Airworthiness Directives; Goodrich Avionics Systems, Inc. TAWS8000 Terrain Awareness Warning System

AGENCY:

Federal Aviation Administration (FAA), DOT.

ACTION:

Notice of proposed rulemaking (NPRM).

SUMMARY:

The FAA proposes to supersede airworthiness directive (AD) 2003-13-08, which currently applies to all Goodrich Avionics Systems, Inc. (Goodrich) TAWS8000 terrain awareness warning systems (TAWS) that are installed on airplanes. AD 2003-13-08 currently requires you to inspect the TAWS installation and remove any TAWS where both the TAWS and any other device are connected to the same baro set potentiometer. AD 2003-13-08 also prohibits future installation of any TAWS8000 TAWS that incorporates hardware “Mod None”, “Mod A”, or “Mod B”. This proposed AD is the result of omitting from AD 2003-13-08 a provision that prohibits reconfiguring an installed TAWS8000 TAWS after it passes the inspection unless it incorporates hardware “Mod C”. This proposed AD would retain the actions of AD 2003-13-08 and would also prohibit future installation or reconfiguration of any TAWS8000 TAWS that does not incorporate hardware “Mod C”. We are issuing this proposed AD to prevent the loading of the baro set potentiometer, which could result in an unacceptable altitude error. That condition could cause the pilot to make flight decisions that put the airplane in unsafe flight conditions.

DATES:

We must receive any comments on this proposed AD by February 2, 2004.

ADDRESSES:

Use one of the following to submit comments on this proposed AD:

• By mail: FAA, Central Region, Office of the Regional Counsel, Attention: Rules Docket No. 2003-CE-47AD, 901 Locust, Room 506, Kansas City, Missouri 64106.
• By fax: (816) 329-3771.
• By e-mail: 9-ACE-7-Docket@faa.gov. Comments sent electronically must contain “Docket No. 2003-CE-47-AD” in the subject line. If you send comments electronically as attached electronic files, the files must be formatted in Microsoft Word 97 for Windows or ASCII.

You may get the service information identified in this proposed AD from Goodrich Avionics Systems, Inc., 5353 52nd Street, SE, Grand Rapids, Michigan 49512-9704; telephone: (616) 949-6600; facsimile: (616) 977-6898. You may view the AD docket at FAA, Central Region, Office of the Regional Counsel, Attention: Rules Docket No. 2003-CE-47-AD, 901 Locust, Room 506, Kansas City, Missouri 64106. Office hours are 8 a.m. to 4 p.m., Monday through Friday, except Federal holidays.

FOR FURTHER INFORMATION CONTACT:

Brenda S. Ocker, Aerospace Engineer, FAA, Chicago Aircraft Certification Office, 2300 East Devon Avenue, Des Plaines, Illinois 60018; telephone: (847) 294-7126; facsimile: (847) 294-7834.

SUPPLEMENTARY INFORMATION:

Comments Invited

How do I comment on this proposed AD? We invite you to submit any written relevant data, views, or arguments regarding this proposal. Send your comments to an address listed under ADDRESSES. Include “AD Docket No. 2003-CE-47-AD” in the subject line of your comments. If you want us to acknowledge receipt of your mailed comments, send us a self-addressed, stamped postcard with the docket number written on it. We will date-stamp your postcard and mail it back to you.

Are there any specific portions of this proposed AD I should pay attention to? We specifically invite comments on the overall regulatory, economic, environmental, and energy aspects of this proposed AD. If you contact us through a nonwritten communication and that contact relates to a substantive part of this proposed AD, we will summarize the contact and place the summary in the docket. We will consider all comments received by the closing date and may amend this proposed AD in light of those comments and contacts.

Discussion

Has FAA taken any action to this point? Reports that the Goodrich TAWS8000 TAWS causes altitude errors in other instruments when both the TAWS and any other device are connected to the same baro set potentiometer caused us to issue AD 2003-13-08, Amendment 39-13208.

The unsafe condition was discovered during the installation of a TAWS8000 TAWS in a Cessna 500 series airplane. The TAWS8000 TAWS was connected to the baro set potentiometer output of a Honeywell (Sperry) BA-141 altimeter that was also connected to a Honeywell AZ-241 Air Data Computer. The altimeter showed that the aircraft was 60 feet higher than the actual altitude. This unsafe condition was confirmed with the laboratory test of a TAWS8000 TAWS installation.

What has happened since AD 2003-13-08 to initiate this proposed action? We omitted from AD 2003-13-08 a provision that prohibits reconfiguring an installed TAWS8000 TAWS after it passes the inspection unless it incorporates hardware “Mod C'.

Since we issued AD 2003-13-08, Goodrich Avionics System, Inc. has also developed a production improvement (Mod C) to eliminate the effect of loading on the baro set potentiometer. Goodrich has issued an alert service bulletin to implement this modification.

We received comments about the language in AD 2003-13-08. Owners/operators are restricted from installing any TAWS8000 TAWS (part number 805-18000-001 that incorporates hardware “Mod None”, “Mod A”, or “Mod B”). When the unit is modified to incorporate hardware “Mod C”, the unit will still have “Mod None”, “Mod A”, or “Mod B” marked on it. The intent of the AD was to allow for hardware modifications other than “Mod None”, “Mod A”, or “Mod B” to be installed.

What are the consequences if the condition is not corrected? AD 2003-13-08, as currently written, could cause confusion as to how to incorporate the actions necessary in correcting the unsafe condition.

Is there service information that applies to this subject? Goodrich Avionics Systems, Inc. has issued Service Memo SM #134, Revised July 9, 2003, and Alert Service Bulletin SB #A117, dated July 9, 2003.

What are the provisions of this service information? Goodrich Avionics Systems, Inc. Service Memo SM #134, Revised July 9, 2003, introduces the release of product improvement hardware “Mod C” and restates the following information from the original issue of Service Memo SM #134:

—The TAWS8000 should not be connected to a baro set potentiometer if that potentiometer is also connected to any other device; and

—In existing installations where both the TAWS and any other device are connected to the same baro set potentiometer, the TAWS8000 should be removed from the aircraft.

Goodrich Avionics Systems, Inc. Alert Service Bulletin SB #A117, dated July 9, 2003, specifies upgrading all TAWS8000 units to include hardware “Mod C”.

FAA's Determination and Requirements of This Proposed AD

What has FAA decided? The FAA has reviewed all available information, including the service information referenced above; and determined that:

—The unsafe condition referenced in this document exists or could develop on type design airplanes equipped with a Goodrich TAWS8000 TAWS, P/N 805-18000-001 that does not incorporate hardware “Mod C”;

—Any airplane with one of these TAWS8000 TAWS units, P/N 805-18000-001 should have the actions specified in the above service information incorporated; and

—AD action should be taken in order to correct this unsafe condition.

What would this proposed AD require? This proposed AD would supersede AD 2003-13-08 with a new AD that proposes to require you to inspect the TAWS installation and modify any TAWS where both the TAWS and any other device are connected to the same baro set potentiometer. This proposed AD would also prohibit future installation or reconfiguration of any TAWS8000 TAWS that does not incorporate hardware “Mod C”.

How does the revision to 14 CFR part 39 affect this proposed AD? On July 10, 2002, we published a new version of 14 CFR part 39 (67 FR 47997, July 22, 2002), which governs FAA's AD system. This regulation now includes material that relates to altered products, special flight permits, and alternative methods of compliance. This material previously was included in each individual AD. Since this material is included in 14 CFR part 39, we will not include it in future AD actions.

Costs of Compliance

How many airplanes would this proposed AD impact? We estimate that this proposed AD affects 80 airplanes in the U.S. registry.

What would be the cost impact of this proposed AD on owners/operators of the affected airplanes? We estimate the following costs to accomplish this proposed inspection:

We estimate the following costs to accomplish any necessary modifications that would be required based on the results of this proposed inspection. We have no way of determining the number of airplanes that may need the modification:

Regulatory Findings

Would this proposed AD impact various entities? We have determined that this proposed AD would not have federalism implications under Executive Order 13132. This proposed AD would not have a substantial direct effect on the States, on the relationship between the national Government and the States, or on the distribution of power and responsibilities among the various levels of government.

Would this proposed AD involve a significant rule or regulatory action? For the reasons discussed above, I certify that this proposed AD:

1. Is not a “significant regulatory action” under Executive Order 12866;

2. Is not a “significant rule” under the DOT Regulatory Policies and Procedures (44 FR 11034, February 26, 1979); and

3. Will not have a significant economic impact, positive or negative, on a substantial number of small entities under the criteria of the Regulatory Flexibility Act.

We prepared a summary of the costs to comply with this proposed AD and placed it in the AD Docket. You may get a copy of this summary by sending a request to us at the address listed under ADDRESSES. Include “AD Docket No. 2003-CE-47-AD” in your request.

List of Subjects in 14 CFR Part 39

• Air transportation
• Aircraft
• Aviation safety
• Safety

The Proposed Amendment

Accordingly, under the authority delegated to me by the Administrator, the Federal Aviation Administration proposes to amend 14 CFR part 39 as follows:

PART 39—AIRWORTHINESS DIRECTIVES

1. The authority citation for part 39 continues to read as follows:

Authority: 49 U.S.C. 106(g), 40113, 44701.