From bdc46ecb65ff170b6a48e992fa42d4e5f42125ea Mon Sep 17 00:00:00 2001
From: Josh Davidson <joshuadavidson2000@gmail.com>
Date: Thu, 27 May 2021 15:42:30 -0400
Subject: [PATCH] Control: Improve EPR calculation for high altitude airports

---
 Systems/libraries.xml | 20 +++++++++++++++++---
 1 file changed, 17 insertions(+), 3 deletions(-)

diff --git a/Systems/libraries.xml b/Systems/libraries.xml
index f9b7e92b..31944162 100644
--- a/Systems/libraries.xml
+++ b/Systems/libraries.xml
@@ -7,7 +7,15 @@
 	<filter>
 		<name>EPR Scale</name>
 		<type>gain</type>
-		<gain>1.0</gain>
+		<gain>
+			<expression>
+				<table>
+					<property>/fdm/jsbsim/velocities/mach</property>
+					<entry><ind>0.09</ind><dep>0.95</dep></entry>
+					<entry><ind>0.15</ind><dep>1.00</dep></entry>
+				</table>
+			</expression>
+		</gain>
 		<input>
 			<expression>
 				<table>
@@ -28,13 +36,19 @@
 			<expression>
 				<difference>
 					<table>
-						<property>/position/altitude-ft</property>
+						<product>
+							<property>/position/altitude-ft</property>
+							<table>
+								<property>/fdm/jsbsim/velocities/mach</property>
+								<entry><ind>0.09</ind><dep>0.1</dep></entry>
+								<entry><ind>0.15</ind><dep>1.0</dep></entry>
+							</table>
+						</product>
 						<entry><ind>    0</ind><dep>0.9852</dep></entry>
 						<entry><ind>43000</ind><dep>0.8584</dep></entry>
 					</table>
 					<table>
 						<property>/fdm/jsbsim/velocities/mach</property>
-						<entry><ind>0.00</ind><dep>0.000</dep></entry>
 						<entry><ind>0.09</ind><dep>0.000</dep></entry>
 						<entry><ind>0.15</ind><dep>0.016</dep></entry>
 						<entry><ind>0.22</ind><dep>0.022</dep></entry>