Copter: all pre-arm checks to be disabled

set ARMING_CHECK parameter to zero to disable

ArduCopter/Parameters.h

@@ -83,7 +83,8 @@ public:
         k_param_pilot_velocity_z_max,
         k_param_circle_rate,
         k_param_sonar_gain,
-        k_param_ch8_option,             // 31
+        k_param_ch8_option,
+        k_param_arming_check_enabled,   // 32
 
         // 65: AP_Limits Library
         k_param_limits = 65,            // deprecated - remove
@@ -339,6 +340,7 @@ public:
     AP_Int8         frame_orientation;
     AP_Int8         ch7_option;
     AP_Int8         ch8_option;
+    AP_Int8         arming_check_enabled;
 
 #if FRAME_CONFIG ==     HELI_FRAME
     // Heli

ArduCopter/Parameters.pde

@@ -419,6 +419,13 @@ const AP_Param::Info var_info[] PROGMEM = {
     // @User: Standard
     GSCALAR(ch8_option, "CH8_OPT",                  CH8_OPTION),
 
+    // @Param: ARMING_CHECK
+    // @DisplayName: Arming check
+    // @Description: Allows enabling or disabling of pre-arming checks of receiver, accelerometer, barometer and compass
+    // @Values: 0:Disabled, 1:Enabled
+    // @User: Standard
+    GSCALAR(arming_check_enabled, "ARMING_CHECK",   1),
+
 #if FRAME_CONFIG ==     HELI_FRAME
     GGROUP(heli_servo_1,    "HS1_", RC_Channel),
     GGROUP(heli_servo_2,    "HS2_", RC_Channel),

ArduCopter/motors.pde

@@ -191,6 +191,12 @@ static void pre_arm_checks(bool display_failure)
         return;
     }
 
+    // succeed if pre arm checks are disabled
+    if(!g.arming_check_enabled) {
+        ap.pre_arm_check = true;
+        return;
+    }
+
     // pre-arm rc checks a prerequisite
     pre_arm_rc_checks();
     if(!ap.pre_arm_rc_check) {