diff --git a/USER_MANUAL.md b/USER_MANUAL.md
index 23d2409a..b0b63d31 100644
--- a/USER_MANUAL.md
+++ b/USER_MANUAL.md
@@ -1030,7 +1030,7 @@ From MAP top-right account icon, or by routed requests from some features (e.g.,
 
 Screen title: **Flight Intelligence**
 
-Powered by Gemini 2.5 Pro with Google Search integration.
+Powered by Gemini 3.6 Flash with Google Search integration.
 
 Capabilities:
 
@@ -1953,7 +1953,7 @@ If the IFD has an ADS-B receiver, AvareX also picks up its **Capstone** ADS-B tr
 
 - Current Pro AI workflows are targeted for iOS/Android only.
 - Access from map account icon → Pro Services → Flight Intelligence.
-- Uses Gemini 2.5 Pro with Google Search integration.
+- Uses Gemini 3.6 Flash with Google Search integration.
 - Source threads:
   - AI feature thread:  
     `https://groups.google.com/g/apps4av-forum/c/wWZUn6TNG1w`
diff --git a/assets/docs/USER_MANUAL.pdf b/assets/docs/USER_MANUAL.pdf
index bb0b4306..8fc4af4f 100644
Binary files a/assets/docs/USER_MANUAL.pdf and b/assets/docs/USER_MANUAL.pdf differ
diff --git a/lib/ai/ai_screen.dart b/lib/ai/ai_screen.dart
index 2a1096e6..c6263dab 100644
--- a/lib/ai/ai_screen.dart
+++ b/lib/ai/ai_screen.dart
@@ -22,7 +22,13 @@ class AiScreen extends StatefulWidget {
 class AiScreenState extends State<AiScreen> {
 
   bool _clear = false;
-  final _model = FirebaseAI.vertexAI().generativeModel(model: 'gemini-2.5-pro', tools: [Tool.googleSearch()]);
+  // gemini-2.5-pro retires Oct 2026. Use stable Gemini 3.6 Flash (Vertex
+  // recommended migration path) rather than gemini-3.1-pro-preview, which
+  // previously failed on Vertex with "attachment is not supported".
+  final _model = FirebaseAI.vertexAI().generativeModel(
+    model: 'gemini-3.6-flash',
+    tools: [Tool.googleSearch()],
+  );
   bool _isSending = false;
   final TextEditingController _editingController = TextEditingController();