Service Bulletin — Inspection and Replacement of Tempest Spark Plugs, Specific Lots
Dear Valued Customer,
We are writing to inform you directly of a product issue affecting specific lots of Tempest spark plugs,
and to provide the accompanying Service Bulletin that explains exactly what to inspect and how to
proceed. We want you to hear this from us first, so you can act quickly and with confidence.



RE: Service Bulletin — Inspection and Replacement of Tempest Spark Plugs, Specific Lots
Dear Valued Customer,
We are writing to inform you directly of a product issue affecting specific lots of Tempest spark
plugs, and to provide the accompanying Service Bulletin that explains exactly what to inspect and
how to proceed. We want you to hear this from us first, so you can act quickly and with confidence.
What Happened
We have been notified of a potential issue with specific lots of Tempest spark plugs. Our
engineering and quality teams moved immediately to investigate, and we quickly identified and
resolved the root cause of the issue. Based on the findings, we are advising that all spark plugs
from the specified lots be inspected so they can be replaced as needed.
What We’re Doing About It
We are issuing the enclosed Service Bulletin. It identifies the specific lots involved and provides
clear, step-by-step instructions for inspection. Please refer to the Service Bulletin for the
complete inspection criteria, lot identification details, and replacement procedure.
Any spark plugs from the specified lots confirmed to exhibit the product issue will be replaced at
no cost to you.
Our Commitment to You
For almost two decades, operators and pilots have trusted Tempest spark plugs to perform reliably,
flight after flight. That trust is the foundation of everything we do. We recognize that
responsibility, and we take it seriously.
Our mission is to provide service that exceeds our customers’ expectations. That mission is tested
most in moments like this one, and we intend to meet it — through swift action, transparent
communication, and by making this right for every customer affected.
What You Should Do Next
Please review the enclosed Service Bulletin to determine whether your inventory or installed plugs
fall within the affected lots. If you have technical questions, need assistance with inspection, or
require replacement product, our team is ready to help and will prioritize your request.
For Assistance with Inspection or Technical Support
Contact Wyette Lowe, Director of Technical Support
SB012 Technical Support Hotline
Phone: (336) 551-2183
Email: SB012@tempestaero.com
For Assistance in Receiving Replacement Product
Contact our Customer Service Team SB012 Customer Service Hotline Phone: (336) 551-2182
Email: SB012@tempestaero.com
We are grateful for the trust you have placed in Tempest and in Victor Sierra Aviation for more
than 40 years. We do not take that trust lightly, and we will continue working to earn it every
day.
Sincerely,
John Herman VP of Sales & Marketing Victor Sierra Aviation Mobile: (770) 328-8797
Email: johnh@victor-sierra.com
Bryan Stamp VP of Operations Victor Sierra Aviation Mobile: (513) 857-9049
Email: bryans@victor-sierra.com
Josh Christopher VP of Engineering Victor Sierra Aviation
Mobile: (864) 314-9462
Email: jchristopher@victor-sierra.com


