**Petition for Rulemaking**

**Submitted by:** James Sparks Richardson Aviation 3800 L incoln Avenue Fort worth, Texas 76106 Telephone: 817 339 7633 Email: jsparks@richav.com

**Action Requested:** Improve the clarity

of s tatements by

revising language in FAR 91.411 and FAR 43 Appendix E related to persons authorized to return an aircraft to service after maintenance other than transponder or altimeter certification. The concern deals with a compromise of the data link between an air data unit and a transponder. Paragraph b, line (3) states “ A certificated mechanic with an airframe rating (static pressure system tests and inspections only).” a s one of the options for return to service. The caveat implies the certif

ied mechanic is not capable of insuring the integrity of the data link. Statements made in paragraph (a) of Part 43 Appendix E do fall in line with the authority

granted an Airframe Mechanic under Part 43.3 which implies that is the qualification for ret urn to s ervice of the s ys tem in paragraph (c) of Appendix E. Aircraft produced during the last decade use integrated s ys tems rel ying on digital technology

to validate the communication between altimetry and surveillance
sy stems and can be verified through the use of Built In Test Equipment (BITE). Enhanced diagnostics need to be included as part of return to service criteria. Airframe manufacturers often include tests for return to service in their approved maintenance programs for Part 25 aircraft. Technicians should be directed to these approved methods as an alternate means of compliance when applicable to fulfilling requirements of Part 43 Appendix E paragraph (c).

**Proposed language:** Please review attached Part 91.411 and P art 43 Appendix E with prop osed changes noted in blue italic and underlined

.
**Proposed benefit to public interest:** The current wording used in Part 91.411 and Part 43 appendix E do not clearly define the role and authorizations for those involved in the different tests and inspec tions listed. The current rules may be interpreted that after maintenance occurring within the two year certification period that it is required to have an appropriatel y rated repairman conduct a transponder test while a mechanic with an airframe rating (or an appropriatel y rated repair facility) conduct the static
sy stem test. By clarifying that the two year component and s ystem certification has different requirements than return to service after maintenance will insure the mostqualified persons wil l be conducting the testing while reducing the perceived need to have a repairman test the transponder and a mechanic validate the static system. Using the onboard dedicated maintenance diagnostic equipment on aircraft with i ntegrated avionics will reduce the burden of redundant testing

.
**Support for the proposed action:** Clarification of qualification for transponder and integrated s ys tem testing has long been subject to interpretation. Advisory Circular AC43.6b was produced to provide guidance but is as ambiguous as the regulations. This situation does need to be put in perspective so that it is understood; certifying altitude indicating and reporting equipment for the 24 month term does require a specific knowledge level skill set and perhaps test equip ment not possessed b y most Airframe Mechanics . A Part 43.3 rated Airframe Mechanic does not have an approval for instrument repair or certifying the full Part 43 Appendix E or F compliance. The M echanic is authorized to perform a check to verify proper al titude reporting allowing return of the aircraft to IFR service. A repairman on the other hand is granted the authority to certify various instruments as meeting the criteria in Part 411 and 413 in accordance with Part 43 Appendix E and F but may not have the authority

to inspect and certify

the aircraft static s ys tem(s)

. An appropriately

rated Airframe Mechanic does currentl y have the authority to perform the sy stem test s necessary for verifying proper integration of the altimeter and transponder and shoul d be provided clear and undisputable guidance on how to approve and document the work performed

.