Cirrus Service Advisory Throws Fuel on G100UL Maintenance Debate

The SA creates a potential dilemma for aircraft maintainers.

Richard Scarbrough

Tuesday, July 16, 2024 at 11:51 AM ET

Verified

Edited By:

Ryan Ewing

GAMI is disputing Cirrus’s claim that use of G100UL voids the warranties on engines supplied by Lycoming and Continental and used in its aircraft. [Credit: Shutterstock]

Key Takeaways:

Cirrus issued a service advisory (SA24-14) against using FAA-approved G100UL fuel in SR Series aircraft due to "inconclusive" materials compatibility concerns (specifically a fuel tank sealant issue) and potential voiding of engine warranties.
This creates a significant dilemma for aircraft maintainers, who must decide whether to return aircraft to service "IAW OEM guidelines" when they might contain FAA-legal but manufacturer-disapproved G100UL fuel.
GAMI, the developer of G100UL, disputes Cirrus's concerns, citing extensive testing, years of safe use (including on their own SR22 with the referenced sealant), and challenging the claim that G100UL voids engine warranties.

See a mistake? Contact us.

In June, Cirrus released a service advisory (SA) regarding the use of fuel that had not been approved for SR Series aircraft. This creates a dilemma for many, including aircraft maintainers.

The issue of what is legal (in FAA terms) and approved (by manufacturers) puts maintainers in a sticky situation. On one hand, the FAA issues a supplemental type certificate (STC) allowing for products to deploy on aircraft, but the engine and/or aircraft manufacturer may not approve or recognize the STC as something permitted for use under the terms of their warranty.