If not for a technical failure, Dick Rutan might have set another world record in the 20th century...

Type: manned high altitude balloon system



Significant date: January 1998 (first flight)

In the autumn of 1997, Interorbital Systems was contracted by Dick Rutan to design and construct 20 pressure-fed propane tanks to provide fuel for the burners of the World Flight WF-1 Global Hilton manned high altitude balloon system. This used a Cameron R-420 envelope, while the 8ft-diameter carbon-fibre sphere, built by Scaled Composites Industries and pressurized to 12,000 feet altitude equivalent, featured a single pilot station and private sleeping quarters for the two crew members to take rounds. The Global Hilton Project represented Interorbital Systems' first man-rated flight system. At the cold temperatures (as low as minus 100° F) found at the balloon's operating altitude above 40,000 feet, propane looses the vapor pressure it has near sea level and cannot flow without assistance. A nitrogen pressurant system provided the boost required to get the propane out of the tanks under these extremely cold conditions. The tanks held 5,000 pounds of propane.

The two pilots of the Global Hilton hot air balloon, Dick Rutan, 59 (who had previously designed the Aeolus 1 for the same purpose), and Dave Melton, 39, attempted to circumnavigate the world nonstop, but free-fell before opening their parachutes and landing in good condition about 100 miles (161 kilometers) away from the take-off site at Albuquerque, New Mexico, after a technical problem dashed their plans. During ground and flight operations, the IOS tank systems had performed flawlessly, but during the flight, a helium cell in the top of the silver balloon ruptured at an altitude of about 9,000 meters (30,000 feet).

Nineteen of the original twenty tanks survived the crash virtually intact. The Rutan team was reportedly "very impressed" with the ruggedness of Interorbital Systems' hardware. Roderick Milliron, president, co-founder and chief scientist of IOS commented, "The requirements of a high-altitude fuel delivery system for the balloon were met with the direct application of the lightweight fuel tank technology and propellant delivery systems we'd already developed for use in our sounding rockets and satellite launch vehicles."

The $1m (£613,000) attempt at one of aviation's last frontiers was the third by a balloon team since December 31, 1997. Chicago millionaire Steve Fossett, whose fourth round-the-world bid ended on the edge of the Black Sea, speculated that a successful trip might need a pressurized capsule. His balloon, Solo Spirit, did not have one. "I'm a little bit discouraged, but nevertheless it was a good flight and so I have to be satisfied with having made a good flight across the Atlantic and made it one third of the way around the world." Fossett had hoped to break his own record of travelling 10,361 miles (16,675 kilometers) in a balloon, or his record for longest flight—six days and two-and-a-half hours. Those records were set in January 1997 when he was forced to land in a mustard field in India after running out of fuel.

January jet streams provide an ideal time to fly. But come February, thunderstorms build and weather conditions become less favourable, said Rutan. "Really the only time to attempt to go around the world is in January. This is when the winds are incredibly strong and the jet streams can go up to 2 or 3 hundred miles and hour. What we are trying to do is to tuck our balloon into the core of one of those jet streams and try not to get into an eddy on the edge where you would go nowhere", said British tycoon Richard Branson, whose attempt was foiled when his Virgin Global Explorer was ripped free by a strong gust of wind. Another balloonist, Kevin Uliassi, left Loves Park, Illinois, on New Year's Eve but an equipment problem forced him to land a few hours later in Indiana.

There are generally two different approaches to the challenge: low-tech low altitude flights and high-tech higher altitude attempts. Cameron Balloons of Bristol, England were involved in both, having designed four of the competing vehicles. Jim Howard, their production director, described these options: "The high-tech high level attempt, you have to produce a capsule which you can live and breath in for up to 21 days; a sealed capsule which is pressurized. The high altitude on the face of it would appear to be the best bet. The lower altitude balloon, you are more likely to encounter different types of weather and be blown off course and other things."

But there are drawbacks to using a more technical balloon, as Don Cameron of Cameron Balloons pointed out, before launching their Breitling Orbiter."This can be an advantage and a disadvantage. It should have better performance, being able to go higher, but with more untried experimental equipment, there is a risk of things going wrong." And on top of the technical problems are the dangers of severe air turbulence and lightning strikes, and the accumulation of ice which forces balloons to make regular excursions into lower and warmer altitudes to melt it.

So in the face of all these difficulties, is it really likely that a team can succeed? Jim Howard is convinced it is only a matter of time. "It isn't just a stupid dream. There are many unmanned balloons that have travelled around the world and come back again. What we do know is it will be done." Anheuser-Busch offered $500,000 (£307,000) to the first person or team to circle the globe in a balloon before December 31, 1999, along with $500,000 to the charity of the winner's choice. In December 1998, Dick Rutan was back with a new ship, the Model 6 DLS World Quest, and a new sponsor, but the same old team. The balloon was now a cluster of 4 AS Superpressure helium balloons.

Yet none of the contenders successfully met the Anheuser-Busch challenge before deadline. Eventually, the round-the-world record was broken in 2002, but by Steve Fossett, in 320 h 33 min, with a Cameron R-550 balloon.

Population: 1 (c/n 001) [N298AR] (former G-BXKG)

Specifications (Cameron 420 balloon):
Design: Rozière
Height: 170 ft.
Volume: 500,000 cubic ft.
Fabric: Poly helium cell with mylar skin
Launch site: Albuquerque, NM, Balloon Fiesta
ParkLaunch Window: January-March 1998
Cruising Altitude: 32,000 and 36,000
Duration: 9-14 days
Speed: 100-200 mph

Specifications (World Flight capsule):
Fuel: quad burner propane system
Diameter: 8 ft. (sphere)
Total weight of balloon: 2,000 pounds

- Inmarsat satellite communications
- VHF-HF-GPS-Radar Altimeter
- 406 MC satellite recovery beacon

Main sponsors: Barron Hilton, Hilton Hotels, Pepsi-Cola

Crew/passengers: 2

Main sources:
- Interorbital Systems
- PBS online
- BBC News (link 1) / BBC News (link 2)
- Global Hilton: An interview with Dick Rutan

Dick Rutan goes back over the Global Hilton adventure

BALLOON LIFE: Was designing the capsule the first step that you took in planning the around the world flight?

DICK RUTAN: Don Cameron told me that there was no problem with the envelope. I figured our discipline was a little bit more advanced to build the capsule. We do structural airborne pressure vessels with wings. I was the first to recognize that I didn't know anything about an envelope. Frankly, I was pretty naive about how balloons even worked. But, I was a quick learner. Steve Fossett and I went to Bristol [England] and went through a Rozière pilot training course. We spent a week with Don Cameron's people and we learned all about Rozièree flying. That was the year before Steve flew the Atlantic with Tim Cole. I spent about three years trying to find a sponsor. During that time I built an altitude chamber and we did all the testing and development of this particular closed loop life support system. Last year we were fortunate enough to receive sponsorship and we teamed up with Richard Abruzzo. Finally convinced Barron [Hilton] to put up the funding for Global Hilton.

BL: At what point did you investigate the feasibility of weather patterns to go around the world?

DR: For about three years I would sit down three or four times a week and copy the jet stream pattern. I watched them develop, break apart in the summer, and then redevelop in the winter time again. So, I thought that I had a pretty good feel for what that was all about. I call the jet stream the race course. So far, all of us, have gotten in the pits, some are spectators around the outside, some of us actually built the race car, and on the way taxing to the race course from the pits we have problems. Nobody has even got to the race course yet. If you don't count Steve working the jet stream, which I don't. My opinion, the real challenge is going to be dealing with the core of the jet around the world. I don't think that anybody as done that. Breitling sure didn't. Steve was never high enough. All the rest of us, we can't even get to the race track.

BL: How big a problem is political considerations?

DR: There has never been over fly problem in any balloon in the world, period. Libya every time granted Steve over flight permission. Both times. Everybody who ever asked Libya, it was approved. Even China approved Breitling overflight, so that wasn't a problem either.

BL: Once the equipment was ready you pretty much took off the first good available day for launching and upper level winds in Albuquerque?

DR: We were supposed to be ready on [January] 5. That's what we had planned for months. The surface conditions were not favorable for a good launch. They were better on the next day. On January 6 I think a lot of people were tired and stressed. Just before inflating I went and canceled to wait for a couple of days. As it turned out people were a lot more rested and had learned a lot more [in those few extra days].

BL: Describe how the flight progressed after take off. And, what was your rate of ascent since there has been great speculation about that?

DR: There has been a lot of speculation that we took off too quick. Also speculation that Kevin [Uliassi] took off to fast. Don Cameron came out here during the accident investigation. I said, if we took off to fast and ruined our envelope and caused our own problem explain that to me. And, of course, there is no explanation for what failed compared to [how] we took off. Probably we did take off a little hot, initially. I have looked at the barograph trace. There were two inversions that we had to go through. In them we actually descending a little bit. We were going up fast. Dave started valving off helium. Then we got it under a real normal rate. We had an average climb rate to 27,000 feet of 362 feet per minute. Once we got out of 10,000 feet we pressurized the cabin. Dave had it under good control all the way up. In fact we just eased into 27,000 feet. We had been level for 12 minutes. We even descended 100 feet. We were perfectly level. We didn't go blasting through float altitude. Although it shouldn't have caused a problem anyway. Then it blew up.

Everything was operating normal. I was really encouraged. After 12 minutes of being level there was a moderate whoosh and a bounce. We looked up and probably a good 50 percent or more of the bottom membrane was totally gone. There wasn't just a rip in the bottom membrane. It was many tears all the way up. Six or eight or more radial tears from the center point of the membrane to where they joined the hot air cone and preceded on up to the top of the envelope. It kept creaking and popping. Then there was one really loud creak that made my determination that we were going to bail out. I flew in a gas balloon once that had a little leak in it. The balloon rotated. Just like any leak, even in a hot air balloon, it acts like a turning vent. With the large crack the balloon started rotating and I could see the horizon going by probably a degree per second. At that point I knew that the structural integrity was in question. If we had just torn the bottom membrane out Dave and I could have flown it to maybe Europe. When you start getting pops and creaks and tears and radial tears up to the top and the balloon starts spinning on you, all of a sudden your options start vanishing. As soon as it blew we declared a May Day. The [balloon] climbed to 31,000 feet just on its own.

BL: Why with the tear did the balloon climb?

DR: The helium cell was under pressure. If it had not been under pressure when it blew up it wouldn't have climbed an inch. When the gas cell ruptured the gas expanded down into the hot air cone which gives you more helium in volume. The balloon climbed. Right away Dave pulled on the helium valve which started a slow descent. Through about 12,000 to 15,000 feet we started to depressurize. Took the top hatch out. Dave took some photographs of the top of the envelope from the bottom. That has been helpful for the NTSB to look at. I think that it was almost two hours later that we decided to abandon the balloon. So it wasn't a decision we made in the heat of the moment. It was under a lot of consultation with the people on the ground. We worked the problem out discussing what was going on and what we were seeing. What it looked like and what our options were. We were going to take it down and land it. It was going to be a heavy weight landing. Dave is really good. The winds in eastern New Mexico were 20 to 25 knots. I asked what the wind speeds were down track and they were all getting worse. To try and land this heavy weight thing with structural problems and still full of fuel, that wasn't a very good option. We thought of dropping propane tanks one at a time. You open the helium valve until it starts down and then jettison 300 pounds of propane. That is a big shock and the balloon ascends again. Vent helium until it comes down and you drop another one. Since we heard this ripping and tearing, especially this last real big creak there was concern if we jettison one of these tanks it could put a shock load up through the balloon and may even rip it and we wind up being a streamer. That was a concern. So all of our options just kind of vaporized and it became evident that we were going to have to abandon [the balloon]. We talked about all this with the people on the ground. We had some good people on the ground. Richard Abruzzo, Mark Sullivan. Really experienced. We decided to bail out.

BL: You have been widely quoted in the press that you told a police officer that the decision to bail out was "Because the rivets were popping."

DR: No, I don't ever remember saying rivets were popping. I don't come from that aluminum world and rivets are not part of my psyche. I am a composite person and I don't hardly ever deal with rivets. You know after all these years [Don Cameron] says that there is no problem with the envelope. The problem is with the capsule. Then he sells me a balloon that comes apart.

BL: Will you buy another Cameron envelope?

DR: Remains to be seen. Need to find out what went wrong. Somebody from there is going to have to tell me what went wrong. I haven't heard a word from anybody at Cameron as to what happened. Don came out and looked at everything. It has to be either operator, design, or material. Those are the only options that there are in why the envelope failed.

BL: How much different is your envelope different from Fossett's, Breitling's, or Uliassi's?

DR: My understanding is that they are all the same design. Same design and same material. They were just upgraded from 270,000 cubic feet to 420,000 cubic feet. That is what I was told by Cameron. Same material, same construction methodology but ramped up. All three, Breitling, Uliassi's and ours.

BL: Have you started building your new gondola yet?

DR: You bet. Not physically but, they are doing a concept in scale. Putting together next year's budget for Barron [Hilton] and we are looking for another envelope. This time I am going to be a lot more interested in structure, testing, and material then I was last time. You understand that whole thing was Richard Abruzzo's responsibility. He was the balloon expert not me. That was why Dave Melton was flying this thing and I was just backup. When we got in the balloon I said, "Dave nobody has flown one of these things. You have got all the experience. You sit in the seat and fly it. I will take care of everything else, all the radio calls, all the housekeeping. You just concentrate on flying this thing and learning how it works." Dave is really good. I don't have any criticism with Dave's flying. He leveled us off right below float altitude. The sun was coming up and I was concerned that as the sun heated us up we were going to ease right up into equilibrium at float and spent the rest of the day housekeeping and getting use to our new home for the next two weeks. Another lesson learned for us is that we have to have a positive termination method. The balloon should land and stay there within a mile after the crew bails out. Otherwise you needlessly endanger people on the ground and we can never do that again.

BL: Will Dave continue in the project with you and how is he doing??

DR: Yes. I asked Shelly, his wife, if she would like to do it again. At the time she was looking at her husband who was laying in the hospital in traction and ready to go into surgery. She said, "I can't imagine not being part of something like this." They are really neat people. [Dave] is home. He went home about a week early from the hospital. He is in a brace.

BL: How does Barron Hilton feel about all this?

DR: Well, Barron Hilton was pretty upset as you can imagine, very concerned about this unmanned balloon heading for Dallas, Texas. But, he understands that particular thing won't happen again. We will go to great length to make sure. First of all the next balloon envelope that we have we are going to test it. Structural load test. We will change some things, minor things on the capsule. Nothing major. Will have fewer propane tanks and bigger. Instead of having 20 tanks we will only have a dozen tanks. Money is not in the bank. But, I feel confident that Barron will continue with our project. If he doesn't then I will find somebody else. As far as I am concerned we are going to do this again. I am not going to quit on this thing. If I have to make the balloon out of tissue paper we are going to do it.

Full interview from Balloon Life available here.