UPDATE #60 - April 16, 1999

PART 1: Upcoming Chats
PART 2: Project News
PART 3: Stuck in the Helicopter Simulation!!
PART 4: Subscribing & Unsubscribing: How to do it

UPCOMING CHATS

QuestChats require pre-registration. Unless otherwise noted, registration
is at:  http://quest.arc.nasa.gov/aero/chats/#chatting

Tuesday, April 20, 1999, 9:30 AM Pacific Daylight Time:
Rich Coppenbarger, aerospace engineer

Rich develops hardware and software systems to help air
traffic controllers manage aircraft as they fly throughout the
nation's skies. One of the software programs he is developing is called
the CTAS, which helps air traffic move smoothly and without
delays. The CTAS is part of the Advanced Air Transportation
Technology (AATT) program, which is designed to help our
nation's air transportation system function better and more
safely, even with more aircraft flying in our skies.

Read Rich Coppenbarger's profile prior to joining this chat.
http://quest.arc.nasa.gov/aero/team/coppenbarger.html

Tuesday, April 27, 1999, 11 AM Pacific Daylight Time:
Ray Oyung, research coordinator, Fatigue Countermeasures Program

Ray is part of a team that works in the Fatigue Countermeasures
Program. The team tries to find ways to reduce the effects of
fatigue, sleep loss, and disruptions to the body's internal
clock on flight crews during flight operations. Ray is also part of a
research team. As a member of the research team, Ray collects
data from experiments focusing on certain aspects of fatigue
and how they affect us.

Read Ray Oyung's profile prior to joining this chat.
http://quest.arc.nasa.gov/aero/team/ray.html


Wednesday, April 28, 1999, 11 AM Pacific Time:
Phillip Luan, instrumentation engineer

Balances used in wind tunnel tests tell engineers how the
force of the wind affects the model. Phillip is responsible for making
sure that balances used for these tests are extremely accurate. He
also helps determine how electrical signals received during the
tests are related to the accuracy of the balances.

Read Phillip Luan's profile and learn more about the Balance Calibration
Lab prior to joining this chat.

http://quest.arc.nasa.gov/aero/wright/team/luan.html
http://quest.arc.nasa.gov/aero/wright/tunnels/balcallab.html

PROJECT NEWS

Customer Survey Coming Your Way

In order to account for the money we spend on these projects, we
occassionally survey our customers to find out how they use the projects
and also to find out how we can improve. We will be sending out an Aerospace Team Online Customer Survey soon. Please take a minute to complete
this an send it back as a reply, or if you prefer you may complete it
online at http://quest.arc.nasa.gov/aero/customer.html Thanks for your
help!


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Wright Flyer Replica Wind tunnel Data Posted with Lesson Plans!

See five runs worth of data and use it with the lesson plans to gain an
understanding of the data.
http://quest.arc.nasa.gov/aero/wright/teachers/angles/data.html

Wind Tunnel Data Lesson Plans

Do you "Know all the Angles"? Learn about lift and drag! Grades 4-8

Why is it important to "Get the Wright Pitch"? and "Watch your Attitude"!
Grades 6-8

Getting "Up, up and Away" - learn what the Wright Brothers learned.
Grades 9-12

http://quest.arc.nasa.gov/aero/wright/teachers

- - - - - - -

Share your classes' experience with the Wright Flyer Data

Win a NASA Party Pack, (posters and lithographs), by sending a note
describing your experience teaching with the Wind Tunnel Data Lesson
Plans. We'd like to know how we can improve. Send a one page description
to slee@mail.arc.nasa.gov

- - - - - - -

Right Flying Colaborative Projects

Several classes have shared their glider flight test results which are
Online at
http://quest.arc.nasa.gov/aero/events/collaborative/gliders/index.html

Look for their final results which are beginning to appear at

http://quest.arc.nasa.gov/aero/events/collaborative/final/  !

STUCK IN THE HELICOPTER SIMULATION!!

By Rich Coppenbarger

April 15, 1999

A couple of years ago I was heavily involved in a project called
pilot-directed guidance. It involved improving helicopter flight low to
the ground, in what we call the nap-of-the-earth. The military would like
to have this capability in order to avoid enemy threats. The idea was to
allow the helicopter to fly as low to the ground as possible, below the
treetops in order to sneak up on an enemy and remain undetected by radar.
The problem with doing this is that helicopters tend to run into obstacles
at low altitudes like power lines and tree branches.

We put camera sensors on the helicopters and developed guidance and
control laws to basically assist the pilot in identifying what these
obstacles were and maneuver away from those obstacles. I contributed by
developing state of the art software called pilot-directed guidance.  I
think the best way to describe this is that it is kind of like a horse and
a rider. If you imagine a horse kind of trotting over the ground, the
horse is usually smart enough to avoid most simple obstacles with out the
rider giving explicit directions to avoid a rock or tree. We wanted to
make the guidance system like a smart horse. We wanted the guidance system
to be able to avoid the low-level obstacles automatically. The pilot would
be able to give the high level steering commands, kind of like pulling on
the reigns of a horse.

I tested this out on simulations on NASAs Vertical Motion Simulator. This
is the largest vertical motion simulator in the world, it can move up and
down 60' and from side to side 40', more than any other simulator. Of
course it's very realistic when you step into the cab. There is realistic
computer-generated imagery up on the windows and it feels very much like
you are actually flying a helicopter.

First we had to develop a mathematical computer model of the helicopter
itself. This needs to run on the simulator and simulate the basic behavior
of the vehicle you are experimenting with. In this case we were testing a
UH60 helicopter called a Black Hawk. We then added pilot-directed guidance
to the simulation. This involved making a pilot-directed control system
interact with the vehicle and putting special displays in front of the
pilot. At first we experimented with a heads-up display. This is a
holographic image that you put in front of the pilot that contains various
symbology. This allows the pilot to look straight out the window and pick
up information like air speed, obstacles, and terrain without having to
look down. I believe that even some automobiles have this type of display.
I know I've seen holographic displays of speedometers on the windshield of
certain automobiles.

We finally ended up using a helmet-mounted display system, which gave the
pilot a lot more range for looking at different symbology. In other words
the pilot could turn his head and see virtual imagery that was placed out
there in the scenery.

We did many simulation runs in low visibility conditions. Typically if the
fog is really dense and the visibility is below 100 feet, the pilot
wouldn't be able to detect a tree that was 200 feet away. We presented the
symbology by painting it on the helmet-mounted holographic display system.
In a sense this allowed the pilot to see through the fog. Even without the
guidance system, the advanced imagery went a long way towards improving
the ability of the pilot to fly the helicopter in poor weather conditions
and at low altitudes.

We worked closely with McDonald Douglas Helicopter Company on this
project. They were interested in developing displays for a rotorcraft
pilot associate system designed for their Apache attack helicopters. We
also had pilots from Sikorsky and Boeing helicopters participate in our
simulations, along with numerous military pilots.

When you first complete the simulation development, you have to test it
and usually the research engineer is the first person to test the
software. Unfortunately, I spent many occasions stranded in the cab of the
simulator in the VMS because of software glitches. No one can encode
perfectly and there are always some bugs in the software. Normally I would
only be stranded for fifteen or twenty minutes while they worked out the
bugs. Sometimes a software bug can cause the simulation cab to jolt,
vibrate, or make loud noises that can be a little frightening for the
occupant. Once the engineers have played guinea pig and ironed out the
major problems and fixed the bugs, the pilots get to fly in order to carry
out the research.

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