Parker Aerospace lightning-safe gravity fuel filler caps are used to lock, seal, and act as an identifier for the gravity fill port of an aircraft fuel tank. The advantages of Parker’s gravity fuel filler cap include the use of a lightweight composite base that meets current lightning-safe standards, O-rings with a fluorosilicone seal, and a lanyard made of polyurethane. Non-lightning-safe caps have lanyards of varied material and type, such as chain links and cables.

Parker Aerospace gravity fuel filler caps are three inches in diameter, and are both indexing and non-indexing. To fuel the aircraft, the caps are manually actuated by lifting and turning the handle, which vents the fuel tank. The cap is then removed from its mating adapter, allowing the aircraft to be refueled.  The cap remains attached to the aircraft by a lanyard. Once refueling is complete, the cap is inserted back into the adapter and the handle is actuated back to a closed position, which effectively reseals the gravity fill refuel port.

Parker Aerospace is the leading provider of Lightning-Safe® products for aircraft, with almost 50 years of lighting protection expertise. Our equipment will work to dissipate the static charge caused by lightning strikes and other electrical upset conditions. Our array of Lightning-Safe products has been designed to meet and even exceed the stringent lightning safety requirements of the aircraft industry.

This Parker technology is grounded on decades of proven on-wing service experience. Parker Aerospace has unique and specialized on-site testing facilities to ensure safety and superior performance of all of its Lightning-Safe products; we were the first to patent a lightning safe seal (1968).  

FEATURES AND ATTRIBUTES:
• Lightning protection
• Ignition prevention to prevent explosions
• Mates with adapter per military standard MS27379
• Design in accordance with safety standard MIL-C-38373B
• For use with all aircraft fuels
• O-ring seal conforms to military standard MS33666

APPLICATIONS:  Parker Aerospace’s gravity fuel filler caps are used on a multitude of aircraft (both winged and rotary) by countless customers worldwide.
• Commercial & regional aviation
• Military
• General aviation
• Business jets


OPTIONAL FEATURES:
• Key lock
• Vented
• Hinged
• Visual fluid level indicator (sight glass)
• Dust cover
• Easy-lift handle
• Contoured adapter