1. PWPS ENGINEERING EGT Spread Awareness

2. This document contains material of a proprietary nature, and is not to be disclosed, used or reproduced in whole or in part, without the express written consent of Pratt & Whitney Power Systems, Inc. EGT Spread Awareness Problem: EGT Spread Limits (Hot Probe to EGT Average) Does Not Always Identify a Problem Mal-distribution of Fuel and Water Between the 9 Fuel Nozzles Can Result in Local Distress of Turbine Airfoils (One Combustion Chamber Running Hotter Than Normal) Background: EGT Is Measured by 9 Individual Probes, One Behind Each of the 9 Combustion Chambers The Individual Probes Are Staggered Such That If All 9 Probes Were Behind One Combustion Chamber, Each Probe Would Be Measuring a Different Circumferential Point of the Chamber. This Is Done in Order to Measure a True Average EGT. Result Is Each Probe Should Be Reading a Different Temperature From Coldest Portion of Combustion Chamber to Hottest Portion

3. This document contains material of a proprietary nature, and is not to be disclosed, used or reproduced in whole or in part, without the express written consent of Pratt & Whitney Power Systems, Inc. Solution: Provide Tracking Tool for EGT Spread (Excel File) Incorporate the EGT Spread File Into the Monitor Screen (Replace Bar Graph) Conducting Evaluation to Insure Maintenance Actions Are Robust for Resolving EGT Spread Issues Two Instances to Date, One Requiring Change Out of Fuel Nozzles on Liquid Fuel Site, Second Requiring Cleaning of Nozzles and Water Injection Mixing Tee Strainers on Liquid Fuel Site. Incorporate Limits Into Software Will Have Button to Delay Drivebacks Until Able to Perform Maintenance Actions EGT Spread Awareness

4. This document contains material of a proprietary nature, and is not to be disclosed, used or reproduced in whole or in part, without the express written consent of Pratt & Whitney Power Systems, Inc. EGT Spread Awareness

5. This document contains material of a proprietary nature, and is not to be disclosed, used or reproduced in whole or in part, without the express written consent of Pratt & Whitney Power Systems, Inc. EGT Spread Awareness