Bug Fix: Helicopters spawning under each other

OpenRA.Mods.RA/Air/Helicopter.cs

@@ -31,6 +31,7 @@ namespace OpenRA.Mods.RA.Air
 	class Helicopter : Aircraft, ITick, IIssueOrder, IResolveOrder, IOrderVoice
 	{
 		HelicopterInfo Info;
+		bool firstTick = true;
 
 		public Helicopter( ActorInitializer init, HelicopterInfo info) : base( init, info ) 
 		{
@@ -121,6 +122,24 @@ namespace OpenRA.Mods.RA.Air
 		
 		public void Tick(Actor self)
 		{
+			if (firstTick)
+			{
+				firstTick = false;
+				if (self.Trait<IMove>().Altitude == 0)
+				{
+					/* not spawning in the air, so try to assoc. with our afld. this is a hack. */
+					var afld = self.World.FindUnits(self.CenterLocation, self.CenterLocation)
+						.FirstOrDefault(a => a.HasTrait<Reservable>());
+
+					if (afld != null)
+					{
+						var res = afld.Trait<Reservable>();
+						if (res != null)
+							reservation = res.Reserve(afld, self, this);
+					}
+				}
+			}
+
 			var aircraft = self.Trait<Aircraft>();
 			if (aircraft.Altitude <= 0)
 				return;