diff --git a/OpenRA.Mods.RA/Air/Aircraft.cs b/OpenRA.Mods.RA/Air/Aircraft.cs
index c4a454ef14..b9b407b1c4 100755
--- a/OpenRA.Mods.RA/Air/Aircraft.cs
+++ b/OpenRA.Mods.RA/Air/Aircraft.cs
@@ -1,6 +1,6 @@
 #region Copyright & License Information
 /*
- * Copyright 2007-2011 The OpenRA Developers (see AUTHORS)
+ * Copyright 2007-2013 The OpenRA Developers (see AUTHORS)
  * This file is part of OpenRA, which is free software. It is made
  * available to you under the terms of the GNU General Public License
  * as published by the Free Software Foundation. For more information,
@@ -19,10 +19,10 @@ using OpenRA.Traits;
 
 namespace OpenRA.Mods.RA.Air
 {
-
 	public class AircraftInfo : ITraitInfo, IFacingInfo, IOccupySpaceInfo, UsesInit<AltitudeInit>, UsesInit<LocationInit>, UsesInit<FacingInit>
 	{
 		public readonly int CruiseAltitude = 30;
+
 		[ActorReference]
 		public readonly string[] RepairBuildings = { "fix" };
 		[ActorReference]
@@ -32,57 +32,47 @@ namespace OpenRA.Mods.RA.Air
 		public readonly int Speed = 1;
 		public readonly string[] LandableTerrainTypes = { };
 
-		public virtual object Create( ActorInitializer init ) { return new Aircraft( init , this ); }
+		public virtual object Create(ActorInitializer init) { return new Aircraft(init, this); }
 		public int GetInitialFacing() { return InitialFacing; }
 	}
 
 	public class Aircraft : IFacing, IPositionable, ISync, INotifyKilled, IIssueOrder, IOrderVoice
 	{
-		public IDisposable reservation;
+		static readonly Pair<CPos, SubCell>[] NoCells = new Pair<CPos, SubCell>[] { };
 
-		public void UnReserve()
-		{
-			if (reservation != null)
-			{
-				reservation.Dispose();
-				reservation = null;
-			}
-		}
+		readonly AircraftInfo info;
+		readonly Actor self;
 
-		public void Killed(Actor self, AttackInfo e)
-		{
-			UnReserve();
-		}
-
-		protected readonly Actor self;
 		[Sync] public int Facing { get; set; }
-		[Sync] public int Altitude { get; set; }
-		[Sync] public PSubPos SubPxPosition;
+		[Sync] public WPos CenterPosition { get; private set; }
+		public CPos TopLeft { get { return CenterPosition.ToCPos(); } }
+		public IDisposable Reservation;
+		public int ROT { get { return info.ROT; } }
 
-		public WPos CenterPosition { get { return PxPosition.ToWPos(Altitude); } }
-		public PPos PxPosition { get { return SubPxPosition.ToPPos(); } }
-		public CPos TopLeft { get { return PxPosition.ToCPos(); } }
-
-		readonly AircraftInfo Info;
-
-		public Aircraft(ActorInitializer init , AircraftInfo info)
+		public Aircraft(ActorInitializer init, AircraftInfo info)
 		{
+			this.info = info;
 			this.self = init.self;
-			if( init.Contains<LocationInit>() )
-				this.SubPxPosition = Util.CenterOfCell( init.Get<LocationInit, CPos>() ).ToPSubPos();
 
-			this.Facing = init.Contains<FacingInit>() ? init.Get<FacingInit,int>() : info.InitialFacing;
-			this.Altitude = init.Contains<AltitudeInit>() ? init.Get<AltitudeInit,int>() : 0;
-			Info = info;
+			if (init.Contains<LocationInit>())
+				SetPosition(self, init.Get<LocationInit, CPos>());
+
+			this.Facing = init.Contains<FacingInit>() ? init.Get<FacingInit, int>() : info.InitialFacing;
+
+			if (init.Contains<AltitudeInit>())
+			{
+				var z = init.Get<AltitudeInit, int>() * 1024 / Game.CellSize;
+				SetPosition(self, CenterPosition + new WVec(0, 0, z - CenterPosition.Z));
+			}
 		}
 
 		public Actor GetActorBelow()
 		{
-			if (Altitude != 0)
+			if (self.CenterPosition.Z != 0)
 				return null;	// not on the ground.
 
 			return self.World.FindActorsInBox(self.CenterPosition, self.CenterPosition)
-				.FirstOrDefault( a => a.HasTrait<Reservable>() );
+				.FirstOrDefault(a => a.HasTrait<Reservable>());
 		}
 
 		protected void ReserveSpawnBuilding()
@@ -94,29 +84,39 @@ namespace OpenRA.Mods.RA.Air
 
 			var res = afld.Trait<Reservable>();
 			if (res != null)
-				reservation = res.Reserve(afld, self, this);
+				Reservation = res.Reserve(afld, self, this);
 		}
 
-		public int ROT { get { return Info.ROT; } }
+		public void UnReserve()
+		{
+			if (Reservation != null)
+			{
+				Reservation.Dispose();
+				Reservation = null;
+			}
+		}
+
+		public void Killed(Actor self, AttackInfo e)
+		{
+			UnReserve();
+		}
 
 		public void SetPosition(Actor self, CPos cell)
 		{
-			SubPxPosition = Util.CenterOfCell(cell).ToPSubPos();
-		}
-
-		public void SetPosition(Actor self, WPos pos)
-		{
-			// TODO: Handle altitude
-			SubPxPosition = PPos.FromWPos(pos).ToPSubPos();
+			// Changes position, but not altitude
+			CenterPosition = cell.CenterPosition + new WVec(0, 0, CenterPosition.Z);
 		}
 
+		public void SetPosition(Actor self, WPos pos) { CenterPosition = pos; }
 		public void SetVisualPosition(Actor self, WPos pos) { SetPosition(self, pos); }
 
 		public bool AircraftCanEnter(Actor a)
 		{
-			if (self.AppearsHostileTo(a)) return false;
-			return Info.RearmBuildings.Contains(a.Info.Name)
-				|| Info.RepairBuildings.Contains(a.Info.Name);
+			if (self.AppearsHostileTo(a))
+				return false;
+
+			return info.RearmBuildings.Contains(a.Info.Name)
+				|| info.RepairBuildings.Contains(a.Info.Name);
 		}
 
 		public bool CanEnterCell(CPos location) { return true; }
@@ -125,20 +125,20 @@ namespace OpenRA.Mods.RA.Air
 		{
 			get
 			{
-				decimal ret = Info.Speed;
+				decimal ret = info.Speed;
 				foreach (var t in self.TraitsImplementing<ISpeedModifier>())
 					ret *= t.GetSpeedModifier();
 				return (int)ret;
 			}
 		}
 
-		Pair<CPos, SubCell>[] noCells = new Pair<CPos, SubCell>[] { };
-		public IEnumerable<Pair<CPos, SubCell>> OccupiedCells() { return noCells; }
+		public IEnumerable<Pair<CPos, SubCell>> OccupiedCells() { return NoCells; }
 
-		public void TickMove(int speed, int facing)
+		public WVec FlyStep(int facing)
 		{
-			var rawspeed = speed * 7 / (32 * PSubPos.PerPx);
-			SubPxPosition += rawspeed * -Util.SubPxVector[facing];
+			var speed = MovementSpeed * 7 * 1024 / (Game.CellSize * 32);
+			var dir = new WVec(0, -1024, 0).Rotate(WRot.FromFacing(facing));
+			return speed * dir / 1024;
 		}
 
 		public bool CanLand(CPos cell)
@@ -150,15 +150,15 @@ namespace OpenRA.Mods.RA.Air
 				return false;
 
 			var type = self.World.GetTerrainType(cell);
-			return Info.LandableTerrainTypes.Contains(type);
+			return info.LandableTerrainTypes.Contains(type);
 		}
 
 		public IEnumerable<Activity> GetResupplyActivities(Actor a)
 		{
 			var name = a.Info.Name;
-			if (Info.RearmBuildings.Contains(name))
+			if (info.RearmBuildings.Contains(name))
 				yield return new Rearm(self);
-			if (Info.RepairBuildings.Contains(name))
+			if (info.RepairBuildings.Contains(name))
 				yield return new Repair(a);
 		}
 
@@ -228,6 +228,7 @@ namespace OpenRA.Mods.RA.Air
 			cursor = self.World.Map.IsInMap(location) ? "move" : "move-blocked";
 			return true;
 		}
+
 		public bool IsQueued { get; protected set; }
 	}
 }
diff --git a/OpenRA.Mods.RA/Air/AttackPlane.cs b/OpenRA.Mods.RA/Air/AttackPlane.cs
index b23da20bd6..fce0c636af 100755
--- a/OpenRA.Mods.RA/Air/AttackPlane.cs
+++ b/OpenRA.Mods.RA/Air/AttackPlane.cs
@@ -1,6 +1,6 @@
 #region Copyright & License Information
 /*
- * Copyright 2007-2011 The OpenRA Developers (see AUTHORS)
+ * Copyright 2007-2013 The OpenRA Developers (see AUTHORS)
  * This file is part of OpenRA, which is free software. It is made
  * available to you under the terms of the GNU General Public License
  * as published by the Free Software Foundation. For more information,
@@ -24,14 +24,13 @@ namespace OpenRA.Mods.RA.Air
 
 		public override Activity GetAttackActivity(Actor self, Target newTarget, bool allowMove)
 		{
-			return new FlyAttack( newTarget );
+			return new FlyAttack(newTarget);
 		}
 
 		protected override bool CanAttack(Actor self, Target target)
 		{
 			// dont fire while landed
-			return base.CanAttack(self, target)
-				&& self.Trait<Aircraft>().Altitude > 0;
+			return base.CanAttack(self, target) && self.CenterPosition.Z > 0;
 		}
 	}
 }
diff --git a/OpenRA.Mods.RA/Air/FallsToEarth.cs b/OpenRA.Mods.RA/Air/FallsToEarth.cs
index 9f62efcc01..5099953e2f 100755
--- a/OpenRA.Mods.RA/Air/FallsToEarth.cs
+++ b/OpenRA.Mods.RA/Air/FallsToEarth.cs
@@ -1,6 +1,6 @@
 #region Copyright & License Information
 /*
- * Copyright 2007-2011 The OpenRA Developers (see AUTHORS)
+ * Copyright 2007-2013 The OpenRA Developers (see AUTHORS)
  * This file is part of OpenRA, which is free software. It is made
  * available to you under the terms of the GNU General Public License
  * as published by the Free Software Foundation. For more information,
@@ -19,6 +19,7 @@ namespace OpenRA.Mods.RA.Air
 
 		public readonly bool Spins = true;
 		public readonly bool Moves = false;
+		public readonly WRange Velocity = new WRange(43);
 
 		public object Create(ActorInitializer init) { return new FallsToEarth(init.self, this); }
 	}
@@ -47,7 +48,7 @@ namespace OpenRA.Mods.RA.Air
 		public override Activity Tick(Actor self)
 		{
 			var aircraft = self.Trait<Aircraft>();
-			if (aircraft.Altitude <= 0)
+			if (self.CenterPosition.Z <= 0)
 			{
 				if (info.Explosion != null)
 					Combat.DoExplosion(self, info.Explosion, self.CenterPosition);
@@ -62,15 +63,14 @@ namespace OpenRA.Mods.RA.Air
 				aircraft.Facing = (aircraft.Facing + spin) % 256;
 			}
 
-			if (info.Moves)
-				FlyUtil.Fly(self, aircraft.Altitude);
-
-			aircraft.Altitude--;
+			var move = info.Moves ? aircraft.FlyStep(aircraft.Facing) : WVec.Zero;
+			move -= new WVec(WRange.Zero, WRange.Zero, info.Velocity);
+			aircraft.SetPosition(self, aircraft.CenterPosition + move);
 
 			return this;
 		}
 
 		// Cannot be cancelled
-		public override void Cancel( Actor self ) { }
+		public override void Cancel(Actor self) { }
 	}
 }
diff --git a/OpenRA.Mods.RA/Air/Fly.cs b/OpenRA.Mods.RA/Air/Fly.cs
index bd900f72b9..198ea181d0 100755
--- a/OpenRA.Mods.RA/Air/Fly.cs
+++ b/OpenRA.Mods.RA/Air/Fly.cs
@@ -1,6 +1,6 @@
 #region Copyright & License Information
 /*
- * Copyright 2007-2011 The OpenRA Developers (see AUTHORS)
+ * Copyright 2007-2013 The OpenRA Developers (see AUTHORS)
  * This file is part of OpenRA, which is free software. It is made
  * available to you under the terms of the GNU General Public License
  * as published by the Free Software Foundation. For more information,
@@ -20,6 +20,23 @@ namespace OpenRA.Mods.RA.Air
 
 		Fly(WPos pos) { this.pos = pos; }
 
+		public static void FlyToward(Actor self, Plane plane, int desiredFacing, WRange desiredAltitude)
+		{
+			var move = plane.FlyStep(plane.Facing);
+			var altitude = plane.CenterPosition.Z;
+
+			plane.Facing = Util.TickFacing(plane.Facing, desiredFacing, plane.ROT);
+
+			if (altitude != desiredAltitude.Range)
+			{
+				var delta = move.HorizontalLength * plane.Info.MaximumPitch.Tan() / 1024;
+				var dz = (desiredAltitude.Range - altitude).Clamp(-delta, delta);
+				move += new WVec(0, 0, dz);
+			}
+
+			plane.SetPosition(self, plane.CenterPosition + move);
+		}
+
 		public static Fly ToPos(WPos pos) { return new Fly(pos); }
 		public static Fly ToCell(CPos pos) { return new Fly(pos.CenterPosition); }
 
@@ -33,16 +50,16 @@ namespace OpenRA.Mods.RA.Air
 			if (d.HorizontalLengthSquared < 91022)
 				return NextActivity;
 
-			var aircraft = self.Trait<Aircraft>();
-			var cruiseAltitude = self.Info.Traits.Get<PlaneInfo>().CruiseAltitude;
-			var desiredFacing = Util.GetFacing(d, aircraft.Facing);
-			if (aircraft.Altitude == cruiseAltitude)
-				aircraft.Facing = Util.TickFacing(aircraft.Facing, desiredFacing, aircraft.ROT);
+			var plane = self.Trait<Plane>();
+			var desiredFacing = Util.GetFacing(d, plane.Facing);
+			var cruiseAltitude = new WRange(plane.Info.CruiseAltitude * 1024 / Game.CellSize);
 
-			if (aircraft.Altitude < cruiseAltitude)
-				++aircraft.Altitude;
+			// Don't turn until we've reached the cruise altitude
+			if (plane.CenterPosition.Z < cruiseAltitude.Range)
+				desiredFacing = plane.Facing;
+
+			FlyToward(self, plane, desiredFacing, cruiseAltitude);
 
-			FlyUtil.Fly(self, cruiseAltitude);
 			return this;
 		}
 
@@ -51,14 +68,4 @@ namespace OpenRA.Mods.RA.Air
 			yield return Target.FromPos(pos);
 		}
 	}
-
-	public static class FlyUtil
-	{
-		public static void Fly(Actor self, int desiredAltitude)
-		{
-			var aircraft = self.Trait<Aircraft>();
-			aircraft.TickMove(PSubPos.PerPx * aircraft.MovementSpeed, aircraft.Facing);
-			aircraft.Altitude += Math.Sign(desiredAltitude - aircraft.Altitude);
-		}
-	}
 }
diff --git a/OpenRA.Mods.RA/Air/FlyCircle.cs b/OpenRA.Mods.RA/Air/FlyCircle.cs
index 24c92d2ad1..9302a5e951 100644
--- a/OpenRA.Mods.RA/Air/FlyCircle.cs
+++ b/OpenRA.Mods.RA/Air/FlyCircle.cs
@@ -1,6 +1,6 @@
 #region Copyright & License Information
 /*
- * Copyright 2007-2011 The OpenRA Developers (see AUTHORS)
+ * Copyright 2007-2013 The OpenRA Developers (see AUTHORS)
  * This file is part of OpenRA, which is free software. It is made
  * available to you under the terms of the GNU General Public License
  * as published by the Free Software Foundation. For more information,
@@ -17,20 +17,16 @@ namespace OpenRA.Mods.RA.Air
 	{
 		public override Activity Tick(Actor self)
 		{
-			var cruiseAltitude = self.Info.Traits.Get<PlaneInfo>().CruiseAltitude;
+			if (IsCanceled)
+				return NextActivity;
 
-			if (IsCanceled) return NextActivity;
+			var plane = self.Trait<Plane>();
 
-			var aircraft = self.Trait<Aircraft>();
+			// We can't possibly turn this fast
+			var desiredFacing = plane.Facing + 64;
+			var cruiseAltitude = new WRange(plane.Info.CruiseAltitude * 1024 / Game.CellSize);
+			Fly.FlyToward(self, plane, desiredFacing, cruiseAltitude);
 
-			var desiredFacing = aircraft.Facing + 64;   // we can't possibly turn this fast.
-			if (aircraft.Altitude == cruiseAltitude)
-				aircraft.Facing = Util.TickFacing(aircraft.Facing, desiredFacing, aircraft.ROT);
-
-			if (aircraft.Altitude < cruiseAltitude)
-				++aircraft.Altitude;
-
-			FlyUtil.Fly(self, cruiseAltitude);
 			return this;
 		}
 	}
diff --git a/OpenRA.Mods.RA/Air/FlyTimed.cs b/OpenRA.Mods.RA/Air/FlyTimed.cs
index 7968d5a9d7..03ee64688f 100755
--- a/OpenRA.Mods.RA/Air/FlyTimed.cs
+++ b/OpenRA.Mods.RA/Air/FlyTimed.cs
@@ -1,6 +1,6 @@
 #region Copyright & License Information
 /*
- * Copyright 2007-2011 The OpenRA Developers (see AUTHORS)
+ * Copyright 2007-2013 The OpenRA Developers (see AUTHORS)
  * This file is part of OpenRA, which is free software. It is made
  * available to you under the terms of the GNU General Public License
  * as published by the Free Software Foundation. For more information,
@@ -20,10 +20,13 @@ namespace OpenRA.Mods.RA.Air
 
 		public override Activity Tick(Actor self)
 		{
-			if( IsCanceled ) return NextActivity;
-			var targetAltitude = self.Info.Traits.Get<PlaneInfo>().CruiseAltitude;
-			if (remainingTicks-- == 0) return NextActivity;
-			FlyUtil.Fly(self, targetAltitude);
+			if (IsCanceled || remainingTicks-- == 0)
+				return NextActivity;
+
+			var plane = self.Trait<Plane>();
+			var cruiseAltitude = new WRange(plane.Info.CruiseAltitude * 1024 / Game.CellSize);
+			Fly.FlyToward(self, plane, plane.Facing, cruiseAltitude);
+
 			return this;
 		}
 	}
@@ -32,15 +35,16 @@ namespace OpenRA.Mods.RA.Air
 	{
 		public override Activity Tick(Actor self)
 		{
-			var targetAltitude = self.Info.Traits.Get<PlaneInfo>().CruiseAltitude;
 			if (IsCanceled || !self.World.Map.IsInMap(self.Location))
 				return NextActivity;
 
-			FlyUtil.Fly(self, targetAltitude);
+			var plane = self.Trait<Plane>();
+			var cruiseAltitude = new WRange(plane.Info.CruiseAltitude * 1024 / Game.CellSize);
+			Fly.FlyToward(self, plane, plane.Facing, cruiseAltitude);
 			return this;
 		}
 
-		public override void Cancel( Actor self )
+		public override void Cancel(Actor self)
 		{
 			base.Cancel(self);
 		}
diff --git a/OpenRA.Mods.RA/Air/HeliAttack.cs b/OpenRA.Mods.RA/Air/HeliAttack.cs
index 87e3de5eed..1ba4d4d417 100755
--- a/OpenRA.Mods.RA/Air/HeliAttack.cs
+++ b/OpenRA.Mods.RA/Air/HeliAttack.cs
@@ -1,6 +1,6 @@
 #region Copyright & License Information
 /*
- * Copyright 2007-2011 The OpenRA Developers (see AUTHORS)
+ * Copyright 2007-2013 The OpenRA Developers (see AUTHORS)
  * This file is part of OpenRA, which is free software. It is made
  * available to you under the terms of the GNU General Public License
  * as published by the Free Software Foundation. For more information,
@@ -17,36 +17,35 @@ namespace OpenRA.Mods.RA.Air
 	public class HeliAttack : Activity
 	{
 		Target target;
-		public HeliAttack( Target target ) { this.target = target; }
+		public HeliAttack(Target target) { this.target = target; }
 
 		public override Activity Tick(Actor self)
 		{
-			if (IsCanceled) return NextActivity;
-			if (!target.IsValid) return NextActivity;
+			if (IsCanceled || !target.IsValid)
+				return NextActivity;
 
 			var limitedAmmo = self.TraitOrDefault<LimitedAmmo>();
 			var reloads = self.TraitOrDefault<Reloads>();
 			if (limitedAmmo != null && !limitedAmmo.HasAmmo() && reloads == null)
-				return Util.SequenceActivities( new HeliReturn(), NextActivity );
-
-			var aircraft = self.Trait<Aircraft>();
-			var info = self.Info.Traits.Get<HelicopterInfo>();
-			if (aircraft.Altitude != info.CruiseAltitude)
-			{
-				aircraft.Altitude += Math.Sign(info.CruiseAltitude - aircraft.Altitude);
-				return this;
-			}
+				return Util.SequenceActivities(new HeliReturn(), NextActivity);
 
+			var helicopter = self.Trait<Helicopter>();
 			var attack = self.Trait<AttackHeli>();
 			var dist = target.CenterPosition - self.CenterPosition;
 
-			var desiredFacing = Util.GetFacing(dist, aircraft.Facing);
-			aircraft.Facing = Util.TickFacing(aircraft.Facing, desiredFacing, aircraft.ROT);
+			// Can rotate facing while ascending
+			var desiredFacing = Util.GetFacing(dist, helicopter.Facing);
+			helicopter.Facing = Util.TickFacing(helicopter.Facing, desiredFacing, helicopter.ROT);
 
+			var cruiseAltitude = new WRange(helicopter.Info.CruiseAltitude * 1024 / Game.CellSize);
+			if (HeliFly.AdjustAltitude(self, helicopter, cruiseAltitude))
+				return this;
+
+			// Fly towards the target
 			if (!target.IsInRange(self.CenterPosition, attack.GetMaximumRange()))
-				aircraft.TickMove(PSubPos.PerPx * aircraft.MovementSpeed, desiredFacing);
+				helicopter.SetPosition(self, helicopter.CenterPosition + helicopter.FlyStep(desiredFacing));
 
-			attack.DoAttack( self, target );
+			attack.DoAttack(self, target);
 
 			return this;
 		}
diff --git a/OpenRA.Mods.RA/Air/HeliFly.cs b/OpenRA.Mods.RA/Air/HeliFly.cs
index 7a77667909..f4ac312b23 100755
--- a/OpenRA.Mods.RA/Air/HeliFly.cs
+++ b/OpenRA.Mods.RA/Air/HeliFly.cs
@@ -1,6 +1,6 @@
 #region Copyright & License Information
 /*
- * Copyright 2007-2011 The OpenRA Developers (see AUTHORS)
+ * Copyright 2007-2013 The OpenRA Developers (see AUTHORS)
  * This file is part of OpenRA, which is free software. It is made
  * available to you under the terms of the GNU General Public License
  * as published by the Free Software Foundation. For more information,
@@ -17,35 +17,48 @@ namespace OpenRA.Mods.RA.Air
 	class HeliFly : Activity
 	{
 		readonly WPos pos;
+
 		public HeliFly(WPos pos) { this.pos = pos; }
 		public HeliFly(CPos pos) { this.pos = pos.CenterPosition; }
 
+		public static bool AdjustAltitude(Actor self, Helicopter helicopter, WRange targetAltitude)
+		{
+			var altitude = helicopter.CenterPosition.Z;
+			if (altitude == targetAltitude.Range)
+				return false;
+
+			var delta = helicopter.Info.AltitudeVelocity.Range;
+			var dz = (targetAltitude.Range - altitude).Clamp(-delta, delta);
+			helicopter.SetPosition(self, helicopter.CenterPosition + new WVec(0, 0, dz));
+
+			return true;
+		}
+
 		public override Activity Tick(Actor self)
 		{
 			if (IsCanceled)
 				return NextActivity;
 
-			var info = self.Info.Traits.Get<HelicopterInfo>();
-			var aircraft = self.Trait<Aircraft>();
+			var helicopter = self.Trait<Helicopter>();
 
-			if (aircraft.Altitude != info.CruiseAltitude)
-			{
-				aircraft.Altitude += Math.Sign(info.CruiseAltitude - aircraft.Altitude);
+			var cruiseAltitude = new WRange(helicopter.Info.CruiseAltitude * 1024 / Game.CellSize);
+			if (HeliFly.AdjustAltitude(self, helicopter, cruiseAltitude))
 				return this;
-			}
+
+			// Rotate towards the target
+			var dist = pos - self.CenterPosition;
+			var desiredFacing = Util.GetFacing(dist, helicopter.Facing);
+			helicopter.Facing = Util.TickFacing(helicopter.Facing, desiredFacing, helicopter.ROT);
 
 			// The next move would overshoot, so just set the final position
-			var dist = pos - self.CenterPosition;
-			var moveDist = aircraft.MovementSpeed * 7 * 1024 / (Game.CellSize * 32);
-			if (dist.HorizontalLengthSquared < moveDist*moveDist)
+			var move = helicopter.FlyStep(desiredFacing);
+			if (dist.HorizontalLengthSquared < move.HorizontalLengthSquared)
 			{
-				aircraft.SetPosition(self, pos);
+				helicopter.SetPosition(self, pos + new WVec(0, 0, cruiseAltitude.Range - pos.Z));
 				return NextActivity;
 			}
 
-			var desiredFacing = Util.GetFacing(dist, aircraft.Facing);
-			aircraft.Facing = Util.TickFacing(aircraft.Facing, desiredFacing, aircraft.ROT);
-			aircraft.TickMove(PSubPos.PerPx * aircraft.MovementSpeed, desiredFacing);
+			helicopter.SetPosition(self, helicopter.CenterPosition + move);
 
 			return this;
 		}
diff --git a/OpenRA.Mods.RA/Air/HeliLand.cs b/OpenRA.Mods.RA/Air/HeliLand.cs
index 00479cae7a..0842b7201f 100755
--- a/OpenRA.Mods.RA/Air/HeliLand.cs
+++ b/OpenRA.Mods.RA/Air/HeliLand.cs
@@ -1,6 +1,6 @@
 #region Copyright & License Information
 /*
- * Copyright 2007-2011 The OpenRA Developers (see AUTHORS)
+ * Copyright 2007-2013 The OpenRA Developers (see AUTHORS)
  * This file is part of OpenRA, which is free software. It is made
  * available to you under the terms of the GNU General Public License
  * as published by the Free Software Foundation. For more information,
@@ -14,27 +14,27 @@ namespace OpenRA.Mods.RA.Air
 {
 	class HeliLand : Activity
 	{
-		public HeliLand(bool requireSpace, int minimalAltitude)
+		bool requireSpace;
+
+		public HeliLand(bool requireSpace)
 		{
 			this.requireSpace = requireSpace;
-			this.minimalAltitude = minimalAltitude;
 		}
 
-		bool requireSpace;
-		int minimalAltitude = 0;
-
 		public override Activity Tick(Actor self)
 		{
-			if (IsCanceled) return NextActivity;
-			var aircraft = self.Trait<Aircraft>();
-			if (aircraft.Altitude == minimalAltitude)
+			if (IsCanceled)
 				return NextActivity;
 
-			if (requireSpace && !aircraft.CanLand(self.Location))
+			var helicopter = self.Trait<Helicopter>();
+
+			if (requireSpace && !helicopter.CanLand(self.Location))
 				return this;
 
-			--aircraft.Altitude;
-			return this;
+			if (HeliFly.AdjustAltitude(self, helicopter, helicopter.Info.LandAltitude))
+			    return this;
+
+			return NextActivity;
 		}
 	}
 }
diff --git a/OpenRA.Mods.RA/Air/HeliReturn.cs b/OpenRA.Mods.RA/Air/HeliReturn.cs
index b1638bcace..5b11319df0 100755
--- a/OpenRA.Mods.RA/Air/HeliReturn.cs
+++ b/OpenRA.Mods.RA/Air/HeliReturn.cs
@@ -1,6 +1,6 @@
-#region Copyright & License Information
+#region Copyright & License Information
 /*
- * Copyright 2007-2011 The OpenRA Developers (see AUTHORS)
+ * Copyright 2007-2013 The OpenRA Developers (see AUTHORS)
  * This file is part of OpenRA, which is free software. It is made
  * available to you under the terms of the GNU General Public License
  * as published by the Free Software Foundation. For more information,
@@ -9,8 +9,8 @@
 #endregion
 
 using System.Linq;
-using OpenRA.Traits;
 using OpenRA.Mods.RA.Activities;
+using OpenRA.Traits;
 
 namespace OpenRA.Mods.RA.Air
 {
@@ -19,16 +19,16 @@ namespace OpenRA.Mods.RA.Air
 		static Actor ChooseHelipad(Actor self)
 		{
 			var rearmBuildings = self.Info.Traits.Get<HelicopterInfo>().RearmBuildings;
-			return self.World.Actors.Where( a => a.Owner == self.Owner ).FirstOrDefault(
-				a => rearmBuildings.Contains(a.Info.Name) &&
-					!Reservable.IsReserved(a));
+			return self.World.Actors.Where(a => a.Owner == self.Owner).FirstOrDefault(
+				a => rearmBuildings.Contains(a.Info.Name) && !Reservable.IsReserved(a));
 		}
 
 		public override Activity Tick(Actor self)
 		{
-			if (IsCanceled) return NextActivity;
-			var dest = ChooseHelipad(self);
+			if (IsCanceled)
+				return NextActivity;
 
+			var dest = ChooseHelipad(self);
 			var initialFacing = self.Info.Traits.Get<AircraftInfo>().InitialFacing;
 
 			if (dest == null)
@@ -40,7 +40,7 @@ namespace OpenRA.Mods.RA.Air
 									.ClosestTo(self);
 
 				if (nearestHpad == null)
-					return Util.SequenceActivities(new Turn(initialFacing), new HeliLand(true, 0), NextActivity);
+					return Util.SequenceActivities(new Turn(initialFacing), new HeliLand(true), NextActivity);
 				else
 					return Util.SequenceActivities(new HeliFly(nearestHpad.CenterPosition));
 			}
@@ -48,7 +48,7 @@ namespace OpenRA.Mods.RA.Air
 			var res = dest.TraitOrDefault<Reservable>();
 			var heli = self.Trait<Helicopter>();
 			if (res != null)
-				heli.reservation = res.Reserve(dest, self, heli);
+				heli.Reservation = res.Reserve(dest, self, heli);
 
 			var exit = dest.Info.Traits.WithInterface<ExitInfo>().FirstOrDefault();
 			var offset = (exit != null) ? exit.SpawnOffsetVector : WVec.Zero;
@@ -56,7 +56,7 @@ namespace OpenRA.Mods.RA.Air
 			return Util.SequenceActivities(
 				new HeliFly(dest.CenterPosition + offset),
 				new Turn(initialFacing),
-				new HeliLand(false, 0),
+				new HeliLand(false),
 				new Rearm(self),
 				NextActivity);
 		}
diff --git a/OpenRA.Mods.RA/Air/Helicopter.cs b/OpenRA.Mods.RA/Air/Helicopter.cs
index a0a8529355..33c5a2d89e 100755
--- a/OpenRA.Mods.RA/Air/Helicopter.cs
+++ b/OpenRA.Mods.RA/Air/Helicopter.cs
@@ -1,6 +1,6 @@
 #region Copyright & License Information
 /*
- * Copyright 2007-2011 The OpenRA Developers (see AUTHORS)
+ * Copyright 2007-2013 The OpenRA Developers (see AUTHORS)
  * This file is part of OpenRA, which is free software. It is made
  * available to you under the terms of the GNU General Public License
  * as published by the Free Software Foundation. For more information,
@@ -19,28 +19,29 @@ namespace OpenRA.Mods.RA.Air
 	{
 		public readonly WRange IdealSeparation = new WRange(1706);
 		public readonly bool LandWhenIdle = true;
-		public readonly int MinimalLandAltitude = 0;
+		public readonly WRange LandAltitude = WRange.Zero;
+		public readonly WRange AltitudeVelocity = new WRange(43);
 
 		public override object Create(ActorInitializer init) { return new Helicopter(init, this); }
 	}
 
 	class Helicopter : Aircraft, ITick, IResolveOrder
 	{
-		HelicopterInfo info;
+		public HelicopterInfo Info;
 		bool firstTick = true;
 
 		public Helicopter(ActorInitializer init, HelicopterInfo info)
 			: base(init, info)
 		{
-			this.info = info;
+			Info = info;
 		}
 
 		public void ResolveOrder(Actor self, Order order)
 		{
-			if (reservation != null)
+			if (Reservation != null)
 			{
-				reservation.Dispose();
-				reservation = null;
+				Reservation.Dispose();
+				Reservation = null;
 			}
 
 			if (order.OrderString == "Move")
@@ -51,10 +52,10 @@ namespace OpenRA.Mods.RA.Air
 				self.CancelActivity();
 				self.QueueActivity(new HeliFly(target));
 
-				if (info.LandWhenIdle)
+				if (Info.LandWhenIdle)
 				{
-					self.QueueActivity(new Turn(info.InitialFacing));
-					self.QueueActivity(new HeliLand(true, info.MinimalLandAltitude));
+					self.QueueActivity(new Turn(Info.InitialFacing));
+					self.QueueActivity(new HeliLand(true));
 				}
 			}
 
@@ -69,7 +70,7 @@ namespace OpenRA.Mods.RA.Air
 				{
 					var res = order.TargetActor.TraitOrDefault<Reservable>();
 					if (res != null)
-						reservation = res.Reserve(order.TargetActor, self, this);
+						Reservation = res.Reserve(order.TargetActor, self, this);
 
 					var exit = order.TargetActor.Info.Traits.WithInterface<ExitInfo>().FirstOrDefault();
 					var offset = (exit != null) ? exit.SpawnOffsetVector : WVec.Zero;
@@ -78,8 +79,8 @@ namespace OpenRA.Mods.RA.Air
 
 					self.CancelActivity();
 					self.QueueActivity(new HeliFly(order.TargetActor.CenterPosition + offset));
-					self.QueueActivity(new Turn(info.InitialFacing));
-					self.QueueActivity(new HeliLand(false, info.MinimalLandAltitude));
+					self.QueueActivity(new Turn(Info.InitialFacing));
+					self.QueueActivity(new HeliLand(false));
 					self.QueueActivity(new ResupplyAircraft());
 				}
 			}
@@ -94,10 +95,10 @@ namespace OpenRA.Mods.RA.Air
 			{
 				self.CancelActivity();
 
-				if (info.LandWhenIdle)
+				if (Info.LandWhenIdle)
 				{
-					self.QueueActivity(new Turn(info.InitialFacing));
-					self.QueueActivity(new HeliLand(true, info.MinimalLandAltitude));
+					self.QueueActivity(new Turn(Info.InitialFacing));
+					self.QueueActivity(new HeliLand(true));
 				}
 			}
 		}
@@ -112,10 +113,12 @@ namespace OpenRA.Mods.RA.Air
 			}
 
 			// Repulsion only applies when we're flying!
-			if (Altitude != info.CruiseAltitude)
+			var altitude = CenterPosition.Z;
+			var cruiseAltitude = Info.CruiseAltitude * 1024 / Game.CellSize;
+			if (altitude != cruiseAltitude)
 				return;
 
-			var otherHelis = self.World.FindActorsInCircle(self.CenterPosition, info.IdealSeparation)
+			var otherHelis = self.World.FindActorsInCircle(self.CenterPosition, Info.IdealSeparation)
 				.Where(a => a.HasTrait<Helicopter>());
 
 			var f = otherHelis
@@ -124,17 +127,17 @@ namespace OpenRA.Mods.RA.Air
 
 			int repulsionFacing = Util.GetFacing(f, -1);
 			if (repulsionFacing != -1)
-				TickMove(PSubPos.PerPx * MovementSpeed, repulsionFacing);
+				SetPosition(self, CenterPosition + FlyStep(repulsionFacing));
 		}
 
 		public WVec GetRepulseForce(Actor self, Actor other)
 		{
-			if (self == other || other.Trait<Helicopter>().Altitude < Altitude)
+			if (self == other || other.CenterPosition.Z < self.CenterPosition.Z)
 				return WVec.Zero;
 
 			var d = self.CenterPosition - other.CenterPosition;
 			var distSq = d.HorizontalLengthSquared;
-			if (distSq > info.IdealSeparation.Range * info.IdealSeparation.Range)
+			if (distSq > Info.IdealSeparation.Range * Info.IdealSeparation.Range)
 				return WVec.Zero;
 
 			if (distSq < 1)
diff --git a/OpenRA.Mods.RA/Air/Land.cs b/OpenRA.Mods.RA/Air/Land.cs
index 36712ce1a4..d6bde50f44 100755
--- a/OpenRA.Mods.RA/Air/Land.cs
+++ b/OpenRA.Mods.RA/Air/Land.cs
@@ -1,6 +1,6 @@
 #region Copyright & License Information
 /*
- * Copyright 2007-2011 The OpenRA Developers (see AUTHORS)
+ * Copyright 2007-2013 The OpenRA Developers (see AUTHORS)
  * This file is part of OpenRA, which is free software. It is made
  * available to you under the terms of the GNU General Public License
  * as published by the Free Software Foundation. For more information,
@@ -16,35 +16,31 @@ namespace OpenRA.Mods.RA.Air
 {
 	public class Land : Activity
 	{
-		Target Target;
+		Target target;
 
-		public Land(Target t) { Target = t; }
+		public Land(Target t) { target = t; }
 
 		public override Activity Tick(Actor self)
 		{
-			if (!Target.IsValid)
+			if (!target.IsValid)
 				Cancel(self);
 
 			if (IsCanceled)
 				return NextActivity;
 
-			var aircraft = self.Trait<Aircraft>();
-			var d = Target.CenterPosition - self.CenterPosition;
+			var plane = self.Trait<Plane>();
+			var d = target.CenterPosition - self.CenterPosition;
 
 			// The next move would overshoot, so just set the final position
-			var moveDist = aircraft.MovementSpeed * 7 * 1024 / (Game.CellSize * 32);
-			if (d.HorizontalLengthSquared < moveDist*moveDist)
+			var move = plane.FlyStep(plane.Facing);
+			if (d.HorizontalLengthSquared < move.HorizontalLengthSquared)
 			{
-				aircraft.SetPosition(self, Target.CenterPosition);
+				plane.SetPosition(self, target.CenterPosition);
 				return NextActivity;
 			}
 
-			if (aircraft.Altitude > 0)
-				--aircraft.Altitude;
-
-			var desiredFacing = Util.GetFacing(d, aircraft.Facing);
-			aircraft.Facing = Util.TickFacing(aircraft.Facing, desiredFacing, aircraft.ROT);
-			aircraft.TickMove(PSubPos.PerPx * aircraft.MovementSpeed, aircraft.Facing);
+			var desiredFacing = Util.GetFacing(d, plane.Facing);
+			Fly.FlyToward(self, plane, desiredFacing, WRange.Zero);
 
 			return this;
 		}
diff --git a/OpenRA.Mods.RA/Air/Plane.cs b/OpenRA.Mods.RA/Air/Plane.cs
index 0d07f8a657..9c90191f72 100755
--- a/OpenRA.Mods.RA/Air/Plane.cs
+++ b/OpenRA.Mods.RA/Air/Plane.cs
@@ -1,6 +1,6 @@
 #region Copyright & License Information
 /*
- * Copyright 2007-2011 The OpenRA Developers (see AUTHORS)
+ * Copyright 2007-2013 The OpenRA Developers (see AUTHORS)
  * This file is part of OpenRA, which is free software. It is made
  * available to you under the terms of the GNU General Public License
  * as published by the Free Software Foundation. For more information,
@@ -16,15 +16,21 @@ namespace OpenRA.Mods.RA.Air
 {
 	public class PlaneInfo : AircraftInfo
 	{
-		public override object Create( ActorInitializer init ) { return new Plane( init, this ); }
+		public readonly WAngle MaximumPitch = WAngle.FromDegrees(10);
+
+		public override object Create(ActorInitializer init) { return new Plane(init, this); }
 	}
 
 	public class Plane : Aircraft, IResolveOrder, ITick, ISync
 	{
+		public readonly PlaneInfo Info;
 		[Sync] public WPos RTBPathHash;
 
-		public Plane( ActorInitializer init, PlaneInfo info )
-			: base( init, info ) { }
+		public Plane(ActorInitializer init, PlaneInfo info)
+			: base(init, info)
+		{
+			Info = info;
+		}
 
 		bool firstTick = true;
 		public void Tick(Actor self)
@@ -49,7 +55,6 @@ namespace OpenRA.Mods.RA.Air
 				self.QueueActivity(Fly.ToCell(target));
 				self.QueueActivity(new FlyCircle());
 			}
-
 			else if (order.OrderString == "Enter")
 			{
 				if (Reservable.IsReserved(order.TargetActor)) return;
diff --git a/OpenRA.Mods.RA/Air/ReturnOnIdle.cs b/OpenRA.Mods.RA/Air/ReturnOnIdle.cs
index ee643df58c..3b9ca48beb 100755
--- a/OpenRA.Mods.RA/Air/ReturnOnIdle.cs
+++ b/OpenRA.Mods.RA/Air/ReturnOnIdle.cs
@@ -1,6 +1,6 @@
 #region Copyright & License Information
 /*
- * Copyright 2007-2011 The OpenRA Developers (see AUTHORS)
+ * Copyright 2007-2013 The OpenRA Developers (see AUTHORS)
  * This file is part of OpenRA, which is free software. It is made
  * available to you under the terms of the GNU General Public License
  * as published by the Free Software Foundation. For more information,
@@ -17,14 +17,13 @@ namespace OpenRA.Mods.RA.Air
 {
 	class ReturnOnIdleInfo : TraitInfo<ReturnOnIdle> { }
 
-	// fly home or fly-off-map behavior for idle planes
-
 	class ReturnOnIdle : INotifyIdle
 	{
 		public void TickIdle(Actor self)
 		{
-			var altitude = self.Trait<Aircraft>().Altitude;
-			if (altitude == 0) return;	// we're on the ground, let's stay there.
+			// We're on the ground, let's stay there.
+			if (self.CenterPosition.Z == 0)
+				return;
 
 			var airfield = ReturnToBase.ChooseAirfield(self, true);
 			if (airfield != null)
@@ -38,13 +37,13 @@ namespace OpenRA.Mods.RA.Air
 
 				// i'd prefer something we own
 				var someBuilding = self.World.ActorsWithTrait<Building>()
-					.Select( a => a.Actor )
+					.Select(a => a.Actor)
 					.FirstOrDefault(a => a.Owner == self.Owner);
 
 				// failing that, something unlikely to shoot at us
 				if (someBuilding == null)
 					someBuilding = self.World.ActorsWithTrait<Building>()
-						.Select( a => a.Actor )
+						.Select(a => a.Actor)
 						.FirstOrDefault(a => self.Owner.Stances[a.Owner] == Stance.Ally);
 
 				if (someBuilding == null)
diff --git a/OpenRA.Mods.RA/Air/ReturnToBase.cs b/OpenRA.Mods.RA/Air/ReturnToBase.cs
index 4fddcdf466..0d19cb48f5 100755
--- a/OpenRA.Mods.RA/Air/ReturnToBase.cs
+++ b/OpenRA.Mods.RA/Air/ReturnToBase.cs
@@ -1,6 +1,6 @@
 #region Copyright & License Information
 /*
- * Copyright 2007-2011 The OpenRA Developers (see AUTHORS)
+ * Copyright 2007-2013 The OpenRA Developers (see AUTHORS)
  * This file is part of OpenRA, which is free software. It is made
  * available to you under the terms of the GNU General Public License
  * as published by the Free Software Foundation. For more information,
@@ -10,8 +10,8 @@
 
 using System;
 using System.Linq;
-using OpenRA.Traits;
 using OpenRA.Mods.RA.Buildings;
+using OpenRA.Traits;
 
 namespace OpenRA.Mods.RA.Air
 {
@@ -46,22 +46,21 @@ namespace OpenRA.Mods.RA.Air
 			if (res != null)
 			{
 				plane.UnReserve();
-				plane.reservation = res.Reserve(dest, self, plane);
+				plane.Reservation = res.Reserve(dest, self, plane);
 			}
 
 			var landPos = dest.CenterPosition;
-			var speed = plane.MovementSpeed * 1024 / Game.CellSize / 5;
 
 			// Distance required for descent.
-			// TODO: Generalize this for arbitrary flight pitches
-			var landDistance = planeInfo.CruiseAltitude * speed;
+			var landDistance = planeInfo.CruiseAltitude * 1024 * 1024 / (Game.CellSize * plane.Info.MaximumPitch.Tan());
 			var altitude = planeInfo.CruiseAltitude * 1024 / Game.CellSize;
 
 			// Land towards the east
 			var approachStart = landPos + new WVec(-landDistance, 0, altitude);
 
 			// Add 10% to the turning radius to ensure we have enough room
-			var turnRadius = (int)(141 * speed / planeInfo.ROT / (float)(Math.PI));
+			var speed = plane.MovementSpeed * 1024 / (Game.CellSize * 5);
+			var turnRadius = (int)(141 * speed / planeInfo.ROT / (float)Math.PI);
 
 			// Find the center of the turning circles for clockwise and counterclockwise turns
 			var angle = WAngle.FromFacing(plane.Facing);
diff --git a/OpenRA.Mods.RA/Air/TargetableAircraft.cs b/OpenRA.Mods.RA/Air/TargetableAircraft.cs
index 49bcd2ffd8..0cbeb27e41 100755
--- a/OpenRA.Mods.RA/Air/TargetableAircraft.cs
+++ b/OpenRA.Mods.RA/Air/TargetableAircraft.cs
@@ -1,6 +1,6 @@
 #region Copyright & License Information
 /*
- * Copyright 2007-2011 The OpenRA Developers (see AUTHORS)
+ * Copyright 2007-2013 The OpenRA Developers (see AUTHORS)
  * This file is part of OpenRA, which is free software. It is made
  * available to you under the terms of the GNU General Public License
  * as published by the Free Software Foundation. For more information,
@@ -9,13 +9,13 @@
 #endregion
 
 using System.Drawing;
-using OpenRA.Graphics;
 using System.Linq;
+using OpenRA.Graphics;
 using OpenRA.Traits;
 
 namespace OpenRA.Mods.RA.Air
 {
-	public class TargetableAircraftInfo : TargetableUnitInfo, Requires<AircraftInfo>
+	public class TargetableAircraftInfo : TargetableUnitInfo
 	{
 		public readonly string[] GroundedTargetTypes = { };
 		public override object Create(ActorInitializer init) { return new TargetableAircraft(init.self, this); }
@@ -24,19 +24,19 @@ namespace OpenRA.Mods.RA.Air
 	public class TargetableAircraft : TargetableUnit
 	{
 		readonly TargetableAircraftInfo info;
-		readonly Aircraft Aircraft;
+		readonly Actor self;
 
 		public TargetableAircraft(Actor self, TargetableAircraftInfo info)
 			: base(self, info)
 		{
 			this.info = info;
-			Aircraft = self.Trait<Aircraft>();
+			this.self = self;
 		}
 
 		public override string[] TargetTypes
 		{
-			get { return (Aircraft.Altitude > 0) ? info.TargetTypes
-									             : info.GroundedTargetTypes; }
+			get { return (self.CenterPosition.Z > 0) ? info.TargetTypes
+				: info.GroundedTargetTypes; }
 		}
 	}
 }
diff --git a/OpenRA.Mods.RA/LeavesHusk.cs b/OpenRA.Mods.RA/LeavesHusk.cs
index 8dce4cdb42..1fc3f91fe3 100644
--- a/OpenRA.Mods.RA/LeavesHusk.cs
+++ b/OpenRA.Mods.RA/LeavesHusk.cs
@@ -1,6 +1,6 @@
 #region Copyright & License Information
 /*
- * Copyright 2007-2011 The OpenRA Developers (see AUTHORS)
+ * Copyright 2007-2013 The OpenRA Developers (see AUTHORS)
  * This file is part of OpenRA, which is free software. It is made
  * available to you under the terms of the GNU General Public License
  * as published by the Free Software Foundation. For more information,
@@ -52,7 +52,7 @@ namespace OpenRA.Mods.RA
 
 				var aircraft = self.TraitOrDefault<Aircraft>();
 				if (aircraft != null)
-					td.Add(new AltitudeInit(aircraft.Altitude));
+					td.Add(new AltitudeInit(aircraft.CenterPosition.Z * Game.CellSize / 1024));
 
 				var facing = self.TraitOrDefault<IFacing>();
 				if (facing != null)
diff --git a/OpenRA.Mods.RA/Missions/Allies03Script.cs b/OpenRA.Mods.RA/Missions/Allies03Script.cs
index f57bd3ac21..9bebeabf7c 100644
--- a/OpenRA.Mods.RA/Missions/Allies03Script.cs
+++ b/OpenRA.Mods.RA/Missions/Allies03Script.cs
@@ -215,9 +215,10 @@ namespace OpenRA.Mods.RA.Missions
 
 			foreach (var aircraft in SovietAircraft())
 			{
+				var pos = aircraft.CenterPosition;
 				var plane = aircraft.Trait<Plane>();
 				var ammo = aircraft.Trait<LimitedAmmo>();
-				if ((plane.Altitude == 0 && ammo.FullAmmo()) || (plane.Altitude != 0 && ammo.HasAmmo()))
+				if ((pos.Z == 0 && ammo.FullAmmo()) || (pos.Z != 0 && ammo.HasAmmo()))
 				{
 					var enemy = FirstUnshroudedOrDefault(enemies.OrderBy(u => (aircraft.CenterPosition - u.CenterPosition).LengthSquared), world, 10);
 					if (enemy != null)
@@ -225,13 +226,13 @@ namespace OpenRA.Mods.RA.Missions
 						if (!aircraft.IsIdle && aircraft.GetCurrentActivity().GetType() != typeof(FlyAttack))
 							aircraft.CancelActivity();
 
-						if (plane.Altitude == 0)
+						if (pos.Z == 0)
 							plane.UnReserve();
 
 						aircraft.QueueActivity(new FlyAttack(Target.FromActor(enemy)));
 					}
 				}
-				else if (plane.Altitude != 0 && !LandIsQueued(aircraft))
+				else if (pos.Z != 0 && !LandIsQueued(aircraft))
 				{
 					aircraft.CancelActivity();
 					aircraft.QueueActivity(new ReturnToBase(aircraft, null));
diff --git a/OpenRA.Mods.RA/Missions/DesertShellmapScript.cs b/OpenRA.Mods.RA/Missions/DesertShellmapScript.cs
index ed185f1ed0..c0e8661733 100644
--- a/OpenRA.Mods.RA/Missions/DesertShellmapScript.cs
+++ b/OpenRA.Mods.RA/Missions/DesertShellmapScript.cs
@@ -221,7 +221,7 @@ namespace OpenRA.Mods.RA.Missions
 
 			chinook.QueueActivity(new HeliFly(lz.CenterPosition + offset)); // no reservation of hpad but it's not needed
 			chinook.QueueActivity(new Turn(0));
-			chinook.QueueActivity(new HeliLand(false, 0));
+			chinook.QueueActivity(new HeliLand(false));
 			chinook.QueueActivity(new UnloadCargo(true));
 			chinook.QueueActivity(new Wait(150));
 			chinook.QueueActivity(new HeliFly(entry));
diff --git a/OpenRA.Mods.RA/Missions/MissionUtils.cs b/OpenRA.Mods.RA/Missions/MissionUtils.cs
index 8bd035139c..e237223096 100644
--- a/OpenRA.Mods.RA/Missions/MissionUtils.cs
+++ b/OpenRA.Mods.RA/Missions/MissionUtils.cs
@@ -47,7 +47,7 @@ namespace OpenRA.Mods.RA.Missions
 			var chinook = world.CreateActor("tran", new TypeDictionary { new OwnerInit(owner), new LocationInit(entry) });
 			chinook.QueueActivity(new HeliFly(lz));
 			chinook.QueueActivity(new Turn(0));
-			chinook.QueueActivity(new HeliLand(true, 0));
+			chinook.QueueActivity(new HeliLand(true));
 			chinook.QueueActivity(new WaitFor(() => chinook.Trait<Cargo>().Passengers.Contains(unit)));
 			chinook.QueueActivity(new Wait(150));
 			chinook.QueueActivity(new HeliFly(exit));
@@ -62,7 +62,7 @@ namespace OpenRA.Mods.RA.Missions
 			chinook.Trait<Cargo>().Load(chinook, unit);
 			chinook.QueueActivity(new HeliFly(lz));
 			chinook.QueueActivity(new Turn(0));
-			chinook.QueueActivity(new HeliLand(true, 0));
+			chinook.QueueActivity(new HeliLand(true));
 			chinook.QueueActivity(new UnloadCargo(true));
 			chinook.QueueActivity(new CallFunc(() => afterUnload(unit)));
 			chinook.QueueActivity(new Wait(150));
diff --git a/mods/d2k/rules/aircraft.yaml b/mods/d2k/rules/aircraft.yaml
index abcb74c285..ff46bdb260 100644
--- a/mods/d2k/rules/aircraft.yaml
+++ b/mods/d2k/rules/aircraft.yaml
@@ -19,7 +19,7 @@
 		LandableTerrainTypes: Sand, Rock, Transition, Spice, Dune
 		RepairBuildings: repair
 		RearmBuildings: starporta,starporto,starporth
-		MinimalLandAltitude: 25
+		LandAltitude: 800
 	RenderUnit:
 	WithCargo:
 		LocalOffset: 0,0,-854