[Redeemer]

It's not just that, you need to change the locomotor as well, here's the locomotor code for the F-35 i'm using (say thanks to Trex for this )

Locomotor F-35Locomotor
  Surfaces = AIR
  Speed = 180 
  SpeedDamaged = 120
  TurnRate = 180
  TurnRateDamaged = 120
  Acceleration = 120
  AccelerationDamaged = 30
  Lift = 120
  LiftDamaged = 80  
  Braking = 120      
  MinTurnSpeed = 0 
  PreferredHeight = 100
  AllowAirborneMotiveForce = Yes
  ZAxisBehavior = SURFACE_RELATIVE_HEIGHT
  CirclingRadius = 100
  Appearance = HOVER ;WINGS
;  PitchInDirectionOfZVelFactor = 1.0
  PitchStiffness = 0.9 ;0.5
  RollStiffness = 0.4
  PitchDamping = 0.9
  RollDamping = 0.8
  ForwardVelocityPitchFactor = 0
  LateralVelocityRollFactor = 0.4
  Apply2DFrictionWhenAirborne = Yes
  AirborneTargetingHeight = 30
  LocomotorWorksWhenDead = Yes
End