To : Cc: Bcc: Subject: Re: Your Petition for Exemption, Docket No. FAA-2012-0582 From: Ross McCurdy <rkmccurdy@yahoo.com> - Monday 07/02/2012 12:50 PM History: This message has been replied to.From: "John.Linsenmeyer@faa.gov" <John.Linsenmeyer@faa.gov> To: rkmccurdy@yahoo.com Sent: Friday, June 29, 2012 1:30 PM Subject: Your Petition for Exemption, Docket No. FAA-2012-0582

Mr. McCurdyMy office is reviewing your petition for exemption from 14 CFR 61.113.

In your petition, you note that the aircraft you intend to use has been modified with a diesel engine and will be consuming an fuel not normally used in general aviation aircraft. We would like to have more information for the docket on the airworthiness status of the aircraft. Could you please send me information about the aircraft's airworthiness status with regard to the engine modification, the nonstandard fuel, and any other relevant information.

Thank you!

John Linsenmeyer FAA Flight Standards Service, AFS-810 Airmen Certification & Training Branch 55 M Street SE, 8th Floor Washington, DC 20003 j ohn.linsenmeyer@faa.gov 202-385-96121 FAA Aviation Safety 

## SPECIAL AIRWORTHINESS INFORMATION BULLETIN

SAIB: NE-11-56 SUBJ: Semi-Synthetic Jet Fuel Date: September 14, 2011 This is information only. Recommendations aren’t mandatory.

Introduction

This Special Airworthiness Information Bulletin (SAIB) advises aircraft operators, Fixed Base Operators (FBOs), FAA repair sta tions and FSDOs, and Foreign Civil Aviation Authorities, that jet fuel made from hydroprocessed fatty acid esters a nd fatty acids (HEFA) or Fischer Tropsch (FT) synthetic blending components that meets the requirements of ASTM International Standard D7566 is acceptable for use on aircraft and engines certifi cated for operation with D1655 Jet A or Jet A-1 jet fuel, provided that it is re-identif ied as D1655 fuel. When re-identified as D1655 fuel, D7566 jet fuel meets all the specification requirements of D 1655 and therefore meets the approved operating limitations for aircraft and engines certificated to operate with D1655 fuel, unless otherwise prohibited by the engine or airc raft type certificate (TC) holder.

Background

The FAA relies on ASTM International to develop fu el specifications that a pplicants may designate as operating limitations for their approved products. These aviation fuel operating limitations may be listed in the product’s Type Certif icate Data Sheet (TCDS), Installa tion Manual, servi ce instructions, or as limitations associated with a supplemental type certificate (STC).

ASTM International issued ASTM Standard Specification D7566, “Standard Specification for Aviation Turbine Fuel Containing Synthesized Hydro carbons,” for drop-in jet fuel from alternative feedstocks in September 2009. This specification defi nes properties for semi-synthetic jet fuel made from blending conventional jet fuel with synthe tic blending components that are specified in individual annexes. These semi-synthetic jet fu els specified in D7566 posse ss essentially identical composition, properties, and performance to conven tional jet fuels. This specification initially included only one annex for synthetic fuel from co al, biomass, and natural gas produced using the FT process. On July 1, 2011, a second annex was added to this specification to permit the use of HEFA synthetic blending components. HEFA is considered a biofuel because it is made from plant oils or animal fats.* Both D7566 and the existing sp ecification for conven tional jet fuel, ASTM International Standard D1655, “Standard Specifi cation for Aviation Turbine Fuels” are crossreferenced to allow D7566 fuels to be re-identifie d as D1655 fuels when they enter the distribution system. When re-identified, D7566 fuels made with HEFA or FT blending components meet existing FAA-approved operating limitations, unless otherwise pr ohibited by the engine or aircraft TC holder.

Recommendations

The following recommendations apply to HEFA or FT fuels meeting ASTM specification D7566 that are re-identified to ASTM D1655 Jet A or Jet A-1 fu els (unless otherwise prohi bited by the engine or aircraft Type Certificate (TC) holder):

1. These fuels are acceptable for use on those airc raft and engines that are approved to operate with Jet A or Jet A-1 fuels meeting D1655.2 2. Operating Limitations in Aircraft Flight Ma nuals, Pilot Operating In structions, or Type Certificate Data Sheets that speci fy ASTM D1655 Jet A or Jet A- 1 fuel are acceptable for use with these fuels. 3. Current aircraft placards that specify Jet A or Jet A-1 fuels are acceptable for use with these fuels. 4. Operating, maintenance or other service documents for aircraft and engi nes that are approved to operate ASTM D1655 Jet A or Jet A-1 fu el are acceptable for use when operating with these fuels.

For Further Information Contact

Mark Rumizen, Aerospace Engineer, FAA, Engi ne & Propeller Directorate, 12 New England Executive Park, Burlington, MA 01803; phone : (781) 238-7113; fax: (781) 238-7199; email: mark.rumizen@faa.gov

. *HEFA is also referred to as Hydroprocessed Renewable Jet (HRJ) and Bio-SPK (synthesized parrafinic kerosene)