Inflating a Balloon

For what seems to be a fairly simple process, teaching a student to inflate properly in the variety of conditions he/she will have to face is difficult. I never considered it to be a tough procedure until I took on the role of the examiner and found that with no help, students would often overlook small elements of the inflation and end up scratching their heads when things didn’t go as planned.

There are many details to attend to for a successful inflation. A checklist is a must for this operation. It helps keep things in sync with no forgotten elements. I will attempt to go through the inflation process highlighting the common pitfalls I see with students.

The layout location and direction can bite even the most confident student. It’s very important to accurately determine wind direction and any side gusts as well as obstructions in the field. Students will often look straight ahead in a field and not notice that there’s a bush or fence within a 20 degree roll of the envelope. To locate properly, the student must visually look at the entire field and pick the area that will allow the most sweep area for the balloon just in case the wind shifts.

The leak/burner check and basket/envelope connection are slightly different for each balloon brand. These procedures are fairly straightforward. However, it is imperative that the student not get distracted while performing even a simple task. Falling prey to a distraction can result in a caribiner not being connected, a hose not being tightened or something worse. Always finish the procedure you started before looking away.

Once the fuel system is tested for leaks and the envelope is connected in preparation for starting the fan, it’s time to brief the crew. This process is usually simple unless it’s breezy and/or you have only 1 crew person. If it’s breezy, it’s important to put the fan on the side that is upwind of any gusting and fudge it further than normal from the basket. The upwind placement of the fan will keep it clear in case the basket is jerked downwind with a gust.

In the case of a breezy inflation, the throat crew should be briefed on the use of the fan kill switch and the rip line in case the pilot is unavailable for such maneuvers. The crown person should be briefed thoroughly as usual. An insufficient crown briefing is one of the problems I often see with students. “As soon as I give you the thumbs up, you’ll hear the burner go and you should walk up with the rope as the envelope goes vertical”. This sounds reasonable enough if you’ve ever experienced an inflation. However, this can be interpreted as simply walking up towards the basket when the burners go off. This would most likely result in a disaster, especially when a student is in control at the burner. It is imperative that the crown briefing include at least the following:

  1. Don’t wrap the rope around your hand or any part of your body
  2. Apply hard resistance to the rope all the way through the inflation until the balloon is vertical and stable.
  3. Dampen any side movements of the envelope by increased pressure or favoring one side and at least controlling the pendulum to the opposite side
  4. Watch you footing as the balloon inflates especially in ice or snow. Jump to the best traction areas and dig in.


There is a lot more that the crown person should know but it’s impossible to explain it all in one session. There is a special relationship between a crown person and a pilot. A benign inflation is simple for both parties. However, when mother nature throws a curve, a successful inflation depends on the skill of the pilot and crown person in equal amounts.

The hot inflation timing and technique are probably the most abused parts of the inflation process. How many times have you watched someone at a rally using a constant burn, chasing a little hole at the bottom of a what looks like a special shape snake balloon. Usually that scene comes just before the hole that mysteriously appears. I see this happen to pilots with of all hours of experience.

There are many techniques to hot inflate a balloon safely. I offer the following description of the procedures that I teach and why. I have yet to have a student burn one of my balloons.

The first rule is that the balloon has to be almost “tight” with cold air before turning on the burner. If impatience takes over and there are still some ripples in the bottom, it’s ok to put in a couple of long blasts. At this point, I insist that the student leave the cockpit area and let the fan finish the work of mixing the 2 or so burns in the envelope. Usually that is enough to do the job. If the envelope’s still not tight, the trick is to pace more burns at long intervals so as to time the tightening of the last ripple with the envelope breaking ground. This technique can be accomplished even with an underpowered fan with a little patience, timing, and a knowledgeable crown person.

When the envelope breaks ground fully inflated, the pilot has many advantages. He/she doesn’t have to do that 30 second straight blast that superheats the mouth area to get the balloon to go vertical. That superheated fabric has very little tolerance for a close lick of the flame before disappearing. Whereas, when the balloon is breaking ground in a tight configuration, the pilot can administer a few burns then lay off for a moment to let the fan cool the mouth, and further mix and tighten the balloon.

This process is repeated until the balloon is vertical. At any time the pilot can stop burning and even get out of the basket. The balloon will just sit at that angle until the pilot decides to finish the inflation. The key to this technique’s success is timing and a skilled crown person. One reason that this works as well as described here is that the crown person is not jerked off their feet with the sudden acceleration of a non stop blast. The slow start allows the balloon to stay under control when the crown person has the least torque on the balloon. Once the balloon arrives at 45 degrees, the crown person owns the balloon. This works even with a small person on a 245.

Once vertical, I prefer to have my crown handle brought back to the basket ASAP unless it’s windy and needed for stabilization.

One other required item necessary for an incident free inflation is a decent fan and its proper placement. Unfortunately, some fans just don’t have what it takes. However, proper placement and good technique can go a long way to make up for a weak fan.

In order to place the fan in its most efficient position, it’s necessary to understand and visualize the airstream pattern. The object of an inflator fan is to fill the balloon with cold air and maintain static pressure across as much of the mouth as possible. The latter item is often overlooked with students. The optimum fan location is one that is far enough back and angled such that the vertical footprint of the air flow is about the size of the mouth when it reaches the mouth.

However, this angle does need to be tweaked some to lesson the crossflow over the burner. There is a happy medium somewhere. You can tell if it’s wrong by standing at the mouth on the other side from the fan. You will feel a brisk breeze hitting you in the face as the air exits the balloon. Finally, the fan must stay running at some level during the hot inflation at least until the balloon is off the ground. This keeps the mouth cooler and helps mix the hot and cold air in the envelope to produce a rounder, tighter envelope.

To perform consistently good inflations requires skill and experience. Sloppy inflations will eventually bite even the most fortunate pilots. Keep your mind on the procedures and be aware of how the balloon’s behaving. Hot inflate in control and you’ll dodge a few trips to the repair station.