Long Range Fuel Tanks
 

I am planning to do a North Atlantic Crossing sometime this year. The route will be through Frobisher Bay, Sondrestrom, Reykjavik, Stornoway and then through the south of France into the Middle East. I live in the middle East and while most airports do have 100LL, the Chuck Yeager in me ( Higher, Farther, etc......) tells me that I may want to go someplace near the ( return flight ) limits of my range which does not have 100LL.

I have a 1975 T337G, Pressurized Skymaster with Riley Intercoolers and 148 Gallon factory Fuel Complement.

I can do the trip with the existing fuel tankage, but I am also thinking that it would be nice to have that extra margin.

Reading the supplement information for one type of available tank system, they have "interesting" limitations that call for a minimum amount of fuel in each tank when operating between certain weights. Also, I will only be able to carry myself and a really light passenger when operating at full fuel ( usefull load after full fiuel becomes about 210 lbs.)

I cannot envision, nor would I seriously contemplate a scenario where I would want to have 4 persons AND full fuel.

The questions I am asking myself ( and they are mostly philosphical ) are questions like:

1. For a man who likes to keep things as simple as possible, does having these tanks make the planning for everyday flying "here and there" unnecessarily complicated?

2. Do my structural safety margins become tighter by having and using these tanks?

3. Is it worth the expense?

4. Any other questions I should be considering?

Any comments from the "Conventional Wisdom, or other wisdom"?

Best Regards,......Barry Sloane, N187

One key question I forgot to mention.

As a 54 year old pilot, at some point in the future I am probably going to start loosing my marbles and I will need to convert my skymaster back into my pension fund.

Do Tip tanks add any significant value to the resale value of an aircraft such as the skymaster?

On your second message you talk about loosing your marbles. Well, I must be loosing mine because, while I understand what you're asking in the second message, I have absolutely no idea of what you're asking in the first message. Can you be more specific?

Ernie

I guess I had envisioned that when one adds tip tanks to the Skymaster, you can merely keep a gallon or two in them until you fill them for long trips.

Instead, the tanks need to have a fairly significant amount of fuel ( 12 gallons each ) in them when operating at weights between 4300 and 4700 lbs ( which is almost always ). This means that rather than keeping your main tanks full at all times to minimize the possiblity of condensation and because you rarely know how many people you will be taking on your next flight, it is best to keep the mains tanks with minimal fuel until you know your payload weight. Even with a Shadin and nortoriously inaccurate fuel gauges, the possiblitites of error increase, and cockpit workload increases with the need to wait until near destination untill electing to transfer fuel to the mains.

On the other hand, having the extra fuel on long trips means you have more options if the weather goes sour.

Which is the lesser evil;... The added complexities of flight planning on long flights which happen only occasionally, or the added complexities of the other shorter flights which will be happening more often?

I guess the question is directed to anyone who has a Skymaster with these tanks installed. Does their management of the operation of the aircraft change significantly by having these tanks?

Does the resale value of the aircraft change significantly due to the presence of these tanks?

Philosophical questions,....yes. Open ended,...yes. I may be over analyzing this, but I am a new Skymaster owner and in new terrorory here. I don't fuly understand how to assess a decision whether or not to install these tanks.

Any thoughts, no matter what they are or from whom would be welcome.

Best Regards,.......Barry Sloane N187

I can't address the operational considerations, because I have never had the tanks. There is a person on this board that has them, but I can't recall who it is. Hopefully he will answer.

Meanwhile, there is another point to consider. If you add tip tanks, the airplane's wing span will increase, and it will no longer fit into a 40' wide hangar. 40' is a very common width for "small" hangars, and the next size up is significantly more expensive. Maybe something to think about for you, maybe something for future buyers to think about that might make the plane harder to sell.

My 2 cents.

Kevin

tip tanks
 

I operate a P337 Riley with 20 gallon tip tanks. True, you now have a 42 foot wingspan and don't fit in standard hangers. But, you also have a 45 knot stall speed! Field length becomes a moot point.....
True, you takeoff with 12.5 gallons in each one most of the time. Gross weight is the biggest issue, when I top off all the tanks, I have to reduce pilot weight to 90 pounds......There is a guy in Nashville who can do tip tanks and increase your max gross to 4900 pounds. Without this, you're up against max gross frequently.
Flight planning and transferring really isn't an issue. Level off, burn the mains 45 minutes to make room, transfer.
Ron

Hi Ron

Thank you for your thoughts. This is just the sort of information I was looking for. I was aware of the standard hangar issue, but it is refreshing to learn that normal operation does not become significantly more complex.

Do you feel that having tip tanks should add anything to the resale value of your plane?

I would be interested in knowing more about the fellow in Nashville. Do you have any contact information for him?

Best Regards,.......Barry Sloane, N187

tip tanks
 

Barry, They've got to be worth something at resale, they cost something! Certainly the mod that adds gross weight would be of value. They also serve as part of a STOL kit, so there's value added from several directions.
I'll try to find the shop that does tip tanks with a gross weight increase; in the mean time, the shop is on the Nashville airport (BNA) and specilaizes in 337 mods. The mod costs $20k.
They really increase your range, 39 gallons is 1.3 hours in the P337, almost 2 more hours in a non-turbo. Carrying 12 gallons per side above a given gross weight isn't an issue, just two more tanks to put gas in when you fill up.......
Ron

gross weight increase
 

Barry, I suspect who you're looking for is Owen Bell:

Aviation Enterprises -- 615-865-1802 (owen.bell@juno.com)

Ron

optional fuel tanks
 

I have a pair of exellent aux wing tank extensions for sale. price is $4000.00 plus shipping. I do not have the plumbing, manual or pumps or PAPER WORK. paper work may be gotten from original337 form from doner a/c
.Walt Simendinger
New York
631-757-7567

Dear Walt,
I am interested in the tip tanks to put on my C336.
do you have the details of the original aircraft?
Regards
James T Grant 205-799-1716

yes, I have the info of the aircraft they came from.
Walt

Still around
 

Walt do you still have the tanks if so let me know cmark2002@msn.com
All the best!
Mark

Range
 

This is all good information, but I might add that you should also inquire about the added weight of the Porta-john :) I fly my 337H with 150Gal tanks for 900mn at 150kts all the time on one specific trip, and it's about all anybody's bladder or seat can take.

Good point, Roger. For me, 3 hours is it, then I need to be looking for that Porta-John, or at least a friendly tree:D;)
I can't imagine 6 hours in the seat without moving, either. It is possible, but difficult, to get up and walk around, let the blood flow back to the legs.