Noah
Well Known Member
After the first flight of my RV-7A last October, I started to get a little empty nest syndrome in my workshop. No parts lying around that needed to be worked on, so I decided I needed a new project. Nothing that would take years, mind you. I have been building and flying hot air balloons for 25 years, and thought it would be cool to build an ultralight hot air balloon which would fit in my RV-7A.
I had built a single place hot air balloon (called a "cloudhopper" in ballooning parlance) 6 years ago, but it would not fit in the airplane, although parts of it could be used in this new system, including the "envelope", or fabric portion, and the burner. The "bottom end" would be pretty much new, and would need to be very minimalistic, with no basket - just a harness, to fit in the airplane. We all know that aircraft are a series of compromises, and this is no different, with the size and weight constraints that the RV imposes. Unfortunately, I cannot take a passenger when hauling this system unless I borrow a balloon fuel tank when I arrive.
Tomorrow I will realize a longtime dream to fly to some far-flung destination and bring my balloon in my RV. There is a small balloon festival way up in Presque Isle Maine, an 8 hour drive or a 2 hour flight in the RV.
Last weekend, after doing a test fit of the balloon in the plane, I did the first flight of the new system, and it was really fun. Strange not to have a basket, and to have your legs dangling down. The whole system weighs 112 Lbs, and carries 10 gallons of propane (42 Lbs) - enough fuel for around a 75 minute flight. The envelope weighs about 55 Lbs, and holds 25,500 cubic ft of air at around 225 degrees F. The system is around 38 ft diameter, and 50 ft. tall when inflated. The harness is made for paramotoring. There is a custom built swivel so that the pilot, harness, burner, and tank can rotate independent of the balloon envelope, so you can still see where you are going if the balloon rotates (which it frequently does).
Balloons are normally inflated with a small gasoline powered inflation fan, but mine will not fit in the plane without modifications. So I am planning to borrow a fan on arrival, or, -this is the cool part - use the RV's 74 inch "inflator fan" to inflate the balloon prior to heating the air and making it buoyant. I hope to bring the system to OSH next summer.
Here are some photos of the system and the first flight...
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I had built a single place hot air balloon (called a "cloudhopper" in ballooning parlance) 6 years ago, but it would not fit in the airplane, although parts of it could be used in this new system, including the "envelope", or fabric portion, and the burner. The "bottom end" would be pretty much new, and would need to be very minimalistic, with no basket - just a harness, to fit in the airplane. We all know that aircraft are a series of compromises, and this is no different, with the size and weight constraints that the RV imposes. Unfortunately, I cannot take a passenger when hauling this system unless I borrow a balloon fuel tank when I arrive.
Tomorrow I will realize a longtime dream to fly to some far-flung destination and bring my balloon in my RV. There is a small balloon festival way up in Presque Isle Maine, an 8 hour drive or a 2 hour flight in the RV.
Last weekend, after doing a test fit of the balloon in the plane, I did the first flight of the new system, and it was really fun. Strange not to have a basket, and to have your legs dangling down. The whole system weighs 112 Lbs, and carries 10 gallons of propane (42 Lbs) - enough fuel for around a 75 minute flight. The envelope weighs about 55 Lbs, and holds 25,500 cubic ft of air at around 225 degrees F. The system is around 38 ft diameter, and 50 ft. tall when inflated. The harness is made for paramotoring. There is a custom built swivel so that the pilot, harness, burner, and tank can rotate independent of the balloon envelope, so you can still see where you are going if the balloon rotates (which it frequently does).
Balloons are normally inflated with a small gasoline powered inflation fan, but mine will not fit in the plane without modifications. So I am planning to borrow a fan on arrival, or, -this is the cool part - use the RV's 74 inch "inflator fan" to inflate the balloon prior to heating the air and making it buoyant. I hope to bring the system to OSH next summer.
Here are some photos of the system and the first flight...