diff --git a/Nasal/aircraft.nas b/Nasal/aircraft.nas index 7c88f8d3d..a8c2b08bc 100644 --- a/Nasal/aircraft.nas +++ b/Nasal/aircraft.nas @@ -846,7 +846,7 @@ var tyresmoke = { }, update: func { var rollspeed = me.get_rollspeed(); - var vert_speed = (me.vertical_speed) ? me.vertical_speed.getValue() : -999; + var vert_speed = (me.vertical_speed) != nil ? me.vertical_speed.getValue() : -999; var groundspeed = me.speed.getValue(); var friction_factor = me.friction_factor.getValue(); var wow = me.wow.getValue();