diff --git a/lib_planes/custom_physics.lua b/lib_planes/custom_physics.lua
index eec787d..66cf91a 100755
--- a/lib_planes/custom_physics.lua
+++ b/lib_planes/custom_physics.lua
@@ -1,7 +1,7 @@
 function airutils.physics(self)
     local friction = self._ground_friction or 0.99
 	local vel=self.object:get_velocity()
-    local new_velocity = vel
+    local new_velocity = vector.new()
 
 	--buoyancy
 	local surface = nil
@@ -24,6 +24,7 @@ function airutils.physics(self)
 	if surface then				-- standing in liquid
         self.isinliquid = true
     end
+    local last_accel = self._last_accel
 
     if self.isinliquid then
         local accell = {x=0, y=0, z=0}
@@ -37,14 +38,22 @@ function airutils.physics(self)
         --local buoyacc = self._baloon_buoyancy*(self.buoyancy-submergence)
         accell = {x=-vel.x*self.water_drag,y=buoyacc-(vel.y*math.abs(vel.y)*0.4),z=-vel.z*self.water_drag}
         if self.buoyancy >= 1 then self._engine_running = false end
-        airutils.set_acceleration(self.object,accell)
-        --new_velocity = vector.add(new_velocity, vector.multiply(accell, self.dtime))
-        self.object:move_to(self.object:get_pos())
-        return
+        if last_accel then
+            accell = vector.add(accell,last_accel)
+        end
+        new_velocity = vector.multiply(accell,self.dtime)
+        --airutils.set_acceleration(self.object,accell)
+        --self.object:move_to(self.object:get_pos())
 	else
         --airutils.set_acceleration(self.object,{x=0,y=airutils.gravity,z=0})
 		self.isinliquid = false
-        --new_velocity = vector.add(new_velocity, {x=0,y=airutils.gravity * self.dtime,z=0})
+        
+        if self._last_accel then
+            last_accel.y = last_accel.y + airutils.gravity --gravity here
+
+            new_velocity = vector.multiply(last_accel,self.dtime)
+        end
+        --self.object:set_acceleration({x=0,y=new_accel.y, z=0})
 	end
 
     if self.isonground and not self.isinliquid then
@@ -85,10 +94,10 @@ function airutils.physics(self)
         end
 
         --self.object:set_velocity(new_velocity)
-        local vel_sum = vector.subtract(new_velocity,vel)
-		self.object:add_velocity(vel_sum)
-
+        --new_velocity = vector.subtract(new_velocity,vel)
     end
 
+    self.object:add_velocity(new_velocity)
+
 end
 
diff --git a/lib_planes/entities.lua b/lib_planes/entities.lua
index 0f08c04..7e19f71 100644
--- a/lib_planes/entities.lua
+++ b/lib_planes/entities.lua
@@ -183,6 +183,7 @@ function airutils.logic(self)
     local velocity = self.object:get_velocity()
     local curr_pos = self.object:get_pos()
     self._curr_pos = curr_pos --shared
+    self._last_accel = self.object:get_acceleration()
 
     self._last_time_command = self._last_time_command + self.dtime
 
@@ -503,14 +504,6 @@ function airutils.logic(self)
         local limit = (self._max_speed/self.dtime)
         if new_accel.y > limit then new_accel.y = limit end --it isn't a rocket :/
 
-        if not self.isinliquid then --why? because whe work water movements in the phisics code
-            new_accel.y = new_accel.y + airutils.gravity --gravity here
-        end
-
-        local vel_to_add = vector.multiply(new_accel,self.dtime)
-        --vel_to_add.y = 0
-        self.object:add_velocity(vel_to_add)
-        --self.object:set_acceleration({x=0,y=new_accel.y, z=0})
     else
         if stop == true then
             self._last_accell = self.object:get_acceleration()
@@ -614,6 +607,7 @@ function airutils.logic(self)
     airutils.testImpact(self, velocity, curr_pos)
 
     --saves last velocity for collision detection (abrupt stop)
+    self._last_accel = new_accel
     self._last_vel = self.object:get_velocity()
     self._last_longit_speed = longit_speed
     self._yaw = newyaw