diff --git a/Assets/Scenes/Main.unity b/Assets/Scenes/Main.unity
index 16eca6c..a2fe10c 100644
--- a/Assets/Scenes/Main.unity
+++ b/Assets/Scenes/Main.unity
@@ -1702,11 +1702,11 @@ MonoBehaviour:
   m_Name: 
   m_EditorClassIdentifier: '::'
   fuelTank: {fileID: 1437557826}
+  altimeter: {fileID: 894314916}
   maxThrust: 1000
   Isp: 300
   throttleRampTime: 2
   minStartupFlow: 0.05
-  g: 9.81
   throttleCurve:
     serializedVersion: 2
     m_Curve:
diff --git a/Assets/Scripts/MainEngine.cs b/Assets/Scripts/MainEngine.cs
index 7d79946..7e25aac 100644
--- a/Assets/Scripts/MainEngine.cs
+++ b/Assets/Scripts/MainEngine.cs
@@ -2,15 +2,15 @@ using UnityEngine;
 
 public class MainEngine : MonoBehaviour
 {
-    [Header("Fuel Source")]
+    [Header("References")]
     public FuelTank fuelTank; // Reference to the fuel tank supplying this engine
+    public Altimeter altimeter; // Reference to the altimeter for gravity calculations
 
     [Header("Engine Settings")]
     public float maxThrust = 1000f; // kN
     public float Isp = 300f;        // seconds
     public float throttleRampTime = 2f; // seconds to reach full throttle
     public float minStartupFlow = 0.05f; // minimum fraction of max flow to maintain ignition
-    public float g = 9.81f;         // gravitational acceleration (m/s^2) (to be replaced)
     public AnimationCurve throttleCurve = AnimationCurve.Linear(0, 0, 1, 1);
 
     [Header("Efficiency Settings")]
@@ -29,6 +29,7 @@ public class MainEngine : MonoBehaviour
     private bool everStarted = false;      // tracks if engine has ever been started
     private float postIgnitionTimer = 0f;  // timer for post-ignition grace period
     private const float postIgnitionGrace = 0.5f; // seconds to allow ramp-up after ignition
+    private float g = 9.81f; // local gravity from altimeter
 
     void Update()
     {
@@ -55,6 +56,8 @@ public class MainEngine : MonoBehaviour
     /// </summary>
     private void HandleEngineState()
     {
+        g = (float)altimeter.gh; // Update local gravity from altimeter each frame
+
         // Check if engine is offline and restartable conditions
 
         if (!engineOnline)