SAE Aero Design East Competition 2005
This webpage documents the second
year that I’ve been the academic advisor for the Wright State
University team that
attended the SAE
Aero Design East competition. The Aero
Design Competition challenges engineering students to conceive, design,
fabricate, and test a radio controlled aircraft that can take off and land
while carrying the maximum cargo. This gives students the opportunity to apply
the knowledge learned in the classroom to a practical problem. In addition to
the flight portion of the competition, the students put their interpersonal
communication skills to work by submitting a formal design report and by giving
a 10-minute presentation to a group of four judges. The maximum allowable
wingspan for the Regular Class was 60 inches, and the engine
displacement was 0.61 cubic inches. A valid flight attempt was one in which the
aircraft took off within a prescribed 200-foot runway, circled the field (away
from the spectators), and landed within a 400-foot runway without losing any
parts of the aircraft. The students
involved were seniors in the Department
of Mechanical and Materials Engineering: Mark Brooks,
Carlos Guttierez, Brett Odgers and Aric Wagner. Unlike last year, we were able
to get started in September, which put us ahead of last years’
team by about four months. The first major objective was to completely
design the plane in Solidworks, which is a
solid-modeling software package that is available to us here at WSU. The reason
for this was to accurately locate the center of gravity (CG) of the plane,
because knowing the location of the CG is critical with respect to the
stability and controllability of the plane. Therefore, the plane was completely
modeled in Solidworks, including the weights of the
balsa, the engine, the servos, the battery, the receiver, and the fuel tank.
Another critical decision in the construction of this years’ aircraft was the
concept of Design for Manufacturability. The wing ribs,
wing D-tube parts and fuselage
bulkheads were designed such that they could be cut out using laser cutting
technology. This was extremely beneficial because a laser cutter is more
precise and repeatable, and the finished product doesn’t have the frayed edges
that normally occur with a razor knife or small saw. Once the pieces were lasered out, the students then built the plane
pretty much as planned, although some minor changes were made, such as
relocating two of the servos and changing the position of the rear landing
gear. Like last year, we went with a tricycle gear. Again, knowing the location
of the CG was critical in order to properly place the rear landing gear.
Originally, the gear was too far aft of the CG, which would result in more lift
being required for the takeoff rotation. Luckily, this was solved by for us, by
a means that I’ll share shortly. After the plane was complete, we loaded it up
and drove to Eddy’s
house (our intrepid pilot) on the Monday before the contest. He looked it over
and did a pre-flight checkout. Everything looked good, so we took it to the
local RC airstrip in Urbana.
By the time we got it in the air, it was nearly dark, as you can see in the
following two short clips.
Maiden
voyage 1
Maiden
voyage 2
Two flawless flights
were enjoyed by all, even though there was no payload in the plane. Did you see
the rolls and the loop? These flights demonstrate that the time and effort
spent in the modeling phase was worthwhile, because the flight characteristics
were excellent, according to Eddy. Last year, we had to put an eight-pound
weight in the plane in order to balance it for flight. The next time we were
all together was Thursday evening in DeLand, Florida.
It had been a long, arduous journey
for the students, but we were really charged to get out to the flight line.
Unfortunately, the weather was very stormy, so we had to cool our heels in the
hotel room until Friday morning. We finally made it to the flight line at the DeLand R/C Club
field around 9:00 a.m. on Friday
morning. We spent the entire morning doing some last-minute checks and tweaks.
We decided not to take it off the ground until later that day, because the
official safety check started at 1:00 p.m. and the presentation was at 4:30
p.m. (The plane had to be present at the presentation). The presentation went
really well, and we couldn’t wait to get back out to the flight line to put the
beast into the air. We watched a couple of our competitors making some initial
flights, and then it was our turn. Eddy did some taxiing with about 8 pounds of
payload in the hold. This was well within the limits of our plane, since the
maximum predicted payload was 17 pounds. At around 6:30 p.m. on Friday, Eddy
revved the engine and took off. It soared beautifully after using only about 50
out of a maximum of 200 feet of the runway. The plane gently rolled to the
right, and then suddenly rolled further to the right, causing a spin. The plane
augered into the grass from about 50 feet in the air
under full power! The nose was completely destroyed, the wing slightly damaged,
parts and pieces were strewn everywhere in a radius of destruction. There was a
smokin’ hole in the grass where the plane hit. We
quickly went out to see the devastation. The pieces were collected, placed in
the van, and brought back to the hotel room. Everyone knew what had to be done:
Roll up our sleeves and get to work! On the bright side, we had an excellent
opportunity to change the location of the landing gear, seeing that it was
completely torn off of the plane. I was so impressed with our students: There
were no complaints, no finger-pointing, just a lot of cooperation and teamwork.
After some takeout from KFC and eight hours of work, we crashed (went to bed,
that is!) at around 2:30 a.m. At 8:30 a.m.,
we were out at the flight
line again, this time with 31 teams from the U.S.,
Brazil and Canada, because the competition had
officially begun. Prior to lifting any weight, we were in sixth place with our
scores from the written report and the presentation. In the first round, we put
1.4 pounds of payload in the bay, went to the runway, took off in about 15
feet, and flew like the wind! A picture-perfect landing followed, and we were
on our way. In Round 2, our pilot decided to play with the running propeller,
and received a cut on his finger that required two stitches at the local
hospital emergency room. Even though he was in pain, he temporarily wrapped his
finger in packing tape and successfully lifted 6.4 pounds. We missed Round 3
because our pilot was out of commission. However, in Round 4 we lifted 10 pounds,
and in Round 5, still on Saturday,
we lifted 15 pounds. This catapulted us into fourth place overall, which was a
great surprise to our fellow competitors later that day. Most of them had left
the competition early on Saturday because of the windy conditions (10 to 15
knot cross-winds). Early on Sunday morning in Round 6, we put 17 pounds on the
bird and went to the runway. The takeoff was flawless, the climb-out perfect,
but the right-hand turn was a little slow, and the plane was
destroyed in the treeline of death next to the runway.
We were so sad to see her go in, because she had performed so well up to that
point. There were many aircraft that met their final fate that morning because
all of the planes were loaded to the gills. A few of the planes decided that it
would be interesting to buzz the crowd, which was not appreciated by the judges
whatsoever! After a total of eight rounds, we were able to retain fourth
place, which we were very happy about, considering that the first and
second place teams were from Brazil
and the third place team was from Canada. I guess that means that we
were first in the nation, right? The most important thing was that we beat Cedarville College,
the University
of Cincinnati and the University
of Dayton. No, wait a
minute, the most important thing was that our team successfully executed a
difficult project, learned a lot about teamwork, and had a great
time doing it.
Here are some remarks
after the contest by Aric Wagner.
Special thanks to:
Staub Laser Cutting
RC Hobby Center
Dean James E. Brandeberry