Over thirty years experience with Original Equipment Manufacturers in the development and application of fatigue and fracture life prediction methodologies. The areas of focus have been establishing engineering applications of theories and incorporating processes to assess the static, durability, and damage tolerance capabilities of structure. This experience base is supported by knowledge of multiple engineering disciplines and an understanding of structural integrity philosophies for the design, manufacturing, and maintenance of aircraft, engines, structures, and other aerospace products.

Present Position & Responsibilities

Officer and Chief Engineer for Analytical Processes / Engineered Solutions, APES, Inc. a Missouri Corporation and a "Small Business", established in early 1997. APES is presently under contract with the USAF to research and develop analytical predictive techniques that assess the interaction of operational cycles and time based age degradation (such as corrosion) on the service life capability of structure. These contracts involve 1) providing the analytical tools to perform the assessments, 2) formulating the “integration” concepts and plans for the many disparate user communities, and 3) assisting in research and data acquisition to expand the models to many field applications. APES also provides advanced stress analyses solutions, linear and non-linear, 2- and 3-dimensional, and fracture mechanics capabilities. Other expert services include load and environmental spectrum evaluations, acoustic and buffet interaction solutions, holistic life assessments, and advanced analytical failure analyses. APES’s policy is to provide Analytical Processes in conjunction with the Engineered Solutions to meet customer challenges.


Experience History


1992 - 1997 Advanced Methods and Special Problems : McDonnell Douglas Corp. St.Louis MO.

·         Provided engineering solutions and support to all enterprise programs in addressing structural problems, conducting product integrity assessments, directing advances in life prediction methods and procedures, promoting cost efficient changes and enhancements in products, and stimulating technology advances.

·         Program Independent Assessments of F/A-18 aircraft to determine levels of risk and provide recommendations to program office to mitigate risk and improve product quality

·         Implemented advanced analytical procedures to improve F-15 depot inspection intervals

·         Performed complex failure analyses for C-17 Full Scale Fatigue Test , F-15, T-45, F/A-18, and SLAM missiles cracks resulting in a process and procedure being documented for an standard industry approach

·         Determined the role of microstructure in fatigue behavior to enable material substitutions to solve manufacturing problems in coordination with establishing a process to ensure product integrity

·         Formulated approach for designing Joint Strike Fighter to meet service life requirements under new joint aircraft specifications

·         Tailoring and implementation of “Critical Component Selection” process across enterprise



1987 - 1991 Structural Integrity Process Development : McDonnell Douglas Corp.

·         Developed design and assembly process to optimize integrity, weight, and cost for transport aircraft lower wing structure

·         Established procedures for implementing ENSIP, MECSIP, and AVIP with subcontractors

·         Conducted F/A-18 Damage Tolerance Assessment for Swiss applications and provided necessary design changes to aircraft to meet service life requirements

·         Fatigue and fracture enterprise processes and procedures development; database, modeling, benchmarking, etc.



1984 - 1986 Large Aircraft, Commercial Aircraft, and Fixed Structures:

Boeing Aircraft, Seattle WA; CASA Madrid Spain; and Sverdrup Technology, Tullahoma TN

·         Evaluation of fatigue techniques and methodology improvements for B-2 applications with Boeing

·         Lead first certification of commercial aircraft under new FAA FAR and JAR damage tolerance specs

·         Damage Tolerance analysis of NASA-Lewis Wind tunnel for continued service of non-stress relieved welded steel structure



1979 - 1983 Fighter Aircraft Airframe Applications: McDonnell Aircraft St. Louis MO

·         Analyst for F-15 Damage Tolerance Assessment and Reliability Centered Maintenance Programs

·         Constructed F-15 Aft Fuselage finite element model, and performed salvages and repairs for production

·         Extensive failure analyses and Solutions; F-15 Upper Wing Spar cracking, Rudder Cable , Jet Fuel Starter Turbine Disk, Inlet Duct Buffet cracking, F/A-18 Bulkhead cracking, etc.



1975 - 1978 Turbine Engine and Rocket Applications: Pratt & Whitney Aircraft WPB, FL

·         Analyst for the Damage Tolerance Assessment of the PWA F100 Engine

·         Developed multi-parameter interpolative crack growth rate relationship models using Hyperbolic sine and double hyperbolic sine algorithms for : R-ratio, frequency, temperature, and environment

·         Established design criteria for Damage Tolerance of Engine Disks and broach slot modeling

·         Failure analysis solutions for high frequency fatigue and fracture of fan and turbine blades



1970 - 1975 Fatigue and Fracture Research: Pratt & Whitney Aircraft R&D Center FL

·         Established test facilities and procedures for fatigue and fracture testing

·         Developed fracture mechanics and damage tolerance concepts for engine industry, which subsequently resulted in the Equivalent Initial Flaw Size concept and Retirement for Cause

·         Performed elevated temperature testing and modeling for thermal mechanical fatigue approximations

·         Created method of strain range partitioning for temperature creep and dwell effects

·         Conducted high pressure hydrogen evaluations and assessment for pressure vessels



Graduate from Georgia Institute of Technology - Mechanical Engineering, Atlanta GA 1973

Co-op Training in many engineering disciplines at Pratt & Whitney Aircraft 1968 -1972

6 years in Engine and Space Applications with Pratt & Whitney Aircraft

 1 year in Structures with Sverdrup Technologies and Boeing Aircraft

2 years in commercial certification of aircraft for CASA in Madrid, Spain

15 years in multiple engineering disciplines and systems McDonnell Douglas

Papers and Presentations

(since 1990)

1.       “An Engineering Procedure to Select and Prioritize Component Evaluation Under USAF Structural Integrity Requirements” USAF Structural Integrity Conference, 1990

2.      “Results From Two MECSIP Studies” USAF Structural Integrity Conference, 1991

3.      “New Aircraft Lower Wing Skin Trade Study” USAF Structural Integrity Program Conference, 1992 and AIAA/ASME/ASCE/AHS/ASC Conference, 1995.

4.      “Durability Versus Damage Tolerance: A Discussion of the US Navy and US Air force Philosophies”,1993

5.       “A Probabilistic Strategy for Aircraft Fleet Inspection Considering Unanticipated Environments” USAF Structural Integrity Program Conference, 1993.

6.      “Fatigue Methods Used in Life Prediction of Navy Aircraft: Current and Future”, USN ONR Fatigue Structural Reliability Workshop, 1994.

7.      “Striation Counting & Marker Band Recognition Applied to Aircraft Test Failures”, ASTM Conference & Symposium, 1994.

8.      “Spectrum Loads Development for Joint Aircraft Structures - Service Life Technology Considerations” USN-ONR Fatigue Structural Reliability Workshop, 1995

9.      “Understanding Fatigue Failure Analyses Under Random Spectrum Loading Using a C-17 Test Article Failure”, ICAF 95-International Committee of Aeronautical Fatigue, Australia,1995 & USAF Structural Integrity Program Conference, 1995

10.  “Approach for Determining the Economic Life of the F-15 Aircraft” USAF Air Logistic Command’s USAF Structural Integrity Conference, 1995

11.  “The Impact on Total Life of Corrosion/Fatigue Interaction - An Engineering Approach”, USAF 4th Aging Aircraft Conference, 1996

12.  “Cyclic Relaxation in Compression-Dominated Structure” Engineering Foundation Conference for Fatigue Damage in Structural Materials, 1996. Published in International Journal of Fatigue: Volume 19 1997.

13.  “Analytical Process Framework for Aging Aircraft”, ASM AEROMAT, 1997

14.  “Damage Accumulation and Spectrum Editing”, USAF Structural Integrity Program Conference, 1997.

15.  “Modeling Corrosion Morphology and Effect of Initial Quality State” presentation located on and, 4 May 1998.

16.  “Tailoring the Structural Integrity Process to Meet the Challenges of Aging Aircraft” Presented at the Fatigue Damage of Structural Materials II, Cape Cod, Massachusetts, September 1998.

17.  “Corrosion is a Structural and Economic Problem: Transforming Metrics to a Life Prediction Method” Presented at the NATO RTO’s Workshop 2 on Fatigue in the Presence of Corrosion, Corfu, Greece, October 1998.

18.  “Integrating Real Time Age Degradation into the Structural Integrity Process” NATO RTO’s Workshop 2 on Fatigue in the Presence of Corrosion, Corfu, Greece, October 1998.

19.  “Determining the Initial Quality State for Materials”, USAF Aircraft Structural Integrity Program Conference, 1998.

20.  “ECLIPSE-Environmental and Cyclic Life Interaction Prediction Software” ASM AEROMAT, 1999.

21.  “Predictive Modeling for Corrosion Management: Modeling Fundamentals” Third Joint NASA/FAA/DoD Conference on Aging Aircraft, 1999.

22.  “Correlation of Life Prediction Methods with Corrosion-Related Tests” USAF Aircraft Structural Integrity Program Conference, San Antonio, Texas, 1999.

23.  “Case Studies for Corrosion/Fatigue Life Assessments” Fourth Joint NASA/FAA/DoD Conference on Aging Aircraft, St. Louis, Missouri, May 2000.

24.  “The Application of p-version Finite Element Methods to Fracture-Dominated Problems Encountered in Engineering Practice” p and hp Finite Element Methods: Mathematics and Engineering Practice Conference (p-FEM2000), St. Louis, Missouri, May 2000.

25.  “Using Holistic Life Predictions to Focus NDI Requirements” 2000 USAF Aircraft Structural Integrity Program Conference, San Antonio, Texas, December 2000.

26.  “Monitoring the Robustness of Corrosion & Fatigue Prediction Models” 2001 USAF Aircraft Structural Integrity Program Conference, Williamsburg, Virginia, December 2001.

27.  Managing Damage in the Wing: Modeling the Interaction of Exfoliation with Static and Fatigue LoadsSixth Joint FAA/DoD/NASA Conference on Aging Aircraft, San Francisco, California, September 2002.

28.  “Integration of Corrosion Effects into an Actual Air Force Tracking Program” 2002 USAF Aircraft Structural Integrity Program Conference, Savannah, Georgia, December 2002.

29.  Fretting Fatigue Model” Final Report for 01 February 2002 - 30 November 2002, SBIR Phase I Report, AFRL-VA-WP-TR-2003-3012, February 2003.

30.  Holistic Life Assessment Methods” Canadian Aeronautics and Space Institute 50th AGM and Conference, 16th Aerospace Structures and Materials Symposium, Montreal, Canada, April 2003.

31.  Sliding a Fretting Model into the Holistic Life Assessment Methods” ICAF 2003-International Committee of Aeronautical Fatigue, Switzerland, May 2003.

32.  “The Application of p-version Finite Element Methods to Fracture-Dominated Problems Encountered in Engineering Practice”, Computers and Mathematics with Applications, Vol. 46, No. 1, June 2003.

33.  Predictive Modeling of Structure Service Life” in ASM Handbook 13A Corrosion: Fundamentals, Testing and Protection, October 2003.

34.  Integration of a Fracture Mechanics-based Fretting Model into Holistic Life Assessments” International Symposium on Fretting Fatigue 4, Lyon, France, 2004.

35.  Demonstration of a Holistic Structural Integrity Process Using Corrosion/Fatigue Interactions from Laboratory Experiments and Field Experience” Sixth International Aircraft Corrosion Workshop, Solomons, Maryland, 2004.

36.  Development and Demonstration of a Holistic Structural Integrity Process using the Initial Discontinuity State Concept for 7050-T7451 Aluminum” Aircraft Structural Integrity Program Conference, Memphis TN, 2004.

37.  Verification of Analytical Models in a Fracture Mechanics Based Approach to Modeling Fretting Fatigue” Fifth International ASTM/ESIS Symposium on Fatigue and Fracture Mechanics, Reno, Nevada, 2005.

38.  Surface Integrity Effects on Aircraft Durability” 2005 Conference on Aerospace Technology and Innovation (CASI 2005), February 2005.

39.  Fretting Fatigue Model” AFRL-VA-WP-TR-2006-3080, Final Report for 01 May 2003 – 30 April 2006, SBIR Phase II Report, May 2006. 150 pages.

40.  Verification of Analytical Models in a Fracture Mechanics Based Approach to Modeling Fretting Fatigue” Journal the ASTM International (Online), Vol. 3, Issue 8, Sept. 2006, 14 pages.

41.  Crack Growth and Stress Intensity Prediction Techniques” AFRL-VA-WP-TR-2006-3043, Final Report for 22 April 2002 – 20 March 2006, March 2006. 64 pages.

42.  Corrosion Modeling and Life Prediction Supporting Structural Prognostic Health Management” ICAF 2007-International Committee of Aeronautical Fatigue, Italy, 2007.

43.  Corrosion and the threat to aircraft structural integrity” In Corrosion Control in the Aerospace Industry, Woodhead Publishing, 2009.

44.  Incorporating Laser Peening Residual Stress into a Holistic Life Assessment Approach” USAF Aircraft Structural Integrity Program Conference, San Antonio, Texas, 2010.

45.  Incorporating Laser Peening Residual Stress into a Holistic Life Assessment Approach” Eleventh International ASTM/ESIS Symposium on Fatigue and Fracture Mechanics, Anaheim, California, 2011.