This is the code you disabled here:

```csharp
		public Activity TakeOff(Actor a)
		{
			self.CancelActivity();
			if (Reservation != null)
			{
				Reservation.Dispose();
				Reservation = null;
			}

			if (a != null)
			{
				if (a.HasTrait<RallyPoint>())
					return new HeliFly(self, Target.FromCell(a.Trait<RallyPoint>().rallyPoint));

				return new HeliFly(self, Target.FromPos(a.CenterPosition));
			}

			return new HeliFly(self, Target.FromPos(self.CenterPosition));
		}
```

and this is what it breaks:

![image](https://cloud.githubusercontent.com/assets/756669/3087793/673e3d64-e561-11e3-82d7-2790c8475ceb.png)

A new plane can't spawn, because you are still reserving it for the last plance that rearmed here. This also regresses the working behavior for helicopters.