Hello

Are there a lot of folks that are still using these caps? The reason i ask is because i looked at a C185 for sale a while back that still had them on it, and i have a buddy that i see about 3 times a year that still has these caps on a 1979 C185.

I have Monarchs on our 182, but just curious as to why people would still run them if there are so many documented problems with them.

Mike

My definition of those are the ones the very old 180's and 182's had that consisted of a sheet metal door covering a well below with a gas cap. The well had a drain that was always plugged and filled with water then went in the tank. I didn't know these still existed into the 185 era. Learn something new every day. Yes, they suck. Monarchs are great IMO.

People still run the original 185 caps for three reasons:

They are cheap and not too bright.

They don't fly much, or not at all

The airplane never overnights outside a hangar.

MTV

"Killer caps" sure is an ominous alias. Who coined it? Are they that dangerous, or is it a dramatization used to stimulate Monarch's sales? Wouldn't there be a mandatory Airworthiness Directive is they killed lots of people?

What's a "killer cap" and how/why does it kill ? I'm wondering if I have these caps. Is it the vent arrangement, the gasket..?

From what i thought, they were the caps that look like a beechcraft bonanza cap. They have a little deal you lift up to open the cap and they sit flush with the wings, from what ive been told they can gather water and you can have problems. FWIW MTV, the 185 guy i see a few times a year has never had his 185 in a hanger other than when its in the shop!


Mike

The flush caps are not the demon some would have you believe!

On any preflight one of your duties is to sump the fuel.

If you do this and you find water then you need to be figuring out why.
Whether you have the flush caps or raised caps.
The other thing is if water is getting in through the cap then the fuel is most likely getting sucked out the cap in flight if the vent system doesn't keep up if it is plugged or partially plugged maybe even possibly cause fuel starvation.
Not only the flush caps, raised caps can do this also.

If you find a problem then fix it!
Install o-rings etc in the old flush type shaw caps.
Not that big of a deal.

They have been around for a long time and will continue to be around for a long time.

Yes the raised caps are better and less maintenance if you have some extra cash you would like to put in your plane then sure, upgrade your caps!

Monarch caps will run $700 a pair.
Cessna Service kit is $2146.00 on cessnaparts.com

Here's a good picture showing the "killer caps".


I would think that these caps would be worse though, as there is actually a "well" to hold water.


What say the experts?

Tango fox is 100% on.

The "killer caps" are not the old 182 and 180 style caps with the sheet metal cover. They are the flush shaw aero caps.

King air, pilatus, caravan all sorts of new production airplanes still use flush caps. They all leak water if the o rings are old or if you take the cap off without blowing away all the accumulated rain water. The biggest reason to switch is probably the price of a new cap. A new shaw cap is 500 bucks. I doubt they make the old plastic ones anymore.

TangoFox wrote::twisted: The flush caps are not the demon some would have you believe!

On any preflight one of your duties is to sump the fuel.

If you do this and you find water then you need to be figuring out why.
Whether you have the flush caps or raised caps.
The other thing is if water is getting in through the cap then the fuel is most likely getting sucked out the cap in flight if the vent system doesn't keep up if it is plugged or partially plugged maybe even possibly cause fuel starvation.
Not only the flush caps, raised caps can do this also.

If you find a problem then fix it!
Install o-rings etc in the old flush type shaw caps.
Not that big of a deal.

They have been around for a long time and will continue to be around for a long time.

Yes the raised caps are better and less maintenance if you have some extra cash you would like to put in your plane then sure, upgrade your caps!

Monarch caps will run $700 a pair.
Cessna Service kit is $2146.00 on cessnaparts.com

Yeah, I guess you're right.....

Because there were several high profile accidents associated with the combination of these caps and bladder tanks, Cessna developed the famous "Shake, rattle and roll" Service bulletin to encourage pilots to
do a better job of draining water from tanks......totally unnecessary, of course......just CYA on their part....and to prevent the FAA from forcing an AD on the subject.

Not long after, Cessna switched from bladder tanks and flush caps to wet wings and raised caps.....for this specific reason......at a cost of I'm guessing a couple hundred thousand to engineer, develop, certify and implement into their production......all a waste of $$$ of course, because the old fillers/tanks were totally safe.

Cessna then developed a kit to replace the flush caps with retrofit raised caps....a few thou to develop and certify, I'd guess......but again, totally unnecessary......

Monarch developed a raised filler/cap modification to address this issue.....no doubt they spent a few thou to develop and certify......totally unnecessary......

Finally, take a look at one of the newer Cessnas, built since the single engine line went back into production......sixteen sump drains......totally unnecessary, though.

Really???

Here's the problem, folks: The airplanes that were equipped with those caps also are equipped with bladder tanks. Those bladder tanks almost always have wrinkles in the bladder material on the bottom of the tanks....it's virtually impossible to get them installed with a totally flat bottom.

Those wrinkles in the tank bottom act as little dams, which will hold water back from flowing downhill into the sumps......until you take off and encounter a little turbulence. Hence, the "shake, rattle and roll" SB.

The problem is worse with seaplanes and amphibs, where the wing is relatively level, and thus the water tends to remain against the o-rings.

Granted, if the o-ring seals (four of them ON EACH WING, by the way, two for the caps, and two for the access ports) are in perfect condition, they don't leak....much.

But, to suggest that you just need to properly sump your tanks during pre flight is simply disingenuous at best, and dangerous at worst.

Again, there's a reason that all the actions I noted were done. Granted, a lot of that was done in response to litigation, but......someone got dead.

And, comparing these caps to Caravans and other airplanes with flush fillers is also disingenuous, since those airplanes all use wet wings, making it much easier to actually remove water from the tanks if any is introduced.

I had an amphib 185 with these caps sit outside during a major deluge once. Sumped the tanks, and found nothing but water. Sumped, and sumped, and.......finally got fuel. Taxiied to the gas pumps to fill up. Thought.....hmmmm......and sumped again....all water. And again, ad nauseum.

Long story short, we had to pull the access ports on those tanks, drain all the fuel out of them, then get inside the tanks and swab all the water out of the bladders with cotton rags. Then, added some fuel, and drained it again......

And, yes, the o-rings were bad on that plane. But, the point is, once you introduce water into those bladders it can be VERY difficult to get it all out of those tanks.

FWIW.

MTV

mtv wrote:People still run the original 185 caps for three reasons:

They are cheap and not too bright.

They don't fly much, or not at all

The airplane never overnights outside a hangar.

MTV

I still run the old style Cessna caps despite dire warnings from my buddies with Monarchs. Why?

Cheap and not too bright - Probably.

I fly nearly every day, commercially.

My plane sits outside year round, mostly in Kodiak and on the Ak Peninsula. We get a little rain.

The reason I have not switched is because I have never had trouble with the caps leaking. I sump religiously and have had plenty of water in the fuel from poor fuel sources. Never on a regular basis from leaking. So what change? Oh, and those buddies with Moanrch caps - yeah they get water too. One had a forced landing due to water in the fuel.

Use what works for you in reality and not what is recommended by someone on the Internet. If you are having problems with water in the fuel you should know it and have it addressed ASAP! If not, why fix what isn't broke?

mtv wrote:

TangoFox wrote::twisted: The flush caps are not the demon some would have you believe!

On any preflight one of your duties is to sump the fuel.

If you do this and you find water then you need to be figuring out why.
Whether you have the flush caps or raised caps.
The other thing is if water is getting in through the cap then the fuel is most likely getting sucked out the cap in flight if the vent system doesn't keep up if it is plugged or partially plugged maybe even possibly cause fuel starvation.
Not only the flush caps, raised caps can do this also.

If you find a problem then fix it!
Install o-rings etc in the old flush type shaw caps.
Not that big of a deal.

They have been around for a long time and will continue to be around for a long time.

Yes the raised caps are better and less maintenance if you have some extra cash you would like to put in your plane then sure, upgrade your caps!

Monarch caps will run $700 a pair.
Cessna Service kit is $2146.00 on cessnaparts.com

Yeah, I guess you're right.....

Because there were several high profile accidents associated with the combination of these caps and bladder tanks, Cessna developed the famous "Shake, rattle and roll" Service bulletin to encourage pilots to
do a better job of draining water from tanks......totally unnecessary, of course......just CYA on their part....and to prevent the FAA from forcing an AD on the subject.

Not long after, Cessna switched from bladder tanks and flush caps to wet wings and raised caps.....for this specific reason......at a cost of I'm guessing a couple hundred thousand to engineer, develop, certify and implement into their production......all a waste of $$$ of course, because the old fillers/tanks were totally safe.

Cessna then developed a kit to replace the flush caps with retrofit raised caps....a few thou to develop and certify, I'd guess......but again, totally unnecessary......

Monarch developed a raised filler/cap modification to address this issue.....no doubt they spent a few thou to develop and certify......totally unnecessary......

Finally, take a look at one of the newer Cessnas, built since the single engine line went back into production......sixteen sump drains......totally unnecessary, though.

Really???

Here's the problem, folks: The airplanes that were equipped with those caps also are equipped with bladder tanks. Those bladder tanks almost always have wrinkles in the bladder material on the bottom of the tanks....it's virtually impossible to get them installed with a totally flat bottom.

Those wrinkles in the tank bottom act as little dams, which will hold water back from flowing downhill into the sumps......until you take off and encounter a little turbulence. Hence, the "shake, rattle and roll" SB.

The problem is worse with seaplanes and amphibs, where the wing is relatively level, and thus the water tends to remain against the o-rings.

Granted, if the o-ring seals (four of them ON EACH WING, by the way, two for the caps, and two for the access ports) are in perfect condition, they don't leak....much.

But, to suggest that you just need to properly sump your tanks during pre flight is simply disingenuous at best, and dangerous at worst.

Again, there's a reason that all the actions I noted were done. Granted, a lot of that was done in response to litigation, but......someone got dead.

And, comparing these caps to Caravans and other airplanes with flush fillers is also disingenuous, since those airplanes all use wet wings, making it much easier to actually remove water from the tanks if any is introduced.

I had an amphib 185 with these caps sit outside during a major deluge once. Sumped the tanks, and found nothing but water. Sumped, and sumped, and.......finally got fuel. Taxiied to the gas pumps to fill up. Thought.....hmmmm......and sumped again....all water. And again, ad nauseum.

Long story short, we had to pull the access ports on those tanks, drain all the fuel out of them, then get inside the tanks and swab all the water out of the bladders with cotton rags. Then, added some fuel, and drained it again......

And, yes, the o-rings were bad on that plane. But, the point is, once you introduce water into those bladders it can be VERY difficult to get it all out of those tanks.

FWIW.

MTV

As I said i do believe raised caps are better!

And there is an AD for tank wrinkles. it came out in the 80's

But the flush caps will work just fine and have done so for i don't know maybe 60-70 years???


Look here: an outfit that has an STC to put them on Twin Commanders.

http://www.commander-aero.com/SERVICE/MODIFICATIONS/Supplemental-Type-Certificates/Lift---Turn-Fuel-Caps.aspx

I guess they should have checked with MTV before going to all the trouble to develop this!



If your 185 with the flush caps o rings had been maintained properly they would not have leaked!!!

And tell me again how you discovered they had a problem
I believe you said something about sumping the tanks??????

Odds are they had been leaking for a while and the previous sumps got a little water and the pilot ignored it???

A1Skinner wrote:I would think that these caps would be worse though, as there is actually a "well" to hold water.


What say the experts?

I don't fall under the expert title -
These are what I have on my 57 182... So sounds like these are *NOT* the ominous killer caps? But as Hank points out, it can become a well to hold water. What I do is use a can of keyboard cleaner (compressed air) and I blow out the drains every other fuel stop or so. I live in sunny California and have it hangared so along with that and doing the wing shake, fuel test - feeling like I should not have any issue's.

I have the flat panel covered caps on my 180 as well. They are not the hump backed ones shown in the other thread, and all indications are that they are original. Apparently they don't kill well, as near as I can tell this aircraft has never lived in a hangar, and the vast majority of it's life was spent in Colorado, Idaho, and Montana....

I too view it as my duty to know exactly what's in my fuel cell and act accordingly. If I lived in SE Alaska and my caps needed repair or changing I might consider utilizing a raised version. Suggesting that anyone and everyone regardless of mission or location should change to another cap style is nothing short of sensationalism. Attaching a name like 'Killer Cap' to a part that has a compromise in its design is equally sensationalism. I can't think of many aircraft components that don't bare some compromise, and most can yeild catastrophic results if not dealt with accordingly, perhaps they are all just killer.. Killer Parts...

I have had both mechanics and pilots scowl at my continued use of the 'Killer Cap' .... little did they know these are the infamous 'Well Caps'... The 'Killer Caps' are what resides on the companies Thrush's..... six flying here, one in Kalifornia and three in Nevada, they are all 'outdoor' airplanes, and apparently their caps all suck at killing as well...

Until recently I thought 'Killer' meant 'cool' or good Here all along I thought people commenting on my 'Killer' MT prop was a good thing perhaps I should try a raised version

Take care, Rob

As has been pointed out already, the so-called "killer caps" (that description was a great marketing ploy by Monarch BTW!) are the flush caps with the locking lever, NOT the recessed well / raised neck caps with the (convex or flat) flapjack covers. I have the original convex flapjack arrangement on my 53 model. I have a set of Monarch caps which came with it when I bought it, but I haven't gotten around to installing them yet. Partly because the spring-loaded flapper (that they tout as preventing gas from being siphoned out if you leave the caps off in flight) don't seem to be compatible with self-fueling out of 5 gallon cans. I dreamed up an adapter to hold the flapper open while fueling that any muffler shop should be able to fabricate on the cheap, so I guess I will eventually get around to installing the monarchs, but I'm not in a big itching hurry.

Yes, Thank you for that clarification

Great explanation Rob. I don't have these caps. I have the raised Cessna ones. I think they are stock on the 62 180? They work great and I don't get water in my tanks. And it's not an inside airplane and don't think it ever has been.

Hey Rob,

Thought I'd mention this. My buddy with a RV-9a found these cool nozzles for his 5 gallon jugs that have a level sensor to shut off when the tank is full. The neck is long enough that it should push the flap down. The cool thing is you can turn it upside down and the flow doesn't start until you push down on it. He throws one in each wing, goes about his business, and comes back to it with equally fueled tanks and jugs shut off and ready to be removed. I switched out my Cessna caps for Monarchs and love them.

Not 100% sure, but this might be the one he uses.

https://www.google.com/shopping/product/5590481012503602517?q=auto+shut+off+gas+can+spout&client=safari&hl=en&biw=1024&bih=671&bav=on.2,or.r_cp.&bvm=bv.88198703,d.cGU&tch=1&ech=1&psi=FykDVciODY7woATH7YL4BQ.1426270491088.5&prds=paur:ClkAsKraX4iaewdy0e5okhzcCZx4JVa2EnegvOuXKYEk1xIJkAMC2XLzi8zsX-b_nrugb2dFQfSNXMqco_p8_bDLSQqTbIEkmyrlJm3pSoiHkmkWk-HGJBzN-BIZAFPVH71P15b9lmd9EuIUDxYg0mDu2l_0Xg&ei=SykDVY66G8ywogTvlICIDw&ved=0CLkCEKYrMAw

Rob wrote:I have the flat panel covered caps on my 180 as well. They are not the hump backed ones shown in the other thread, and all indications are that they are original. Apparently they don't kill well, as near as I can tell this aircraft has never lived in a hangar, and the vast majority of it's life was spent in Colorado, Idaho, and Montana....

I too view it as my duty to know exactly what's in my fuel cell and act accordingly. If I lived in SE Alaska and my caps needed repair or changing I might consider utilizing a raised version. Suggesting that anyone and everyone regardless of mission or location should change to another cap style is nothing short of sensationalism. Attaching a name like 'Killer Cap' to a part that has a compromise in its design is equally sensationalism. I can't think of many aircraft components that don't bare some compromise, and most can yeild catastrophic results if not dealt with accordingly, perhaps they are all just killer.. Killer Parts...

I have had both mechanics and pilots scowl at my continued use of the 'Killer Cap' .... little did they know these are the infamous 'Well Caps'... The 'Killer Caps' are what resides on the companies Thrush's..... six flying here, one in Kalifornia and three in Nevada, they are all 'outdoor' airplanes, and apparently their caps all suck at killing as well...

Until recently I thought 'Killer' meant 'cool' or good Here all along I thought people commenting on my 'Killer' MT prop was a good thing perhaps I should try a raised version

Take care, Rob

Yeah, I hear Kalifornia and Nevada are getting a shitload of precipitation these days....

And, just to clarify, I'm not the one that called them "killer caps".

Comparing to other aircraft really isn't relevant, because it's the combination of the old fuel bladders AND the caps that MAY cause problems. I've got around 3000 hours in these airplanes, and only had this issue once.

Once was enough, thanks.

MTV

FWIW, I have the well-type fuel caps on my P172D (no flapper covers like early 180s/182s have), which were standard on earlier 172s. Whenever I park her outside for awhile, I put these guys on, which keeps water out of the well and out of the fuel cap vents:



They work pretty well--in the 11 years I've had my airplane, I haven't had any water in either tank. So that I won't forget to take them off, I extended the "Remove Before Flight" tags which were on them (and easy to miss during pre-flight) with cords, which I drape over the leading edge and loop around the struts.

Cary