The Hot Air Balloon
By John Proctor
San Diego State College
It all started back in the spring of 1966, when I first met Mr. Tracy Barnes. It was only by chance that I happened to make his acquaintance, for I was helping a friend of mine, Paul Anderson, on his senior project. A small gasoline engine, which was operating a winch, was making quite a racket in the relatively vacant Engineering Building at San Diego State College. Mr. Barnes, unfamiliar with the college campus, was looking for an aerospace engineering professor. He was attracted by the noise, and upon investigating found us working on the winch apparatus. He was quite interested in winches as he uses them extensively in his business for controlling balloons. When we turned the engine off, he chatted with us, inquiring as to what we were doing. After Paul’s brief explanation he asked where he might find the aerospace professor he was seeking. My curiosity got the best of me, and I asked what he wanted with him. Tracy replied that he was looking for two new crew members for a cross-country hot air balloon ride. Two old crew members had quit because of various difficulties. I was immediately interested. It sounded intriguing to travel across the United States in a hot air balloon. I explained my qualifications which evidently were more than adequate. I was offered a job on the spot. However, I was still pessimistic, but Paul urged me to take him up on his offer.
After having thought about it for a few days, I decided to give it a try. I traveled to Brown Field where Mr. Barnes had his base of operations and accepted the job offer. There I found most of the equipment we would use on our trip. I had only a few weeks of school left, with the last of my finals on the fourth of June. Tracy planned a launching in the early hours of Sunday, the fifth of June.
He had made three rather unsuccessful attempts to fly out of San Diego County, but he was only about eighty miles from his starting place at the beach in front of the Hotel del Coronado in San Diego. The trip had originally started on the ninth of April, but due to a disastrous crash in the San Diego Mountains, he was delayed until the fifth of June making repairs. He was also injured in the crash which destroyed his original gondola.
The original gondola was made basically of aluminum, and was triangular in shape, approximately ten feet to a side. The fuel tanks were stored in the corners, which were padded with large cushion pads to absorb the impact of landing. The gondola contained a cabin heater, altimeter, rate of climb indicators, sleeping cots, two-way radios, radar transponder, television, temperature indicators, and valves for controlling the burners. With the destruction of this gondola a new one had to be made, thus adding to the delay.
I arrived at Jacumba, California, the spot of the crash, in the early hours of the fifth of June. Jacumba is a little town in San Diego County not far from the Mexican-American border, and high in the mountains. Mr. Barnes was encamped in a little place called McCain’s Valley. The only people awake were a few newsmen and some curious individuals who had become interested in the trip. They were sitting around a campfire which took the edge off the cold night air. As dawn approached the camp began to stir. Equipment was unpacked and checked. This being my first time to work with the balloon, I was not exactly sure what to do, but I soon caught on, as I got yelled at for doing the wrong things. Tracy wanted to launch as near as possible to his crash site on the desert rim, but the winds were beginning to increase. The decision was made to move the balloon to a better launching spot. The best available launch site was McCain’s Valley.
We rolled the seventy-foot-tall balloon out on the meadow and attached the lines to the gondola. The balloon was attached to a Jeep via a power take-off winch mounted on the front of the Jeep. Having cleared all the cars out of the way and moved most of the people back, we began to inflate the balloon.
The balloon was inflated by tipping the gondola over on its side and holding the bottom of the balloon open while small, gasoline powered blowers filled the 90,000 cubic feet cavity. (This was the largest balloon of the hot air type ever built in the United States.) After we had the balloon about half inflated we had to stop because the surface wind was blowing it around on the ground making it impossible to launch. The most dangerous time of the entire launching sequence was when the balloon was between half inflation and full inflation as it would “cup” and hold the air like a huge sail. With a fifteen mile an hour gust of wind it would drag the Jeep across the field like a child dragging a toy car. This was one reason for the quick deflation or safety valve mechanism.
This safety valve mechanism was at the top of the balloon and had to be chocked before the balloon was fully inflated. The mechanism consisted of six ten feet long zippers radiating out-ward from center like spokes on a wheel. The three triangular pieces formed by the arrangement were connected together by a pin plate assembly. The pin, which was attached to one plate, was tapered. Through this tapered pin was passed two smaller pins about a quarter of an inch in diameter, which prevented the plates from separating. These pins were attached to two steel cables, or ripcords, which ran the full length of the balloon to the gondola. The zippers were zipped closed and the fly removed so that a breakable Seam was formed. Each zipper was undone about an inch to insure proper opening when the pins were removed from the tapered pin, thus allowing the plates to separate along the zippered seams from the force of the hot air inside. This device only malfunctioned once, and that was in the second flight of the trip in Spring Valley, California, when the zippers accidentally opened at eighteen-hundred feet. This forced both the pilot and the co-pilot to bail out.
A second attempt was made to launch the balloon, and this attempt was successful. This was my first launching, and I was awed as the curious bystanders and the airplane that circled overhead. As soon as the balloon was airborne, I wound in the winch cable and hitched up a small flatbed trailer to the rear of the Jeep. The launch was over and it was up to the rest of the ground crew to break camp. I set off in pursuit of the balloon.
This sequence repeated itself quite often as launching succeeded launching, and we all became seasoned ground crew members. However, due to adverse weather and terrain conditions the balloon was trailered a majority of the way from California to Iowa.
The fabric of the balloon was made of a plastic called Dacron. This is very similar to nylon, but it withstands temperatures ten times better than nylon. There were almost two thousand yards of material in the two balloons. The balloons were made in sections, thus preventing any major tears from developing if one small section burst. This worked fine under normal conditions. However, flying through pine trees proved to be too much for these seams, and large portions of the balloon were torn. Also, on the Tarentum-New Kensington bridge over the Allegheny River, in Pennsylvania, large sections were damaged when the balloon snagged on the bridge.
There were twenty-four gores, the orange-peel like sections running from top to bottom, and the seam of each gore on the outside balloon contained a small steel cable running to the top and tying to one of the three plates in the valve mechanism. They were grouped into four sections at the bottom, each group tying to one corner of the gondola. In addition to these there were twenty-four cables attached to the inside balloon, but these went only a short distance up the balloon. Later, in Rolfe, Iowa, these cables were removed, and the edges of the inside balloon were tied to the outside balloon by a heavy nylon string. The cables were removed because they got tangled and caused delays in launching. Also, six of them were rendered useless when the pilot light valve was jammed open on impact with the ground, and wind blew the fabric over the hot burners. After this, about six of the short cables were useless, as the fabric they were attached to no longer existed and there was just a melted glob of plastic fused to the ends of them.
In addition to the large rapid deflation valve at the top, the balloon contained a small venting valve near the middle of one gore. This valve consisted of a three feet diameter opening in both balloons, with one opening being just high enough so that when the balloon was fully inflated the fabric from one balloon covered the hole in the other. There was a steel cable attached to the inside balloon, and when this was pulled on it caused the hole in the inside balloon to line up with the outside one, so in effect the shutter mechanism vented off excess hot air for quicker handling responses of the balloon. The steel cable was attached to a single cable that ran down the gore seam to the gondola. This was just a bare cable dangling in the gondola, so as to distinguish it from the ripcord cables which had ski-rope type handles attached to them. It was difficult to use this valve when the balloon was ascending because of the terrific pressure built up by the hot air.
The new gondola which replaced the one destroyed in the San Diego Mountains consisted of a large wicker basket about four feet long, two feet wide, and three feet high. This basket proved most versatile, and it flexed much more on impact than would have the aluminum one. However, it was open to the elements which consisted of extremely cold temperatures at high altitudes (about 0 °F) and heat from the burners at low altitudes. There was no breeze to keep one cool at a low altitude because the balloon moved along with the same speed as the wind.
Mounted on top of the gondola on large rattan bows were three different burners. These were of the type used on tar wagons to keep the tar hot. They consisted of a series of coiled pipe through which the liquid propane passed. The propane was emitted through a jet at the bottom of the coils. When the burners were lighted the flame went up inside the coils, thus heating the liquid in the coils to vapor form so that it would burn. Later, pieces of steel were inserted between the coils to spread the flame out, and thus get better heating. This heat exchanger became a problem at high altitudes and it was not uncommon to have large icicles hanging from the burners at twenty thousand feet.
This problem was corrected by connecting a small burner and a large burner together, thus getting better diffusion of the heat. Ordinarily, one small burner ran off of a regulator and two large burners were connected to an instant on-off valve. Connecting one large burner with the small one presented some problems at launching time because the flame would be spread over a greater area, and thus be more susceptible to surface winds than the single burner. The single burner produced more of a “jet” of flame about twenty-five feet in length whereas the two burners combined produced a flame only about ten feet long.
Because the burners were fastened to the top of the gondola it was necessary to rock the basket around on the ground when launching to always keep the flame in the middle of the 10 feet diameter opening, until the balloon contained enough hot air to stand upright. Due to the fact that the gondola weighed about thirteen hundred pounds it was necessary to enlist the help of several by-standers. These people were rather skeptical as the roar of the burners sounded like a jet engine and the heat coming back from them would singe hair and burn faces. Once I became entangled in the cables when the balloon rolled sideways from a gust of wind and I was drawn near the burners, singing the right side of my face, even though l was still a foot from the flame. Thus, I developed a healthy respect for the burners and was always careful to be on the outside of the cables.
When the burners were turned off, they were reignited by a pilot light mounted between them. This pilot ran off of a vapor tap from one of the tanks located on the side of the gondola. The balloon carried a hundred and twenty gallons of liquid propane, which it burned up in four to eight hours. This was below the projected time of twelve to twenty-four hours. Later in Monmouth, Illinois, a rubberized coating was added to the inside of the balloon, thus extending the flying time to nearly ten hours.
Heat was a critical problem, for on takeoff the balloon would sometimes reach a temperature of 350 °F, which was close to the melting point of the fabric (400 °F). With the burners putting out a total of eight million BTU’s, too much elapsed time could cause the top of the balloon to melt. This would have been disastrous at a relatively low altitude, for a parachute would have been useless for the pilot.
The fuel was contained in eight fifteen-gallon aluminum cylinders. The cylinders were placed on plates lashed to the sides of the gondola, and were also lashed to the gondola with nylon rope. A protective hose covering was added to the ropes to prevent excessive chafing of the rope when the gondola was on its side. However, the friction developed by the hose against the tanks was tremendous, making it very difficult to satisfactorily tighten the ropes.
Of the eight tanks, seven of them were liquid taps only, while the eighth had both a liquid and vapor tap. The vapor tap was for operation of the pilot light, and was originally connected directly to it with no regulating device to cut down the pressure of the tank. This setup proved to be unfavorable when a jammed valve allowed the burner to melt part of the balloon as previously described. To correct this, the liquid taps were connected to a manifold using armored flexible hose, which ran to a quick release valve and a regulator. Both sides of the gondola were rigged identically so that in case of a failure of one side the other would act as a backup safety device. Each manifold with its quick shut off valve was connected to one of the large burners on the top of the gondola. These were used for take offs and climbing, as their combined output was eight million BTUs.
Instrumentation in the gondola consisted of a standard altimeter, two rate of climb indicators (one standard, calibrated in thousand feet per minute; the other an “instantaneous” rate of climb calibrated in hundred feet per minute), a radar transponder with variable settings, and aircraft ICD-I60 radio with Omni and ADF, a magnetic compass, instrument lights, a heat sensor in the balloon, a one-hundred-watt business communicator radio, and a citizen’s band radio. Power was supplied by a standard twelve-volt aircraft battery mounted under the pilot’s seat. With the main units being mounted under the seat, the remote-control units were mounted on both sides and in front of the seat by means of tying them onto the rattan basket.
A thermocouple was attached near the top of the balloon, and dangled by its own wires about three feet into the interior of the balloon. The wires ran down a seam between the gores and were attached to a milliampere gauge in the gondola. This was calibrated by the use of a conversion chart to degrees Fahrenheit. This was the only temperature sensing device in the balloon.
The basket had a mahogany floor with two 2×4 runners of wood. There was a large sheet of aluminum taking up most of the floor, this being used for a ground plane for the radio equipment. Holes were bored in the floor and the antennas were allowed to trail out the bottom when the balloon was in flight. To the best of my knowledge the KX-160 and the radar transponder were never used. We were plagued by communications problems in the vehicles due to the vibration and rough terrain. The battery in the gondola was charged after each flight by connecting it to an alternator in one of the jeeps.
As far as handling characteristics went, the balloon had a maximum rate of climb and descent of about nine-hundred feet per minute. However, on takeoff the rate of ascent was held to five hundred feet per minute for the first few thousand feet, and then was dropped down to around two hundred feet per minute. This was to allow time to burn off some of the excess fuel load, and thus lighten the balloon’s take-off weight of about thirteen hundred pounds.
For survival equipment, the pilot carried a tote bag which contained fresh water, food, and emergency equipment. Chest pack chutes were worn to give relatively easy sitting positions to the pilot, as a back-type parachute would have been too cumbersome in the cramped quarters. On high altitude flights of up to twenty-five thousand feet a thermal suit was worn and oxygen was carried. The oxygen container consisted of a large rubberized black bag in which about fifty cubic feet of oxygen was stored at low pressure. The bag was only about half inflated at take off and would become fully inflated at eighteen thousand feet. It had an escape valve so that the pressure could not build up and burst it. The bag was tied to the side of the gondola just before launching. Oxygen was obtained by the use of an oxygen mask. The color of the bag was black so that it would absorb as much heat as possible at a high altitude where the temperature was much less than at takeoff. The weight was the determining factor in using a bag instead of a heavy tank.
My main job was head of the ground crew, although I did get a few opportunities to fly in the balloon as co-pilot. These were low level flights in which we drifted through tree tops and cornfields. When the burners were shut down it was a dead quiet so that you could hear the people on the ground quite distinctly. It was a unique experience, like riding a magic carpet just a few hundred feet above the ground.
The ground crew consisted of three members: Robert Bogan of Austin, Texas; Stewart Toumquist of Minneapolis, Minnesota, and myself. Stew’s main job was to photograph the trip. Bob was Tracy’s brother-in-law. Our vehicles consisted of three jeeps: a Universal, a Wagoneer, and a Gladiator pickup. The Universal was equipped with a power take off winch via a new V-6 engine. For communications, all the vehicles were equipped with business communicators with the Universal having a radio direction finder and a Citizen’s band radio. There was a small converted boat trailer hitched behind the Universal that was used to transport the gondola and balloon. I drove this rig almost thirteen thousand miles in two and a half months in an attempt to keep up with the balloon. The pickup was fitted with a large self-contained camper in which we lived for most of the western part of the trip. In the Midwest and further east the local populace was kind enough to invite us into their homes. Behind the pickup was a trailer that contained our repair equipment and extra fuel tanks as well as oxygen and hydrogen cylinders. The hydrogen was used to send up small observation balloons just prior to launching to get an indication of prevailing winds. Even though we carried extra Propane cylinders we preferred to have a truck refuel the balloon because of the difficulty in removing and repairing the tanks.
All in all, the trip was a full course in hot air ballooning under almost every type of condition possible. Hot air balloons were man’s first manned flight machines, and are today becoming a fast-developing sport. No doubt it will become more and more common to see these graceful globes sailing along above the treetops.
Across The Land On Hot Air – Tracy Barnes talks to Sports Illustrated about the 1966 hot-air balloon trip across the United States.
Tracy Barnes – Learn about Tracy Barnes at ‘BlimpWorks’.