diff --git a/agenda/trip.py b/agenda/trip.py
index cbb72fc..b0c50cf 100644
--- a/agenda/trip.py
+++ b/agenda/trip.py
@@ -93,6 +93,7 @@ def load_flight_bookings(data_dir: str) -> list[StrDict]:
     """Load flight bookings."""
     bookings = load_travel("flight", "flights", data_dir)
     airlines = yaml.safe_load(open(os.path.join(data_dir, "airlines.yaml")))
+    iata = {a["iata"]: a["name"] for a in airlines}
     airports = travel.parse_yaml("airports", data_dir)
     for booking in bookings:
         for flight in booking["flights"]:
@@ -101,7 +102,7 @@ def load_flight_bookings(data_dir: str) -> list[StrDict]:
             if flight["to"] in airports:
                 flight["to_airport"] = airports[flight["to"]]
             if "airline" in flight:
-                flight["airline_name"] = airlines.get(flight["airline"], "[unknown]")
+                flight["airline_name"] = iata.get(flight["airline"], "[unknown]")
 
             flight["distance"] = travel.flight_distance(flight)
     return bookings
diff --git a/validate_yaml.py b/validate_yaml.py
index d23fd0e..ec34a52 100755
--- a/validate_yaml.py
+++ b/validate_yaml.py
@@ -13,43 +13,86 @@ import agenda.trip
 import agenda.types
 
 config = __import__("config.default", fromlist=[""])
-
 data_dir = config.PERSONAL_DATA
 
-trip_list = agenda.trip.build_trip_list(data_dir)
-print(len(trip_list), "trips")
 
-coords, routes = agenda.trip.get_coordinates_and_routes(trip_list, data_dir)
-print(len(coords), "coords")
-print(len(routes), "routes")
+def check_trips() -> None:
+    """Check trips."""
+    trip_list = agenda.trip.build_trip_list(data_dir)
+    print(len(trip_list), "trips")
 
-flights = agenda.travel.parse_yaml("flights", data_dir)
-print(len(flights), "flights")
-
-trains = agenda.travel.parse_yaml("trains", data_dir)
-print(len(trains), "trains")
-
-conferences = agenda.conference.get_list(os.path.join(data_dir, "conferences.yaml"))
-print(len(conferences), "conferences")
-
-today = date.today()
-last_year = today - timedelta(days=365)
-next_year = today + timedelta(days=2 * 365)
-
-events = agenda.events_yaml.read(data_dir, last_year, next_year)
-print(len(events), "events")
-
-airports = typing.cast(
-    dict[str, agenda.types.StrDict], agenda.travel.parse_yaml("airports", data_dir)
-)
-print(len(airports), "airports")
-for airport in airports.values():
-    assert "country" in airport
-    assert agenda.get_country(airport["country"])
+    coords, routes = agenda.trip.get_coordinates_and_routes(trip_list, data_dir)
+    print(len(coords), "coords")
+    print(len(routes), "routes")
 
 
-stations = agenda.travel.parse_yaml("stations", data_dir)
-print(len(stations), "stations")
-for station in stations:
-    assert "country" in station
-    assert agenda.get_country(station["country"])
+def check_flights() -> None:
+    """Check flights."""
+    flights = agenda.travel.parse_yaml("flights", data_dir)
+    print(len(flights), "flights")
+
+
+def check_trains() -> None:
+    """Check trains."""
+    trains = agenda.travel.parse_yaml("trains", data_dir)
+    print(len(trains), "trains")
+
+
+def check_conferences() -> None:
+    """Check conferences."""
+    conferences = agenda.conference.get_list(os.path.join(data_dir, "conferences.yaml"))
+    print(len(conferences), "conferences")
+
+
+def check_events() -> None:
+    """Check events."""
+    today = date.today()
+    last_year = today - timedelta(days=365)
+    next_year = today + timedelta(days=2 * 365)
+
+    events = agenda.events_yaml.read(data_dir, last_year, next_year)
+    print(len(events), "events")
+
+
+def check_airports() -> None:
+    """Check airports."""
+    airports = typing.cast(
+        dict[str, agenda.types.StrDict], agenda.travel.parse_yaml("airports", data_dir)
+    )
+    print(len(airports), "airports")
+    for airport in airports.values():
+        assert "country" in airport
+        assert agenda.get_country(airport["country"])
+
+
+def check_stations() -> None:
+    """Check stations."""
+    stations = agenda.travel.parse_yaml("stations", data_dir)
+    print(len(stations), "stations")
+    for station in stations:
+        assert "country" in station
+        assert agenda.get_country(station["country"])
+
+
+def check_airlines() -> None:
+    """Check airlines."""
+    airlines = agenda.travel.parse_yaml("airlines", data_dir)
+    print(len(airlines), "airlines")
+    for airline in airlines:
+        assert airline.keys() == {"icao", "iata", "name"}
+
+
+def check() -> None:
+    """Validate personal data YAML files."""
+    check_trips()
+    check_flights()
+    check_trains()
+    check_conferences()
+    check_events()
+    check_airports()
+    check_stations()
+    check_airlines()
+
+
+if __name__ == "__main__":
+    check()