From 37e49906d16321b1e361b5bc6bf70e177eec6daa Mon Sep 17 00:00:00 2001
From: henry1952 <49370322+henry1952@users.noreply.github.com>
Date: Thu, 11 Apr 2019 19:01:07 +0200
Subject: [PATCH] Update mode_s.c

---
 mode_s.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/mode_s.c b/mode_s.c
index e8387a1..43c387d 100644
--- a/mode_s.c
+++ b/mode_s.c
@@ -568,9 +568,9 @@ int decodeModesMessage(struct modesMessage *mm, unsigned char *msg)
         mm->CC = getbit(msg, 7);
     }
 
-    // CF (Control field)
+    // CF (Control field, see Figure 2-2 ADS-B Message BaselineFormat Structure)
     if (mm->msgtype == 18) {
-        mm->CF = getbits(msg, 5, 8);
+        mm->CF = getbits(msg, 6, 8);
     }
 
     // DR (Downlink Request)