The FAA have issued document No.: 2012-20111019001 as follows:

AFFECTED PRODUCTS:
Subcomponents and brackets produced by Chelton Avionics, Inc. (dba Wulfsberg Electronics Division) Emergency Locator Transmitters (ELTs)

PURPOSE:
This notification advises all aircraft owners, operators, manufacturers, maintenance organizations, and parts distributors regarding ELT subcomponents and brackets produced without Federal Aviation Administration (FAA) production approval.

BACKGROUND:
Information received during a FAA suspected unapproved parts investigation (SUP), confirmed that Chelton Avionics, Inc. (dba Wulfsberg Electronics Division) sold ELT subcomponents without FAA approval between June 2010 and April 15, 2011 to 29 customers. Additionally, Chelton Avionics, Inc. (dba Wulfsberg Electronics Division) sold ELT brackets without FAA approval between September 9, 2010 and November 17, 2010 to one customer. Chelton Avionics, Inc. (dba Wulfsberg Electronics Division) is located at the following physical address: 6400 Wilkinson Drive, Prescott, AZ 86301. Artex Aircraft Supplies previously held FAA Technical Standard Order Approval (TSOA) for the parts listed below.

RECOMMENDATIONS:
Regulations require that type-certificated products conform to their type design. Aircraft owners, operators, maintenance organizations, and parts distributors are encouraged to inspect their aircraft, aircraft records, and/or parts inventories for unapproved ELT subcomponents and brackets installed on aircraft. Appropriate action should be taken to remove them from service. If unapproved ELT subcomponents and brackets are found in existing inventory, it is recommended that they be quarantined to prevent installation.

FURTHER INFORMATION:
You can obtain further information concerning this investigation, and guidance regarding the above-referenced SUP from the FAA Manufacturing Inspection District Office (MIDO) listed below. In addition to compliance with the above recommendations, we would appreciate any information concerning the discovery of Chelton Avionics, Inc. (dba Wulfsberg Electronics Division) ELT subcomponents and brackets from any source, the means used to identify the source, and the action taken to remove them from service.

For the full list of part numbers etc, see FAA document 2012-20111019001