diff --git a/src/aircraft_cmd.cpp b/src/aircraft_cmd.cpp
index 5b5746563a..05d6d4c055 100644
--- a/src/aircraft_cmd.cpp
+++ b/src/aircraft_cmd.cpp
@@ -149,10 +149,10 @@ static StationID FindNearestHangar(const Aircraft *v)
 		const AirportFTAClass *afc = st->airport.GetFTA();
 
 		/* don't crash the plane if we know it can't land at the airport */
-		if ((afc->flags & AirportFTAClass::SHORT_STRIP) && (avi->subtype & AIR_FAST) && !_cheats.no_jetcrash.value) continue;
+		if (afc->flags.Test(AirportFTAClass::Flag::ShortStrip) && (avi->subtype & AIR_FAST) && !_cheats.no_jetcrash.value) continue;
 
 		/* the plane won't land at any helicopter station */
-		if (!(afc->flags & AirportFTAClass::AIRPLANES) && (avi->subtype & AIR_CTOL)) continue;
+		if (!afc->flags.Test(AirportFTAClass::Flag::Airplanes) && (avi->subtype & AIR_CTOL)) continue;
 
 		/* Check if our last and next destinations can be reached from the depot airport. */
 		if (max_range != 0) {
@@ -1373,7 +1373,7 @@ static void MaybeCrashAirplane(Aircraft *v)
 	Station *st = Station::Get(v->targetairport);
 
 	uint32_t prob;
-	if ((st->airport.GetFTA()->flags & AirportFTAClass::SHORT_STRIP) &&
+	if (st->airport.GetFTA()->flags.Test(AirportFTAClass::Flag::ShortStrip) &&
 			(AircraftVehInfo(v->engine_type)->subtype & AIR_FAST) &&
 			!_cheats.no_jetcrash.value) {
 		prob = 3276;
diff --git a/src/airport.cpp b/src/airport.cpp
index a46e30a88e..21fa384323 100644
--- a/src/airport.cpp
+++ b/src/airport.cpp
@@ -35,7 +35,7 @@
  * @param short_strip Airport has a short land/take-off strip.
  */
 #define AIRPORT(name, num_helipads, short_strip) \
-	AIRPORT_GENERIC(name, _airport_terminal_ ## name, num_helipads, AirportFTAClass::ALL | (short_strip ? AirportFTAClass::SHORT_STRIP : (AirportFTAClass::Flags)0), 0)
+	AIRPORT_GENERIC(name, _airport_terminal_ ## name, num_helipads, AirportFTAClass::Flags({AirportFTAClass::Flag::Airplanes, AirportFTAClass::Flag::Helicopters}) | (short_strip ? AirportFTAClass::Flags{AirportFTAClass::Flag::ShortStrip} : AirportFTAClass::Flags{}), 0)
 
 /**
  * Define a heliport.
@@ -44,7 +44,7 @@
  * @param delta_z Height of the airport above the land.
  */
 #define HELIPORT(name, num_helipads, delta_z) \
-	AIRPORT_GENERIC(name, nullptr, num_helipads, AirportFTAClass::HELICOPTERS, delta_z)
+	AIRPORT_GENERIC(name, nullptr, num_helipads, AirportFTAClass::Flag::Helicopters, delta_z)
 
 AIRPORT(country, 0, true)
 AIRPORT(city, 0, false)
@@ -56,7 +56,7 @@ HELIPORT(helidepot, 1, 0)
 AIRPORT(intercontinental, 2, false)
 HELIPORT(helistation, 3, 0)
 HELIPORT(oilrig, 1, 54)
-AIRPORT_GENERIC(dummy, nullptr, 0, AirportFTAClass::ALL, 0)
+AIRPORT_GENERIC(dummy, nullptr, 0, AirportFTAClass::Flags({AirportFTAClass::Flag::Airplanes, AirportFTAClass::Flag::Helicopters}), 0)
 
 #undef HELIPORT
 #undef AIRPORT
diff --git a/src/airport.h b/src/airport.h
index 6f3548e382..da347daa47 100644
--- a/src/airport.h
+++ b/src/airport.h
@@ -154,12 +154,12 @@ struct AirportFTA {
 struct AirportFTAClass {
 public:
 	/** Bitmask of airport flags. */
-	enum Flags : uint8_t {
-		AIRPLANES   = 0x1,                     ///< Can planes land on this airport type?
-		HELICOPTERS = 0x2,                     ///< Can helicopters land on this airport type?
-		ALL         = AIRPLANES | HELICOPTERS, ///< Mask to check for both planes and helicopters.
-		SHORT_STRIP = 0x4,                     ///< This airport has a short landing strip, dangerous for fast aircraft.
+	enum class Flag : uint8_t {
+		Airplanes   = 0, ///< Can planes land on this airport type?
+		Helicopters = 1, ///< Can helicopters land on this airport type?
+		ShortStrip  = 2, ///< This airport has a short landing strip, dangerous for fast aircraft.
 	};
+	using Flags = EnumBitSet<Flag, uint8_t>;
 
 	AirportFTAClass(
 		const AirportMovingData *moving_data,
@@ -192,8 +192,6 @@ public:
 	uint8_t delta_z;                         ///< Z adjustment for helicopter pads
 };
 
-DECLARE_ENUM_AS_BIT_SET(AirportFTAClass::Flags)
-
 
 const AirportFTAClass *GetAirport(const uint8_t airport_type);
 uint8_t GetVehiclePosOnBuild(TileIndex hangar_tile);
diff --git a/src/order_cmd.cpp b/src/order_cmd.cpp
index 175becfe08..408862b5f7 100644
--- a/src/order_cmd.cpp
+++ b/src/order_cmd.cpp
@@ -1729,7 +1729,7 @@ void CheckOrders(const Vehicle *v)
 					message = STR_NEWS_VEHICLE_HAS_INVALID_ENTRY;
 				} else if (v->type == VEH_AIRCRAFT &&
 							(AircraftVehInfo(v->engine_type)->subtype & AIR_FAST) &&
-							(st->airport.GetFTA()->flags & AirportFTAClass::SHORT_STRIP) &&
+							st->airport.GetFTA()->flags.Test(AirportFTAClass::Flag::ShortStrip) &&
 							!_cheats.no_jetcrash.value &&
 							message == INVALID_STRING_ID) {
 					message = STR_NEWS_PLANE_USES_TOO_SHORT_RUNWAY;
diff --git a/src/station_cmd.cpp b/src/station_cmd.cpp
index d461ee5718..550564a9bd 100644
--- a/src/station_cmd.cpp
+++ b/src/station_cmd.cpp
@@ -2591,7 +2591,7 @@ CommandCost CmdBuildAirport(DoCommandFlag flags, TileIndex tile, uint8_t airport
 	/* Distant join */
 	if (st == nullptr && distant_join) st = Station::GetIfValid(station_to_join);
 
-	ret = BuildStationPart(&st, flags, reuse, airport_area, (GetAirport(airport_type)->flags & AirportFTAClass::AIRPLANES) ? STATIONNAMING_AIRPORT : STATIONNAMING_HELIPORT);
+	ret = BuildStationPart(&st, flags, reuse, airport_area, GetAirport(airport_type)->flags.Test(AirportFTAClass::Flag::Airplanes) ? STATIONNAMING_AIRPORT : STATIONNAMING_HELIPORT);
 	if (ret.Failed()) return ret;
 
 	if (st != nullptr && st->airport.tile != INVALID_TILE) {
diff --git a/src/vehicle.cpp b/src/vehicle.cpp
index d06bfa4070..6e1f842874 100644
--- a/src/vehicle.cpp
+++ b/src/vehicle.cpp
@@ -3075,7 +3075,7 @@ bool CanVehicleUseStation(EngineID engine_type, const Station *st)
 
 		case VEH_AIRCRAFT:
 			return (st->facilities & FACIL_AIRPORT) != 0 &&
-					(st->airport.GetFTA()->flags & (e->u.air.subtype & AIR_CTOL ? AirportFTAClass::AIRPLANES : AirportFTAClass::HELICOPTERS)) != 0;
+					st->airport.GetFTA()->flags.Test(e->u.air.subtype & AIR_CTOL ? AirportFTAClass::Flag::Airplanes : AirportFTAClass::Flag::Helicopters);
 
 		default:
 			return false;