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Meet: Andrew Hahn

Conceptual Aircraft Designer
Ames Research Center, Moffett Field, CA
My Journals
Chat
Archive
Who am I
I am a conceptual airplane designer. What this means
is that I, and other members of my branch, design airplanes at a very
basic level. We don't get into the nuts and bolts details that are necessary
when someone actually sits down to build an airplane. Instead, we use
previous designs and engineering judgment to estimate what we think a
particular design is capable of doing. In a way, it is like trying to
tell the future. We start with a set of requirements to get a basic idea
of what the airplane should look like. We think about how big the wings
are, whether the wings are swept, what kind of engine to use and other
pretty basic questions. Our job is to take a look at all of the requirements
and constraints and see if we can fit in technologies that make sense,
considering things like cost limitations. In the end, we come up with
the basic configuration of an airplane.
We have a joke that most of the airplanes around have
been designed on the back of napkins at coffee houses. Actually a lot
of the design starts that way. People just start trying to convey what
it is they're thinking by making simple drawings and sketches. That's
actually the fun part, but obviously there is a lot more to design than
that. There's a big non-fun part which is having to do the work of deciding
whether or not those sketches make any sense. It's interesting work but
it is also very difficult and intense. You have to know a lot of math.
You have to have a lot of computer skills. You have to be able to use
physics on a daily basis. One of the things that takes getting used to
is that there is no "right" answer. When your teacher gives you a problem
to solve, it usually has only one answer and she or he can look it up
in a solution guide. My job is challenging because we are trying to find
the best answer we can from very many possible solutions and there is
no clear way of knowing how good the one we wind up with is. On top of
that, the difference between a good design and a very good design may
be only a few percent in drag, weight or cost.
Tools Used
We use a bunch of computer codes that range from
something that's just text driven, not a lot of fun to look at, all the
way to computational fluid dynamics, which is a lot of fun to look at.
Each code solves a different part of the design puzzle, and we then combine
all of the individual answers into one over all solution. Not all of our
work is on individual airplane designs though. A lot of our work is intended
to improve the tools of design, to make airplane design more accurate,
faster, and easier. We have a lot of person-years of development into
our computer programs. One of the programs we are working on right now
has been in development since 1960s. It's almost as old as I am.
Who Do I Work For?
Our customer is first and foremost the American people.
Our research helps people both directly and indirectly. We help people
directly by participating in large projects, like the ERAST program, that
build airplanes for atmospheric science. These airplanes will allow scientists
to fly their instruments to places they have never been able to so they
can study our atmosphere, its weather, and pollution. We help people indirectly
by doing basic research that individual aircraft companies really can't
do by themselves. This spreads the cost and risk of trying new ideas over
the entire industry which will benefit everyone who hops on a plane to
see family for the holidays, who is defended by our armed forces, or who
flies light airplanes for fun. That sounds like just about all of us.
Past Projects
In the past, I have worked on Buoyant Quad Rotors
(blimps with helicopters attached), jet transports, fighters, bombers,
and Short Takeoff Vertical Landing (STOVL) airplanes. Some of my work
is for civilian use and some is for the military. For example, my group
once did a study for the Navy. They wanted to know what the future Navy
should look like, and the way to do this was to design a bunch of future
navies and to try them against each other. We supplied the airplanes for
those potential future navies.
Right now I am doing work on the ERAST program which
is for very high altitude airplanes. We have four companies that are tasked
to build airplanes that will carry an atmospheric science payloads to
as high as 85,000 feet. My job is to support them because their design
capability doesn't completely cover the range of flight conditions that
these planes will see. To give you an idea of how hard this mission is
to do, the altitude requirement is about two and a half times higher than
most airliners cruise at and is about 10,000 feet higher than the U-2
spy plane can fly. The only airplanes capable of flying at this altitude
for any length of time have been big, expensive, and way too fast for
the instruments to work. These design problems are really complicated
and specific to a mission that has little commercial value, so we can't
expect private companies to each have the same capabilities that NASA
has. It would actually be wasteful in terms of resources and could bankrupt
them. It is much better for us to each work on the part that we can do
best and share what we know. NASA is in a really good position to share
because we are not in competition with anybody and so we try to help all
of the companies that work with us.
Career Path
I grew up in Buffalo, New York. I have had a basic
interest in airplane, car, and boat design since I was small. Besides
having the basic interest, I needed a good foundation in science or math
and English. I tried very hard in school because I knew it would give
me the best chance of achieving my dream of designing airplanes. I did
pretty good, and I went off to college, not knowing how difficult it would
be.
Luckily, I managed to get through my undergraduate
work. My degree is in aerospace engineering from Embry-Riddle Aeronautical
University, in Daytona Beach, Florida. It's named after Mr. Embry and
Mr. Riddle who started teaching flying and mechanics just 22 years after
the Wright Brothers' first flight.
Getting the job at NASA was really an accident. I
wasn't looking for a job at the time, but my roommate had a job and he
asked if I could come with him. NASA said yes and two days later we left
Florida to take co-op positions at the Ames Research Center in Northern
California.
Career Likes and Dislikes
Job satisfaction is one of the things that keep me
getting up in the morning. It's very important to enjoy what you do. My
job requires creativity, enthusiasm, curiosity, and interpersonal skills
as well as the more obvious technical skills. I like the people I work
with and have a lot of freedom to choose the projects I work on. I especially
like to learn, and working at NASA provides both the opportunity and the
means to learn many things. Unfortunately, a lot of engineering can be
boring and drudgery. This job really isn't like that. My work is far enough
from the details that need to be worked on when you actually try to build
an airplane that it doesn't become a drudge. It's exciting because I get
to work on a lot of very different airplanes. There are always parts of
your job you don't like. Sometimes you're forced to work hard on certain
details that are not particularly interesting, but you need to work on
them in order to be able to prove that you are right. Sometimes there
is time pressure because either you owe somebody some analysis or they
owe you and the deadline is getting close. Of course, there's always administrative
problems that seem to take too much time to work out.
The Early Years
I was kind of a nerd when I was a kid. I used to ride
my bike over to the library an awful lot. I read just about every book
they had on airplanes and boats and models. I have actually built many
airplane and boat models. I also enjoy flying model gliders. I've flown
real airplanes, too, but I haven't finished getting my license. While
there weren't any adults who nurtured my interest in airplanes, I have
had good science and math teachers who made a difference. They helped
me learn the things I needed to. While I don't find math and science really
interesting by themselves, they allow me to pursue the work that I do
find interesting. It's kind of like getting excited about a wrench. You
don't get excited about the wrench itself, but when you can take the bolt
off and fix your bike, then you're happy. You need to have the tools to
be able to do the job.
Advice
Follow your heart. It doesn't matter if it's airplane
design or anything else. You will spend a lot of your life working so
it is really important that your job be a rewarding part of your life.
Sometimes this will require sacrifice. Sometimes you will not get what
you want, but you have to try. If you try for something, you might achieve
it. If you don't, then it is guaranteed that you won't achieve it and
you will always wonder if you could have.
Personal Information
I am trying to get my master's in aerospace engineering
at Stanford University part time. It is really hard, but I decided I needed
to know more to continue doing good work.
I have a daughter who is almost two now. She is the
greatest joy in my life. I don't have as much time for my hobbies now,
but I can ski, scuba dive, fly a real airplane, fly model gliders and
ride motorcycles.
Chat Archive
March 31, 1998
November 8, 2000
May
18 - 23, 2001, Design a Mars Plane forum
May 22, 2001 Design a Mars Airplane
webcast
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