I-Series Adapted From Proven Military Technology

The FAA has granted TSO approval to Hartzell Engine Technologies LLC (HET) for its new I-Series of aircraft cabin heaters. Adapted from its military proven S-Series heaters, the I-Series heaters contain a new combustion tube constructed of Inconel, a material proven to provide superior performance over ceramic coated stainless steel in extreme temperature applications. The I-Series heaters also feature a replaceable spark plug with an integral ground electrode to improve serviceability.

Hartzell’s new I-Series heaters directly replace Hartzell and Janitrol branded B-Series heaters and are exempt from the requirements of Airworthiness Directive 2004-21-05 applicable to the B-Series. The FAA has approved HET Service Bulletin A-101 revision G to provide installation approval for the I-Series in place of the B-Series. Hartzell will also offer factory rebuilt I-Series heaters and field upgrade kits to convert a B-Series heater to the new I-Series.

"Since purchasing the business in late 2010, Hartzell Engine Technologies has been investing heavily in product and manufacturing improvements," said Hartzell Engine Technologies president, Mike Disbrow. "The new I-Series represents a major advancement in general aviation heater technology and gives us a robust platform we can build on for future improvements to our cabin heater product line.”

Hartzell has extensive positive field experience with Inconel in its military applications. In addition, using test methods from the gas turbine engine industry, a comparative evaluation between the two materials was performed using a burner rig dynamic oxidation test which demonstrated that Inconel exhibited no significant oxidation, whereas stainless steel displayed erosion and material loss under the same conditions. Elimination of the need for ceramic coating also reduces risk introduced from application process variability, such as humidity, surface preparation and coating thickness. In addition, flame front testing conducted inside the new I-Series combustion tube, using high temperature videography, ensured that the combustion process does not unevenly or excessively heat any part of the combustion tube. 

FMI: www.hartzellenginetech.com