Flying an aircraft that you built yourself sounds like it is dangerous--and it can
be.
For certified aircraft, the FAA requires a safe aircraft design and excellent quality
controls during construction. Certified aircraft have the benefit of a design proven by
thousands of hours flown by the company and other customers. Plus, all the parts are
certified so that you know you aren't getting some low-quality parts from a hardware
store.
So why would you give up that safety for a homebuilt balloon? Well, if you do things
right, your homebuilt balloon can be extremely safe as well. Here are some of the safety
points of the balloon I created:
 | A proven shape. This balloon has been calculated using the same types
of calculations that hot air balloon manufacturers have used since Justin H. Smalley came
up with the article "Determination of the Shape of a Free Balloon: Balloons with Zero
Super pressure and Zero Circumferential Stress", dated December 21 1963. |
| Strong fabric. This balloon uses the same style of rip-stop in most
balloons built today. The fabric has a urethane coating that helps reduce air leakage. The
fabric can handle over 40 lbs per square inch before breaking. During flight, it is
unlikely the fabric will encounter more than just a few pounds. The real stress on fabric
is while it is being handled in the ground. |
| Strong seams. I used flat-fell seams to construct the balloon. The
thread goes through each panel twice when making a stitch. This type of seam has been used
in many types of commercially made balloons without any problem. |
| Strong load tapes. The vertical load tapes can handle 4,000 lbs each.
They connect to the basket 12 times. |
| Fewer load tape connections. The load tapes go up, over the top, and
down the other side of the balloon without any breaks. So there are no sewn connections at
the top of the balloon to break. |
| Doubled load tape at the mouth. Since nylon cuts easier while under
strain, a loose segment of load tape is sewn on the inside of the load tape near the mouth
where the load tape forms a loop that the carabiners attach to. |
| Horizontal load tapes. While the design of the balloon is intended to
eliminate horizontal stress, there are smaller load tapes at the bottom, top, and wrapped
around three other locations in the balloon. |
| Over-rated carabiners. The carabiners are life-safety rated. Over 6700
lbs for each of the 12 carabiners connecting the Kevlar cables to the balloon. Over 16,000
lbs for each of the 3 carabiners connecting the cables to the basket. We could hang a
semi-truck off these carabiners. |
| Certified basket. I am using the same basket from a certified balloon
system. |
| Certified burner system. The burner, tanks, and fuel hoses are all from
a certified balloon undercarriage. |
| Certified top. The parachute top came out of my old balloon. The top
only has a few hours on it, and is practically new. All the parachute cords, etc. are the
same as what was on my certified system. |
