E8-26856. Filtered Flight Data; Technical Correction and Extension of Comment Period

AGENCY:

Federal Aviation Administration (FAA), DOT.

ACTION:

Supplemental notice of proposed rulemaking (SNPRM); correction and extension of comment period.

SUMMARY:

The FAA is correcting an SNPRM published in the Federal Register on August 15, 2008, regarding filtered flight data. Questions from industry caused us to conclude that the intent expressed in the preamble is inconsistent with the proposed rule language. This document will clarify our intent and the rule language. We are also extending the comment period to allow for consideration of this clarification by all interested parties.

DATES:

The comment period will close December 29, 2008.

FOR FURTHER INFORMATION CONTACT:

For technical questions concerning this proposed rule contact Brian A. Verna, Avionics Systems Branch, Aircraft Certification Service, AIR-130, Federal Aviation Administration, 800 Independence Avenue, SW., Washington, DC 20591; telephone [phone]; fax [phone]; e-mail [e-mail]. For legal questions concerning this proposed rule contact Karen L. Petronis, Senior Attorney for Regulations, Regulations Division, Office of the Chief Counsel, AGC-200, Federal Aviation Administration, 800 Independence Avenue, SW., Washington, DC 20591; telephone [phone]; fax [phone]; e-mail [e-mail].

Background

Following the publication of a supplemental notice of proposed rulemaking on filtered flight data (SNPRM; 73 FR 47857, August 15, 2008), the FAA was contacted by members of the industry seeking clarification of our intent and the scope of specific provisions. A summary of that meeting has been placed in the docket for this rule.

Issues raised at the meeting caused us to realize that the intent of the rule as stated in the preamble is inconsistent with the proposed rule text. We are restating the intent here and providing revised proposed rule text.

While this preamble discussion uses part 121 as its reference, it also applies to parts 125 and 135 and their comparable sections. During our review, we also discovered that the SNPRM change to a separate section (proposed § 121.346) caused us to inadvertently omit an applicability reference for airplanes covered under § 121.344a. We have added that reference as part of this correction.

The definition of filtering, proposed § 121.346(a), remains as it was in the SNPRM. Comments should address that section of the proposed rule as published in the SNPRM.

Proposed § 121.346(b) now states that any parameter required to be recorded may be filtered as long as the recorded signal value continues to meet the requirements of Appendix M.

Paragraph (c) contains a list of parameters that we consider critical from the standpoint of accuracy and accident investigation when complying with the required accuracy under the expanded definition of dynamic conditions in Appendix M. This list has not changed from the SNPRM. If any parameter in the paragraph (c) list is being filtered, and the filtered, recorded data do not meet Appendix M, then the certificate holder must choose one of the following courses of action:

• Remove the filtering; or
• Demonstrate by test and analysis that the original sensor signal value can be reconstructed from the recorded filtered data. If an operator attempts to show by test and analysis that the data can be reconstructed but the tests and analyses fail, or the results cannot be repeated, the filtering must be removed.

The restructured language of the rule text has obviated the need for the second list of parameters. They are already covered by paragraph (b); they may be filtered as long as the recorded signal value meets Appendix M. We presume that these parameters are already in compliance with Appendix M since that compliance is required by the 1997 rule changes.

The compliance paragraph has been redesignated as (d), and has been changed to include the correct paragraph references; compliance time remains unchanged.

All other provisions of the proposed rule, including the definition of filtering, remain as proposed in the SNPRM published on August 15, 2008. Because of the confusion generated by the SNPRM language published in August, we are extending the comment period for the rule as corrected until December 29, 2008.

Correction

PART 121—OPERATING REQUIREMENTS: DOMESTIC, FLAG, AND SUPPLEMENTAL OPERATIONS

1. On page 47867, in the first column, remove proposed § 121.346(b) and (c) and add in their place corrected paragraphs (b), (c) and (d) to read as follows:

§ 121.346

Flight recorders—filtered data.

* * * * *

(b) An original sensor signal for any flight recorder parameter required to be recorded under § 121.344 of this part may be filtered only if the recorded signal value continues to meet the requirements of Appendix B or M of this part, as applicable.

(c) For a parameter described in § 121.344(a)(1) through (7), (9), (11) through (18), (26), (32), (42), (43), (68), (70), (77), or (88), or the corresponding parameter in Appendix B of this part, if the recorded signal value is filtered and does not meet the requirements of Appendix B or M of this part, as applicable, the certificate holder must:

(1) Remove the filtering and ensure that the recorded signal value meets the requirements of Appendix B or M of this part; or

(2) Demonstrate by test and analysis that the original sensor signal value can be reconstructed from the recorded data. This demonstration requires that:

(i) The FAA determine that the procedure submitted by the certificate holder as its compliance with paragraph (c)(2) of this section is repeatable; and

(ii) The certificate holder maintain documentation of the procedure required to reconstruct the original sensor signal value.

(d) Compliance. After (four years from effective date), no aircraft flight data recording system may filter any parameter listed in paragraph (c) of this section that does not meet the requirements of Appendix M or B of this part unless the certificate holder possesses test and analysis procedures that have been approved by the FAA. The procedures must be submitted to the FAA no later than the completion of the next heavy maintenance check after [six months after effective date] but not later than [two years after the effective date].

2. On page 48767 in the second column, add amendatory instruction 2a to amend section 121.344a(e) to read as follows:

2a. Amend § 121.344a by revising paragraph (e) to read as follows:

§ 121.344a

Digital flight data recorders for 10-19 seat airplanes.

* * *

(e) All airplanes subject to this section are also subject to the requirements and exceptions stated in §§ 121.344(g) through (k) and 121.346 of this part.

* * * * *

PART 125—CERTIFICATION AND OPERATIONS: AIRPLANES HAVING A SEATING CAPACITY OF 20 OR MORE PASSENGERS OR A MAXIMUM PAYLOAD CAPACITY OF 6,000 POUNDS OR MORE; AND RULES GOVERNING PERSONS ON BOARD SUCH AIRCRAFT

3. On page 47867, in the second column, remove proposed § 125.228(b) and (c) and add in their place corrected paragraphs (b), (c) and (d) to read as follows:

§ 125.228

Flight recorders—filtered data.

* * * * *

(b) An original sensor signal for any flight recorder parameter required to be recorded under § 125.226 of this part may be filtered only if the recorded signal value continues to meet the requirements of Appendix D or E of this part, as applicable.

(c) For a parameter described in § 125.226 (a)(1) through (7), (9), (11) through (18), (26), (32), (42), (43), (68), (70), (77), or (88), or the corresponding parameter in Appendix D of this part if the recorded signal value is filtered and does not meet the requirements of Appendix D or E of this part, as applicable, the certificate holder must:

(1) Remove the filtering and ensure that the recorded signal value meets the requirements of Appendix D or E of this part; or

(2) Demonstrate by test and analysis that the original sensor signal value can be reconstructed from the recorded data. This demonstration requires that:

(i) The FAA determine that the procedure submitted by the certificate holder as its compliance with paragraph (c)(2) of this section is repeatable; and

(ii) The certificate holder maintain documentation of the procedure required to reconstruct the original sensor signal value.

(d) Compliance. After (four years from effective date), no aircraft flight data recording system may filter any parameter listed in paragraph (c) of this section that does not meet the requirements of Appendix D or E of this part unless the certificate holder possesses test and analysis procedures that have been approved by the FAA. The procedures must be submitted to the FAA no later than the completion of the next heavy maintenance check after [six months after effective date] but not later than [two years after the effective date].

PART 135—OPERATING REQUIREMENTS: COMMUTER AND ON DEMAND OPERATIONS AND RULES GOVERNING PERSONS ON BOARD SUCH AIRCRAFT

4. On page 47868, in the first column, remove proposed § 135.156(b) and (c) and add in their place corrected paragraphs (b), (c) and (d) to read as follows:

§ 135.156

Flight recorders—filtered data.

* * * * *

(b) An original sensor signal for any flight recorder parameter required to be recorded under § 135.152 of this part may be filtered only if the recorded signal value continues to meet the requirements of Appendix F of this part, as applicable.

(c) For a parameter described in § 135.152(h)(1) through (7), (9), (11) through (18), (26), (32), (42), (43), (68), (70), (77), or (88), if the recorded signal value is filtered and does not meet the requirements of Appendix F of this part, as applicable, the certificate holder must:

(1) Remove the filtering and ensure that the recorded signal value meets the requirements of Appendix F of this part; or

(2) Demonstrate by test and analysis that the original sensor signal value can be reconstructed from the recorded data. This demonstration requires that:

(i) The FAA determine that the procedure submitted by the certificate holder as its compliance with paragraph (c)(2) of this section is repeatable; and

(ii) The certificate holder maintain documentation of the procedure required to reconstruct the original sensor signal value.

(d) Compliance. After (four years from effective date), no aircraft flight data recording system may filter any parameter listed in paragraph (c) of this section that does not meet the requirements of Appendix F of this part unless the certificate holder possesses test and analysis procedures that have been approved by the FAA. The procedures must be submitted to the FAA no later than the completion of the next heavy maintenance check after [six months after effective date] but not later than [two years after the effective date].

Issued in Washington, DC, on November 6, 2008.

Pamela Hamilton-Powell,

Director, Office of Rulemaking.