What's new
Van's Air Force

Don't miss anything! Register now for full access to the definitive RV support community.

A Homebuilt Ultralight Hot Air Balloon for my RV-7A

Noah

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...

i
[/URL] [/IMG]
 
Now there's the coolest thing I've seen lately.

Noah....plans! Can we get plans?
 
That's The Engineer! To design a flying craft which fits in an RV! I'll catch you up North Navy guy :D


iceofRangeley.jpg
 
pilottangocharlie said:
Very cool! What is required to fly something like that?
Click to expand...
This is one of the beautiful things about this system. No pilot certificate is required to fly it, since it is an ultralight, and no airworthiness inspection or certification is required; there is no registration number. But getting some instruction would definitely be a good idea. 14 CFR 103 covers ultralight vehicles in the USA.
 
Last edited:
That is awesome! Ballooning is a totally different kind of flying from what most of us do. It is very fun. This combines the sports in a great way!
 
Noah, what sort of pilot weight capacity does it have? Right now I'd go 230 in winter clothes. Would I need a bigger envelope, and is that likely to bust Part 103 empty weight?
 
Awesome

Hey Noah, Wow, very cool. All you need now is a buddy with an RV10 to pick you up anywhere downwind!
 
DanH said:
Noah, what sort of pilot weight capacity does it have? Right now I'd go 230 in winter clothes. Would I need a bigger envelope, and is that likely to bust Part 103 empty weight?
Click to expand...

Dan - some info here. Looks like 16-20 pounds of lift capacity per 1,000 cu ft of envelope. Temp is the limiting factor with 225 being about the max. Cooler = longer TBO. The bigger the envelope the lower the delta vs. ambient.

http://www.apexballoons.com/balloons/
 
So...

Do you have to replace the rubber on the landing gear very annual?

That is very cool!

Wait, can you have a ?cool? hot air balloon?
 
Are rules different for balloons, does 10 gallons of propane qualify an an ultralight, for airplane ultralights there is a max 5 gallons gas?
 
Last edited:
DanH said:
Noah, what sort of pilot weight capacity does it have? Right now I'd go 230 in winter clothes. Would I need a bigger envelope, and is that likely to bust Part 103 empty weight?
Click to expand...

Dan, you should be fine with this size envelope. No way you would bust the Part 103 limits. You don't want to exceed 275F skin temp, 250F is max continuous. I design for 225 to maximize fabric life. In a non-porous balloon, avg. internal temp is approximately the same as the max skin temp at the top due to boundary layer and convective skin cooling. Assuming 230 Lb pilot, 112 Lb system, 43 Lb fuel, and 10 Lb of gear:

jzh9b5.png
 
Last edited:
Greenley said:
Are rules different for balloons, does 10 gallons of propane qualify an an ultralight, for airplane ultralights there is a max 5 gallons gas?
Click to expand...

FAA Advisory Circular 103-7 says the following: http://rgl.faa.gov/Regulatory_and_Guidance_Library/rgAdvisoryCircular.nsf/list/AC%20103-7/$FILE/Signature.pdf


(2) Free Balloons... The weight of the fuel, in the case of a hot-air balloon, ...is not included in the weight specified in § 103.1(d).
d. Free Balloons are Considered "Unpowered." A balloon, for Part 103 eligibility, is considered an unpowered ultralight...

So basically, there is no limit to the amount of fuel that you carry, as long as your empty weight stays below 155 Lbs.
 
David Paule said:
How do you get back to the airport?
Click to expand...

Balloons always use a chase vehicle and chase crew to pick you up when you land. Sometimes if that is not an option I try to land near another balloon (if at a festival) and bum a ride back with them. But that is pretty unusual.
 
Noah,
I would love to see you fly at the annual Alabama Jubilee Hot Air Balloon Classic held each Memorial Day Weekend in Decatur, AL. The number of balloons is usually limited to about 60 due to the physical size of the open field at the city park where it's held.

We have several unusual balloons each year, but yours would certainly be unique in its own way.

I know it's a long trip from RI, but if you attend, let me know and we'll make provisions for you. :)
 
Another approach, which I used for a few years, is to get a paraglider. Not the motorized craft but the true glider. Mine weighed about 40 pounds in its pack, and was the size of a large backpack.

It fit easily into the back of my non-RV airplane. It ought to fit an RV, too.

Fly somewhere, hike up to the launch point, make your flight and pack it up.

Not as cool as a balloon but it was fun.

Dave
 
Quick heat

How quickly, once inflated, does it begin to produce lift?

I am thinking you could design this as a bailout system! Jettison the canopy, the airstream inflates it and you let the aircraft fall away from you while you hit the burner...no?:p:eek:
 
Noah, I hope you can make the XLTA festival here in Bethlehem, CT. I live on the airport (CT01) and have a 7A. I also have a balloon but it won't fit in the 7, it's a Lindstrand 77.

Dan Decker
 
Noah made the Festival

He is on the way back from Presque Isle. Pirep, pictures, trophy?


Noahfrombaloonfestival.jpg
 
What a weekend, Mt. Kathadin was awesome! Got 3 flights with the cloudhopper in, we had a big high pressure area over the northeast the whole weekend. Pix to follow...
 
David Paule said:
Another approach, which I used for a few years, is to get a paraglider. Not the motorized craft but the true glider. Mine weighed about 40 pounds in its pack, and was the size of a large backpack.

It fit easily into the back of my non-RV airplane. It ought to fit an RV, too.

Fly somewhere, hike up to the launch point, make your flight and pack it up.

Not as cool as a balloon but it was fun.
Click to expand...

In fact - with a modern convertable harness my paraglider rig is down to about 28lbs now...
 
Can't believe I left work at 1:15 PM on Friday and was ballooning in Northern Maine by 5:30 PM! Only with an RV!

Northern Maine, Mt Katahdin
a680a78a.jpg

Presque Isle, Maine
6db2498f.jpg

Yay! Made it here, need to buy propane pronto!
7065f1c5.jpg

Launched from fairgrounds, was just here an hour ago in the RV
599e1841.jpg

Hangin' out
c29dfb25.jpg

0bff52c4.jpg

Since I have no ground crew, I'm hanging with my buddies Bill and Sam. Don't want them to get too far away from me!
cc5770c4.jpg

Sam also flies a cloudhopper (and 747s, C-130s, and Lear Jets)...
44b62222.jpg

Everybody in town is chasing balloons...
b568be70.jpg
 
Cool Shadows
26c7e23c.jpg

Harvest Time
50ae8b34.jpg

Safe Landing
90698429.jpg

Balloon Glow
4355998a.jpg

Saturday Morning Flight, Sam Launching
31a5f8b8.jpg
 
Morning Fog over the River
29d596f7.jpg

VFR On Top (My Camera has a Problem)
94057b8b.jpg

Should I do a splash & dash?
11d2877a.jpg

River Reflections
41e79b24.jpg

Self Portrait over Oat Crop
c4f6b429.jpg

My Hero, Joe Kittinger launched his solo transatlantic balloon from here. http://en.wikipedia.org/wiki/Joseph_Kittinger
3b0f8ad2.jpg

56c2e07b.jpg

eef6b69e.jpg

High Wind Landing Sunday AM in Plowed Field - 18 knots in a cloud of dust. No injuries!
810fe0f5.jpg

Ouch! Maybe my wife can "Shout it Out"?
8addde51.jpg
 
rv7boy said:
Noah,
I would love to see you fly at the annual Alabama Jubilee Hot Air Balloon Classic held each Memorial Day Weekend in Decatur, AL. The number of balloons is usually limited to about 60 due to the physical size of the open field at the city park where it's held.

We have several unusual balloons each year, but yours would certainly be unique in its own way.

I know it's a long trip from RI, but if you attend, let me know and we'll make provisions for you. :)
Click to expand...

Thanks Don, that sounds cool!
 
Dan92 said:
Noah, I hope you can make the XLTA festival here in Bethlehem, CT. I live on the airport (CT01) and have a 7A. I also have a balloon but it won't fit in the 7, it's a Lindstrand 77.

Dan Decker
Click to expand...

I hope to be there, Dan! How do you like landing the 7A on a 1400 ft grass strip? I have been thinking a LOT about whether I should land there in my RV! How are the approaches?

If anybody else is interested in experimental Lighter Than Air, XLTA is the Oshkosh of ballooning. This is the weekend after next. Here is a link to their website:
http://xlta.org/
 
XLTA

Noah, CT01 has good approaches. Landing to the south, you approach over a swamp and landing to the north there is a tree line you have to fly over but it is far enough away that you can descend to use the whole runway. If you are interested, fill out the hold harmless form at:http://www.whelanfarmsairport.com/ and call Tom to get permission. I will pm you with his cell number.

Dan Decker
 
You must log in or register to reply here.
Back
Top