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 Fuel Caps?

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 while refuelling.

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 skin panels.

- 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.