Category Flying and Gliding

If you’re not in the balloon’s gondola during a flight, there’s still a lot of fun you can have as a member of the chase crew.

Chase crews are an integral part of hot-air ballooning, and there are plenty of balloon fanatics who prefer the joy of the chase to the placid dreaminess that the pilot and passengers enjoy in flight. Those who stay with a balloon crew long enough and become good enough at their job sometimes earn a special nickname—“Ace – Chase.”

Plane Talk

As a first-time balloon passenger, you’ll have a ceremonial initiation to look forward to. After your first flight you’ll stand silently in front of your experienced ballooning friends while they solemnly read this poem;

The winds have welcomed you with softness The sun has blessed you with warm hands You have flown so high and so well That God has joined you in your laughter

And has set you gently back into the loving arms of Mother Earth.

Then they’ll have you clasp your hands behind your back and lift a glass of champagne using only your mouth and your teeth. Once you drink down the champagne without spilling a drop and without usingyour hands, you’re a member of the ballooning fraternity.

At the beginning of a flight, chase crew members help haul the heavy equipment out of a truck, lay out the envelope, and help attach it to the gondola. They lay out the ropes and lines that are used to control the balloon during inflation. They attach fuel tanks to the balloon and check the few modest instruments that the pilot uses to keep tabs on the flight.

Chase crew members help hold the envelope open while it begins to inflate, they help passengers and pilot get settled in for the flight, and they hang on to the balloon to provide human ballast as it grows buoyant enough to take off. With an order from the pilot, the crew members release their grip on the gondola, and the balloon is on its way.

Using a combination of road maps, their own notes from scouting trips, a two-way radio linkup with the pilot, and some tips and hints from local residents, the chase crews follow the balloon across the countryside in a caravan of trucks, vans, and cars.

While balloons usually cover the ground far more slowly than a car can travel, the balloon has the advantage of getting to its destination “as the crow flies.” The chase crew, on the other hand, has to contend with traffic lights, dead-end roads, pasture gates, and unfriendly property owners who don’t share a fondness for ballooning. There are even some balloon haters out there, who may have been spoiled to the joys of the sport when unskilled or inconsiderate crews trampled their crops, damaged their property, and generally made pests of themselves.

The very best chase crews can predict the future—that is, accurately judge where the balloon might be heading, and get there first. That gives the crew time to find convenient access roads or at least to get permission from a land owner before traipsing all over his property. Pilots can help chase crews immensely by planning— and executing—a landing within easy distance of a road or vacant field.

Once the landing is made and congratulations are passed around, it’s time for the chase crew and the pilot to lay the envelope out carefully so that it can be stuffed into a bag and stored. The gondola is disassembled and hauled onto a truck. After most flights, the crew pops the cork for a champagne celebration, then heads off for a hearty breakfast to talk about the morning’s adventure.

Most of the time, the landing of a hot-air balloon is pretty uneventful. But the rare exception makes for the stories that balloon pilots tell around the late-night campfires at balloon festivals.

When the winds are strong, balloons can be smacked around pretty badly during landing. The gondola can hit the ground hard, then be dragged for hundreds of feet before the hot air can be vented and the envelope comes to rest. Rocky terrain can toss passengers and pilots around like dolls.

Sometimes the winds pick up unexpectedly, and there aren’t many options but to get the basket on the ground as quickly and as safely as possible. Depending on the geography, that could mean coming down in a pasture, where cow flops put a whole new twist on the definition of a landing hazard. Sometimes, the landing takes place in a cultivated field, flattening a swath of marketable crops in the process.

Turbulence

Do you think having a parachute on your back would make bal­looning a little safer? Think again. Most experts say that a parachute fall should begin at 2,000 feet above the ground. Balloons sometimes don’t get much higher than a few dozen feet Also, because of their large surface area and wind resistance, bal­loons don’t fall very fast even at their worst

Perhaps the most dangerous landings happen near cities or towns where balloons are forced down in a residential area. It seems a summer doesn’t go by that the local headlines don’t include some sort of ballooning mishap such as a landing on a residential street or in someone’s swimming pool. In some cases, injuries can result, but they’re usually no more severe than a few bumps and bruises.

When a balloon pilot runs out of propane and hot air, it’s time for a landing—no matter what lies below. That’s why balloonists keep a little fuel in the propane tanks just in case. There’s no feeling like being out of fuel and headed straight toward a Saguaro cactus or a radio transmitter antenna as you approach to land. If you have fuel left in the tanks, a few seconds of burn will slow the descent just enough to clear a dangerous obstacle. That’s why pilots land with as much as 40 percent of their fuel still in the tank. It just doesn’t make sense to push the limits of safety.

When the time and location are right for a landing, the pilot begins to let the air cool in the envelope. The balloon starts down, and with short blasts on the burner, the balloon enters a controlled descent of about 600 feet per minute, give or take 200 feet per minute. When the balloon is very close to landing, the pilot uses the burner to slow the descent rate to a gentle 100 feet per minute when it’s time to touch down.

When selecting a landing spot, pilots have to keep two important questions in mind: Is there enough clear space downwind for the envelope to deflate, and can the chase

crew get to the balloon from a nearby road without too much trouble? (We’ll take a closer look at the chase crew later in this chapter.)

When considering whether there is enough downwind space for the envelope to deflate, the area required depends on the wind speed. If the wind is fairly calm, the balloon will descend nearly vertically and the gondola, will often remain upright after landing. In such a case, the landing should be planned for a clearing that provides at least 70 feet or so of clear space downwind so that the envelope can be conveniently laid out, deflated, and prepared to be packed away.

If the wind is blowing much faster than a couple of miles per hour, the pilot has to plan for a larger clearing in which to land. That’s because the wind will drag the balloon over the ground for some distance after it lands. When it’s windy, a balloon could take as much as 1,000 feet to come to a full stop with the deflated envelope laid out along the ground.

Balloon pilots soon get on intimate terms with the wind. Most of us think of gusts and breezes, if at all, as having an unpredictable, capricious nature, but to a balloon pilot, they follow some rules of thumb. Once you become a balloon pilot, understanding these wind patterns will become almost second nature:

• Day, or anabatic, wind. Don’t sweat the Greek word. Anabatic simply means uphill, and anabatic winds are the wind currents that sometimes flow uphill when daytime sun heats a south-facing hillside or mountain slope that gets full sunshine. Because anabatic winds often flow in a different direction from higher-altitude winds, balloon pilots can use them to steer course, though with plenty of caution.

• Night, or katabatic, wind. Three guesses what this one means. That s right, katabatic winds are the downhill breezes that develop after sunset when the uphill anabatic winds lose energy. Katabatic winds can be deep and powerful, so pilots usually give those south-facing slopes a respectful margin.

•Ridge waves. These can cause a bumpy ride, but they’re usually not hazardous. As their name implies, ridge waves are winds that are flowing perpendicular to a series of ridges; they can rise and descend in waves that resemble the gradual upward and downward pattern of sea swells.

•Valley wind. This is a fun wind pattern for most balloon pilots because it can allow them to turn on a dime, or on what passes for a dime in ballooning circles. Wind flowing in the deepest part of a valley tends to parallel the valley’s trough, and if the wind aloft is crossing the valley at a perpendicular angle, a descent into the valley wind can cause the balloon to turn sharply, a relatively spectacular maneuver in a sport where direction changes generally happen slowly.

There are other wind patterns, and the more experience a pilot has in ascending and descending, the more variations on the basic wind patterns he will add to his mental catalog.

Once in the air, the pilot controls the balloon’s altitude by firing the burners to rise into the winds blowing in one direction or permitting the balloon to cool in order to descend into the winds blowing in another direction.

The wind is everything to a balloon pilot. It determines not only the distance a balloon will travel in the time it takes it to use all its propane fuel, but it also determines where the pilot should take off from. That’s right—a balloon pilot doesn’t necessarily start his flight planning by thinking about where he will land. Sometimes the planning process runs backward.

The Plan

Let’s say a hot-air balloon pilot wants to make a flight that lasts about an hour, and he wants to land in Uncle Herman’s pasture. The planning process doesn’t begin with the question of where to take off from. Instead, the pilot, using the best weather information available from government agencies and reports from other pilots, starts his planning by figuring out the winds at different altitudes and tracing backward. Based on the winds near the ground and the winds aloft, where would a balloon have to take off from to fly over Uncle Herman’s spread one hour later?

Once the answer has been calculated carefully, the balloon pilot can lay out his maps and begin to calculate his takeoff point. That’s where he and his crew drive their trucks, vans, and trailers and begin the task of launching the balloon.

Other times, a balloon pilot decides his course based on where he wants to take off from and how long he wants to stay aloft. Using maps and carefully studying wind information published by the weather service, the pilot plots the location where the balloon will probably come down. With an X marking the spot, he discusses driving routes with his ground crew, and a plan is laid out to get the envelope rolled up and get everything stowed in the chase truck.

But in most cases, pilots and chase crews simply enjoy the mystery of not knowing where a flight will take them. They find a convenient launch site, send up a small helium balloon to test the direction of the wind above the ground, and take off. Once in the air, the pilot begins planning his route and, later, identifying good landing sites. Meanwhile, on the ground, the chase crew does its level best to keep up.

Now that we’ve heated the air inside the balloon’s envelope using the burners, let’s look at the physics behind what makes the balloon actually fly. The whole thing goes back to a Greek math whiz named Archimedes. According to legend, Archimedes stepped into a too-full bath and had a flash of insight that balloonists can relate to.

When Archimedes stepped into a tub that had been filled to the rim, he noticed he became lighter and lighter as more of his body went under the water. Not only did he seem to become lighter, but the water level rose and spilled over the edge of the tub as he sat down. In an inspired moment, Archimedes understood that the amount of weight he seemed to lose was equal to the weight of the water that spilled out of the tub.

The first thing Archimedes did was jubilantly holler, “Eureka! ” (“I found it! ”) as he ran naked through the streets of Syracuse, Sicily. The next thing he did was write down what we know as Archimedes’s principle A body immersed in fluid loses weight equal to the weight of the amount of fluid it displaces. Because air is a fluid—or rather, a gas that behaves like a fluid—Archimedes’ principle applies to balloons.

Let’s say the envelope of a balloon holds three tons of air when fully inflated. Now, let’s say that air has been heated by a few million BTUs of propane flames until it is good and warm and, as we’ve seen, a little lighter. Instead of weighing three tons, it now weighs only two and a half tons. It’s still occupying the same volume as three tons of unheated air, though, so the balloon is about a half-ton, or 1,000 pounds, lighter than air. It’s ready to fly!

Liftoff!

Once a balloon crew, usually four to five people plus a pilot, arrive at the launch site, they begin a takeoff ritual that can take anywhere from a few minutes to a half­hour to complete.

First, the envelope is laid out on its side and connected to the gondola, which is also laid on its side. While a pair of crew members hold the mouth of the envelope open, the pilot begins to inflate the envelope using a cold-air fan. The cold-air fan opens the balloon’s envelope enough to allow the pilot to walk into it to inspect the fabric of the envelope and the interior rigging and pulleys. The ropes that snake through the pulleys operate the fabric panels in the balloon’s crown that can be opened to release hot air quickly, either for a rapid descent or to keep the balloon on the ground after landing.

The inspection complete, the pilot gives his assignment orders to the chase crew. Some will be needed to hold the gondola down as the balloon inflates and lightens. Others will have to grab hold of the crown rope that hangs outside the envelope from its top center. The chase crew is crucial to keeping the balloon steady as it bobs in a downwind direction while inflating.

As the balloon envelope gets closer to full inflation and liftoff, the pilot helps the passengers into the gondola and gives them a safety briefing before the crew lets the ropes loose.

If you’re even the slightest bit ; squeamish about heights, you may want to ease into hot-air ballooning before taking a full flight Airplanes have a cabin structure that lends a sense of security and reduces the sense of vulnerability. To test your reac­tion to a balloon night, take a tethered flight that ascends only a few dozen feet off the ground.

But the takeoff isn’t complete yet. As the balloon gets lighter and lighter, but not ready for actual takeoff, the pilot will order “hands off.” He wants to get a feel for the balloon’s buoyancy and test the effect the winds might have on it when it lifts off.

The pilot orders “hands off” once more, and continues to inflate the balloon to its full buoyancy. Once he is certain the winds are safe and the balloon has enough lift to clear any nearby trees, buildings, or hills, the pilot orders “hands off” one last time, and the ground crew lets go. The balloon is flying!

When the balloon lifts off, the ground crew’s job is just beginning. They jump into cars, trucks, and vans and race downwind, maps and walkietalkies in hand, to try to keep up with the balloon and arrive at the landing site before, or at least very shortly after, the pilot lands.

What makes a hot-air balloon fly? The answer couldn’t be any simpler: Warm air rises. Period.

Of course, the details of how to generate the heat, harness the hot air, and control a balloon in flight make the sport of ballooning a far more complex matter. But the underlying principle is simple enough.

The Air That You Heat

If you weigh two equal – size parcels of air that are at different temperatures, the warmer one will weigh less. For example, if you fill one large trash bag with cool air from your basement, and fill another one with hot air from the attic, the one filled with attic air will weigh less. Of course, a trash bag only holds a couple of cubic feet of air weighing about a pound, so you’d need a pretty sensitive scale to measure the tiny difference!

But when you start talking about a bag of air holding from 70,000 to 100,000 cubic feet of air standing seven stories high or taller, and measuring more than 50 feet across, the difference in weight becomes considerably more measurable. And on this enormous scale, the buoyant effects of warm air are amplified exponentially.

The air inside a hot-air balloon is heated by propane flames shooting from the nozzles of liquid propane gas tanks. The tanks range in capacity from 10 gallons to 20 gallons each. Burning between 30 and 40 gallons of propane per flight, the burners generate 10 million to 30 million British Thermal Units, or BTUs.

The flames generated by the propane burners keep the air inside the balloon’s envelope much hotter than the surrounding air even on a warm summer day. The difference in temperature between the air inside the envelope and the air outside it becomes even more pronounced in the cool hours of the morning and evening, when balloon pilots prefer to fly because of generally calmer wind.

The Envelope, Please

The balloon’s envelope is coated with a layer of polyurethane impregnated with chemicals like silicone or neoprene to fill in the natural pores in the cloth and hold in the hot air better. The air inside a balloon reaches temperatures of over 200°F—pretty hot, but not hot enough to ignite the envelope material. Often, designs, logos, or slogans are placed on the outside of the envelope using an applique technique that lets balloon owners and sponsors create words and designs large enough to fill a billboard. As we touch on later, the sport of ballooning is not exactly immune to the commercialization craze.

There’s a dang good reason that you don’t see as many helicopters taking off and landing from your local airport on a sunny summer day as you do airplanes and gliders: Helicopters are too expensive for almost anyone to afford. In fact, pound for pound, helicopters are undoubtedly the most expensive form of aviation around—not counting Pentagon-funded military aviation, of course.

Even the smallest helicopter model now in widespread use, the two-seat Robinson R-22, will set you back almost $160,000 fresh off the factory floor. Its slightly larger cousin, the four- seat R-44, sells for more than $280,000. For true rotor-heads, nothing is going to get between them and the helicopters they love. But the “inexpensive” R-22 boasts a top safe speed of less than 100 miles per hour, far slower than any airplane being produced today.

Helicopter flying lessons aren’t cheap either. The price of the Robinson R-22 plus an instructor for an hour runs $170 or more. Rental of a truly powerful helicopter, a Bell 206 Jet Ranger, costs $625 per hour, and that’s an instructor. In addition to the cost of the helicopter and instructor, the costs that we outline in Chapter 13, “Getting Off the Ground: Becoming an Airplane Pilot,” apply to helicopter students as well.

Still, there’s something to be said for an aircraft that’s capable of landing almost anywhere it’s legal and safe to land, from a deserted beach to a mountain meadow to a desert mesa. That’s the capability that helicopter pilots love, not to mention the challenge of flying a craft that is among the most difficult in the sky to fly really well.

Chapter 11

Up, Up, and Away: Hot-Air Balloons

In This Chapter

, V Ballooning and a Greek philosopher ^ From liftoff to landing >- Reading the wind

^ The surging popularity of hot-air ballooning V Helium balloons circle the globe

Balloonists became the first true aviators when the Montgolfier brothers invented the hot-air balloon in the eighteenth century. From the day the Montgolfiers staged their balloon demonstration for Louis XVI and Queen Marie Antoinette to the late nineteenth century, when people tried to motorize them with primitive gasoline engines, balloons were literally the only way to fly. (For a review of the role of balloons in the history of flight, turn to Chapter 1, “The Earliest Aviators.”)

With the turn of the twentieth century and the Wright brothers’ invention of the airplane, however, interest in balloons faded. Only recently has ballooning—and its close cousin, blimp flying—experienced a renaissance, thanks in part to advertisers, a historymaking world-circling flight by a brave team of aeronauts in 1999, and a group of flyers in a field outside Albuquerque, New Mexico.

Helicopter engineers are at work at labs and airports all over the country trying to refine and improve helicopters. One man, Ron Barrett, has invented a new electronic method of controlling the pitch of helicopter blades.

Barrett devised a combination of materials that contort when exposed to an electric field, a characteristic known as piezoelectric elasticity. He discovered that by applying small electric charges to a series of precise points along a helicopter’s rotor blade, he could cause the blade to twist to control the lift it produces.

The Barrett blades could reduce the number of parts in a helicopter’s hub dramatically. Already, in a test model, a hub using 94 parts was replaced by one needing just five. If the technology ever finds its way into commercial use, it could dramatically reduce the high cost of inspecting and maintaining helicopter hubs.

Another man, James Cycon of Sikorsky, found a new way to stack the blades of a helicopter. Instead of one main rotor and one tail rotor, Cycon simply stacked two blades rotating in opposite directions, thereby canceling each other’s torque. The result was a flying doughnut of sorts. Both rotors are shrouded inside a covering that protects the blades, meaning that the unmanned craft, which Sikorsky called “Cypher,” can fly into forested areas, for example, without being damaged by tree branches or other obstructions that could bring an ordinary helicopter crashing to the ground.

Perhaps the most pervasive myth about helicopters is that when they lose engine power, they’re doomed to crash. In reality, a helicopter pilot has plenty of landing options open to him if the engine goes south—but he has to be on his toes.

Even without engine power, helicopters can glide to the ground using a principle called autorotation. But it’s a maneuver that requires a lot of skill and a refined sense of timing, and pilots have to spend many hours practicing such landings.

When the engine is working correctly, it pulls air from above the main rotor and accelerates it downward using the angled blades of the rotor to generate lift. When the engine fails, though, the pilot must control the helicopter so that the direction of the wind through the rotor comes from below. That wind helps keep the rotor turning and producing enough lift to allow the helicopter to glide.

As the pilot nears the ground for an autorotation landing, he doesn’t have any engine power, so he has to make his one landing attempt count. Just before the helicopter reaches the ground, the pilot uses the cyclic pitch control to tilt the rotor toward the tail. That motion allows the rotor to generate extra lift for a few moments and slows the downward speed. The pilot must have accurate timing. If he’s done it right, that extra lift comes just in time to set the helicopter down safely. Good pilots make it look easy, but an autorotation landing can frazzle a student pilot’s nerves.

Plane Talk

Actor Harrison Ford learned firsthand how risky autorotation landings can be. In summer 1999. he and a flight instructor were practicing the maneuver at a small airport northwest of Los Angeles when something went wrong. The helicopter, a Bell 206 Jet Ranger, crash – landed in a dry riverbed and toppled over on its side. The actor and his instructor both walked away from the crash.