diff --git a/libraries/AC_PID/AC_HELI_PID.cpp b/libraries/AC_PID/AC_HELI_PID.cpp
index 242286556d..b9a02191b3 100644
--- a/libraries/AC_PID/AC_HELI_PID.cpp
+++ b/libraries/AC_PID/AC_HELI_PID.cpp
@@ -11,25 +11,41 @@ const AP_Param::GroupInfo AC_HELI_PID::var_info[] PROGMEM = {
     // @DisplayName: PID Proportional Gain
     // @Description: P Gain which produces an output value that is proportional to the current error value
     AP_GROUPINFO("P",    0, AC_HELI_PID, _kp, 0),
+
     // @Param: I
     // @DisplayName: PID Integral Gain
     // @Description: I Gain which produces an output that is proportional to both the magnitude and the duration of the error
     AP_GROUPINFO("I",    1, AC_HELI_PID, _ki, 0),
+
     // @Param: D
     // @DisplayName: PID Derivative Gain
     // @Description: D Gain which produces an output that is proportional to the rate of change of the error
     AP_GROUPINFO("D",    2, AC_HELI_PID, _kd, 0),
-    // @Param: IMAX
-    // @DisplayName: PID Integral Maximum
-    // @Description: The maximum/minimum value that the I term can output
-    AP_GROUPINFO("IMAX", 3, AC_HELI_PID, _imax, 0),
+
     // @Param: FC
     // @DisplayName: PID+FF FeedForward Gain
     // @Description: FF Gain which produces an output value that is proportional to the current error value
     AP_GROUPINFO("FF",    4, AC_HELI_PID, _ff, 0),
+
+    // @Param: IMAX
+    // @DisplayName: PID Integral Maximum
+    // @Description: The maximum/minimum value that the I term can output
+    AP_GROUPINFO("IMAX", 5, AC_HELI_PID, _imax, 0),
+
+    // @Param: FILT_HZ
+    // @DisplayName: PID Input filter frequency in Hz
+    // @Description:
+    AP_GROUPINFO("FILT_HZ", 6, AC_HELI_PID, _filt_hz, AC_PID_FILT_HZ_DEFAULT),
     AP_GROUPEND
 };
 
+/// Constructor for PID
+AC_HELI_PID::AC_HELI_PID(float initial_p, float initial_i, float initial_d, float initial_imax, float initial_filt_hz, float dt) :
+    AC_PID(initial_p, initial_i, initial_d, initial_imax, initial_filt_hz, dt)
+{
+     _ff = 0.0f;
+}
+
 float AC_HELI_PID::get_ff(float requested_rate) const
 {
     return (float)requested_rate * _ff;
@@ -38,11 +54,11 @@ float AC_HELI_PID::get_ff(float requested_rate) const
 // This is an integrator which tends to decay to zero naturally
 // if the error is zero.
 
-float AC_HELI_PID::get_leaky_i(float error, float dt, float leak_rate)
+float AC_HELI_PID::get_leaky_i(float leak_rate)
 {
-	if((_ki != 0) && (dt != 0)){
+	if((_ki != 0) && (_dt != 0)){
 		_integrator -= (float)_integrator * leak_rate;
-		_integrator += ((float)error * _ki) * dt;
+		_integrator += ((float)_input * _ki) * _dt;
 		if (_integrator < -_imax) {
 			_integrator = -_imax;
 		} else if (_integrator > _imax) {
diff --git a/libraries/AC_PID/AC_HELI_PID.h b/libraries/AC_PID/AC_HELI_PID.h
index 575b526024..b475adb3d5 100644
--- a/libraries/AC_PID/AC_HELI_PID.h
+++ b/libraries/AC_PID/AC_HELI_PID.h
@@ -12,45 +12,19 @@
 #include <math.h>
 #include <AC_PID.h>
 
-// Examples for _filter:
-// f_cut = 10 Hz -> _filter = 15.9155e-3
-// f_cut = 15 Hz -> _filter = 10.6103e-3
-// f_cut = 20 Hz -> _filter =  7.9577e-3
-// f_cut = 25 Hz -> _filter =  6.3662e-3
-// f_cut = 30 Hz -> _filter =  5.3052e-3
-#define AC_HELI_PID_D_TERM_FILTER 0.00795770f    // 20hz filter on D term
-
 /// @class	AC_HELI_PID
-/// @brief	Object managing one PID control
+/// @brief	Heli PID control class
 class AC_HELI_PID : public AC_PID {
 public:
 
-    /// Constructor for PID that saves its settings to EEPROM
-    ///
-    /// @note	PIDs must be named to avoid either multiple parameters with the
-    ///			same name, or an overly complex constructor.
-    ///
-    /// @param  initial_p       Initial value for the P term.
-    /// @param  initial_i       Initial value for the I term.
-    /// @param  initial_d       Initial value for the D term.
-    /// @param  initial_imax    Initial value for the imax term.4
-    ///
-    AC_HELI_PID(
-        const float &   initial_p = 0.0,
-        const float &   initial_i = 0.0,
-        const float &   initial_d = 0.0,
-        const int16_t & initial_imax = 0.0,
-        const float &   initial_ff = 0.0) :
-        AC_PID(initial_p, initial_i, initial_d, initial_imax)
-    {
-		 _ff = initial_ff;
-    }
-    
+    /// Constructor for PID
+    AC_HELI_PID(float initial_p, float initial_i, float initial_d, float initial_imax, float initial_filt_hz, float dt);
+
     /// get_ff - return FeedForward Term 
     float       get_ff(float requested_rate) const;
     
     /// get_leaky_i - replacement for get_i but output is leaded at leak_rate
-    float       get_leaky_i(float error, float dt, float leak_rate);
+    float       get_leaky_i(float leak_rate);
     
     // accessors
     float       ff() const { return _ff.get(); }