Narrative:

This aircraft had not been flown in free flight by this pilot for approximately 5 months, but was still within annual inspection. At the end of the flying season last yr, this envelope was apparently nearing the end of its useful life as evidenced by higher fuel consumption and the need to operate the burner longer and more frequently to stay at equilibrium. The flight in question was the first free flight of the new flying season. Pilot weight: 190. Passenger were 1 adult and 2 children totaling approximately 285 pounds additional. I inflated the balloon and boarded passenger. The balloon required many long burns to reach equilibrium and 'weigh- off.' I then heated an additional amount which would normally have produced a 300-400 FPM rate of climb. We took off but, even with additional heating, the balloon would not exceed a 150 FPM rate of climb. I became concerned because the balloon was operating near the maximum envelope operating temperature. Ambient temperature was estimated at about 80 degrees F. I chose not to climb very high because climbing requires even higher envelope temperatures. The balloon required long and frequent heating to maintain 100 FPM rate of climb. I climbed only to 700 ft AGL and found a 30 degree shift in wind direction which took me in the direction of some closer landing sites. I leveled off and broadcast a 'pan- pan' alert to my ground crew, who were experienced balloonists and knew I would be landing as soon as practical. I did not tell the passenger that anything was amiss. The balloon required about a 6 second burn at 12- 15 second intervals to remain at constant altitude. In other words, I was operating the burner at least 50 percent of the time. I reconfirmed my decision to land as soon as practical because I was concerned that I would not have a safe margin of climb performance in the event that an aborted landing might become necessary due to obstructions or power lines. I was also concerned that the high fuel consumption might leave me with insufficient fuel to find a landing site after a normal flight of 1 hour. During the flight of about 35 mins necessary to find a landing site without disturbance to people or livestock on the ground, I never climbed above 700 ft AGL and spent about 50 percent of the flight at or below 500 ft AGL. This was a sunday morning flight between XA40 and XB15 local time and it is likely that I disturbed people on the ground with the sound of the burner being operated so frequently. Normally, I would have climbed to at least 1000 ft AGL (although this was not a congested area) to avoid disturbing the public or frightening livestock. I landed uneventfully on a rural baseball field. Fuel consumption for the flight was about 15 gallons which indicates a rate of about 23 gallons per hour. In my opinion, normal fuel consumption for a balloon this size in good condition should be about 14-17 gallons per hour, depending upon load and ambient temperature. In retrospect, I should have expected reduced performance from this envelope after considering it had undergone several months of further deterioration packed up 'in the bag' after the last flying season. I should have aborted the flight prior to takeoff when the balloon was heated to equilibrium and was so close to maximum envelope operating temperature. Had I made this decision, I would not have had to fly so low as to disturb the public on a morning flight. I also would not have potentially risked my safety and that of my passenger in the event that normal climb performance of the aircraft became necessary. After the flight, I related the facts to the balloon owner and recommended that the balloon receive an annual inspection prior to further flight to determine if the envelope can be operated within certification parameters. Callback conversation with reporter revealed the following information: the reporter was flying an admas ax-7 hot air balloon that did not belong to him. The envelope had more than 300 hours of flying time. He checked the 'tell tale' which indicated that the envelope had not been overheated but could not indicate the porosity condition. The reporter suggested to the owner that the envelope be given a new annual. The reporter does not know if this has been done. The reporter has been transferred away from the location of the balloon.

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Original NASA ASRS Text

Title: A HOT AIR BALLOON PLT LANDED ASAP BECAUSE HE SUSPECTED THAT HIS ENVELOPE WAS VERY POROUS.

Narrative: THIS ACFT HAD NOT BEEN FLOWN IN FREE FLT BY THIS PLT FOR APPROX 5 MONTHS, BUT WAS STILL WITHIN ANNUAL INSPECTION. AT THE END OF THE FLYING SEASON LAST YR, THIS ENVELOPE WAS APPARENTLY NEARING THE END OF ITS USEFUL LIFE AS EVIDENCED BY HIGHER FUEL CONSUMPTION AND THE NEED TO OPERATE THE BURNER LONGER AND MORE FREQUENTLY TO STAY AT EQUILIBRIUM. THE FLT IN QUESTION WAS THE FIRST FREE FLT OF THE NEW FLYING SEASON. PLT WT: 190. PAX WERE 1 ADULT AND 2 CHILDREN TOTALING APPROX 285 LBS ADDITIONAL. I INFLATED THE BALLOON AND BOARDED PAX. THE BALLOON REQUIRED MANY LONG BURNS TO REACH EQUILIBRIUM AND 'WEIGH- OFF.' I THEN HEATED AN ADDITIONAL AMOUNT WHICH WOULD NORMALLY HAVE PRODUCED A 300-400 FPM RATE OF CLB. WE TOOK OFF BUT, EVEN WITH ADDITIONAL HEATING, THE BALLOON WOULD NOT EXCEED A 150 FPM RATE OF CLB. I BECAME CONCERNED BECAUSE THE BALLOON WAS OPERATING NEAR THE MAX ENVELOPE OPERATING TEMP. AMBIENT TEMP WAS ESTIMATED AT ABOUT 80 DEGS F. I CHOSE NOT TO CLB VERY HIGH BECAUSE CLBING REQUIRES EVEN HIGHER ENVELOPE TEMPS. THE BALLOON REQUIRED LONG AND FREQUENT HEATING TO MAINTAIN 100 FPM RATE OF CLB. I CLBED ONLY TO 700 FT AGL AND FOUND A 30 DEG SHIFT IN WIND DIRECTION WHICH TOOK ME IN THE DIRECTION OF SOME CLOSER LNDG SITES. I LEVELED OFF AND BROADCAST A 'PAN- PAN' ALERT TO MY GND CREW, WHO WERE EXPERIENCED BALLOONISTS AND KNEW I WOULD BE LNDG AS SOON AS PRACTICAL. I DID NOT TELL THE PAX THAT ANYTHING WAS AMISS. THE BALLOON REQUIRED ABOUT A 6 SECOND BURN AT 12- 15 SECOND INTERVALS TO REMAIN AT CONSTANT ALT. IN OTHER WORDS, I WAS OPERATING THE BURNER AT LEAST 50 PERCENT OF THE TIME. I RECONFIRMED MY DECISION TO LAND AS SOON AS PRACTICAL BECAUSE I WAS CONCERNED THAT I WOULD NOT HAVE A SAFE MARGIN OF CLB PERFORMANCE IN THE EVENT THAT AN ABORTED LNDG MIGHT BECOME NECESSARY DUE TO OBSTRUCTIONS OR PWR LINES. I WAS ALSO CONCERNED THAT THE HIGH FUEL CONSUMPTION MIGHT LEAVE ME WITH INSUFFICIENT FUEL TO FIND A LNDG SITE AFTER A NORMAL FLT OF 1 HR. DURING THE FLT OF ABOUT 35 MINS NECESSARY TO FIND A LNDG SITE WITHOUT DISTURBANCE TO PEOPLE OR LIVESTOCK ON THE GND, I NEVER CLBED ABOVE 700 FT AGL AND SPENT ABOUT 50 PERCENT OF THE FLT AT OR BELOW 500 FT AGL. THIS WAS A SUNDAY MORNING FLT BTWN XA40 AND XB15 LCL TIME AND IT IS LIKELY THAT I DISTURBED PEOPLE ON THE GND WITH THE SOUND OF THE BURNER BEING OPERATED SO FREQUENTLY. NORMALLY, I WOULD HAVE CLBED TO AT LEAST 1000 FT AGL (ALTHOUGH THIS WAS NOT A CONGESTED AREA) TO AVOID DISTURBING THE PUBLIC OR FRIGHTENING LIVESTOCK. I LANDED UNEVENTFULLY ON A RURAL BASEBALL FIELD. FUEL CONSUMPTION FOR THE FLT WAS ABOUT 15 GALLONS WHICH INDICATES A RATE OF ABOUT 23 GALLONS PER HR. IN MY OPINION, NORMAL FUEL CONSUMPTION FOR A BALLOON THIS SIZE IN GOOD CONDITION SHOULD BE ABOUT 14-17 GALLONS PER HR, DEPENDING UPON LOAD AND AMBIENT TEMP. IN RETROSPECT, I SHOULD HAVE EXPECTED REDUCED PERFORMANCE FROM THIS ENVELOPE AFTER CONSIDERING IT HAD UNDERGONE SEVERAL MONTHS OF FURTHER DETERIORATION PACKED UP 'IN THE BAG' AFTER THE LAST FLYING SEASON. I SHOULD HAVE ABORTED THE FLT PRIOR TO TKOF WHEN THE BALLOON WAS HEATED TO EQUILIBRIUM AND WAS SO CLOSE TO MAX ENVELOPE OPERATING TEMP. HAD I MADE THIS DECISION, I WOULD NOT HAVE HAD TO FLY SO LOW AS TO DISTURB THE PUBLIC ON A MORNING FLT. I ALSO WOULD NOT HAVE POTENTIALLY RISKED MY SAFETY AND THAT OF MY PAX IN THE EVENT THAT NORMAL CLB PERFORMANCE OF THE ACFT BECAME NECESSARY. AFTER THE FLT, I RELATED THE FACTS TO THE BALLOON OWNER AND RECOMMENDED THAT THE BALLOON RECEIVE AN ANNUAL INSPECTION PRIOR TO FURTHER FLT TO DETERMINE IF THE ENVELOPE CAN BE OPERATED WITHIN CERTIFICATION PARAMETERS. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: THE RPTR WAS FLYING AN ADMAS AX-7 HOT AIR BALLOON THAT DID NOT BELONG TO HIM. THE ENVELOPE HAD MORE THAN 300 HRS OF FLYING TIME. HE CHKED THE 'TELL TALE' WHICH INDICATED THAT THE ENVELOPE HAD NOT BEEN OVERHEATED BUT COULD NOT INDICATE THE POROSITY CONDITION. THE RPTR SUGGESTED TO THE OWNER THAT THE ENVELOPE BE GIVEN A NEW ANNUAL. THE RPTR DOES NOT KNOW IF THIS HAS BEEN DONE. THE RPTR HAS BEEN TRANSFERRED AWAY FROM THE LOCATION OF THE BALLOON.

Data retrieved from NASA's ASRS site as of July 2007 and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.