I'm wondering what the options are for increasing the range in a RV-9; specifically as it relates to increasing fuel supply. What has been done along these lines? Does this involve different wing tanks? additional wing tanks? What about adding a supplemental tank like the RV-12 has in the cockpit? I'm sure various mods can be done, but would it be a major hassle and time consumer? Thanks
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Options for increasing xc range in -9
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db1yg
Well Known Member
Hi Mark,
I had the same desire when I was building my 9a--ie I wanted at least another 8 gallons capacity. This desire may have been influenced by the capacity of my prior ride--a Mooney 201 which had 66 gallons of fuel capacity. Since I had quick build wings, a redesign of the wing tanks was not an option. I ended up plumbing an extra fuel line from the baggage area to the Vans fuel selector--I used the extra fuel selector port which normally has a pipe plug installed. That way, if after flying the plane and gaining some experience, I could use a temporary aux fuel tank located in the baggage area--disconnect and store when not needed.
Another approach that I am aware of is a slow build 9a that was modified during the build process to incorporate an extra wing bay to add capacity to each wing tank. Sorry, I don't recall who it was but I seem to remember he was from Kansas.
SafeAir also has aux tanks that are used in the short wing RVs (I think RV8 "Beautiful Doll" has them) which are available as a kit. They do add complexity and wt and I don't know if they are available for the 9.
The simplest/most elegant solution is the addition of a wing bay to the stock tanks since new plumbing/pumps/etc. are not required but it does add to the build process and possibly wing stress.
BTW, after 4 years I have never felt the need too use the aux tank capability I built into my 9a---my own personal flight duration is well within the range of the stock tanks.
Hope this helps,
Cheers,
db
I had the same desire when I was building my 9a--ie I wanted at least another 8 gallons capacity. This desire may have been influenced by the capacity of my prior ride--a Mooney 201 which had 66 gallons of fuel capacity. Since I had quick build wings, a redesign of the wing tanks was not an option. I ended up plumbing an extra fuel line from the baggage area to the Vans fuel selector--I used the extra fuel selector port which normally has a pipe plug installed. That way, if after flying the plane and gaining some experience, I could use a temporary aux fuel tank located in the baggage area--disconnect and store when not needed.
Another approach that I am aware of is a slow build 9a that was modified during the build process to incorporate an extra wing bay to add capacity to each wing tank. Sorry, I don't recall who it was but I seem to remember he was from Kansas.
SafeAir also has aux tanks that are used in the short wing RVs (I think RV8 "Beautiful Doll" has them) which are available as a kit. They do add complexity and wt and I don't know if they are available for the 9.
The simplest/most elegant solution is the addition of a wing bay to the stock tanks since new plumbing/pumps/etc. are not required but it does add to the build process and possibly wing stress.
BTW, after 4 years I have never felt the need too use the aux tank capability I built into my 9a---my own personal flight duration is well within the range of the stock tanks.
Hope this helps,
Cheers,
db
hydroguy2
Well Known Member
There are wing tanks available that add 10 or so. you could build bigger fuel during initial construction, another 10. Then you could remove the Pax seat and build a fuel tank or bladder that filled that space and extended into the baggage space....Let's say 40gals total to keep the CG ok. There you have a potential 90+gals....or 15 hrs at 6GPH.....where ya' going?
This option appeals to me the most because it seems to be the simplest and doesn't drastically impose on the design limitations of the plane. I assume any aux tank and fuel works against your baggage allowance though. At 75# baggage allowance, that only allows for an additional 10 gallon tank behind the seat. Did you actually build/buy an aux tank or have you just done the plumbing for one? Do you have any photos you can share?
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db1yg
Well Known Member
Hi Mark,
Sorry, I do not have any pics but I can tell you what is involved. I rotated the mount position of the fuel selector so that left and right tank selection is at 9 o'clk and 3 o'clk (vs stock 10 and 2), off is at 12 o'clk, and the aux selection is at the 6 o'clk position when seated in the plane. The alum aux fuel line was simply run down the center channel of the cockpit under the floor, adele clamped to the side supports, and terminated in a bulkhead fitting through a floor stringer under the left baggage floor. A simple AN cap is installed when the aux tank is not in use. A hinged access door can be easily fitted to the baggage floor to accomodate a quick connect for the aux tank which would be center located and strapped to the floor. I never bought a fuel tank but you can purchase, at reasonable prices, many different sizes of tanks which are designed for race cars. Check Jeg's Auto Parts as a source. Also remember that you will have to provide venting to the outside with a high loop to avoid siphoning. I was going with an 8 gallon unit to insure the wt was reasonable when full and lifting the tank into the baggage area as well as to retain some baggage capability.
Hope this helps,
Cheers,
db
Sorry, I do not have any pics but I can tell you what is involved. I rotated the mount position of the fuel selector so that left and right tank selection is at 9 o'clk and 3 o'clk (vs stock 10 and 2), off is at 12 o'clk, and the aux selection is at the 6 o'clk position when seated in the plane. The alum aux fuel line was simply run down the center channel of the cockpit under the floor, adele clamped to the side supports, and terminated in a bulkhead fitting through a floor stringer under the left baggage floor. A simple AN cap is installed when the aux tank is not in use. A hinged access door can be easily fitted to the baggage floor to accomodate a quick connect for the aux tank which would be center located and strapped to the floor. I never bought a fuel tank but you can purchase, at reasonable prices, many different sizes of tanks which are designed for race cars. Check Jeg's Auto Parts as a source. Also remember that you will have to provide venting to the outside with a high loop to avoid siphoning. I was going with an 8 gallon unit to insure the wt was reasonable when full and lifting the tank into the baggage area as well as to retain some baggage capability.
Hope this helps,
Cheers,
db
The Hotel Whiskey ER tanks offered by SafeAir add about 13 lbs. They do have the tanks just about ready for the -9. They just need to find someone to work with them a little. They need a set of tips to fit the tanks.
They added 9 gallons to my -6 and weigh 13.3 lbs.
Finley Atherton
Well Known Member
Diamond,
I can understand your desire for more fuel. I had the same thoughts when building my 9A. However like db in post #2, I have never actually needed extra fuel in 260 hrs flying. I typically cruise at about 150 kts true at 7,500 to 9,500 ft and use about 6 gal/hr. This gives a total endurance of about 6 hours or over 5 hrs with a 45 minute reserve. Obviously if you want to go faster then your fuel consumption increases dramatically.
Fin
9A
I can understand your desire for more fuel. I had the same thoughts when building my 9A. However like db in post #2, I have never actually needed extra fuel in 260 hrs flying. I typically cruise at about 150 kts true at 7,500 to 9,500 ft and use about 6 gal/hr. This gives a total endurance of about 6 hours or over 5 hrs with a 45 minute reserve. Obviously if you want to go faster then your fuel consumption increases dramatically.
Fin
9A
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Some of us are planning on additional fuel supply for long legs, either cross-country or over-water, as I am. My goal was/is to have an aircraft that can ultimately handle a round-the-world flight, which means some pretty serious water legs, which means some pretty serious fuel capacity. For normal everyday flying, no, there's really not much need for them. Your bladder is a bigger limitation than your fuel supply in *most* cases.
I converted my outboard leading edges to fuel tanks, effectively doubling the capacity of the aircraft at a dry-weight expense of only 11 pounds TOTAL, and I'll also make provisions for a passenger-seat bladder tank. Between those mods I'll have enough fuel for the long trans-oceanic hops.
I converted my outboard leading edges to fuel tanks, effectively doubling the capacity of the aircraft at a dry-weight expense of only 11 pounds TOTAL, and I'll also make provisions for a passenger-seat bladder tank. Between those mods I'll have enough fuel for the long trans-oceanic hops.
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pierre smith
Well Known Member
A tip from my Air Tractor experience for you guys with full length tanks...
...was learned at our NAAA (Ag av meeting) meeting in Reno, last December.
Leland Snow told me that regardless of how they configured the different tank options on Air Tractors, the dealers always had a customer who either wanted more fuel and sometimes, less fuel, so they ingeniously solved that problem:
They built large tanks that go most of the way along the wing, between spars, but about half-way, put in a solid, barrier rib with a pipe plug in it that you either leave in ,for smaller fuel capacity, or remove via an inspection plate on the top, reach in and remove the plug...voila!!... double tank size. Re-proseal the inspection plate and re-install. I thought that it was a pretty trick solution to an age old problem and something you 'Round-the-worlders' might appreciate.
You'll then have an inboard fuel cap and an outer one for when the large fuel capacity is needed.
This way, when you get done with your trip and don't need that much fuel out there, put the plug back in and have smaller tanks.
Best,
...was learned at our NAAA (Ag av meeting) meeting in Reno, last December.
Leland Snow told me that regardless of how they configured the different tank options on Air Tractors, the dealers always had a customer who either wanted more fuel and sometimes, less fuel, so they ingeniously solved that problem:
They built large tanks that go most of the way along the wing, between spars, but about half-way, put in a solid, barrier rib with a pipe plug in it that you either leave in ,for smaller fuel capacity, or remove via an inspection plate on the top, reach in and remove the plug...voila!!... double tank size. Re-proseal the inspection plate and re-install. I thought that it was a pretty trick solution to an age old problem and something you 'Round-the-worlders' might appreciate.
You'll then have an inboard fuel cap and an outer one for when the large fuel capacity is needed.
This way, when you get done with your trip and don't need that much fuel out there, put the plug back in and have smaller tanks.
Best,
n2prise
Well Known Member
Long range fuel tanks and RV-9A...
Mark,
I visited Bernie Kerr in South Florida who built a Mazda rotary-powered RV-9A with the outer leading edges converted to fuel tanks. He wanted to be able to fly round trip to South Carolina using auto fuel for his engine. You can see his airplane on my web site at this link.
http://www.n2prise.org/bernie01.htm
Here is the photo you want to see on that web page:
As for being an earth-rounder, you will have to put a ferry tank in the right seat position with no more than 42 gallons in it. You will want to do a number of weight and balance scenarios for your airplane design proposals to decide where to place the extra fuel needed beyond the 38 gallons in the regular tanks and the 42 gallons in the ferry tank in the right seat. To cover the 2300+ statute miles to Hawaii from California, you will need 90 gallons of gas with no wind conditions at 140 knots or 160 MPH. Add your reserves for head winds and safety margin, and you may want to carry 115 gallons total. That should provide just over 19 hours of flying time.
My airplane has the normal fuel tanks, but being a guy who pushes 240 pounds, I checked the W&B with two guys at 250 pounds in the seats, 100 pounds of baggage in the back, and full fuel. My airplane empty weight is about 100 pounds more than Van's likes to build them. I came up with a gross weight of 2,000 pounds that stayed within the CG limits with full or minimum fuel. My airplane has a Hartzell constant speed prop on an O-320 for power. The prop helped move the CG forward to help the W&B at gross weight. The CG moves aft with low fuel on board. I flew it at that weight to Oshkosh 2006. The takeoff roll is a bit longer, but once airborne, the flight characteristics were just fine.
Study the work done by Jon Johanson on the Van's Aircraft web site. He has flown his RV-4 around the world three times, east, west, and over the north pole from Canada to Scotland on the third time. I met Jon briefly at the Van's Aircraft banquet for Oshkosh 2004 as seen at the bottom of this web page:
http://www.n2prise.org/osh2004e.htm
Mark,
I visited Bernie Kerr in South Florida who built a Mazda rotary-powered RV-9A with the outer leading edges converted to fuel tanks. He wanted to be able to fly round trip to South Carolina using auto fuel for his engine. You can see his airplane on my web site at this link.
http://www.n2prise.org/bernie01.htm
Here is the photo you want to see on that web page:
As for being an earth-rounder, you will have to put a ferry tank in the right seat position with no more than 42 gallons in it. You will want to do a number of weight and balance scenarios for your airplane design proposals to decide where to place the extra fuel needed beyond the 38 gallons in the regular tanks and the 42 gallons in the ferry tank in the right seat. To cover the 2300+ statute miles to Hawaii from California, you will need 90 gallons of gas with no wind conditions at 140 knots or 160 MPH. Add your reserves for head winds and safety margin, and you may want to carry 115 gallons total. That should provide just over 19 hours of flying time.
My airplane has the normal fuel tanks, but being a guy who pushes 240 pounds, I checked the W&B with two guys at 250 pounds in the seats, 100 pounds of baggage in the back, and full fuel. My airplane empty weight is about 100 pounds more than Van's likes to build them. I came up with a gross weight of 2,000 pounds that stayed within the CG limits with full or minimum fuel. My airplane has a Hartzell constant speed prop on an O-320 for power. The prop helped move the CG forward to help the W&B at gross weight. The CG moves aft with low fuel on board. I flew it at that weight to Oshkosh 2006. The takeoff roll is a bit longer, but once airborne, the flight characteristics were just fine.
Study the work done by Jon Johanson on the Van's Aircraft web site. He has flown his RV-4 around the world three times, east, west, and over the north pole from Canada to Scotland on the third time. I met Jon briefly at the Van's Aircraft banquet for Oshkosh 2004 as seen at the bottom of this web page:
http://www.n2prise.org/osh2004e.htm
flyboy1963
Well Known Member
long legs
...don't forget to check out Todd Bartrim's rotary powered RV-9a 'Endurance'. He has a lot of great ideas on his web pages, including multiple tanks.
...don't forget to check out Todd Bartrim's rotary powered RV-9a 'Endurance'. He has a lot of great ideas on his web pages, including multiple tanks.
