Mark J. Shuart and Bob Daugherty, authors of part of the email traffic
on Columbia debris issues, talked with reporters. See their statements
+ View Transcript in Acrobat PDF(306 Kb)
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
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
1978 Master of Science
Virginia Polytechnic Institute and
1985 Doctor of Philosophy
University of Delaware
1996 Program for Management Development
Graduate School of Business Administration
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