The fan, without a doubt, is the most dangerous piece of equipment associated with ballooning. Please take the fan seriously! When the number of crew people is short and there are not enough people for each crew station many pilots will leave the fan untended. The fan can be a very dangerous piece of equipment when untended. It might seem quite funny to watch a fan flying along backward at about 50 miles per hour on a hard surface. Funny, that is, until it hits something. Your pilot better hope that it hits a tree or retaining wall instead of a person or a car. The insurance company will love this kind of claim. They'll love it so much that the pilot's insurance premiums will probably go out of sight for the next 10 years. Oh, you have one of those fans with a brake or something that sticks down into the ground to hold it still. Well, the torque could cause it to tip and this can be just as dangerous. The fan tips, the guard hits the ground and bends or comes apart. The fan blade spins at over 800 RPM and a fan blade hitting the ground at that speed will cause the blade to shatter and eject pieces at great velocity. Also, when the blade hits the ground it can throw stones or dirt out at high velocity that can maim or even kill. If there are only two people at the mouth I'd rather see one holding the mouth open and the other operating the fan.
Before operating the fan make sure that you have been thoroughly instructed in how the controls work. You need to know how to turn it on, but most of all, how to turn it off. You will see all kinds of fans from 2 HP to 10 HP. Some have wheels on the front, some have wheels on the back, some have wheels front and back and some have no wheels at all. Most fans are gasoline driven, but I have seen propane fueled fans and I'm sure somewhere there is an electric fan run off the chase vehicle battery. The fan blade or prop is usually wooden but the use of metal and plastic has become popular lately. If you are in ballooning for any length of time you will see fans that are well cared for and you will see fans that are neglected. If you run across a fan that has been neglected, watch out. Any pilot who neglects this important piece of equipment is probably a pilot who neglects other important equipment. Beware!!
Upkeep of the fan is not a crew responsibility, however, if you see something wrong with the fan make sure that the pilot is made aware of the situation. Two things to watch for would be any unusual vibration or any unusual noise when the fan is in operation. Any unusual vibration could be caused by a prop that is out of balance. This condition can be dangerous to anyone in the vicinity of the fan since the blade could shatter causing sharp pieces of material to be thrown out at very high velocity. If the fan makes any kind of unusual noise during operation it usually means that it is low on oil. Continuing to operate the fan when it is low on oil will cause severe damage to the engine. If you hear any unusual noise or feel any unusual vibration while the fan is in operation you should shut it down immediately. The inflation can always be restarted when the problem is sorted out and corrected.
It does not take much effort to keep a fan in good operating condition. The engine should be tuned up at the beginning of each flying season. I don't mean just installing a new spark plug. I mean a real tune up including adjusting the floats, carburetor and linkages and most of all, checking to be sure that the fan cage is secure. Normally this service can be obtained from a local lawn mower service company at a nominal cost. The prop should be kept clean to cut down on drag. A light wiping with detergent should be enough, but light sanding and revarnishing of a wooden prop is not out of the picture. I have been to balloon races where a dealer who sells fan engines has had representatives that will check and tune up your fan free of charge. That is one of the best services I have ever seen at a balloon race and I'd like to see it again.
After the balloon has been stretched out on the ground you are ready to crank up the fan. I will assume that we are working with a full complement of crew people and one person is assigned to the fan. The person operating the fan should have gloves as certain parts of the fan get very hot during the operation of the fan. Also, some fans will shock you when you are trying to shut them off without gloves. Pilots should use care in choosing their fan person. The person working the fan should not be wearing any loose clothing or accessories that could get caught up in the air flow. Especially dangerous would be anyone with extra long hair which could get sucked into the air stream. Also, in winter you need to be alert for long scarves or jackets with draw strings. I have seen scarves and draw strings get sucked up into fans and yanked off causing skin abrasions.
When the fan is in operation the crew person operating the fan should always stand to the rear of the fan. One of this person's duties would be to keep people from standing directly to the side of the fan. If, for some reason, the prop became damaged it could cause injury to anyone standing to the side of the fan. For the same reason, the person crewing the fan should never lean over the fan. Some fans have throttle controls that allow you to vary the speed of the fan while other fans have only one speed, FAST. If the speed can be controlled the speed is at the discretion of the pilot. Some like to start slow until they get the top in before increasing speed while others go full blast from the very beginning. If your pilot does not tell you what he or she wants, ASK. You are part of the crew, you are performing an important task and you need to know what the pilot expects.
Placement of the fan during cold inflation is up to the discretion of the pilot. There has been a lot of discussion over the years on where the fan should be placed. Some say on the left and others say on the right. Some say in front of the basket while others say even with the basket . I'm going to tell you how and why we do it on my balloon. This is not the only way and it may not be the best way, but it is my way and I am comfortable with this procedure. One specific thing I do is quite controversial and will probably bring many negative comments, however, I have been doing it for 15 years and nothing bad has happened.
First, I place my fan on the left side of my basket. This is not due to the direction of the exhaust as many may assume. I personally believe that all exhaust gets sucked up into the air stream and blown into the balloon regardless of where the fan is placed. I am right handed and when hot inflating I operate the burner with my right hand. If something went wrong during hot inflation and my fan person left his or her post I could reach out with my left hand and turn off the fan while continuing to activate the burner.
Second, at the very beginning of my cold inflation I place the fan as close to the mouth of the balloon as possible. At this stage of the inflation the opening is usually quite small and I want as much air as possible directed into the balloon. As the balloon becomes inflated and the opening becomes larger, I move the fan back little by little until it is even with the back edge of the basket. Many years ago I went to the trouble of checking the air flow from the fan during a series of inflations. I attached 2-3 foot long pieces of knitting yarn around the mouth of the balloon, one at each load tape. During the cold inflation I watched these pieces of yarn. Sometimes they blew in and sometimes they blew out. This gave me an indication of the air flow and I adjusted the location of the fan to keep as many pieces of yarn blowing in as possible. I found that once the balloon is about half to 3/4 full the air flow will begin to circulate in one side and out the other. To keep his circulating air from exiting the balloon I angle the fan so that the blast of air crosses the mouth from left to right. The air blast from the fan pushes the exiting air from the left side back into the balloon's right side.
Third, when the balloon is fully inflated and I begin the hot inflation the person crewing the fan is directed to keep the fan running. Many pilots will have the fan turned off as soon as the burner is activated. During our hot inflation, not only do we leave the fan on, but we S.L.O.W.L.Y. tilt the fan back to follow the mouth of the balloon as it rises off the ground. I used to kill the fan at the first sight of flame from the burner but I found that I was frequently replacing fabric around the mouth of the balloon that had been over heated during the inflation. Keeping the fan on during the burn pushes the heat up into the balloon faster and keeps the fabric around the mouth cooler. I know that tilting the fan is not recommended by many, however, it can be done safely if it is done slowly. Any quick movement of the fan while in operation puts a lot of pressure on the hub and blade due to the torque generated by the spinning blade. If the fan is moved slowly this pressure is kept at a minimum. I have discussed and demonstrated this procedure to factory representatives from both Briggs & Stratton and Honda. Both said that tilting the fan should not be a problem as long as the fan is tilted slowly and not tilted more than 30 degrees. If tilted more than 30 degrees it could affect the oil flow inside the fan and cause engine damage.
One additional and important thing to remember when operating the fan. Parts of the fan become very hot. Make certain that you are careful to avoid these areas which are usually around the exhaust and muffler, especially when lifting the fan back into the chase vehicle. It is usually best to have two people lift the fan back into the vehicle so you are not tempted to push the fan up with your leg or thigh which could easily come into contact with the muffler.
Let me reiterate that I have described the way we handle the fan on my balloon. Many people will disagree with this method and have their own way of handling the fan. Their way is probably not wrong as long as basic safety procedures are followed. The main thing to keep in mind is that the fan is a dangerous piece of equipment, but if handled properly the danger can be kept at a minimum. As always, please forward comments or suggestions to me at P. O. Box 830011, Richardson, Texas 75083 or e-mail: firstname.lastname@example.org. (New E-mail address.)