Cirrus Airworthiness Concerns Raised With G100UL

California A and P Michael Luvara says he's been told by the owner of a Cirrus SR22 that its composite structure has been damaged by exposure to GAMI's G100UL unleaded fuel to the point where it will have to be ferried to an authorized repair center to be fixed. But GAMI founder George Braly says he's personally inspected the same airplane and the damage is cosmetic only. Further, he said, the fuel has been extensively tested in collaboration with Cirrus and does not damage the structure. Braly's full statement appears below.

Luvara made the comments in the release of his third video showing results of his own testing of G100UL with paint, fuel lubricants and rubber components after some aircraft that have used it since it became available for sale in California reported problems, mainly with paint. He calls the Cirrus owner's experience "serious" and said it has to be investigated. Meanwhile, his third video on the results of his testing reinforce results of his earlier efforts and also show what he says is swelling of rubber fuel lines. The video was released on Wednesday evening.

Braly traveled to Reid-Hillview and Watsonville Airports last weekend to speak with owners of aircraft who have reported issues since the fuel went on sale there in October and November of 2024. He has also been doing his own version of Luvara's tests and said he's been unable to replicate his results, even when using individual components of the fuel known to have solvent properties. He noted that the California 100LL Luvara is using as a control in his tests is likely different in formulation from the 100LL available to him at his home base in Oklahoma. Concerning the Cirrus, he said his own SR22 has been using G100UL for 14 years with no issues and there are now more than a dozen that have been burning it since it became available for sale. His full statement is as follows:

Braly said he's "personally inspected that Cirrus and has found no evidence of any airworthiness issue.   It is, obviously, a cosmetic concern, as a result of a prolonged leakage from the drain sump on one side of that Cirrus.   That on site evaluation of that 
Cirrus at RHV is consistent with earlier very extensive testing of the use of G100UL Avgas and its compatibility with the epoxy structures used in Cirrus aircraft.  That testing was done both by GAMI and by Cirrus Aircraft.  That testing (done independently by Cirrus Aircraft) demonstrated that G100UL Avgas does not in any way degrade the Cirrus fiberglass wing structure.  That  Cirrus test data was approved by the FAA.   It is also worth noting, GAMI’s Cirrus TN SR22, has had G100UL Avgas in the fuel tanks for most of the last 14 years and for all of the last two years.   There are no leaks and no evidence of any issue of any kind.   Anyone that has any concern about this matter is invited to visit GAMI and inspect that aircraft, and GAMI’s’ recently acquired SR-20 Cirrus, which has had G100UL in the wing tanks for the last three months.”