We are currently having Groh Aviation just outside of Indy install a set of the Monarch Aux Tanks on the newly acquired ’55 180. I thought I would share this modification with the group since it is on an early 180 with a STOL kit. Due to the way Cessna manufactured the early 180’s we have to keep the main tank blatters instead of going with the Monarch. I will update the proggress as we go.

Thanks for the pictures! I look forward to seeing the process.

Looks cool how many Gallons increase ? Saw a set being added to wing in Idaho with wings off of 180.

Very cool, this is a mod that I would really like to do as well. Thanks for posting, more details would be appreciated [emoji2]

Quickdraw1 wrote:......... Due to the way Cessna manufactured the early 180’s we have to keep the main tank blatters instead of going with the Monarch. .........

Can you elaborate? I took a quick look at the Hartwig / Monarch website but didn't see the fuel cell application described except in very general terms ( aka "Cessna").

Thanks for posting. While the slant tank bladders work fine, it would be nice if we could install new that are made of the same red plastic that I carry fuel to the plane from the gas station. Lots of E85 and 100% biodiesel carried in those same jugs for years and they seem to still be in good shape. Are your new aux Monarch tanks fiberglass? I think so????? Any way to know if it is the good resin that is resistant to ethanol????

I helped install a set of Monarch mains in a '56. They were not the same material as the aux tanks - they were grey plastic with the angle in one corner.. Do they not make that kit anymore?
I installed both in my '76. A long project but I have 97 gallons and it's probably paid for itself.

Last set of Monarch tanks I installed were some sort of rotomolded plastic lic those red jerry cans, would like to know what they're made out of these days.

Not disparaging Monarch tanks at all, but Flint also makes aux tanks for 180s and 185s (as well as all the other 100 and 200 series Cessnas). The internal aux tanks fit inside the ends of the wings and add 23 gallons (smaller than the Monarch tanks). The external aux tanks (185, 206, 210) add 3' to the wing span (might not fit in some T-hangars) and add 28-30 gallons depending on model, plus increase the gross weight by 250 to 400 lbs, depending on model. My IA has some experience adding the internal tanks and says it's relatively straight-forward, but time consuming. Obviously the internal tanks reduce the usable load by the weight of the tanks (34 lbs) plus the weight of fuel (138 lbs), about the weight of one passenger. The external aux tanks add more to the gross weight than the weight of the tanks and fuel.

All that FWIW.

Cary

Thanks everyone below I am going to answer all of the questions from the past day.

182 STOL Driver – It is around 90 gallons of useable fuel.

Hotrod180 – Hartwig does not promote any of the Monarch main or aux fuel tanks. You have to talk to Butch in the Hartwig Canadian office to get any info on the Monarch tanks.

180Marty – I will be posting some new pictures today but from what it looks like they are plastic. I will reach out to Josh at Groh Aviation to see if there is any info in the paperwork regarding ethanol.

Mudwagon –Yes you are correct. In the 90’s when I first learned about Monarch they offered slant main tanks for early 180’s. Come to find out from Butch at Hardwig is that the old Monarch company was sued a few times because the tanks did not fit in all the early 180 due to the variation in the slant in those wings when Cessna built them. So they do not sell the mains anymore which is a major bummer. I think this helps with some of Hotrod180’s question as well.

Cary – There are two reason we did not go with Flint. The first being that the aux tanks feed the mains by gravity not a pump and the second is the location of the fuel.

I cant wait to see more pics!

There is a set of main and aux tanks for sale on Alaskas list right now. http://alaskaslist.com/1/posts/10_Trans ... Tanks.html

.

Hey guys below you will find the new pictures I got from Josh at Groh Aviation. The first pics I posted were sent to me on Tuesday of last week. Due to a crazy week at work and home there was a delay in posting. The new pictures are in numerical order on how they were sent to me.













From what Josh stated in his e-mail to me is that they are almost done with this mod.

Glacier - I have not seen the connection myself but can go by what Butch at Hartwig told me. He said that the new blattters will have a nipples installed on them to make the connection to the aux tank via a piece of pipe. I hope this helps.

Quickdraw1 wrote:Thanks everyone below I am going to answer all of the questions from the past day.
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Cary – There are two reason we did not go with Flint. The first being that the aux tanks feed the mains by gravity not a pump and the second is the location of the fuel.

Yeah, the Flints are clear out at the end of the wings compared to the Monarchs. Earlier Flints were gravity fed to the mains, but they found that fuel transfer was more reliable by pumping them from the auxiliaries to the mains. I have no opinion about whether one is better than the other, just commented in case anyone wanted to consider an alternative.

Cary

Never flown with Flint or Monarch aux tanks, but I think I'd rather have that fuel weight closer inboard than way out at the tip.

75lbs on the wingtip seems like a lot of weight to me over a long arm. I've flown a 53 180 with monarchs in the tips, had a 1/4 turn valve and they drained into the main tanks. It was nice to have all that fuel if need be.

I flew a 206 with early Flint tip tanks. Those tanks, unlike the 170/180 tanks, just screw onto the end of the wing. They all have pumps, and they T into the fuel outlet line from the main tank. Those tanks are waaaay out there, since they actually extend the wing at least 18 inches a side. They also permit increase of gross weight to 3800 pounds, and added weight does NOT have to be in the tanks.

That is indeed a lot of weight way out there, but I've never heard of a failure or any issues with those tanks.

I do agree, however, that all that weight out there makes the plane kind of lumbering on the ground.

MTV

I'm not an engineer, maybe one can pipe up, but I believe hanging that fuel weight out there counterintuitively makes the wing stronger, something about balancing the weight on either side of the strut. This is why the early beaver gross weight increase limited the last 240lbs or so to fuel in the tip tanks. Am I right about this or misremembering my talk with the DER?

I'm unfamiliar with beaver gross weights, but a lot of aircraft have zero fuel weight limits. It has to do with cabin or cargo bay structure capacity. King Air's have a similar deal where they can take up to the max takeoff gross but only so much can be non-fuel weight.

In flight the struts will be in tension, so the weight in the tips won't do any worse than make it feel more sluggish in roll until the fuel's burned off (higher angular inertia). All that extra weight would be flying, not riding along.

On the ground I imagine you'd see slower rolling rates but larger roll attitude changes as you rolled over bumps at lower speeds for the same reason.

I'm unfamiliar wither specifics on the flint certification process, but I'm pretty sure those loads were tested to failure and then a fat margin applied before they got certified. I wouldn't be worried about it if I wanted more fuel for long cross countries and more wing area all the time. I mean, I wouldn't expect to have fuel in the tips for rough field ops anyway.

I am planning on adding these to my 56 180. How much were the tanks and how much was your install cost?

I still for the life of me do not understand why Hartwig does not advertise them.

Paul Brown