longitudinal: dict[str, Any]) -> list[dict[str, Any]]:
             break
         index += take - 1  # 경계 1측점 중복
     if len(spans) == 1:
-        return [{"id": "longitudinal", "label": "종단도", **spans[0]}]
+        return [{"id": "longitudinal", "label": "종단도", "number": 1, "total": 1, **spans[0]}]
     return [
-        {"id": f"longitudinal_{number}", "label": f"종단도({number})", **span}
+        {"id": f"longitudinal_{number}", "label": f"종단도({number})", "number": number, **span}
+        | {"total": len(spans)}
         for number, span in enumerate(spans, start=1)
     ]
 
@@ -660,6 +668,7 @@ def build_longitudinal_drawing(
     # A1 도각: 콘텐츠가 이미 종이 mm라 도각도 실치수(1:1)로 두고 위치만 맞춘다.
     # 그림 좌하단 = 작도영역 좌하단 — 장마다 같은 자리에서 시작한다.
     bbox = entities_bbox(entities)
+    entities.extend(long_plan_entities(longitudinal, drawing_id, chunk, bbox))  # 521-2
     if bbox:
         entities.extend(
             frame_entities(
@@ -682,6 +691,7 @@ def build_longitudinal_drawing(
             _layer(DESIGN_LAYER_ID, "계획선"),
             _layer(LONG_GRID_LAYER_ID, "그래프 격자", locked=True),
             _layer(LONG_TABLE_LAYER_ID, "측점표"),
+            _layer(LONG_PLAN_LAYER_ID, "평면 위치도"),
             _layer(FRAME_LAYER_ID, "도각", locked=True),
         ],
     }
diff --git a/B07_DesignDetail/B07_DesignDetail_Engine_Cad_LongPlan.py b/B07_DesignDetail/B07_DesignDetail_Engine_Cad_LongPlan.py
new file mode 100644
index 000000000..d8ba01233
--- /dev/null
+++ b/B07_DesignDetail/B07_DesignDetail_Engine_Cad_LongPlan.py
@@ -0,0 +1,224 @@
+"""B07 종단도 우측 상단 평면 위치도(521-2 · 요구 340-2) — 장마다 작도 영역 우상단 칸 하나.
+
+칸 = 작도 영역 우상단 5 mm 안쪽 150×100 mm(작도 영역 좌하단 = 그림 좌하단 · `frame_entities`
+bottom_left). 척도 = 종단 축척 `plan` 칸(None = 자동). 방위표만 도각 층.
+  - 자동: 전체 노선을 칸에 맞춤(분모 500 단위 올림) · 전체 노선 가는 선 · 이 장 구간 굵게.
+  - 척도 정함: 이 장 중심 확대 · 이 장 굵게 · 밖 노선 흐린 파선 · 칸 밖은 잘림.
+칸 내용 = 노선 · 이 장 시 · 종점 측점 글 · 방위표 · 「평면도 S=1/n」 · 「n/N 장」.
+좌표 = 종단 측점 center_x · center_y — 없으면 칸 안 그림. 서버 단독(CLAUDE.md 5장 ③).
+"""
+
+import math
+from collections.abc import Iterator
+from typing import Any
+
+from shapely.geometry import LineString, Point
+from shapely.geometry import box as shapely_box
+
+from B07_DesignDetail.B07_DesignDetail_Engine_Cad import (
+    DESIGN_COLOR,
+    TABLE_LABEL_COLOR,
+    TABLE_LINE_COLOR,
+    _stations,
+    _text_entity,
+    infer_station_interval,
+    polyline_entity,
+    station_no_label,
+)
+from B07_DesignDetail.B07_DesignDetail_Engine_Cad_PlanLabels import text_rect
+from B07_DesignDetail.B07_DesignDetail_Engine_Template import (
+    compass_entities,
+    drawing_scale,
+    usable_area,
+)
+
+LONG_PLAN_LAYER_ID = "b07-long-plan"
+BOX_W, BOX_H = 150.0, 100.0  # 칸 크기(종이 mm)
+_INSET = 5.0  # 작도 영역 테두리에서 안쪽
+_MAP_PAD = (4.0, 10.0, 4.0, 4.0)  # 칸 안 노선 자리 여백(좌 · 하 · 우 · 상) — 아래는 글 줄
+_AUTO_STEP = 500  # 자동 분모 올림 단위
+_FONT = 2.5
+_COMPASS = 12.0
+_ROUTE_COLOR = "#7d8590"  # 전체 · 밖 노선 — 흐리게
+
+
+def plan_box(content_bbox: tuple[float, float, float, float]) -> tuple[float, float, float, float]:
+    """칸 (x0, y0, x1, y1) — 그림 좌표(작도 영역 좌하단 = 그림 좌하단)."""
+    usable_w, usable_h = usable_area()
+    x1 = content_bbox[0] + usable_w - _INSET
+    y1 = content_bbox[1] + usable_h - _INSET
+    return (x1 - BOX_W, y1 - BOX_H, x1, y1)
+
+
+def _plan_points(longitudinal: dict[str, Any]) -> list[tuple[float, float, float]]:
+    """종단 측점의 (누가거리 m, x, y) — `Router_Support_Basin.plan_stations` 와 같은 셈."""
+    points: list[tuple[float, float, float]] = []
+    for station in _stations(longitudinal):
+        x, y = station.get("center_x"), station.get("center_y")
+        if all(isinstance(v, (int, float)) and not isinstance(v, bool) for v in (x, y)):
+            points.append((float(station["chainage_m"]), float(x), float(y)))
+    return sorted(points)
+
+
+def _shapes(entities: list[dict[str, Any]]) -> Iterator[Any]:
+    """엔티티 → shapely 도형(선 · 글 사각 · 원) — 칸 겹침 판정용."""
+    for entity in entities:
+        yield from _shapes(entity.get("children") or [])
+        shape = entity.get("shapeData") or {}
+        if "startPoint" in shape:
+            a, b = shape["startPoint"], shape["endPoint"]
+            yield LineString([(a["x"], a["y"]), (b["x"], b["y"])])
+        elif "basePoint" in shape:
+            base, options = shape["basePoint"], shape.get("options") or {}
+            direction = options.get("textDirection") or {}
+            yield shapely_box(
+                *text_rect(
+                    str(shape.get("label") or ""),
+                    base["x"],
+                    base["y"],
+                    float(options.get("fontSize", _FONT)),
+                    str(options.get("textAlign", "center")),
+                    (float(direction.get("x", 1.0)), float(direction.get("y", 0.0))),
+                )
+            )
+        elif "center" in shape:
+            center = shape["center"]
+            yield Point(center["x"], center["y"]).buffer(float(shape.get("radius", 0.0)))
+
+
+def plan_box_overlaps(
+    longitudinal: dict[str, Any],
+    entities: list[dict[str, Any]],
+    content_bbox: tuple[float, float, float, float] | None,
+) -> bool:
+    """그래프 · 측점표가 칸을 덮는가 — 칸을 안 그리는 종단(좌표 없음)은 늘 거짓."""
+    if content_bbox is None or len(_plan_points(longitudinal)) < 2:
+        return False
+    x0, y0, x1, y1 = plan_box(content_bbox)
+    if content_bbox[2] < x0 or content_bbox[3] < y0:
+        return False
+    region = shapely_box(x0, y0, x1, y1)
+    return any(region.intersects(shape) for shape in _shapes(entities))
+
+
+def _auto_denominator(points: list[tuple[float, float, float]], map_w: float, map_h: float) -> int:
+    width = max(p[1] for p in points) - min(p[1] for p in points)
+    height = max(p[2] for p in points) - min(p[2] for p in points)
+    need = max(width / map_w, height / map_h) * 1000.0
+    return max(_AUTO_STEP, math.ceil(need / _AUTO_STEP) * _AUTO_STEP)
+
+
+def _clipped(
+    drawing_id: str,
+    points: list[tuple[float, float]],
+    region: Any,
+    suffix: str,
+    color: str,
+    dash: list[int] | None = None,
+    width: int = 1,
+) -> list[dict[str, Any]]:
+    """종이 점열을 칸 노선 자리로 잘라 PolyLine 들로."""
+    if len(points) < 2:
+        return []
+    clipped = LineString(points).intersection(region)
+    parts = getattr(clipped, "geoms", [clipped])
+    out = []
+    for index, part in enumerate(parts):
+        if isinstance(part, LineString) and not part.is_empty:
+            line = polyline_entity(
+                drawing_id,
+                list(part.coords),
+                LONG_PLAN_LAYER_ID,
+                color,
+                suffix=f"{suffix}:{index}",
+                dash=dash,
+                width=width,
+            )
+            if line:
+                out.append(line)
+    return out
+
+
+def long_plan_entities(
+    longitudinal: dict[str, Any],
+    drawing_id: str,
+    chunk: dict[str, Any],
+    content_bbox: tuple[float, float, float, float] | None,
+) -> list[dict[str, Any]]:
+    """이 장의 평면 위치도 칸 — 좌표 없거나 그림이 비면 빈 목록."""
+    points = _plan_points(longitudinal)
+    if content_bbox is None or len(points) < 2:
+        return []
+    start_m, end_m = chunk.get("start_m"), chunk.get("end_m")
+    if start_m is None or end_m is None:
+        start_m, end_m = points[0][0], points[-1][0]
+    inside = [p for p in points if start_m - 1e-6 <= p[0] <= end_m + 1e-6]
+    x0, y0, x1, y1 = plan_box(content_bbox)
+    left, bottom, right, top = _MAP_PAD
+    map_box = (x0 + left, y0 + bottom, x1 - right, y1 - top)
+    map_w, map_h = map_box[2] - map_box[0], map_box[3] - map_box[1]
+
+    fixed = drawing_scale("longitudinal").get("plan")
+    denominator = fixed or _auto_denominator(points, map_w, map_h)
+    focus = inside if fixed and inside else points
+    center_x = (min(p[1] for p in focus) + max(p[1] for p in focus)) / 2.0
+    center_y = (min(p[2] for p in focus) + max(p[2] for p in focus)) / 2.0
+    mm = 1000.0 / denominator
+    box_cx, box_cy = (map_box[0] + map_box[2]) / 2.0, (map_box[1] + map_box[3]) / 2.0
+
+    def paper(x: float, y: float) -> tuple[float, float]:
+        return (box_cx + (x - center_x) * mm, box_cy + (y - center_y) * mm)
+
+    region = shapely_box(*map_box)
+    border = [(x0, y0), (x1, y0), (x1, y1), (x0, y1), (x0, y0)]
+    entities = [polyline_entity(drawing_id, border, LONG_PLAN_LAYER_ID, TABLE_LINE_COLOR, ":box")]
+    entities += _clipped(
+        drawing_id,
+        [paper(x, y) for _c, x, y in points],
+        region,
+        ":all",
+        _ROUTE_COLOR,
+        dash=[3, 3] if fixed else None,
+    )
+    entities += _clipped(
+        drawing_id, [paper(x, y) for _c, x, y in inside], region, ":this", DESIGN_COLOR, width=3
+    )
+    interval_m = infer_station_interval(_stations(longitudinal))
+    for name, (chainage, x, y) in (("start", inside[0]), ("end", inside[-1])) if inside else ():
+        px, py = paper(x, y)
+        if region.contains(Point(px, py)):
+            entities.append(
+                _text_entity(
+                    f"{drawing_id}:lplan:{name}",
+                    station_no_label(chainage, interval_m),
+                    px,
+                    py + _FONT,
+                    LONG_PLAN_LAYER_ID,
+                    _FONT,
+                    TABLE_LABEL_COLOR,
+                )
+            )
+    number, total = int(chunk.get("number") or 1), int(chunk.get("total") or 1)
+    for name, label, x, align in (
+        ("scale", f"평면도 S=1/{denominator:,}", x0 + left, "left"),
+        ("page", f"{number}/{total} 장", x1 - right, "right"),
+    ):
+        entities.append(
+            _text_entity(
+                f"{drawing_id}:lplan:{name}",
+                label,
+                x,
+                y0 + bottom / 2.0,
+                LONG_PLAN_LAYER_ID,
+                _FONT,
+                TABLE_LABEL_COLOR,
+                align=align,
+            )
+        )
+    # 방위표 = 다른 평면 도면처럼 도각 층(잠금)
+    compass = compass_entities(
+        f"{drawing_id}:lplan",
+        (x0 + left + _COMPASS / 2.0, y1 - top - _COMPASS / 2.0),
+        _COMPASS,
+    )
+    return [entity for entity in entities if entity] + compass
diff --git a/B07_DesignDetail/B07_DesignDetail_Engine_Template.py b/B07_DesignDetail/B07_DesignDetail_Engine_Template.py
index 0c2aea39b..ba274b87d 100644
--- a/B07_DesignDetail/B07_DesignDetail_Engine_Template.py
+++ b/B07_DesignDetail/B07_DesignDetail_Engine_Template.py
@@ -97,7 +97,8 @@ def add_title_fields(extra: dict[str, str]) -> None:
 # 읽는 프로젝트 = 위 문맥 변수(라우터가 세움) — 엔진 서명을 고치지 않는다.
 DRAWING_SCALES_FILE = "drawing_scales.json"
 DRAWING_SCALE_DEFAULTS: dict[str, dict[str, int | None]] = {
-    "longitudinal": {"x": DRAWING_SCALE_LONG_H, "y": DRAWING_SCALE_LONG_V},
+    # plan = 종단 장 우측 상단 평면 위치도(521-2) · None = 자동(노선을 칸에 맞춤)
+    "longitudinal": {"x": DRAWING_SCALE_LONG_H, "y": DRAWING_SCALE_LONG_V, "plan": None},
     "cross": {"x": DRAWING_SCALE_CROSS, "y": DRAWING_SCALE_CROSS},
     # 토적 세로 = 1 mm 당 50 ㎥ → 표기 1:50,000 (분모 / 1000 = 종이 1 mm 의 ㎥)
     "mass_haul": {"x": None, "y": int(DRAWING_SCALE_MASSHAUL_V_M3_MM * 1000)},
diff --git a/B07_DesignDetail/B07_DesignDetail_Router_Support.py b/B07_DesignDetail/B07_DesignDetail_Router_Support.py
index 17e9e38f8..7231becdb 100644
--- a/B07_DesignDetail/B07_DesignDetail_Router_Support.py
+++ b/B07_DesignDetail/B07_DesignDetail_Router_Support.py
@@ -90,6 +90,7 @@ from B07_DesignDetail.B07_DesignDetail_Router_Support_Io import (
     _read_manifest,
     _station_map,
     _write_manifest,
+    release_old_long_sheets,
 )
 from B07_DesignDetail.B07_DesignDetail_Router_Support_Plan import (
     PLAN_KIND_ID,
@@ -196,6 +197,7 @@ def write_cross_layout(
 def _drawing_list(project_root: Path, longitudinal_path: Path) -> list[DesignDrawingItem]:
     longitudinal = _read_json(longitudinal_path)
     station_by_chainage = _station_map(longitudinal)
+    release_old_long_sheets(project_root)  # 521-2
     manifest_drawings = _read_manifest(project_root)["drawings"]
     # 종단도: 측점 30개 초과 시 30개 단위 분할 도면을 각각 목록에 노출한다(N-1-1).
     drawings = [
diff --git a/B07_DesignDetail/B07_DesignDetail_Router_Support_Io.py b/B07_DesignDetail/B07_DesignDetail_Router_Support_Io.py
index d1936097b..e6e3b7494 100644
--- a/B07_DesignDetail/B07_DesignDetail_Router_Support_Io.py
+++ b/B07_DesignDetail/B07_DesignDetail_Router_Support_Io.py
@@ -80,3 +80,31 @@ def _write_manifest(project_root: Path, manifest: dict[str, Any]) -> None:
     temporary = path.with_suffix(".tmp")
     temporary.write_text(json.dumps(manifest, ensure_ascii=False, indent=2), encoding="utf-8")
     temporary.replace(path)
+
+
+def release_old_long_sheets(project_root: Path) -> None:
+    """평면 위치도(521-2) 앞 확정 종단 저장본 — 종단만 모두 한 번 풂(칸 · 장 나눔이 바뀜).
+
+    풀린 장의 저장본은 `_write_manifest` 가 걷으니 다음부터는 새 저장본(칸 층 있음)만 남음.
+    """
+    # 엔진 → 양식 → 이 모듈 차례라 위에서 부르면 돌고 돎
+    from B07_DesignDetail.B07_DesignDetail_Engine_Cad_LongPlan import LONG_PLAN_LAYER_ID
+
+    manifest = _read_manifest(project_root)
+    confirmed = [
+        (drawing_id, entry)
+        for drawing_id, entry in manifest["drawings"].items()
+        if _LONG_ID.fullmatch(drawing_id) and entry.get("confirmed")
+    ]
+    if not confirmed:
+        return
+    # ponytail: 첫 장만 봄 — 옛 장은 한꺼번에 풀리므로 새 장과 섞이지 않음
+    saved = _design_root(project_root) / "drawings" / f"{confirmed[0][0]}.json"
+    try:
+        if f'"{LONG_PLAN_LAYER_ID}"' in saved.read_text(encoding="utf-8"):
+            return
+    except OSError:
+        pass
+    for _drawing_id, entry in confirmed:
+        entry["confirmed"] = False
+    _write_manifest(project_root, manifest)
diff --git a/B07_DesignDetail/B07_DesignDetail_Router_Support_Scale.py b/B07_DesignDetail/B07_DesignDetail_Router_Support_Scale.py
index f2e971a90..006ecc1b2 100644
--- a/B07_DesignDetail/B07_DesignDetail_Router_Support_Scale.py
+++ b/B07_DesignDetail/B07_DesignDetail_Router_Support_Scale.py
@@ -36,7 +36,7 @@ router = APIRouter(prefix="/api/projects", tags=["B07 Design Detail"])
 
 # 분모 범위(정수) — 기본 · 자동 후보(토적 500~6,000 · 전개도 50~5,000)를 모두 담음.
 SCALE_RANGES: dict[str, dict[str, tuple[int, int]]] = {
-    "longitudinal": {"x": (100, 10000), "y": (10, 2000)},
+    "longitudinal": {"x": (100, 10000), "y": (10, 2000), "plan": (500, 50000)},
     "cross": {"x": (10, 1000), "y": (10, 1000)},
     "mass_haul": {"x": (100, 20000), "y": (1000, 1000000)},
     "development": {"x": (10, 10000), "y": (10, 10000)},
@@ -65,7 +65,7 @@ def checked_scales(scales: Any) -> dict[str, dict[str, int | None]]:
             if value is not None and (
                 isinstance(value, bool) or not isinstance(value, int) or not low <= value <= high
             ):
-                name = "X(가로)" if axis == "x" else "Y(세로)"
+                name = {"x": "X(가로)", "y": "Y(세로)"}.get(axis, "평면도")
                 raise ValueError(
                     f"{_KIND_LABEL[kind]} {name} 축척은 1/{low:,}~1/{high:,} 사이 정수로 적으세요."
                 )
diff --git a/B07_DesignDetail/B07_DesignDetail_UI_Settings_Scale.ts b/B07_DesignDetail/B07_DesignDetail_UI_Settings_Scale.ts
index c868e41bb..5556e1c72 100644
--- a/B07_DesignDetail/B07_DesignDetail_UI_Settings_Scale.ts
+++ b/B07_DesignDetail/B07_DesignDetail_UI_Settings_Scale.ts
@@ -1,6 +1,7 @@
 /* =============================================================================
  * B07_DesignDetail_UI_Settings_Scale.ts
  * ⚙ 모달 X · Y 축척 칸(485-2 · 요구 280-5) — 종단 · 횡단 · 토적 · 전개도만.
+ *   종단 = 셋째 칸 「평면도」(521-2 · 우측 상단 평면 위치도) — 칸은 서버 기본값 열쇠 그대로.
  *
  *   칸 = 분모 정수 · 범위 밖 = 칸 붉게 + [축척 저장] 꺼짐 · 기본이 자동인 칸(토적 X · 전개도) = 「자동」
  *   [축척 저장] = 그 종류 저장본이 있으면 n 장 물음(취소 = 그대로) → PUT → 화면 다시 세움(도면 다시 그림)
@@ -32,10 +33,8 @@ const LABEL: Record<DrawingScaleKind, string> = {
   mass_haul: "토적도",
   development: "전개도",
 };
-const AXES = [
-  ["x", "X(가로) 1/"],
-  ["y", "Y(세로) 1/"],
-] as const;
+type Axis = keyof DrawingScaleAxes;
+const AXIS_LABEL: Record<Axis, string> = { x: "X(가로) 1/", y: "Y(세로) 1/", plan: "평면도 1/" };
 
 const isScaleKind = (kind: string): kind is DrawingScaleKind => kind in LABEL;
 
@@ -86,9 +85,11 @@ function buildScaleFields(
   data: DrawingScales,
   save: (next: DrawingScaleAxes) => Promise<void>,
 ): void {
-  const fields = AXES.map(([axis, label]) => {
-    const fallback = data.defaults[kind][axis];
-    const range = data.ranges[kind][axis];
+  const axes = Object.keys(data.defaults[kind]) as Axis[];
+  const fields = axes.map((axis) => {
+    const label = AXIS_LABEL[axis];
+    const fallback = data.defaults[kind][axis] ?? null;
+    const range = data.ranges[kind][axis] ?? [1, 1];
     const [min, max] = range;
     const field = createInputField({ label, type: "number", compact: true, min, max });
     field.root.classList.add("b07-scale__field");
@@ -99,7 +100,7 @@ function buildScaleFields(
       if (auto) auto.input.checked = value === null;
       field.input.disabled = value === null && !!auto;
     };
-    set(data.scales[kind][axis]);
+    set(data.scales[kind][axis] ?? null);
     const read = () => readScaleAxis(field.input.value, !!auto?.input.checked, range);
     return { axis, field, auto, fallback, set, read };
   });
@@ -107,13 +108,14 @@ function buildScaleFields(
   const saveButton = createButton({
     label: "축척 저장",
     onClick: () => {
-      const [x, y] = fields.map((f) => f.read()) as [number | null, number | null];
+      const read = fields.map((f) => [f, f.read() as number | null] as const);
       const now = data.scales[kind];
-      if (x === now.x && y === now.y) {
+      if (read.every(([f, value]) => value === (now[f.axis] ?? null))) {
         showToast("바뀐 축척이 없습니다.", "info");
         return;
       }
-      void save({ x: scaleToSend(x, fields[0].fallback), y: scaleToSend(y, fields[1].fallback) });
+      const next = Object.fromEntries(read.map(([f, v]) => [f.axis, scaleToSend(v, f.fallback)]));
+      void save(next as DrawingScaleAxes);
     },
   });
   // 칸 밑 오류 글은 숨기고(틀린 칸만 길어짐) 줄 아래 한 줄로 알림
@@ -127,7 +129,8 @@ function buildScaleFields(
       const result = f.read();
       const message = typeof result === "string" ? result : undefined;
       f.field.setError(message);
-      if (message) errors.set(message, [...(errors.get(message) ?? []), f.axis.toUpperCase()]);
+      const name = f.axis === "plan" ? "평면도" : f.axis.toUpperCase();
+      if (message) errors.set(message, [...(errors.get(message) ?? []), name]);
     }
     alertLine.textContent = [...errors].map(([m, axes]) => `${axes.join(" · ")}: ${m}`).join(" / ");
     alertLine.hidden = errors.size === 0;
diff --git a/resources/tester/helper_280_5_b07_settings.cjs b/resources/tester/helper_280_5_b07_settings.cjs
index dc3a440fa..5c00e358d 100644
--- a/resources/tester/helper_280_5_b07_settings.cjs
+++ b/resources/tester/helper_280_5_b07_settings.cjs
@@ -97,19 +97,19 @@ const calls = [];
 let failConfirm = false;
 const SCALES = {
   scales: {
-    longitudinal: { x: 1000, y: 200 },
+    longitudinal: { x: 1000, y: 200, plan: null },
     cross: { x: 100, y: 100 },
     mass_haul: { x: null, y: 50000 },
     development: { x: null, y: null },
   },
   defaults: {
-    longitudinal: { x: 1000, y: 200 },
+    longitudinal: { x: 1000, y: 200, plan: null },
     cross: { x: 100, y: 100 },
     mass_haul: { x: null, y: 50000 },
     development: { x: null, y: null },
   },
   ranges: {
-    longitudinal: { x: [100, 10000], y: [10, 2000] },
+    longitudinal: { x: [100, 10000], y: [10, 2000], plan: [500, 50000] },
     cross: { x: [10, 1000], y: [10, 1000] },
     mass_haul: { x: [100, 20000], y: [1000, 1000000] },
     development: { x: [10, 10000], y: [10, 10000] },
@@ -413,6 +413,18 @@ const drawings = [
   s.btn("축척 저장").click();
   await tick();
   scale.same = { calls: calls.length, toasts: toasts.slice(toastAt).map((t) => t[1]) };
+  // 평면 위치도 칸(521-2) — 셋째 칸 · 자동 끔 → 범위 밖 붉음 → 1/3,000 저장
+  s = await scaleOf("longitudinal");
+  scale.planStart = s.state();
+  s.toggle(s.autos[0]);
+  s.type(s.inputs[2], "400");
+  scale.planLow = s.state();
+  s.type(s.inputs[2], "3000");
+  calls.length = 0;
+  s.btn("축척 저장").click();
+  await tick();
+  await tick();
+  scale.planSent = calls.find((c) => c[0] === "scales")?.[1];
 
   s = await scaleOf("mass_haul");
   scale.massStart = s.state();
diff --git a/resources/tester/test_280_5_b07_drawing_scales.py b/resources/tester/test_280_5_b07_drawing_scales.py
index 98c74390b..33db4e526 100644
--- a/resources/tester/test_280_5_b07_drawing_scales.py
+++ b/resources/tester/test_280_5_b07_drawing_scales.py
@@ -244,7 +244,14 @@ def test_전개도_가로_세로(project: Path) -> None:
 
 def test_범위_검사() -> None:
     assert checked_scales({"cross": {"x": 100, "y": None}}) == {"cross": {"x": 100, "y": None}}
+    # 종단 평면 위치도(521-2) = 1/500~1/50,000 · null = 자동
+    assert checked_scales({"longitudinal": {"plan": 3000}}) == {
+        "longitudinal": {"x": None, "y": None, "plan": 3000}
+    }
+    with pytest.raises(ValueError, match="평면도 축척은 1/500~1/50,000"):
+        checked_scales({"longitudinal": {"plan": 400}})
     for bad in (
+        {"longitudinal": {"plan": 50001}},
         {"plan": {"x": 500}},
         {"standard": {"x": 50}},
         {"cross": {"x": 5}},
@@ -287,7 +294,7 @@ def test_바꾼_종류만_저장본_풂(project: Path) -> None:
     drawings = _read_manifest(project)["drawings"]
     assert not drawings["longitudinal_1"]["confirmed"]
     assert drawings["cross_00020m"]["confirmed"] and drawings["cover"]["confirmed"]
-    assert read_drawing_scales(project)["longitudinal"] == {"x": 500, "y": 200}
+    assert read_drawing_scales(project)["longitudinal"] == {"x": 500, "y": 200, "plan": None}
     # 보낸 종류만 바뀜 — 앞서 쓴 종단은 남음 · 횡단 = 측점 설계 잠정 몫
     invalidated, stale = write_drawing_scales(
         project, project / "none.json", {"cross": {"x": 100, "y": 50}}
@@ -314,5 +321,5 @@ def test_GET_PUT_범위_밖_400(project: Path, monkeypatch: pytest.MonkeyPatch)
     assert not drawing_scales_path(project).exists()  # 거절 = 안 씀
     put = client.put(url, json={"scales": {"longitudinal": {"x": 500, "y": 200}}})
     assert put.status_code == 200
-    assert put.json()["scales"]["longitudinal"] == {"x": 500, "y": 200}
+    assert put.json()["scales"]["longitudinal"] == {"x": 500, "y": 200, "plan": None}
     assert put.json()["invalidated"] == {}
diff --git a/resources/tester/test_280_5_b07_settings.py b/resources/tester/test_280_5_b07_settings.py
index 9fec1b557..274d72d7e 100644
--- a/resources/tester/test_280_5_b07_settings.py
+++ b/resources/tester/test_280_5_b07_settings.py
@@ -229,22 +229,27 @@ def test_485_2_축척_칸_판정(out):
 
 def test_485_2_종단_축척_저장(out):
     scale = out["scale"]
-    assert scale["longLabels"] == ["X(가로) 1/", "Y(세로) 1/"]
-    assert scale["longStart"]["values"] == ["1000", "200"]
-    assert scale["longStart"]["autos"] == []  # 종단 = 자동 없음
+    assert scale["longLabels"] == ["X(가로) 1/", "Y(세로) 1/", "평면도 1/"]
+    assert scale["longStart"]["values"] == ["1000", "200", ""]
+    assert scale["longStart"]["autos"] == [True]  # 종단 = 평면도 칸만 자동(521-2)
     for bad in ("longLow", "longFrac"):  # 범위 밖 · 소수 = 붉음 + 저장 꺼짐
-        assert scale[bad]["errors"] == [RANGE, None]
+        assert scale[bad]["errors"] == [RANGE, None, None]
         assert scale[bad]["save"] is False
-    assert scale["longOk"]["errors"] == [None, None] and scale["longOk"]["save"] is True
+    assert scale["longOk"]["errors"] == [None, None, None] and scale["longOk"]["save"] is True
     # 저장본 2장 — 물음 [취소] = 요청 없음 · 모달 그대로
     assert scale["cancel"] == {"calls": ["ask"], "open": True, "closed": 0}
     save = scale["save"]
     assert "저장본 2장" in save["ask"]
-    assert save["sent"] == {"longitudinal": {"x": 500, "y": None}}  # Y = 기본 → null
+    assert save["sent"] == {"longitudinal": {"x": 500, "y": None, "plan": None}}  # 기본 → null
     assert save["open"] is False
     assert save["closed"] == [[True, "longitudinal"]]  # 화면 다시 세움 · 같은 도면
-    assert scale["reset"]["values"] == ["1000", "200"]  # [기본값] = 칸만
+    assert scale["reset"]["values"] == ["1000", "200", ""]  # [기본값] = 칸만
     assert scale["same"] == {"calls": 0, "toasts": ["바뀐 축척이 없습니다."]}
+    # 평면 위치도 칸(521-2) — 처음 자동(칸 꺼짐) · 1/500 밑 = 붉음 · 1/3,000 저장
+    assert scale["planStart"]["disabled"] == [False, False, True]
+    assert scale["planLow"]["errors"] == [None, None, "1/500~1/50,000 사이 정수"]
+    assert scale["planLow"]["save"] is False
+    assert scale["planSent"] == {"longitudinal": {"x": None, "y": None, "plan": 3000}}
 
 
 def test_485_2_토적_전개도_자동(out):
diff --git a/resources/tester/test_b07_long_sheet.py b/resources/tester/test_b07_long_sheet.py
index 85002c341..032141a8f 100644
--- a/resources/tester/test_b07_long_sheet.py
+++ b/resources/tester/test_b07_long_sheet.py
@@ -1,4 +1,10 @@
-"""B07 종단도 — 장마다 그림 좌하단 = 작도영역 좌하단 · 고정 축척 · 넘치면 장을 더 나눔 (59-3)."""
+"""B07 종단도 — 장마다 그림 좌하단 = 작도영역 좌하단 · 고정 축척 · 넘치면 장을 더 나눔 (59-3).
+
+우측 상단 평면 위치도(521-2) — 칸 자리 · 그래프와 안 겹침 · 장마다 강조 구간 · 척도.
+"""
+
+import json
+import math
 
 import pytest
 
@@ -7,7 +13,21 @@ from B07_DesignDetail.B07_DesignDetail_Engine_Cad_Long import (
     build_longitudinal_drawing,
     longitudinal_chunks,
 )
-from B07_DesignDetail.B07_DesignDetail_Engine_Template import entities_bbox, usable_area
+from B07_DesignDetail.B07_DesignDetail_Engine_Cad_LongPlan import (
+    LONG_PLAN_LAYER_ID,
+    plan_box_overlaps,
+)
+from B07_DesignDetail.B07_DesignDetail_Engine_Template import (
+    drawing_scales_path,
+    entities_bbox,
+    usable_area,
+    use_project_templates,
+)
+from B07_DesignDetail.B07_DesignDetail_Router_Support_Io import (
+    _read_manifest,
+    _write_manifest,
+    release_old_long_sheets,
+)
 
 
 def _longitudinal(count: int, interval: float, slope: float) -> dict:
@@ -57,3 +77,123 @@ def test_wide_interval_splits_more() -> None:
     # 40 m 간격 30측점 = 1,160 mm > 작도영역 폭 → 30개보다 적게 담는다
     chunks = longitudinal_chunks(_longitudinal(40, 40.0, 0.0))
     assert len(chunks) > 2
+
+
+# ── 우측 상단 평면 위치도(521-2 · 요구 340-2) ─────────────────────────────────
+def _with_xy(longitudinal: dict) -> dict:
+    for station in longitudinal["stations"]:
+        chainage = station["chainage_m"]
+        station["center_x"] = 200000.0 + chainage
+        station["center_y"] = 500000.0 + 60.0 * math.sin(chainage / 150.0)
+    return longitudinal
+
+
+def _plan_sheets(longitudinal: dict) -> list[dict]:
+    """장마다 그래프 bbox · 칸 엔티티 · 굵은(이 장) 선 꼭짓점 · 글."""
+    sheets = []
+    for chunk in longitudinal_chunks(longitudinal):
+        entities = build_longitudinal_drawing(longitudinal, chunk["id"], chunk)["entities"]
+        graph = [e for e in entities if e["layerId"] not in (FRAME_LAYER_ID, LONG_PLAN_LAYER_ID)]
+        plan = [e for e in entities if e["layerId"] == LONG_PLAN_LAYER_ID]
+        bold = [
+            (child["shapeData"][key]["x"], child["shapeData"][key]["y"])
+            for entity in plan
+            for child in entity.get("children") or []
+            if child["lineWidth"] == 3
+            for key in ("startPoint", "endPoint")
+        ]
+        texts = [e["shapeData"]["label"] for e in plan if e["type"] == "Text"]
+        sheets.append(
+            {
+                "graph": graph,
+                "bbox": entities_bbox(graph),
+                "plan": plan,
+                "bold": bold,
+                "texts": texts,
+            }
+        )
+    return sheets
+
+
+def test_평면_칸_작도영역_우상단_안_겹침_장마다_강조() -> None:
+    longitudinal = _with_xy(_longitudinal(66, 20.0, 0.05))
+    sheets = _plan_sheets(longitudinal)
+    usable_w, usable_h = usable_area()
+    lows = []
+    for number, sheet in enumerate(sheets, start=1):
+        x0, y0 = sheet["bbox"][0], sheet["bbox"][1]
+        box = entities_bbox(sheet["plan"])
+        # 칸 = 작도 영역 우상단 5 mm 안쪽 150×100 mm
+        assert box == pytest.approx(
+            (x0 + usable_w - 155.0, y0 + usable_h - 105.0, x0 + usable_w - 5.0, y0 + usable_h - 5.0)
+        )
+        assert not plan_box_overlaps(longitudinal, sheet["graph"], sheet["bbox"])
+        assert f"{number}/{len(sheets)} 장" in sheet["texts"]
+        assert any(text.startswith("평면도 S=1/") for text in sheet["texts"])
+        assert sheet["bold"]  # 이 장 구간 굵게
+        lows.append(min(x for x, _y in sheet["bold"]) - box[0])
+    # 자동 = 모든 장이 같은 축척 · 같은 자리 — 굵은 구간만 장마다 오른쪽으로 옮겨 감
+    assert lows == sorted(lows) and len(set(lows)) == len(lows)
+
+
+def test_칸을_덮으면_측점_줄여_장_더_나눔() -> None:
+    # 25 m 간격 30 측점 = 725 mm(폭 안) · 오르막 그래프가 우상단 칸을 덮음
+    plain = longitudinal_chunks(_longitudinal(60, 25.0, 0.1))
+    with_box = _with_xy(_longitudinal(60, 25.0, 0.1))
+    assert longitudinal_chunks(with_box)[0]["end_m"] < plain[0]["end_m"]
+    for sheet in _plan_sheets(with_box):
+        assert not plan_box_overlaps(with_box, sheet["graph"], sheet["bbox"])
+
+
+def test_좌표_없으면_칸_없음() -> None:
+    assert all(not sheet["plan"] for sheet in _plan_sheets(_longitudinal(40, 20.0, 0.0)))
+
+
+def test_척도_정하면_이_장_확대_밖_흐린_파선(tmp_path) -> None:
+    longitudinal = _with_xy(_longitudinal(66, 20.0, 0.05))
+    use_project_templates(tmp_path)
+    try:
+        path = drawing_scales_path(tmp_path)
+        path.parent.mkdir(parents=True, exist_ok=True)
+        path.write_text(json.dumps({"longitudinal": {"plan": 3000}}), encoding="utf-8")
+        sheets = _plan_sheets(longitudinal)
+    finally:
+        use_project_templates(None)
+    for sheet in sheets:
+        assert "평면도 S=1/3,000" in sheet["texts"]
+        assert any(entity.get("lineDash") for entity in sheet["plan"])  # 밖 노선 파선
+        box = entities_bbox(sheet["plan"])
+        xs = [x for x, _y in sheet["bold"]]
+        # 이 장 중심 = 칸 노선 자리 가운데
+        assert (min(xs) + max(xs)) / 2.0 == pytest.approx((box[0] + box[2]) / 2.0, abs=1.0)
+
+
+def test_칸_앞_확정_종단만_한_번_풂(tmp_path) -> None:
+    drawings = tmp_path / "B07_DesignDetail" / "drawings"
+    drawings.mkdir(parents=True)
+    old = {"kind": "longitudinal", "confirmed": True, "file": "x"}
+    _write_manifest(
+        tmp_path,
+        {
+            "drawings": {
+                "longitudinal_1": dict(old),
+                "longitudinal_2": dict(old),
+                "cross_00020m": {"kind": "cross", "confirmed": True, "file": "x"},
+            }
+        },
+    )
+    for name in ("longitudinal_1", "longitudinal_2", "cross_00020m"):
+        (drawings / f"{name}.json").write_text('{"layers": []}', encoding="utf-8")
+    release_old_long_sheets(tmp_path)
+    after = _read_manifest(tmp_path)["drawings"]
+    assert not after["longitudinal_1"]["confirmed"] and not after["longitudinal_2"]["confirmed"]
+    assert after["cross_00020m"]["confirmed"]
+    assert not (drawings / "longitudinal_1.json").exists()  # 옛 저장본 걷힘
+    # 새 확정본(칸 층 있음)은 그대로
+    after["longitudinal_1"] = dict(old)
+    _write_manifest(tmp_path, {"drawings": after})
+    (drawings / "longitudinal_1.json").write_text(
+        json.dumps({"layers": [{"id": LONG_PLAN_LAYER_ID}]}), encoding="utf-8"
+    )
+    release_old_long_sheets(tmp_path)
+    assert _read_manifest(tmp_path)["drawings"]["longitudinal_1"]["confirmed"]