Anyone have experience with this Twinco Nacelle Tank STC?

[ScottB]

Hello to everyone....

I just returned home from a week of flying our Twinco hauling loads of relief supplies to the hardest hit islands in the Bahamas where homes were leveled as the eye of hurricane Irene passed directly over them as a Category 3, nearly Category 4. I was flying supplies stocked at KFXE and then running out to distribute the supplies to the islands and back. Several times I was wishing I had more fuel on board so I could have made the round trip without having to use the extra time and money for a fuel stop out there - at $7.25 per gallon. So, I was surfing the web today in and effort to see what our options are for adding capacity and range when needed.

The options I've come across so far are: Webco nacelle tanks with 10.2 gallons per side ($2,200-ish), Tip tanks by JL Osbourne at 15 gals per side ($9,000 -ish!), and Phill-Air nacelle tanks at 20 gallons per side (No price listed). Or, a Turtlepac of my choosing and location for special occasions.

I had heard of the first two before but never heard of the Phill-Air STC before today - anyone have any experience with it? Care to share? Here's a link: http://www.phill-air.com/?opt=maintenance

Anyone have other wisdom to share about your experience seeking more fuel capacity for your Twinco? Tip tanks seem to have a lot of advantages but they come with a hefty price!

We are a non-profit and looking for the most cost effective solution that works well - and is reliable. This plane is also being used to distribute water purification and chlorine generator units through out Haiti to deal with the Cholera problem there - so extra range on that trip will be huge benefit at well.

Thanks, Scott

[Kristin Winter]

I have the Osborne tanks. I think that the issue is how much is the extra 125 lbs on the gross weight worth.

Kristin

[jeffrey aryan]

Scott,

I don't have any experience with either. But my comment would be this.

The Webco tanks will give you one extra hour of flight time and the Phil Air tanks would give you two hours extra of flight time. Can you, your passengers and bladders hold out ?
Next I don't think a weight increase is allowed with either system. Please keep everyone informed of your progress.

Good luck,

Jeff Aryan

[ScottB]

[N3322G]

Scott,

I have experience with:
15 gal Osborne tips
10.2 Webco nacelle tanks - Phil has a good reputation but I haven't used his tanks
19.2 Miller wet wings
ferry tank

Aside from what Kristin mentioned, I like the tip tanks because they are gravity fed.
Next preference are the nacelle tanks - they pump to the aux

Last preference are the wet wings as they leaked and I have now disabled and they pumped to the mains with an ugly over the wing fuel line.

Ferry tanks are also usually gravity feed but take cabin space.

Hope this helps.

[Trevor Laundy]

Scott, I fly my Turboprop across Europe regularly. Your points on airfield availability, avgas availability and pricing as well as straight range, are daily considerations here.

If the tip tanks weren't already there I would buy them tomorrow. Plus 30gals is a lot of cruise range and coupled with +125 lbs MTOW and a possible small increase in speed / better high altitude performance from end plate effect, they are certainly worth the cost when operating over here. I have found them reliable and easy to use (and easy to not use).

I am also interested in the nacelle tank options but there is a permanent weight penalty with both and I have a thought (only) of taking my aircraft round the world - and for really long legs (Pacific) one would still need a ferry tank in the cabin.

I would be grateful for advice on ferry tanks for twincoms.

Trevor

[N3322G]

Scott and Trevor,

One additional tank I've heard about but not seen is aft of the baggage compartment where some folks have run skis. It was used by a French Twin Co in the 1992 world race so it may have been a ferry tank with temporary install approval. It was not a good idea as the CG was much further aft. What appeared to be similar speed modded twin com's, flew 10 kts different ... but then again some of that may have been race experience as what is now my twin was flown by famed race pilot and Mom, Marion Jayne - she was named a 100 aviation hero for the first century of flight and is inducted into the Pioneer Aviation Hall of Fame. She and my sister won 2nd that year to a sharp pilot team in a turbo assisted Bonanza with 100 gal tip tanks with Mom's norm asp. twin and no ferry tank, just 182 gal in 10 tanks in the wings.

Re: ferry tanks - we put a 72 gal one in the fuselage as far froward as possible behind the pilot/co-pilots seat while still allowing for oxygen tanks and required ditching raft and the HF radio sitting on tpo for the 1994 race. It was custom built by a shop, Brent's in Oakland, CA. We carefully computed W/B and what order to burn the total of 11 on board tanks. We had the FAA 90 day waiver to be 30% over gross so our W/B may be different than your configuration.

Let me caution you that CG and W/B is a really big deal as you likely already know in pitch-sensitive TwinCo's. There was a TwinCo lost crossing the Atlantic. The best guess is the ferry tank came loose of its harness and rolled back upon take-off. The plane and crew were not found IIRC.

Hope this helps.

BTW even with 252 gal on board and 27% over expanded gross, we did climb at least 500 fpm - might have been higher but we were racing for speed. Advantages we had included: Mom and I weighed a total of 260 lbs vs FAA standard 370 lbs. Pays to be short sometimes. We carried one 30 lb suitcase for both of us for 24 days. We ended up with the Gold that year. Great memories.

[Trevor Laundy]

Pat,
Thanks for that.

Fine family achievements

My father flew Spitfires from North Australia in WWII - unfortunately my own flying is much more pedestrian!

With regard to ferry tanks, I have spent a fair amount of time crawling around the back of my aircraft and I would not fancy putting a temporary fuel tank in that position - very inaccessible as well as a long way back. I know my C of G position very well, it is far forward (as is common with turbo-ed aircraft, and moving the battery to the aft position has done no more than put the C of G WITHIN the envelope. Having a Miller nose I have the option to put 130lbs very far forward if there were a ferry tank where the rear seats normally are. I know from experience that the aircraft will fly well with very forward C of G e.g. when all the ferry fuel had burned off.

I am thinking that if my aspiration to RTW becomes fact, and I have to look at a 2000nm leg from Hawaii to SoCal, a 160gal TurtlePac in the back will be the solution. Otherwise, I will continue with my 114 gal configuration which gives me 850nm, more on a good day.

I would be doing it single crew, 190 lbs.

Regards,

Trevor

[N3322G]

Scott, please excuse hijacking your thread a bit -

Trevor, the www.earthrounders.com website has a lot of routes folks have taken. Can't quite recall what year she did it but I helped a friend of mine prep for racing a Twinco London to Australia (cool to hear about your Dad flying there) then she continued across the Pacific - look for Denise Water's route. I can put you in touch with her to know what she did for fuel on that route if you are interested.

[ScottB]

Well, I spoke to Paul at Phill-Air and the price I was quoted for the 40 gallon tank STC was $9,500 installed. I asked about the STC Kit price and there was some hesitation and a reluctance to sell the kit for us to install. Kit price if sold would be about $7,200.

Also got a quote from Osbourne today for the tip tanks and the kit price was $7,200. With the increase gross weight and aerodynamic advantages of the tip tanks this seems like the best choice to install first with price being the same. Tip tanks sounds like an easier install also. Anyone with experience installing the tip tanks have any tips to share on the installation? Looks like we'll be heading this direction.

Thanks.

[MULEFLY]

Scott... it may not be enough fuel for you but for a heck of a lot less...

http://webcoaircraft.com/cat-nacelle.html

Kit and STC are listed at $2,195... I realize that they don't update their prices on their web page too often... but still it is a $5K difference for a kit and STC... 35 hours at $80 per hour would be about $2,800 -- you would be in for about $5K total... $4K less than the 2 quotes that you have received.

All the best!
Jim

[Robert Wesley]

A couple of years ago I was living in the caribbean and looking for exended tankage for my twinco.
I do not like the looks of the tip tanks so was looking for other options.
At that time I visited the Phil-air shop and talked to Paul.
He has a very well run shop, and it looked like he did good work, and has Comanche experience.
He was doing a panel upgrade and nacell tank install when I visited.
the nacell tanks are a great fit in the nacells, and the quality of the workmanship on the tanks was top notch.
He install was very professional and neat.
It looked like the best system avialable.
It did not have a gross weight increas like the Miller wing tanks.
Sinc then I no longer live in St. Croix so the need for tankage has droped on my priority list, but I still plan on installing them in the future.
bob

[ScottB]

Pat,

I've just been able to read this post again. For us, installing tip tanks will be first but a rear fuselage tank could perhaps be an alternative to the nacelle tanks. Sounds like it may be a decent idea if tank and installation were thought out carefully. Since the TwinCo is nearly at it's forward CG limit with full fuel, adding a tank in back seems like it may be a good place to put fuel. Sounds like it was probably a one-off install with field approval but nothing to say it couldn't done again. I'll have to crunch some W&B numbers to see if that makes sense.

Thanks


[quote="N3322G"]Scott and Trevor,

One additional tank I've heard about but not seen is aft of the baggage compartment where some folks have run skis. It was used by a French Twin Co in the 1992 world race so it may have been a ferry tank with temporary install approval. It was not a good idea as the CG was much further aft. What appeared to be similar speed modded twin com's, flew 10 kts different ...

[patbarry]

Extra fuel is definitely of value to you. I am very familiar with all of the optiopns:

Osborne tip tanks = 30 gallons
Webco = 20 gallons
Capco System from Phil-Air (Paul Philips) = 40 gallons
Miller wet wing tanks. + it's irrelevant since nobody is going to do this job anyway. Parts aren't available and it's a wet wing - trying to redo the sealant is awful.

The Webco system is a simple drop-in tank in each nacelle - but only ten gallons a side.
The Osborne tanks are 15 gallons a side but the weight on the outer portion of the wing concerns me. I've seen stress cracks around rivets in wings where Osborne tanks have been used - they were certified on the aircraft in flight, but not on the ground. The taxi with full tips over bumps and gullies stresses the wing skins and can create cracks over time.
Capco / Phil Air - excellent, but a few dollars more. As for the kit' and getting the job done locally - forget it. The installation of the three tanks each side is precise, and an inexperienced person could easily screw it up. This is the best option by far, but unless you have Paul do the installation you then you are taking a risk - and you won't save money, It's an 80 hour installation and, judging by your quoted numbers, you would get a discount of two grand if you just bought the parts. It would still cost you the same two grand in time if you did it yourself.

My personal feelings that it's better to put the weight over the wheels. That leaves the Webco system or the Paul Phillips system. I reckon it is worth spending a few grand more for the Paul Phillips system since it provides greater range and is a quality system.

Pat