To all,

I've acquired a Javelin aux fuel tank and was planning to install it this winter. However in the euphoria of the moment I'd didn't fully realize just how much of the recently added baggage door it would block, NUTS. Has anyone on the forum done this mod, was it as functional as hoped and was the reduction in baggage area and access an issue ?

Cheers,

I have not done this mod, but I've seen both a 170 and a 172 which had this mod. FWIW, it was a factory option when my airplane was built, and it's discussed in the operators manual, but it's not an option that I have.

My observation is that it materially limits the stock baggage area, which isn't all that big on 170s or older 172s to begin with. The 170 I've seen with it has an ad hoc extended baggage area--don't know whether that was with an STC or 337 or simply doing it.

So I guess you install it, and recognize that the stock baggage area is significantly compromised. I'm guessing that you don't all that often use the back seat for passengers, so perhaps that's not a big issue for you.

Cary

Loss of space in baggage area is one thing, but if you fill that tank, you’ll move the cg significantly aft as well, further limiting what you can carry in baggage.

And, of course, you now have quite a lot of gas in the cockpit.

I’ve known a few folks who had these installed in 170s, and they made do. So, how bad do you need extra gas? Enough to lose a good bit of baggage space on EVERY flight, plus have to deal with CG? If so, suck it up and deal with it. If not, there’s probably a market in the things.

MTV

Thanks for the input, I do want/need a bit “extra” on occasion however I also carry a reasonable amount of “soft load” in an extended baggage area so C of G is a concern. All that said maybe the better option is a mod to create larger main tanks, anyone have experience with this mod ?

Was it a good deal? Why not do the tip tank mod instead? Is it because it's $5,000????

Mapleflt wrote:Thanks for the input, I do want/need a bit “extra” on occasion however I also carry a reasonable amount of “soft load” in an extended baggage area so C of G is a concern. All that said maybe the better option is a mod to create larger main tanks, anyone have experience with this mod ?

I put a Javelin tank in a 170B with a 220 Frank on it. The rear seat was removed and not used so there was still a lot of room back there. And room to put baggage up where the rear seat normally goes. So it worked out well in that respect.

What floats do you have? Is there an STC to put a compartment in one or both floats? You could haul some stuff in there if you’re short on baggage space, or better yet, put a couple Jerry cans in there for the trips where you need a little extra gas to get you home.

I did pick up the Javelin tank for a reasonable price, $5k for the tip tanks isn’t so much the issue, it’s the weight of the fuel that far out that gives me the willies a bit.

Yes, I wasn’t paying enough attention to the aircraft and that you’re on floats.

Remove the (useless) back seat, put cargo where it was and forward. If the photo is of your floats, they’re EDO 2000, so small hatches if you have hatches, but install some anyway to keep CG forward.

Aft CG isnt going to be your friend in a 170 on EDOs.

I put Flint tip tanks in my 170 on floats, and would do it again. I never had any issues with tip fuel, but I was on bigger floats too. I liked the Flints. Not cheap, but neither are any of the other options. Swap wings for 175 wings, or install Del Aire tanks.

Del Air tanks probably cost about what Flint tanks do all told.

Extra gas on floats is really nice.

MTV

DelAir tanks are nice but if you have another way to get it approved, fitting long range tanks in the wings is about the same price and less money if you scrounge a set.
You could even weld the old sight gauges back in.

If you have a way to get it approved

I have a Javelin tank in my 170B with a 180 Lycoming, it was installed by a previous owner. My airplane also has a baggage door and I do not consider the space it takes up to be a problem. What I consider the greatest problem is that the limitations for the installation require the legally allowable baggage carried to be reduced by 6 pounds for every gallon of gas in the tank, and If I remember correctly the weight of the installation itself reduces the baggage capacity by 13 pounds and a new baggage placard indicating that is required. So if the tank is full you can not legally carry any baggage in the baggage compartment. I have used the tank twice in about 150 hrs of flying, the first time it work great but you do have to burn the right tank dry before you can transfer fuel, so it requires two hours before you use the fuel. When you are transferring fuel to the right tank you are required to operate off the left tank. It requires some planning as it takes 45 minutes to transfer the full 18 gallons. The second time I used it I tried to transfer fuel on the return leg home from an airport without fuel but the transfer stopped with 8 gallons remaining in the Javelin. I had enough fuel to get home but that 8 gallons would have made the last 15 minutes much more comfortable. Having extra fuel available is nice especially with the 180 hp engine but I would not choose a system requiring transferring of fuel. For me I would be the Delair tanks, no transferring and significantly less unusable fuel than the long range tanks (Cessna 175 tanks) that a few have gotten field approved for 170's. That higher unusable fuel eats into your useful load whether you are carrying extra fuel for the flight or not.

just my 2 cents worth

Tim

Stock 170B tanks hold 42 gallons total,
as I recall the 175 tanks hold 50 (but wiki says 52).
Probably a lot of expense for an extra hour or so range, but maybe worth it to you?
(don't forget the painting to match & paperwork costs)

I think the DelAir LR tanks add 7-1/2 per side, so 15 additional total.
DelAir doesn't have much of an online presence,
but FWIW I did find a video showing DelAir LR tank install:

https://www.youtube.com/watch?v=MeSmNbJsYHQ

In all the years and hours I used the Flint tanks in my 170, they always worked like a charm. After fifteen or more years, one fitting in one wing started leaking, which was a simple fix. Otherwise, bomb proof. Transferring fuel does take some planning, but not really a big deal.

The transfer pumps are the Sam pumps that Maule uses in their fuel system.

MTV

hotrod180 wrote:Stock 170B tanks hold 42 gallons total,
as I recall the 175 tanks hold 50 (but wiki says 52).
Probably a lot of expense for an extra hour or so range, but maybe worth it to you?
(don't forget the painting to match & paperwork costs)

I think the DelAir LR tanks add 7-1/2 per side, so 15 additional total.
DelAir doesn't have much of an online presence,
but FWIW I did find a video showing DelAir LR tank install:

https://www.youtube.com/watch?v=MeSmNbJsYHQ

Not quite. Stock 170B tanks have 37 gallons USEABLE. Stock 175 tanks hold 52 gallons, with 43 useable, which gives a 170 6 more gallons, at least in theory. In fact, some of that unusable fuel in the 175 tanks is useable, unless you’re performing some pretty weird maneuvers. But in any case six gallons still helps. I have a friend with these tanks in a 170 who regularly uses 48 to 50 gallons.

Nevertheless, if you need lots of fuel, the Flint tanks bring useable fuel in a 170 to 60 gallons.

MTV

Just to put the information out there. The 170A, 170B and early 172 have 42 gal tanks with 37 gal usable so you carry 30 pounds of unusable fuel, where as the 175 (referencing the 175 FAA Aircraft Type Certificate) has 52 gal tanks with 42 gal usable so you carry 60 pounds of unusable fuel. The unusable fuel for the 170, early 172, and 175 are based on the fact that the tanks have only one pickup centered at the wing root as opposed a forward and aft pickup found in later model 172's. So to get 5 gallon (45 minutes or less) of additional fuel you carry not only the small difference in the weight of the larger tanks but 24 pounds of extra fuel on every flight. The legal unusable fuel on the Delair tanks is much less I believe. On the Javelin tank the unusable is only 1/2 gal and I believe but am not certain that the Flint tanks also have a low unusable fuel number,

Tim


corrected 170B usable fuel and additional usable fuel with 175 tanks

bat443 wrote:Just to put the information out there. The 170A, 170B and early 172 have 42 gal tanks with 36 gal usable so you carry 36 pounds of unusable fuel, where as the 175 (referencing the 175 FAA Aircraft Type Certificate) has 52 gal tanks with 42 gal usable so you carry 60 pounds of unusable fuel. The unusable fuel for the 170, early 172, and 175 are based on the fact that the tanks have only one pickup centered at the wing root as opposed a forward and aft pickup found in later model 172's. So to get 6 gallon (45 minutes or less) of additional fuel you carry not only the small difference in the weight of the larger tanks but 24 pounds of extra fuel on every flight. The legal unusable fuel on the Delair tanks is much less I believe. On the Javelin tank the unusable is only 1/2 gal and I believe but am not certain that the Flint tanks also have a low unusable fuel number,

Tim

The numbers I provided earlier were from the aircraft operators manual of my 175. 9 gallons of unusable fuel, 4.5 per side. That's also the marking on the fuel selector on this 1958 airplane.

Cut and pasted from the 175 TCDS: Fuel capacity 52 gal. (two 26 gal. tanks in wing (+48); 43 gal. usable).


The 37 gallons usable in my 1952 170 was also from the operator's handbook. Cut and pasted from the TCDS: Fuel capacity
42 gals. total, 37 gals. usable (Two 21 gal. tanks in wings at +48)).

And, my 170B had fore and aft fuel lines. The forward tank outlets was where the Flint tank lines Tee'd in.

MTV

Thank's MTV corrected the 170B usable fuel in my previous post. I agree that the "straight" 175 has 43 gal usable, the 175A and B have 42 gal usable, and the 175C and P172D (for Cary) have 41.5 gal usable, so pick a number you like. It still doesn't change my point that you carry more than just the weight of the fuel tank on every flight, regardless of how you add fuel capacity, more with some choices than others.

I don't doubt that your 170B had tanks with two fuel pickups each but I just reviewed the 170B parts manual and that is not how they left the factory. Each tank had one pickup just aft of the fuel gauge and the line runs aft and down the door post.

Tim

Abrupt turn and thread drift, I'm leaning towards MTV's suggestion of float hatches. As he notes they will be small but I also see them as "multi-functional" so has anyone done a set of these on EDO 2000's

Yes, I installed a set on my 2000s on a Super Cub.

MTV

mtv wrote:….. If the photo is of your floats, they’re EDO 2000, so small hatches if you have hatches, but install some anyway to keep CG forward. Aft CG isnt going to be your friend in a 170 on EDOs....

"So small hatches".....how small are these small hatches?
Big enough for a standard 5 gallon gas can,
or would it be a bushbag or smaller cans show?