Adding a 2nd fuel tank to a 1948 170 left wing

N4104V · Post by **N4104V** » Fri Oct 24, 2003 12:04 am

I am planning to add second 12.5 gallon tank to the left wing of my 170. I would like to talk to someone who has done this mod about your experience and flying after adding the tank.

Thanks, J Davis

zero.one.victor · Post by **zero.one.victor** » Fri Oct 24, 2003 4:55 pm

I have the extra tank in my ragwing. A previous owner added it,so I don't have anything to say about the installation. Don't know if anything special is involved, probably just duplicate the RH side. Also don't know what paperwork is required--probably a field approval 337 which might not be too easy to get these days. That previous owner "forgot" to log the installation. Apparently nobody's ever caught that at annual time,except me.
Flying: with the 4th tank,I'm placarded for 50 gallons total,46 usable. This may be a bit optimistic. Probably more like 42 or 43 usable.Can't seem to get much more in the tank in the 3-point attitude--probably could if it was a nosedragger. The added tank has it's own sump drain,I wouildn't mind adding that to the outboard tank on the RH side if/when I have to mess with the fabric under there.
My airplane seems to feed faster out of the RH tanks than the left,so I usually switch to "left" after takeoff with full tanks & fly that way for a while.
Seems like a worthwhile mod,especially if you have the fabric off the LH wing anyway. Having 10 or 11 gallons more usable fuel would be a real advantage,especially on a trip.

Eric

mrpibb · Post by **mrpibb** » Fri Oct 24, 2003 10:23 pm

When I recover my ragwing I was also thinking of adding a fouth tank, Eric was yours a field approval or was there a stc holder for the mod?
If you have the 337 I would like to know how it was installed, pos. a copy if you wouldn't mind. Is there anyone else out there who has info on the adding of a fourth tank to the 48?
Vic

3958v · Post by **3958v** » Sat Oct 25, 2003 1:56 am

Vic I have the second tank in the left wing and it sure is nice for long trips. Real comfortable to stay up for an extra hour. My instalation was a duplicate of the right wing instalation. If you are interested I might be able to help you with the tanks. Look in the directory and give me a call if you want. Bill K.

N2540V · Post by **N2540V** » Sat Oct 25, 2003 3:26 am

I have located my copy of the 337 that was used to install my extra tank.
I checked the date (July 1952) and it is older than me

Drop me a pm and I can mail you a copy.
Jim N2540V

zero.one.victor · Post by **zero.one.victor** » Sat Oct 25, 2003 5:13 am

The 170 Assn's list of 337's indicates at least one ( if not more ) for installation of a second LH tank. Copies are available for like a buck each--contact Velvet at Assn HQ for more info.

Eric

mit · Post by **mit** » Sat Oct 25, 2003 9:00 pm

N2540V wrote:I have located my copy of the 337 that was used to install my extra tank.
I checked the date (July 1952) and it is older than me
Drop me a pm and I can mail you a copy.
Jim N2540V

I believe that 1952 is old enough to qualify as (approved data) for the modification. Which would make it much easier to get a field approval.

The International Cessna 170 Association