H

Hubitom1

Member
Hi everyone,

new to the entire thing of building wings and things out of raw material. Bought someones empennage, fished it (with the appropriate amount of mistakes, off course), and hopefully getting the wings pretty soon.

I am thinking about putting range extenders into my 7A. Does anyone have some input about the entire thing? I searched for it,and only HWA came up. Are they the only guys offering a solution, and if so, who's got them installed? Good experience, bad?

Would it be worth producing them at home? Did anyone do that? Would you do it again?

Well, thanks in advance for every input.

Thomas
 
Aux tanks

Hi Thomas and welcome.

I know of one and heard of several others that have rolled their own. The one I know of bought non-pre-punched leading edge wing skins, more tank ribs, back baffles, z-brackets etc and basically made the existing tanks bigger, by about 50% (I'm guessing here, but definately more than the ER tube style.)

Bevan
RV7A not flying yet but
gascolators and shut-off valves successfully installed in the wing roots :)
 
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Bevan,

thanks for the reply. Do you know by any chance if he made the tanks longer, or deeper? Do you know by any chance who he/she is, and is there a chance to get in touch with that person?

Thomas
 
The tanks are just a longer (span-wise) version of the original design. They extend further out towards the tip but not all the way to the tip.

Not comfortable about sending out his contact info. I would have to ask him to contact you.

Bevan
 
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Scott and Bevan,

thanks so much for the idea (and information). Bevan, that would be more than appreciated if you did. I do not expect anyone giving out my information, either. So yes, if this gentleman wouldn't mind me contacting him that would be great.

Thomas
 
It's really your call...

...because guys have made extended range tanks that occupy the passenger seat for a flight to Australia...others have a tank in the floor of the baggage area and still others, have modded the wingtips into tanks. One guy has full span leading edge tanks...the variety is anything and everything...not all necessarily well engineered. Contact John Harmon for info on adding to the existing fuel tanks.

Best,
 
Pierre,

tried to find the name John Harmon in members area, and it did not return a result. How would I be able to get in touch with him?

Thanks,

Thomas
 
yes, it's been homebrewed

I've added leading edge aux tanks to my -7 (not yet flying), following the example & techniques of two others who did the same on -9's (both flying successfully). Email me off-list if you want some pics, or to discuss what was done. There's a site out there somewhere documenting an engineering study of one installation.

Charlie
[email protected]
(tied up until Friday)
 
er in 4

I just had HW install tanks in my 4. Wow! 9.8 extra in fuel = 175 NM extra range. My 4 already had the "6" tanks installed so HW built a custom tank that fit perfectly. The install they did was very clean and professional. I dropped my plane off and 7 days later Smokey flew it home for me. They (er tanks) fill the mains with air pressure when I open the valve. So simple. Flew Non stop from Indianapolis to Orlando and still had 13 remaining.... priceless
 
Anyone else working on or have more details on the outboard leading edge fuel tanks?

This is something I will definitely do on my 10.
 
"HW" ? give me another hint! ;-)
I could use more fuel in my four...

DM



rv4bill said:
I just had HW install tanks in my 4. Wow! 9.8 extra in fuel = 175 NM extra range. My 4 already had the "6" tanks installed so HW built a custom tank that fit perfectly. The install they did was very clean and professional. I dropped my plane off and 7 days later Smokey flew it home for me. They (er tanks) fill the mains with air pressure when I open the valve. So simple. Flew Non stop from Indianapolis to Orlando and still had 13 remaining.... priceless
Click to expand...
 
After some talking with Charlie (great hour I spent with him on the phone) and some thinking I came to the conclusion that I will do leading edge tanks, but construct them like they were wing tanks. Off course with some modifications.

First of all, fitting the main spar into the leading edge with goo dripping all over the place doesn't seem to be the approach I want to go. So here's my thinking (and please hammer away if you think that I'm full of ... ya know, the brown eye thing {although I have blue ones! :)}) ...

The main tanks have that rear spar in there with the rivet line on the outside I think (I do actually get my wings next week, so this here is based on some talking, and a lot of assumptions). So I will buy another of those spars, as well as 2 main tank ribs and possibly Z-brackets. The remainder of the original wing spars will be trimmed to length plus flange for riveting. Don't know if I'm ending up in a lightening hole, but I will cross that bridge when I get there.

That should be much simpler than using the main spar as your rear wall. Now to one of the debating points.

Since the main tank is screwed into place with nut plates, why not using the same concept for the outside portion? Sure there's more action going on load wise, but would it be too much for the screws to keep that extra tank in place? It would give me a bit more peace of mind if I could access the **** things a bit easier other than inspection openings.

Anyone out there that would argue my idea?

Bestest flying to all of you.

Thomas
 
A word of caution here!

PLEASE; do not modify the fuel system unless you are fully confident that your system has been engineered correctly.
The fuel system is the very LAST thing that you want to have problems with.

If you modify your fuel system and call me for A/W inspection, be prepared to provide me with engineering data showing adequate fuel flow and wing structure.
 
Mel said:
PLEASE; do not modify the fuel system unless you are fully confident that your system has been engineered correctly.
The fuel system is the very LAST thing that you want to have problems with.

If you modify your fuel system and call me for A/W inspection, be prepared to provide me with engineering data showing adequate fuel flow and wing structure.
Click to expand...

Would you consider the HW tanks to meet this standard? (Or capable of, assuming they are installed in a sane manner, of course. :))
 
Mel said:
PLEASE; do not modify the fuel system unless you are fully confident that your system has been engineered correctly.
The fuel system is the very LAST thing that you want to have problems with.

If you modify your fuel system and call me for A/W inspection, be prepared to provide me with engineering data showing adequate fuel flow and wing structure.
Click to expand...

Post #4 has some pretty good data. Also there is a hand full of RVs with extended leading edge tanks flying now. Just FYI. By all means... critique away, I want to make sure I make the right decision here.
 
Sorry, it was late when I wrote this! :(

I meant to say that I would be cutting the wing ribs to length plus flange. Oopsie!

Thomas
 
Mel, you are correct about the fact that no one needs to have problems with fuel, or the wing in itself. Both are kinda important for staying aloft, and making a controlled landing. But other people are flying with this solution already. So it's doable. I see your point of providing data for structural and technical correctness when it comes time for inspection. I have to get going on this aspect.

Thanks for your input.

Thomas
 
OK, went back to Pat Tuckey's Web site (http://napwars.com/RV-8HTML/home.htm) and read through his excerpt. Also tried to get in touch with him. Unfortunately have not heard back from him (yet).

Does anyone know Pat, or if he's still flying? His flight testing took place at GPM (Grand Prairie), just outside Dallas/Ft. Worth.
 
DCat22 said:
Would you consider the HW tanks to meet this standard? (Or capable of, assuming they are installed in a sane manner, of course. :))
Click to expand...

The HW tanks ARE well engineered and are nicely done as are a few others. My point was that just because Joe Pilot did something and it worked doesn't necessarily mean that it was done correctly.

PS; I have the ER tanks in my RV-6.
 
Hubitom1 said:
OK, went back to Pat Tuckey's Web site (http://napwars.com/RV-8HTML/home.htm) and read through his excerpt. Also tried to get in touch with him. Unfortunately have not heard back from him (yet).

Does anyone know Pat, or if he's still flying? His flight testing took place at GPM (Grand Prairie), just outside Dallas/Ft. Worth.
Click to expand...

I traded emails back and forth with him close to a year ago when I followed his tank design on my 9A, I converted both leading edge sections to fuel tanks as he did on his 8A. He does have some good engineering reviews of his design, I wouldn't have done mine without knowing the numbers worked. I will look and see if I can find my copy of it or you might be able to get one direct from him. IIRC the engineering review showed the leading edge tanks (full of fuel) would fail about a 1/2 G-force AFTER the main spar was gone. The dangerous part comes in ground ops, because fuel on the outboards increases the spar bending moment at the fuselage, so landing with fuel in the outboards should be considered an emergency operation only, and extreme care should be exercised during taxi/TO with fuel in the outboards. Likewise, you want to plumb your system to burn the fuel in the outboards first.

As Mel said - changing the fuel system SHOULD NOT be taken lightly, make sure you know what you are doing before you do it, and be prepared to defend your actions with logic when people start asking questions (because they will). I'm not saying not to do it, just saying that caution is advised.
 
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Greg,

thanks so much for your reply. I will definitely weigh all the pros and cons before starting that part. Would you mind if I could talk to you about it privately?

Thomas
 
Thomas, Greg, and anyone else with more info,

I've also sent Pat an email this morning without a reply yet. If there is anymore details as to the leading edge tanks please post it here for others to see or at the very least, send us a PM. I'll do the same.

Pats Initial flight testing documentation ended at just shy of 20 hours hobbs. He never got to the point of filling up all 4 tanks. So more actual facts/info of flying experience with the extended LE tanks is needed before I modify my future wings. It would be great for others that have done this to chime in.

I'll be following this thread very closely.
 
Tuckey responds

Ok guys, I am sorry I haven't been e-mailing and putting new stuff on my website, I have been busy flying.

I have flown the airplane with full fuel and every combination downwards from there. I have even (very carefully) landed with fuel in the outboard tanks. So far I have had exactly zero problems with the system.

Since I finished flight testing, I have not been very motivated to update my website. I really would rather spend my time flying. At some point I will finish putting up the rest of the test data - it just shows that everything works exactly as planned.

I have not answered many e-mails lately because most of them ask the same questions:

1. I don't know anyone who will sell you the tanks off my airplane (yes, I have been asked that in many e-mails. One guy actually asked me to supply him with the address of the tank manufacturer.).

2. No I won't send you a detailed engineering analysis. All the engineering data I have is on my website or in my head. My analysis was all simple comparative - there are no detailed technical numbers.

3. Yes, I am happy I made the extended range tanks.

4. No, I really wouldn't do it differently next time. A slightly thicker skin with no pre-punched holes would probably look better, but it would weigh more and would not change anything about the design or operation of the tanks.

Good luck with whatever you decide to do with YOUR airplane, but remember that changing fuel system design should be done with great caution.

Pat
 
Pat,

It's great to hear from you. Few questions.

Have you had ANY hiccups in relations to your fuel system?

How many hours on the hobbs now?

How often do you find your self taking off with full fuel in all 4 tanks and landing with reserves?

Would you do it again?

thanks again...
 
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