From 610595bfb9e63043dfa38ee190bfdfd83c84f993 Mon Sep 17 00:00:00 2001
From: Paul Riseborough <p_riseborough@live.com.au>
Date: Sat, 11 Jul 2015 10:55:36 +1000
Subject: [PATCH] AP_NavEKF: Prevent position drift between arming and takeoff
 when using OF

---
 libraries/AP_NavEKF/AP_NavEKF.cpp | 1 +
 1 file changed, 1 insertion(+)

diff --git a/libraries/AP_NavEKF/AP_NavEKF.cpp b/libraries/AP_NavEKF/AP_NavEKF.cpp
index c2f7daa305..5c8745cb58 100644
--- a/libraries/AP_NavEKF/AP_NavEKF.cpp
+++ b/libraries/AP_NavEKF/AP_NavEKF.cpp
@@ -1005,6 +1005,7 @@ void NavEKF::SelectFlowFusion()
         flowRadXY[0]        = 0.0f;
         flowRadXY[1]        = 0.0f;
         omegaAcrossFlowTime.zero();
+        flowDataValid = true;
     }
     // If the flow measurements have been rejected for too long and we are relying on them, then revert to constant position mode
     if ((flowSensorTimeout || flowFusionTimeout) && PV_AidingMode == AID_RELATIVE) {