From b6d0208287c1f60b40f65ffda61689a3fba77548 Mon Sep 17 00:00:00 2001
From: Peter Barker <pbarker@barker.dropbear.id.au>
Date: Fri, 22 Jan 2021 10:28:26 +1100
Subject: [PATCH] Plane: allow arming in all auto-throttle modes

... except QRTL and QLAND which are now universally denied for arming.
---
 ArduPlane/AP_Arming.cpp | 11 ++++-------
 ArduPlane/mode.h        |  9 +++++++++
 2 files changed, 13 insertions(+), 7 deletions(-)

diff --git a/ArduPlane/AP_Arming.cpp b/ArduPlane/AP_Arming.cpp
index c1d6a1dec8..2e1fd4d7d7 100644
--- a/ArduPlane/AP_Arming.cpp
+++ b/ArduPlane/AP_Arming.cpp
@@ -153,14 +153,11 @@ bool AP_Arming_Plane::arm_checks(AP_Arming::Method method)
             check_failed(true, "Non-zero throttle");
             return false;
         }
+    }
 
-        // if not in a manual throttle mode and not in CRUISE or FBWB
-        // modes then disallow rudder arming/disarming
-        if (plane.control_mode->does_auto_throttle() &&
-            (plane.control_mode != &plane.mode_cruise && plane.control_mode != &plane.mode_fbwb)) {
-            check_failed(true, "Mode not rudder-armable");
-            return false;
-        }
+    if (!plane.control_mode->allows_arming()) {
+        check_failed(true, "Mode does not allow arming");
+        return false;
     }
 
     //are arming checks disabled?
diff --git a/ArduPlane/mode.h b/ArduPlane/mode.h
index 706493e086..886a22aff2 100644
--- a/ArduPlane/mode.h
+++ b/ArduPlane/mode.h
@@ -63,6 +63,9 @@ public:
     // returns a string for this flightmode, exactly 4 bytes
     virtual const char *name4() const = 0;
 
+    // returns true if the vehicle can be armed in this mode
+    virtual bool allows_arming() const { return true; }
+
     //
     // methods that sub classes should override to affect movement of the vehicle in this mode
     //
@@ -320,6 +323,8 @@ public:
     // methods that affect movement of the vehicle in this mode
     void update() override { }
 
+    bool allows_arming() const override { return false; }
+
     bool allows_throttle_nudging() const override { return true; }
 
     bool does_auto_throttle() const override { return true; }
@@ -488,6 +493,8 @@ public:
     // methods that affect movement of the vehicle in this mode
     void update() override;
 
+    bool allows_arming() const override { return false; }
+
 protected:
 
     bool _enter() override;
@@ -506,6 +513,8 @@ public:
     // methods that affect movement of the vehicle in this mode
     void update() override;
 
+    bool allows_arming() const override { return false; }
+
 protected:
 
     bool _enter() override;