Lawnchair Larry
Flies!
Physical Science, grades 8 to 12
Objective: Students will research
and experiment to discover the lifting power of helium gas.
Materials (optional):
- Helium balloons
- Calipers (to measure balloon diameter)
- Calculators
- Spring scales
The Darwin Award is presented each year to the person who improves
the gene pool by eliminating her or (usually him) self in the
most creative way. The 1997 nominee of the Darwin Award: Larry
Walters of Los Angeles-one of the few Darwin contenders to survive
his brush with fate. Larry's boyhood dream was to fly. When he
graduated from high school, he joined the Air Force in hopes
of becoming a pilot. Unfortunately, poor eyesight disqualified
him. When he was finally discharged, he had to satisfy himself
with watching jets fly over his backyard.
One day, Larry, had a bright idea.
He decided to fly. He went to the local Army-Navy surplus store
and purchased 45 weather balloons and several tanks of helium.
The weather balloons, when fully inflated, would measure more
than four feet across. Back home, Larry securely strapped the
balloons to his sturdy lawn chair. He anchored the chair to the
bumper of his jeep and inflated the balloons with the helium.
He climbed on for a test while it was still only a few feet above
the ground. Satisfied it would work, Larry packed several sandwiches
and a six-pack of Miller Lite, loaded his pellet gun-figuring
he could pop a few balloons when it was time to descend-and went
back to the floating lawn chair. He tied himself in along with
his pellet gun and provisions. Larry's plan was to lazily float
up to a height of about 30 feet above his back yard after severing
the anchor and in a few hours come back down.
Things didn't quite work out that
way.
When he cut the cord anchoring the
lawn chair to his jeep, he didn't float lazily up to 30 or so
feet. Instead he streaked into the LA sky as if shot from a cannon.
He didn't level of at 30 feet, nor did he level off at 100 feet.
After climbing and climbing, he leveled off at 11,000 feet. At
that height he couldn't risk shooting any of the balloons, lest
he unbalance the load and really find himself in trouble. So
he stayed there, drifting, cold and frightened, for more than
14 hours.
Then he really got in trouble.
He found himself drifting into the
primary approach corridor of Los Angeles International Airport.
A United pilot first spotted Larry. He radioed the tower and
described passing a guy in a lawn chair with a gun. Radar confirmed
the existence of an object floating 11,000 feet above the airport.
LAX emergency procedures swung into full alert and a helicopter
was dispatched to investigate. LAX is right on the ocean. Night
was falling and the offshore breeze began to flow. It carried
Larry out to sea with the helicopter in hot pursuit.Several miles
out, the helicopter caught up with Larry. Once the crew determined
that Larry was not dangerous, they attempted to close in for
a rescue but the draft from the blades would push Larry away
whenever they neared. Finally, the helicopter ascended to a position
several hundred feet above Larry and lowered a rescue line. Larry
snagged the line and was hauled back to shore. The difficult
maneuver was flawlessly executed by the helicopter crew. As soon
as Larry was hauled to earth, he was arrested by waiting members
of the LAPD for violating LAX airspace.
As he was led away in handcuffs,
a reporter dispatched to cover the daring rescue asked why he
had done it. Larry stopped, turned and replied nonchalantly,
"A man can't just sit around."
Here
is a short documentary video about Larry's flight, by Ted Fisher
First Challenge: Was
Larry a hero or a fool?
The reading above suggests Larry
was a fool, but some folks say he was an adventurer, to be admired
instead of ridiculed. Read a different account of Larry's flight,
written by one of Larry's many friends. Then write an explanation
of your own opinion. Considering the evidence, was Larry a fool
or a hero?
Larry Walters,
Airborne Adventurer
Optional Hands on Activity:
1. Fill balloons with helium (one
per group).
2. Measure their diameter. Divide
the diameter in half to find the radius.
3. Calculate the volume of gas inside.
(The volume of a sphere is found by multplying 4/3 pi times the
radius cubed)
4. Attach gram weights to the balloon
until you have balanced the lift. By measuring the weight it
takes to bring the balloon down, you have measured its lift,
or bouyant force.
5. Use this data to answer the questions
about Larry below.
Questions:
1. How much helium, in cubic feet,
will a balloon hold, if it is a sphere 4 feet in diameter?
2. How much lift will this gas offer?
How much lift did all 45 of Larry's balloons create?
3. Assuming Larry, his beer, chair
and BB gun all together weighed 200 lbs, how many balloons should
he have used for a gentle ascent?
4. What would normal weather patterns
lead you to believe Larry's fate would have been had he blown
out to sea? Would he have been blown to Japan?
Helpful Links:
Air Travellers
The
"Official Darwin Awards" Page
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