Welcome to The online forum and website of the Helio Aircraft Association, Inc.

Main Menu

Long range tanks (problem)

Started by Gary, October 27, 2019, 10:02:44 AM

Previous topic - Next topic


Any Helio owners with long range tanks aware of issues? I’ve heard the install of the tank can cause a structural weakness and possibly poorly rigged ailerons. Any truth to this?


What do you mean by long range tank ?  Are we reffering to the 120 gallons wing compare to a 60 gallons wing ?

As you see, i am referring not to a 60 gallons tank vs a 120, but a 60 gallons wing

There is more difference to a 120g wing than juste the installation of two outside inside tank.  There is structural change as the length of the pickup of the wing spar near the fuselage.  They are considerably longer.

A 120 gallons wing works as well as a 60 gallons wing for flying.  Besides the weight of it, empty or not, naturally.

If we are talking about a inside the cabin long range tank,  the T valve  on the roof on the tube between the two tank can be changer to a cross ( 4 way )  fitting to allow the connection of the inside the cabin long range tank.  With a a one way valve.   Then you are filling both tanks at the same time.  But you need a pump.  The installation drawing on the U10 manual looks like if the fuel is gravity feeded towards the floor




Thanks Louis for the info. Yes I am referring to the 60 per wing rancher than the typical 30 gallon per wing. I assumed the extended 60 wing would require the removal of a rib or two. The only two Helios that I am aware losing a wing or a breakup both had the 120 gallon long range tanks

Doug Johnson

At least one other person believes there is a correlation between wing separations and the 120 gal long range fuel tanks. Personally I don't believe the 'Long Range Fuel Tanks' contributed to any of the wing separation, primarily because of structural changes to the wing mentioned by Louis when long range fuel tanks are installed.

The wings on the stallion and the twin Helio which use the same wing and the same attach bolts both have 55 gal wing tip tanks. An identical wing to the a/c that had wing separations, is used with the STCed XLR fuel tanks there are only 3 of those that I know of, they have 6 fuel tanks with 2 placed in the farthest out board bay and the experimental turbine H-15 has airfoil shaped wing tip tanks that actually make the wing 18 inches longer also uses an identical wing.

On the H7/800 wing after c/n H2 the wing attach on the top is changed to a bolt similar to the bottom and the take off weight is increased to 4000 lbs, landing weight remains at 3800 lbs this was done by basically incorporating the 3800 lb upgross STC by increasing the wall thickness of the diagonals in the upper and lower bays of the crashcage/fuselage.

My understanding is that fuel tanks are generally placed in the wing for a couple reason foremost is that it is doesn't take up space in the fuselage that could be used in other ways and that it allow the fuel to be placed closer to the CG and a wing location doesn't place as much load stress on the aircrafts airframe.

There were more than 2 a/c that had wing failures. Turbulence was also connected to most of the aircraft that had wing failures a couple were connected to G-load from maneuvering. At least one of the a/c that had a wing failure had recently had the wings changed or removed and replaced, which may have contributed to the failure

I had a long somewhat confidential conversation with the now deceased Factory Engineer Robert Casebeer about this. I believe he hinted at something. He explained that the Wing attach bolts are 0 tolerance, and the machining of the fittings that the bolts go through was contracted out a vendor. The holes were first drilled then reamed to 0 tolerance. The vendor had a problem with this reaming and some of the holes had scratches deep in the holes and of course during the inspection process these were detected and rejected, I believe He was telling me these scratches could have led to corrosion and stress cracks in the scratches.

Robert didn't say so but later thinking about it the Factory may have suspected that not all were caught during the inspection process, but this would never have been admitted.

I assume the magnaflux process that is now in place would catch this.


Very informative Doug, thanks. I wasn’t sure, just assumed the removal of a rib would have given up some structural strength. Just looking at a purchase between two Helios and 60 gal vs the 120 gal

Doug Johnson

Personally, I would always go with the 120 gal wing if possible. Sometimes when flying to the 60 gal destination, not having to refuel because you started with twice as much fuel as you needed comes in real handy for a variety of reasons, a little thought and you can think of reasons.

Another thing you can do is haul non-alcohol fuel for generators, chainsaws, boat motors, 4-wheelers or whatever in one or both of the outboard bladders. Just use a piece plastic tubing wired to the drain, to fill up a gas can.


Quote from: Doug Johnson on December 12, 2019, 01:49:10 PM

Another thing you can do is haul non-alcohol fuel for generators, chainsaws, boat motors, 4-wheelers or whatever in one or both of the outboard bladders

I use AVGAS for my honda generator, chainsaw, and before, the ski-doo.  Anything that did not have a catalytic filter.  Now the new ski-doo have catalytic filter, so i can't anymore.  The lead would clog the filter.

Avgaz is a little more difficult to start at cold temperature.  Less volatile than the winter auto gaz. 



Quote from: Doug Johnson on December 12, 2019, 04:49:48 AM
Factory Engineer Robert Casebeer

Doug, please refresh my memory.  Mr. Casebeer was working at the factory ?  And he was an engineer ?  And Mr. Brent was the engineer of the type certificate ?

Is it Mr. Casebeer that was this fine gentleman that did the hand work on the modified cowling and from who i bought the aluminum legs for my H800 ?  What was the airport he was based at ?  There was a 800 there in a hangar, very low time.


Doug Johnson

Louis, the question you ask about the engineers is one that probably could be answered best by Ken Noe

Steve Ruby I'm sure would have a better off the cuff answer as well.

Clarence Brent and Robert Casebeer were both engineers with the Helio factory. I think Clarence was the Chief engineer.

I believe that Clarence continued working on the Helio after the factory closed the first time as an independent engineer and Robert Casebeer worked for Helio Enterprises inc.

I think they both worked on the type certificate for the H-7/800.

Clarence developed some oher Helio STCs (now owned by Gordon Cragg) and He was the engineer that worked on H-5 (the low time Helio you speak of), H-5 was used for some gear leg drop tests. H-5 was also used to develope some speed mods Wheel pants and a modified cowling that reduced drag and gave better cooling I don,t believe Clarence ever got aroun to sumitting the paperwork. I believe it was owned by Luigi Chinetti when you saw H-5.

see H-5 here

As far as the automootive fuel that I sometimes carried in myoutboard tanks for snowmobiles, chainsaws whatever was the automotive fueland that was available on Merrill field Anchorage for A/C STCed for automotive fuel. I also flew ultralights and had a couple engine failures before figuring out 2 cycle engines are highly prone to lead fouling when you use 100LL or even 80/86 avgas.

I could if needed burn the autogas in the GO-480. A few times when AV gas was difficult to find out in the bush I did use some autofuel usually mixed 50/50 with avgas. I also tried to avoid high altitude and high performance useage with auofuel.

I will give ken Noe a call, maybe add to this.

Kevin Dunn


As Doug said they were both engineers.

Bob Casebeer was the Designated Manufacturing Inspection Representative (DMIR) for the factory in Pittsburg. Along with working for Helio, Clarence Brent also had his own engineering business, Brentwing Engineering.



Clarence was indeed the Chief Engineer. I meet with Clarence in his home in the fall of 1998 at his home in Pittsburg KS.  He had boxes of data. I gave him $500 for a few items that were useful. One was a study of the rocket launchers and the other the wing load tech data for the 3800 lbs gross weight increase.  BTW I sent these to someone many years and have not gotten them back.  They are part the the data backing the STC for our camera. I believe Steve Murray purchased the rest of Clarence’s boxes of data about the same time. I got the impression from Clarence that he thought, he was 92 as I remember, the carry through AD was a bum deal but felt the fix made the wing fail safe. I’ll let others decide that one.  I also met Ken Noe at his place in OK, maybe 2000.  He and Casebeer had a stash of Helio parts from the the closed factory. One item of interest was the jig for the Tri Gear engine mount/nose gear. No idea where all that stuff went.

Kevin Dunn

Ken Noe introduced me to Bob at his house in Pittsburg not too long before he passed. He still had boxes of stuff!!