I had participated in the last 15 annual BALLOON WEEKS at Chateau d’Oex, Switzerland and although I made some flights over the Alps (West to East), I had never crossed the Alps from North to South into Italy. So again this year, my crew and I were ready to go at the first opportunity. We planned a Long Jump, with the goal set at 300 km (180 miles), which would make our flight a new national distance record (Luxembourg).
After waiting for three days in heavy rain for a suitable weather pattern to develop, we finally got a low pressure system (970 hPa) over the north of Ireland and a high pressure of 1035 hPa sitting to its south over the North Atlantic, giving us winds from 320-340 at 4000-6000m (13000-19600 feet) with 40 to 60 knots. We had unlimited visibility, and meteorological conditions perfect in Italy with a forecast 10 knots maximum ground speed, and no major changes expected until 18:00 local time. A heavy turbulence warning over the Alps had been issued, but our planned altitude was well above it.
The balloon was a standard Cameron A-105 of 3000 cubic meters loaded to 100 kg of its maximum permissible weight, and as Swiss regulations require a second pilot on board for such flights, I was happy to have my friend Jules Backes, also a certified record observer from the Luxembourg National Aeroclub, come along as observer and safety pilot on this flight.
160 kg of propane was carried in 8 stainless steel cylinders, of which 2 were sealed, only to be used in case of an emergency, and all were methane-pressurized to 7 bars. The equipment on board included a 9 liter "on demand" oxygen system (giving a 4.5 hour autonomy at 3 liters/minute/person) with three masks, 3 VHF radios, GPS, Mode "C" transponder (altitude encoding), ELT (emergency locator transmitter), PC- Barograph, Ball 655, and a spare standard aircraft altimeter. Additionally we carried a complete set of high mountain survival gear.
The balloon was inflated, and after receiving the launch "green" from the competition official, we lifted off at 08:43 local time. As Chateau d’Oex is a well- protected site, the takeoff was made in calm conditions. According to our plan we used the lower westerly winds to drift east climbing at 400 ft/min, and caught the northerly winds over Gstaad. This allowed for a perfect route between the Monte Rosa (4634m - 15200 feet) and the Matterhorn (4477m - 14688 feet) into Italy. As our go/no go decision was 5 miles north of the Rhone Valley (our last opportunity to land before being definitely committed to the Alps crossing), all systems were re-checked during the initial climb. Having found no problems, I confidently decided to continue.
At 09:00 we contacted Geneva Radar. We were cleared to climb to our requested FL 195 (19500 feet). At 09:11, 28 minutes into the flight, at 15000 feet (-15 C) right over the Rhone Valley, we experienced our first problem: flameout on both burners (Cameron MK4 Super with vapor fed pilot-flames). After having desperately tried to re- light one pilot-flame, I ended up re-lighting one silent burner with my lighter, igniting the main burners with the silent burner, and the pilot-flames with the main burners. This experience cost us 2 minutes, some adrenaline, and a drop of a few hundred feet.
At 09:15, back at 15000 feet, we had our second flameout on both burners. This time I managed to re-light the burners in less than two minutes (I guess I was expecting this one) and we resumed our climb to FL 195. I was beginning to worry about this situation when we lost the two burners again going through 15000 feet. By this time we had run out of landing opportunities and were committed to continue. I managed to re- light the burners again by way of the silent burner, but this time the pilot-flames would not stay lit. After having frantically tried for a few minutes to readjust the regulators on both burners, I realized by now that we were in real trouble. We were right on track for the highest peaks at 15000 feet and traveling 47 knots, but a safe crossing was not possible below 19500 feet if we wanted to stick to the rule that you need to clear the peaks by at least 1000 feet for each 10 knots in wind speed to stay out of the severe turbulence.
I decided to use a silent burner as a pilot-flame, knowing perfectly well that this was a very unsafe option for the whole flight, as the valve would eventually freeze and start leaking. At 09:43, having reached 17600 feet, the valve did start leaking and caught fire. As I had prepared for this, I did not have any problem putting an end to the fire at the valve. But I had not foreseen that the valve had dripped quite a puddle of fuel on the basket cushion floor. This fuel, thanks to a burning drop from the burner, had also caught fire and was quietly licking at our feet. I was really surprised to see this happen, and in my nearly 20 years in ballooning, I had never seen or heard of such an occurrence. Stunned, with both burners out, and fire on board, down we went.
The fire was rapidly extinguished and our concentration was back to the burners again. I managed to re-light and decided, as a last resort, to leave the silent burner at rest and to keep the main burners going alternatively with short burns from now on, re- lighting the left one with the dying flame of the right one, and vice versa. Adding to our problems, I realized that we did have a tremendous fuel consumption.
We were already on our two last unsealed cylinders, leaving us an estimated maximum endurance of little more than 60 minutes. At our actual speed of around 35 knots, this was clearly not enough to get over the Alps and make a safe landing in Italy. While Jules was at the burners trying to go for FL 195, I was sorting out our remaining options. As it was out of the question to make a safe landing below, I decided to go looking for higher wind speeds at levels above FL 195. I contacted Milano on VHF and asked for clearance to FL 240. To my greatest surprise the controller readily agreed and even asked me to switch off my transponder - as he was getting too many blips on his radar screen!
At 10:00, while on our way up to FL240, the Ball 655 quit. Our standby altimeter and wristwatch became primary flight instruments. At 10:12, we reached FL 240 and found a wind carrying us along at 50 knots. I was pretty confident we could make it if we could stay at this altitude long enough. The temperature was -36 C, but the sun was shining, so we did not feel the cold at all.
The Monte Rosa, the Matterhorn and the Italian border were coming up very fast now and the view over the Alps was spectacular. Alas, we had no time to enjoy it as at 10:13 both burners abruptly quit. Down we went, and fast (7000 feet in 4 minutes). This time we were in real trouble as we were coming down exactly over the highest peak in the range - Monte Rosa (15200 feet). The burners re-lit in time to level out at 17000 feet. The recovery had been remarkably fast and the ensuing climb was a bit of a surprise to us, but not for long. After a smooth climb at 400 ft/min for 4 minutes, the balloon started to shudder violently and tilt, and down we went once again. This time the burners had not quit, but we had been caught in the severe turbulence just above the Monte Rosa.
We came out of this chaos at 16000 feet with roughly 40 kg of fuel left and still a long way to go to find a safe landing place. The terrain below was still snow-covered peaks with deep and narrow valleys in between. We knew that we had to go down and we expected to make a new encounter with the turbulence. We opted for a moderate descent rate of 600 ft/min in order to get out fast if necessary. At 13500 feet the descent stopped abruptly and changed into a moderate climb for two minutes. This time we waited for the associated fast acceleration and braced ourselves for what was to come. To our greatest surprise nothing of that sort happened, and the balloon settled again in a descent that we allowed to develop to a speed of 1000 ft/min. On our way down we realized that we had recovered our pilot-flames and our Ball 655 and that all the systems were working perfectly again. Once below 12000 feet, we went on normal breathing, and stowed the oxygen system away.
After a 14 minute descent, we leveled out at 3000 feet and started looking for a place to land. Although we were out of the higher mountains by now, the terrain was still very hilly with lots of forests and narrow valleys. Our ground speed was a reasonable 10 knots so we had a fair chance to find a suitable landing spot with our remaining fuel. At 11:20 we finally saw what we thought was our last chance to come down unharmed: a small village, nestled in a narrow dead-end valley, Coggiola in the province of Vercelli. At 11:31 I made a gentle stand-up landing on the main road of the village, bang on the trailing antenna of our transponder ($100), among hundreds of spectators, minor traffic chaos, and with no fuel left. Two minutes later, the Carabinieri arrived and helped pack the balloon in order to clear the road. Many of the villagers had never seen a balloon before, and when they learned that we came from Switzerland over the Alps, we were treated like heroes. Four hours later, after a huge picata milanese and lots of Chianti and Espresso at Luisa’s Taverna, our crew, with 350 km on the counter, arrived, and we were on our way home.
Back in Chateau d’Oex, we discovered that nearly all of the 16 pilots who had made the flight had experienced some pilot-flame and fuel consumption problems, and that three pilots had to abort the crossing enroute. The fire we experienced during our crossing came back to my mind, and I realized what had escaped me then. Propane has a boiling temperature of -43 C (at 1013 hPa) and should still easily evaporate at - 15 C (at 500 hPa). There could never have been a puddle of liquid propane on our cushion floor. An Austrian pilot who also flew from Chateau d’Oex, emptying his cylinders for the trip home, found some liquid fuel accumulating in a puddle at a temperature of around 0 C. We concluded that the organizers had been supplied with some kind of contaminated fuel that was evidently not pure propane, but probably a mix of propane and butane (boiling point 1 C). Also we had never flown on methane- pressurized master cylinders at high altitudes, and this may have contributed to our problems.
This fuel problem did not effect our flying at lower altitudes and higher temperatures, especially as we always flew with nitrogen or methane-pressurized slave cylinders, and non-pressurized, heated master cylinders. That it affected our high altitude flying seems obvious after our horrifying experience, and I realize now that the biggest mistake I made during the flight was my inability to recognize the butane when I saw it accumulating on the floor. In fact, as my fuel management strategy for this flight was to take off on the two master cylinders and to fly these to the 30% level (enough to feed the pilot-flames for more than 4 hours), I did not realize that due to a high butane proportion in our fuel we drew on propane-methane vapor until there was not enough propane left in the fuel mixture (propane evaporates before butane) to guarantee a sufficient vapor pressure. Had I switched the pilot-flames to our two full spare master cylinders, I believe we would not have experienced the same problems.
After many lengthy discussions, I believe that knowing what we knew then, we made the right decisions and reacted correctly to all the emergencies that faced us during this flight, but I am willing to learn. We did not achieve a long distance (121 km), we did not qualify for the Long Jump because we used too much fuel, we did not break our National distance record (we did take a new National altitude record!), but we learned a lot and came away very lucky to have survived.