In the previous segment of this article, I wrote about several ways a pilot can kill a balloon. I will provide a few more examples for your review, in the hope that you will not repeat them. The examples provided in this article are all based on actual balloons brought into repair stations, or observed at launch sites.
Perform a “ballistic tether”
A tethered or moored balloon is typically attached to the ground by three or more ropes tied to securely fixed or heavy objects. Normally, two of the ropes are tied upwind of the balloon, and at least one more is tied downwind, in case of a possible wind shift, and for crew assistance in positioning the balloon.
A pilot properly trained in tether operations is aware that the lift is affected by the weight of the tether ropes, and the aerodynamic lift caused by airflow across the top of the envelope (otherwise known as “false” lift). This is actually real lift for a tethered balloon as long as the wind continues.
In a passenger tether, the passenger loading can change as a group of heavy passengers are replaced by lighter passengers. If the pilot does not manage the excess buoyancy caused by the loading change by venting or allowing the envelope to cool, the balloon may perform a pop-up launch, only to be stopped at the end of the tether ropes. The pilot may also perform a long burn, and wait for the balloon to snap to the end of the ropes. This is a ballistic tether - and it will cause heavy shock loading on the tether rope anchors, the tether rope attachments to the balloon system, and may also bend or break the basket support structures and wicker. If you have a problem removing pins, unlocking carabiners, or you observe wicker damage along the top of the basket, the system may have been subjected to such a tether.
Poor Basket Housekeeping
In almost any landing in other than calm conditions, the basket will scoop up various forms of debris. This generally consists of vegetation, soil, sand, and gravel. All of these materials can cause varying amounts of damage to the basket.
The grit and gravel often fall behind the fuel cylinders and into the scuff leather when the basket is laid down for inflation or deflation. During transportation, the basket is typically upright, and normal vibration causes the sand and gravel to move under the fuel cylinders. More vibration causes the fuel cylinders to grind the grit into the floor and roughen the metal ring at the bottom of the cylinder. If this activity continues long enough, the sanding action will eventually wear a hole in the basket floor, requiring it to be repaired or replaced.
This wear can be prevented in several ways. We periodically remove the cylinders and use a shop vacuum to remove the grit. We also cover the metal ring with two layers of silver duct tape, that we replace when it becomes worn. Others use a split piece of rubber hose over the ring. One large manufacturer supplies plastic trays for use under the cylinders. They are attached with double sided tape, and look like the drip trays used under flower pots.
The soil and vegetation often become trapped between the scuff leather and the wicker. This combination will retain moisture, and will promote rotting of both the basket floor and the wicker. If the area between the leather and the floor is not periodically cleaned out, the floor may separate from the sides of the basket. If the problem becomes severe, you will need some expensive repairs or a new basket.
The soil and vegetation can be removed while you have the cylinders and instruments removed. Cover any open fuel lines with tape, plugs, or dust caps. Turn the basket upside down. Pound on the scuff leather with a rubber mallet or a short piece of wooden closet pole until no more dirt falls out.
There are many opportunities to damage balloon equipment on the way to and from the launch and landing sites. Entering a garage with the uprights installed on a basket can be an expensive mistake. The uprights may be bent or broken, the burner may be damaged, or the fuel lines may be destroyed. Even on a low trailer, the uprights will be more than the typical 7 foot clearance of a garage door or a parking structure. In the back of a full sized 4x4 pickup, the burner may require more than 11 feet of clearance, and may catch low hanging trees in many residential areas.
Pickup beds and trailers have sharp edges. If the basket slides against the bed rails or does not clear the tailgate opening, the wicker will be torn up and eventually it will need replacement. Padding either the basket or the sharp objects with cardboard, foam pads, or moving blankets will reduce or eliminate such damage.
An envelope can take on the appearance of a sail. If the envelope bag is not properly secured and enclosed, the wind can cause the bag to open. Once a small pocket of envelope fabric catches the wind, it can start pulling the rest of the envelope out of the bag, and onto the highway. Dragging the envelope along the road can cause serious snags, tears, and abrasions in a very short distance. When you close the bag, make sure that it is closed securely. Turn it over so the opening is not where the wind can reach it. Tie it down securely so it can’t roll off the truck or trailer bed. You don’t want to turn a perfectly good envelope into a car cover.
How NOT to kill your balloon
If you see anything that doesn’t look right, it may not be. Call your local repair station for advice. They welcome your business, and would like to see you come in to fix small problems before they become big expensive or dangerous problems.