Frequently Asked Questions about Monarch Replacement Premium Caps
- What tanks do the Premium Caps fit?
If you have bladders installed, we will provide you with large round
plates. These plates interface with Monarch rigid tanks as well. If
your Cessna has wet-wings, we will provide you a set with either small
round or an oval plate, depending on the serial number of your airplane.
- What advantages do Monarch Premium Caps have over the original
equipment in my Cessna 180 through 210?
The Monarch Premium Cap Set upgrades your fuel inlets in many ways:
The inlet plate is made from .080" clear-anodized aluminum to resist
warping. It is a rigid plate that holds it’s shape when installed.
The plate is die-formed to raise the inlet hole about 3/16" above
the surface of the wing so any water running down the wing is diverted
away from your fuel inlet holes. It is a true "raised inlet"
fuel cap. The cap is a stainless steel umbrella with a ratchet mechanism
to prevent overtightening. It is designed to protect the inlet hole
from direct water ingress.
Below the inlet hole we have designed an inlet neck the extends down
into the tank. At the bottom of this neck is a flapper valve that prevents
massive amounts of fuel from siphoning out of your tanks if your caps
are ever left off or loose. We have documented a case where a plane
equipped with Monarch Premium Fuel Caps has taken off without caps.
The entire flight was made with very little fuel loss.
- Does the Monarch Premium Fuel Cap allow jet fuel to be introduced
into the tank?
No, our inlet is 1.5" at the widest point to keep jet fuel nozzles
out. Your insurance company may give you a discount on your premiums
or pay for a portion of these caps due to this fact. Usually all they
need is something in print. (such as this document) If they need a formal
letter or a drawing, we will be happy to provide it to them.
- Do I have to drain my tanks when installing Monarch Premium
We recommend it, since you will be scraping off old sealant and possibly
some paint and applying new sealant, it is likely you will have some
debris fall down into the tank. A large shop rag on the floor of the
empty tank will catch all the debris.
- Why is the retaining chain so light?
The reason we chose to use a light retaining chain is that if the
cap is ever left off, it won’t flail about and damage your wing
while in flight. It’s only purpose is to hold the cap on the wing
If the chain did not break, you would probably have to replace the
cap plate and have extensive wing skin repair done on your plane. The
cost of replacing a single cap is far less than repairing aluminum wing
- What is the installation time?
Usually 1.5 hours per side. See the question below on sealant for
total time the plane will be out of service.
- Do I need to order sealant with my cap set?
If your mechanic does not stock it, you may order Sealpak sealant
directly from us when you order your caps. One tube is enough to install
two cap plates. This sealant is non-structural so you can remove your
cap plates relatively easily at a later date. It is required for installation
on wet-wing fuel caps, but it is an option on bladder cap installations.
Monarch Air keeps all of it’s sealant within the date codes and
in refrigeration until time of shipment. This sealant has a shelf life
of six months; so if you order sealant from us when you order your caps,
you need to have your caps installed right away.
It is recommended that you have a hangar temperature of at least 70
degrees when using this sealant. It needs at least 24 hours to set;
more if the temperature is at the low end of the allowable spectrum.