Mark J. Shuart and Bob Daugherty, authors of part of the email traffic on Columbia debris issues, talked with reporters. See their statements and biographies.
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Statement by Mark J. Shuart
March 10, 2003

Good afternoon, my name is Mark Shuart and I am the Director for Structures & Materials at the Langley Research Center
I would like to open today's discussion with two background comments.

The first comment is that the Langley Research Center is widely recognized for its technical expertise in aerospace. As part of that capability, the NASA Langley structures and materials organization has been identified as the Agency's Center of Excellence in that discipline. The structures and materials organization participated in orbiter tile research in the early 1980's and helped analyze the Challenger accident and return the Shuttle to flight. Recently, an outside organization, the National Transportation Safety Board, sought our expertise, and we are currently assisting them in the accident investigation for American Airlines 587.

My second comment follows the first. The reason we are experts in structures and materials is because of our people and facilities. A fine example of our personnel is Bob Daugherty. Bob has more than 20 years experience in landing dynamics, the area that looks at wheels, landing gear, run ways, and how they all interact. He is a senior research engineer and has received several awards for his contributions to human space flight. I trust his judgment because of his demonstrated track record.

It is my pleasure to yield the microphone to Bob Daugherty.

Statement by Bob Daugherty
March 10, 2003

My name is Bob Daugherty. I'm a Senior Research Engineer at Langley Research Center where I have worked for almost 23 years. At the Aircraft Landing Dynamics Facility, we do research on advanced landing gear systems; we characterize aircraft and spacecraft takeoff and landing performance with mathematical models to describe things like steering and braking friction; and we work from time to time on solving operational problems for a number of commercial and other governmental agencies. In one form or another, I've worked on shuttle tire and landing issues for about 18 years.

First, let me say that I don't know what caused the Columbia tragedy but I do firmly believe the Columbia Accident Investigation Board will figure out the cause and offer solutions to prevent it from happening again. And I feel, like everyone at NASA, that we owe this to the families and to the public.

Second, why am I speaking with you today? Honestly, I was very surprised by the attention my writing received. I view my involvement as a small sideline focused on landing issues. And, I've been in somewhat of a quandary -- I really do believe that the best thing I can do for the investigation is to talk to the Investigative Board first. On the other hand, I hate it that my words are being misinterpreted. My quandary has now been relieved since the Board has said they don't mind if I speak up. So I want to clear the air as much as possible and I hope you'll excuse me in advance if we get into any technical areas where I may still feel it's best to talk to the board first.

Finally, before taking questions, I'd like to mention what I consider my most important point. And that is my intention with my emails. I was asked a question from a long-time friend and colleague about whether we had ever simulated a landing with two flat tires. After some thinking, I believed that was the wrong question. The thing that might get you in that predicament would manifest itself way before you got to the runway. I simply wanted to present the whole range of issues between catastrophe and a perfect landing. I wanted to make sure that everybody could be as ready as possible for any eventuality. The email was intended to spark discussion to ensure there were such plans and I believe they did just that.

Mark J. Shuart

Director for Structures & Materials
NASA Langley Research Center
Hampton, VA 23681

1976 Bachelor of Science with Distinction
Engineering Science and Mechanics
Virginia Polytechnic Institute and
State University

1978 Master of Science
Engineering Mechanics
Virginia Polytechnic Institute and
State University

1985 Doctor of Philosophy
Applied Sciences
University of Delaware

1996 Program for Management Development
Graduate School of Business Administration
Harvard University

2000 Leadership for a Democratic Society
Federal Executive Institute

Dr. Mark J. Shuart has been an employee of the NASA Langley Research Center since June 1977. He is a nationally recognized authority on the failure mechanics of composite materials and structures and on the behavior of composite materials and structures in general. As a research engineer, Dr. Shuart conducted experimental and analytical research on the linear and nonlinear responses and failure characteristics of composite structural components subjected to various static and dynamic loading conditions. He has directed major contracts with Boeing, the former McDonnell Douglas, and Lockheed-Martin to develop composite structures technology for primary aircraft structures. He has directed grant activities at several major universities. Dr. Shuart has held the management positions of Assistant Head of the Structural Mechanics Branch, Assistant Chief of both the Structures Division and the Materials Division, and Chief of both the Materials Division and the Structures Division. He currently leads the Structures & Materials Competency. This organization develops and delivers useable research and technology results to enable Agency program offices to meet program objectives and to enable the Agency to develop future aerospace materials and structures. To achieve this mission, the Structures & Materials Competency initiates, organizes and conducts experimental and analytical research in the areas of advanced materials and processes, mechanics and durability, metals and thermal structures, analytical and computational methods, aeroelasticity, structural dynamics, and nondestructive evaluation sciences. The products of this research have found numerous aerospace and non-aerospace applications. Dr. Shuart is the author or co-author of more than 85 formal publications, referenceable oral presentations, and other significant contributions that describe advanced structures and materials technologies. He is an Associate Fellow of the American Institute of Aeronautics and Astronautics. He has received the Outstanding Alumni Award from the Center for Composite Materials at the University of Delaware. He has also received the NASA Outstanding Leadership Medal. He lives in Hampton, Virginia, with his wife, Jane, and their two daughters, Amy and Emily.

Bob Daugherty Biography

Date of Birth: September 20, 1958
Place of Birth: Norfolk, VA

Mr. Daugherty attended Virginia Polytechnic Institute and State University and graduated in 1981 with a Bachelor of Science degree in Aerospace and Ocean Engineering. Upon graduation, he began full-time work at NASA Langley Research Center after having worked the previous three summers at Langley as a summer student.

Mr. Daugherty is a Senior Research Engineer at the Aircraft Landing Dynamics Facility (ALDF) in the Structural Dynamics Branch of the Structures and Materials Competency. Research there is centered on developing the technology to implement new kinds of aircraft landing systems, to describe the frictional relationship between tires and pavements, and to improve the safety of takeoff and landing operations of military and commercial aircraft and spacecraft.

Mr. Daugherty has conducted research on such things as air cushion landing gear systems, aircraft steering phenomena, and tire-generated water spray and engine ingestion. Mr. Daugherty is the author or co-author of over twenty-five NASA and conference publications and has received the NASA Manned Flight Awareness Award for his contributions to Shuttle Orbiter landing safety on three occasions. He also received the Silver Snoopy Award from the STS-37 crew in the Astronaut Office. Other research has been directed towards measuring and modeling the landing dynamics of the Shuttle Orbiter with emphasis on tire wear problems and landing techniques with flat tires. More recently, Mr. Daugherty was involved with the Landing Systems Research Aircraft (LSRA) project which used a highly modified Convair 990 aircraft to perform full-scale tests on Orbiter landing gear components, especially tires, which resulted in a texture modification of the KSC runway to increase crosswind limits for landing. Mr. Daugherty has conducted research on the active control of landing gears to alleviate unwanted structural vibration of aircraft operating on rough runways, with special emphasis on supersonic-type aircraft such as the High-Speed Civil Transport. Current research has centered on defining the behavior of radial aircraft tires for use on commercial aircraft fleets.