diff --git a/src/features/flights-map/hooks/useGeolocationDefault.test.tsx b/src/features/flights-map/hooks/useGeolocationDefault.test.tsx
new file mode 100644
index 00000000..6ae84e06
--- /dev/null
+++ b/src/features/flights-map/hooks/useGeolocationDefault.test.tsx
@@ -0,0 +1,162 @@
+/**
+ * @vitest-environment jsdom
+ */
+
+import { describe, it, expect, vi, beforeEach, afterEach } from "vitest";
+import { renderHook } from "@testing-library/react";
+import { StrictMode, type ReactNode } from "react";
+import { useGeolocationDefault } from "./useGeolocationDefault.js";
+import { transformDictionaries } from "@/shared/dictionaries/index.js";
+import type { IDictionaries, IRawDictionaries } from "@/shared/dictionaries/index.js";
+import type { IFlightsMapFilterState } from "../types.js";
+
+const raw: IRawDictionaries = {
+  regions: [],
+  countries: [{ code: "RU", title: { ru: "Россия" }, world_region_id: 500374 }],
+  cities: [
+    { code: "MOW", title: { ru: "Москва" }, country_code: "RU", has_afl_flights: true, location: { lat: 55, lon: 37 } },
+    { code: "LED", title: { ru: "Санкт-Петербург" }, country_code: "RU", has_afl_flights: true, location: { lat: 60, lon: 30 } },
+  ],
+  airports: [
+    { code: "SVO", city_code: "MOW", title: { ru: "Шереметьево" }, has_afl_flights: true, location: { lat: 55, lon: 37 } },
+    { code: "LED", city_code: "LED", title: { ru: "Пулково" }, has_afl_flights: true, location: { lat: 60, lon: 30 } },
+  ],
+};
+const dictionaries: IDictionaries = transformDictionaries(raw, "ru");
+
+function makeFilter(
+  overrides: Partial<IFlightsMapFilterState> = {},
+): IFlightsMapFilterState {
+  return {
+    connections: false,
+    domestic: false,
+    international: false,
+    ...overrides,
+  };
+}
+
+interface GeolocationMock {
+  getCurrentPosition: ReturnType<typeof vi.fn>;
+}
+
+function installGeolocation(mock: GeolocationMock | undefined): void {
+  Object.defineProperty(navigator, "geolocation", {
+    value: mock,
+    writable: true,
+    configurable: true,
+  });
+}
+
+function successMock(lat: number, lon: number): GeolocationMock {
+  return {
+    getCurrentPosition: vi.fn((success: PositionCallback) => {
+      success({
+        coords: {
+          latitude: lat,
+          longitude: lon,
+          accuracy: 0,
+          altitude: null,
+          altitudeAccuracy: null,
+          heading: null,
+          speed: null,
+          toJSON: () => ({}),
+        },
+        timestamp: 0,
+        toJSON: () => ({}),
+      } as GeolocationPosition);
+    }),
+  };
+}
+
+function errorMock(): GeolocationMock {
+  return {
+    getCurrentPosition: vi.fn((_success, error?: PositionErrorCallback) => {
+      error?.({
+        code: 1,
+        message: "permission denied",
+        PERMISSION_DENIED: 1,
+        POSITION_UNAVAILABLE: 2,
+        TIMEOUT: 3,
+      } as GeolocationPositionError);
+    }),
+  };
+}
+
+describe("useGeolocationDefault", () => {
+  let lastState: IFlightsMapFilterState = makeFilter();
+  let setFilterState: (updater: (prev: IFlightsMapFilterState) => IFlightsMapFilterState) => void;
+
+  beforeEach(() => {
+    lastState = makeFilter();
+    setFilterState = (updater) => {
+      lastState = updater(lastState);
+    };
+  });
+
+  afterEach(() => {
+    installGeolocation(undefined);
+  });
+
+  it("sets departure to nearest city when filter is empty and geolocation succeeds", () => {
+    installGeolocation(successMock(55.1, 37.1));
+    renderHook(() =>
+      useGeolocationDefault(dictionaries, lastState, setFilterState),
+    );
+    expect(lastState.departure).toBe("MOW");
+  });
+
+  it("does not update when filter.departure is already set", () => {
+    lastState = makeFilter({ departure: "LED" });
+    installGeolocation(successMock(55.1, 37.1));
+    renderHook(() =>
+      useGeolocationDefault(dictionaries, lastState, setFilterState),
+    );
+    expect(lastState.departure).toBe("LED");
+  });
+
+  it("does not update when filter.arrival is already set", () => {
+    lastState = makeFilter({ arrival: "MOW" });
+    installGeolocation(successMock(55.1, 37.1));
+    renderHook(() =>
+      useGeolocationDefault(dictionaries, lastState, setFilterState),
+    );
+    expect(lastState.departure).toBeUndefined();
+  });
+
+  it("does nothing when geolocation permission is denied", () => {
+    installGeolocation(errorMock());
+    renderHook(() =>
+      useGeolocationDefault(dictionaries, lastState, setFilterState),
+    );
+    expect(lastState.departure).toBeUndefined();
+  });
+
+  it("does nothing when navigator.geolocation is missing", () => {
+    installGeolocation(undefined);
+    renderHook(() =>
+      useGeolocationDefault(dictionaries, lastState, setFilterState),
+    );
+    expect(lastState.departure).toBeUndefined();
+  });
+
+  it("does nothing when dictionaries is null at callback time", () => {
+    installGeolocation(successMock(55.1, 37.1));
+    renderHook(() =>
+      useGeolocationDefault(null, lastState, setFilterState),
+    );
+    expect(lastState.departure).toBeUndefined();
+  });
+
+  it("invokes getCurrentPosition exactly once under StrictMode", () => {
+    const mock = successMock(55.1, 37.1);
+    installGeolocation(mock);
+    const wrapper = ({ children }: { children: ReactNode }) => (
+      <StrictMode>{children}</StrictMode>
+    );
+    renderHook(
+      () => useGeolocationDefault(dictionaries, lastState, setFilterState),
+      { wrapper },
+    );
+    expect(mock.getCurrentPosition).toHaveBeenCalledTimes(1);
+  });
+});
diff --git a/src/features/flights-map/hooks/useGeolocationDefault.ts b/src/features/flights-map/hooks/useGeolocationDefault.ts
new file mode 100644
index 00000000..700ab306
--- /dev/null
+++ b/src/features/flights-map/hooks/useGeolocationDefault.ts
@@ -0,0 +1,65 @@
+/**
+ * Sets the flights-map filter's departure to the nearest city based on
+ * browser geolocation, if the user has not already typed a departure or
+ * arrival. Fires once per mount. Silent on permission denial or missing
+ * geolocation API. Matches Angular `UserLocationService` + `DictionariesService.locate`.
+ */
+
+import { useEffect, useRef } from "react";
+import {
+  findCityByCoord,
+  type IDictionaries,
+} from "@/shared/dictionaries/index.js";
+import type { IFlightsMapFilterState } from "../types.js";
+
+export function useGeolocationDefault(
+  dictionaries: IDictionaries | null,
+  filterState: IFlightsMapFilterState,
+  setFilterState: (
+    updater: (prev: IFlightsMapFilterState) => IFlightsMapFilterState,
+  ) => void,
+): void {
+  const appliedRef = useRef(false);
+  const dictRef = useRef(dictionaries);
+  dictRef.current = dictionaries;
+  const filterRef = useRef(filterState);
+  filterRef.current = filterState;
+  const setFilterRef = useRef(setFilterState);
+  setFilterRef.current = setFilterState;
+
+  useEffect(() => {
+    if (appliedRef.current) return;
+    if (typeof navigator === "undefined" || !navigator.geolocation) {
+      appliedRef.current = true;
+      return;
+    }
+
+    appliedRef.current = true;
+
+    navigator.geolocation.getCurrentPosition(
+      (pos) => {
+        const d = dictRef.current;
+        const f = filterRef.current;
+        if (!d) return;
+        if (f.departure || f.arrival) return;
+
+        const city = findCityByCoord(
+          d,
+          pos.coords.latitude,
+          pos.coords.longitude,
+        );
+        if (!city) return;
+
+        setFilterRef.current((prev) =>
+          prev.departure || prev.arrival
+            ? prev
+            : { ...prev, departure: city.code },
+        );
+      },
+      () => {
+        // Silent: permission denied / timeout / unavailable.
+      },
+      { enableHighAccuracy: false, timeout: 5000 },
+    );
+  }, []);
+}