Hartzell Propeller Inc.
One Propeller Place
Piqua, OH 45356-2634 USA
Tel: +1-937-778-4200
Fax: +1-937-778-4215
November 9, 2019
Mailing Address
Subject: Introducing NYCO Grease GN 3058 as Hartzell Propeller’s Preferred Lubricant

Hartzell has received an increasing number of field reports of propellers exhibiting leaks. Our
investigation of these reports have determined the vast majority of these leaks are the result of
oil separation in the grease used to lubricate the blade thrust bearings. Further investigation
revealed the formulation of our previously preferred lubricant had been revised and the revised
formula seemed to exhibit a higher degree of oil separation.
Hartzell undertook an initiative to address the findings of our investigation. As part of this
initiative, we subjected a variety of greases from our preferred manufacturer, as well as
greases from various other manufacturers, to a series of test. This testing confirmed the
increase in the oil separation characteristics of the revised formulation of our preferred grease
and revealed that there were several grease options that provided better overall performance.
As a result of the testing, we would like to take this opportunity to inform you that Hartzell
Propeller Inc. has selected NYCO Grease GN 3058 as our preferred grease.
NYCO Grease GN 3058 is a newer lithium complex synthetic grease that is making inroads
into the aviation field. In our testing, NYCO GN 3058 exhibited the least amount of oil
separation of all the greases tested. In addition to exhibiting the highest degree of stability,
NYCO GN 3058 provides improved wear resistance, improved corrosion resistance and better
resistance to water washout.
This letter is intended to serve as an advanced notification of Hartzell’s decision to switch to
NYCO GN 3058 as our preferred grease. Beginning January 1, 2020, Hartzell Propeller Inc. will
implement the use of NYCO GN 3058 Grease as our preferred grease in the production of new
propellers. Also, in January of 2020, Hartzell will introduce revised Instructions for Continued
Airworthiness indicating NYCO GN 3058 as our preferred grease.
As has been our practice for many years, new propellers will contain a label that indicates the
type of grease used to lubricate the propeller during initial manufacture. Additionally, we require
the use of a similar label on propellers that have been overhauled in the field. It is imperative
that your technicians refer to this label when servicing the propeller to assure that they use the
same grease currently in service on the propeller as defined on the label attached to the
propeller. Mixing of NYCO GN 3058 with other greases is not permitted. If NYCO GN 3058 is
inadvertently mixed with another grease, the propeller will need to be removed from the
aircraft, disassembled, cleaned and serviced with all new grease. This corrective action will be
required within thirty flight cycles or three months from when the propeller was inappropriately
greased; whichever occurs first.

Hartzell recognizes the impact this change may have on the aviation community and has
partnered with NYCO to take actions to make this switch as convenient as possible. First,
NYCO has a network of over twenty-five distributors located around the world. They are
working to place various quantities of product at these distributors in preparation for the
December implementation. The grease will be available as 400 gram cartridges, 1 kilogram
cans and 35 pound pails. A list of NYCO distributors and their location is included with this
letter. Next, Hartzell will maintain stocks of the grease, in the previously mentioned packaging,
at our location in Piqua, Ohio beginning November 25, 2019
We believe switching to NYCO GN 3058 to be the best course of action to improve the service
experience of our mutual customers and appreciate your understanding and support.
If you have any questions or concerns, please feel free to contact Hartzell Propeller Inc.
Technical Support at:
Phone: +1(800) 942-7767 (option 3)
Dean Ward
Director – Product Support
Hartzell Propeller Inc.
Enclosure: NYCO Worldwide Distributors and Subsidiaries Networ