02-16307. Airworthiness Directives; Honeywell, Inc. Part Number HG1075AB05 and HG1075GB05 Inertial Reference Units

AGENCY:

Federal Aviation Administration, DOT.

ACTION:

Final rule.

SUMMARY:

This amendment adopts a new airworthiness directive (AD) that applies to certain Honeywell, Inc. part number (P/N) HG1075AB05 and HG1075GB05 inertial reference units (IRU) that are installed on aircraft. This AD requires you to inspect the affected IRU's for proper function and remove the IRU either immediately or at a certain time depending on the result of the inspection. This AD is the result of a report that these IRU's may not function when using backup battery power in certain installations. The actions specified by this AD are intended to ensure the correct transition of the IRU to backup battery power upon the loss of primary power. Failure of an IRU to transition to backup battery power could result in loss of attitude, heading, and position reference and lead to the pilot making flight decisions that put the aircraft in unsafe flight conditions.

DATES:

This AD becomes effective on August 9, 2002.

The Director of the Federal Register approved the incorporation by reference of certain publications listed in the regulations as of August 9, 2002.

ADDRESSES:

You may get the service information referenced in this AD from Honeywell, Inc., Customer Response Center at 1-877-436-2005. You may view this information at the Federal Aviation Administration (FAA), Central Region, Office of the Regional Counsel, Attention: Rules Docket No. 2001-CE-28-AD, 901 Locust, Room 506, Kansas City, Missouri 64106; or at the Office of the Federal Register, 800 North Capitol Street, NW., suite 700, Washington, DC.

FOR FURTHER INFORMATION CONTACT:

Wesley Rouse, Aerospace Engineer, FAA, Chicago Aircraft Certification Office, 2300 E. Devon Avenue, Des Plaines, Illinois 60018; telephone: [phone]; facsimile: [phone].

SUPPLEMENTARY INFORMATION:

Discussion

What Events Have Caused This AD?

A ground test for proper inertial reference unit (IRU) function revealed a wiring defect that is attributed to a manufacturing error on certain Honeywell, Inc. part number (P/N) HG1075AB05 and HG1075GB05 IRUs. This wiring defect disables the IRU's capability to detect a loss of primary input power and transition to backup battery input power in some installations.

The affected IRU's incorporate the following:

—P/N HG1075AB05: any serial number (last four digits) 0644 through 0723 (excluding 0652 and 0659) that incorporates modification status 3; and

—P/N HG1075GB05: any serial number (last four digits) 0652 or 0659 that incorporates modification status 2.

What Is the Potential Impact if FAA Took No Action?

This condition, if not corrected, could result in loss of attitude, heading, and position reference and lead to the pilot making flight decisions that put the aircraft in unsafe flight conditions.

Has FAA Taken Any Action to This Point?

We issued a proposal to amend part 39 of the Federal Aviation Regulations (14 CFR part 39) to include an AD that would apply to certain Honeywell, Inc. part number (P/N) HG1075AB05 and HG1075GB05 inertial reference units (IRU) that are installed on aircraft. This proposal was published in the Federal Register as a notice of proposed rulemaking (NPRM) on January 28, 2002 (67 FR 3844 ). The NPRM proposed to require you to inspect any affected IRU for proper function and remove the IRU either immediately or at a certain time depending on the result of the inspection.

Was the Public Invited to Comment?

The FAA encouraged interested persons to participate in the making of this amendment. The following presents the comments received on the proposal and FAA's response to each comment:

Comment Issue No. 1: Change the List of Aircraft That Could Have an Affected IRU Installed

What Is the Commenter's Concern?

One commenter requests FAA to focus on those aircraft where the affected IRUs would most likely be installed. The commenter acknowledges that this equipment could be installed on other aircraft through the technical standard order (TSO) or supplemental type certificate (STC), but points out that the IRUs are primarily used on Dassault Falcon Jets.

What Is FAA's Response to the Concern?

We concur that these IRUs are primarily used on Dassault Falcon Jets. We will add a note in the AD that states these IRUs are primarily used on early manufactured Dassault Falcon Jets, but could be incorporated on other aircraft through the TSO or an STC.

Comment Issue No. 2: Write the Applicability To Ensure That Certain IRU Units Are Not Affected

What Is the Commenter's Concern?

One commenter requests that FAA change the Applicability so aircraft incorporating the following are not affected by this AD:

—An IRU with a part number of (P/N) HG1075AB05, any serial number (last four digits) 0644 through 0723 (excluding 0652 and 0659), that incorporates modification status 7; and

—An IRU with a P/N of HG1075GB05, serial number (last four digits) 0652 or 0659, that incorporates modification status 6.

The commenter points out that this change will make it clear that the AD does not apply to aircraft that already incorporate a modified IRU.

What Is FAA's Response to the Concern?

We concur that those airplanes with either of these configurations are not affected by the AD. The presumption in the AD is that if the units do not incorporate the affected modification status, then they have the corrected modification status. We concur that this can be confusing and we are rewriting the Applicability to clarify this.

Comment Issue No. 3: Add the Toll Free Phone Number of Where to Obtain Service Information

What Is the Commenter's Concern?

One commenter requests that FAA add the toll free telephone number of Honeywell Commercial Aviation Products to aid in the customer obtaining service information.

What Is FAA's Response to the Concern?

We concur and will add this toll free number in the AD.

FAA's Determination

What Is FAA's Final Determination on This Issue?

After careful review of all available information related to the subject presented above, we have determined that air safety and the public interest require the adoption of the rule as proposed except for the additions described above and minor editorial corrections. We have determined that these additions and minor corrections:

—Provide the intent that was proposed in the NPRM for correcting the unsafe condition; and

—Do not add any additional burden upon the public than was already proposed in the NPRM.

Cost Impact

How Many Airplanes Does This AD Impact?

We estimate that this AD affects 80 airplanes in the U.S. registry.

What Is the Cost Impact of this AD on Owners/Operators of the Affected Airplanes?

We estimate the following costs to accomplish the inspection and modification:

Labor cost	Parts cost	Total cost per airplane	Total cost on U.S. operators
2 workhours at $60 per hour = $120	Honeywell to provide at no cost	$120	$9,600

Regulatory Impact

Does This AD Impact Various Entities?

The regulations adopted herein will 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. Therefore, it is determined that this final rule does not have federalism implications under Executive Order 13132.

Does This AD Involve a Significant Rule or Regulatory Action?

For the reasons discussed above, I certify that this action (1) is not a “significant regulatory action” under Executive Order 12866; (2) is not a “significant rule” under 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. A copy of the final evaluation prepared for this action is contained in the Rules Docket. A copy of it may be obtained by contacting the Rules Docket at the location provided under the caption ADDRESSES.

List of Subjects in 14 CFR Part 39

• Air transportation
• Aircraft
• Aviation safety
• Incorporation by reference
• Safety

Adoption of the Amendment

Accordingly, under the authority delegated to me by the Administrator, the Federal Aviation Administration amends part 39 of the Federal Aviation Regulations (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.

§ 39.13

[Amended]

2. FAA amends § 39.13 by adding a new AD to read as follows:

2002-13-07 Honeywell, Inc.: Amendment 39-12795; Docket No. 2001-CE-28-AD.

(a) What aircraft are affected by this AD? This AD affects any aircraft, certificated in any category, that incorporates one of the following:

(1) Inertial Reference Unit (IRU) part number (P/N) HG1075AB05, any serial number (last four digits) 0644 through 0723 (excluding 0652 and 0659), that incorporates modification status 3. This AD does not apply to these units if they incorporate modification status 7; or

(2) IRU P/N HG1075GB05, any serial number (last four digits) 0652 or 0659, that incorporates modification status 2. This AD does not apply to these units if they incorporate modification status 6.

Note 1:

These IRUs are primarily used on early manufactured Dassault Falcon Jets, but could be incorporated on other aircraft through the technical standard order (TSO) or supplemental type certificate (STC).

(b) Who must comply with this AD? Anyone who wishes to operate an aircraft with any of the equipment identified in paragraph (a) of this AD installed must comply with this AD.

(c) What problem does this AD address? The actions specified by this AD are intended to ensure the correct transition of the IRU to battery power upon the loss of primary power. Failure of an IRU to transition to backup battery power could result in loss of attitude, heading, and position reference and lead to the pilot making flight decisions that put the aircraft in unsafe flight conditions.

(d) What actions must I accomplish to address this problem? To address this problem, you must accomplish the following:

Actions	Compliance	Procedures
(1) Inspect any affected IRU for proper function	Within the next 50 hours time-in-service (TIS) after August 9, 2002 (the effective date of this AD)	In accordance with the instructions in Honeywell Alert Service Bulletin HG1075AB-34-A0013, dated May 21, 2001; or Honeywell Alert Service Bulletin HG1075GB-34-A0005, dated May 21, 2001, as applicable.
(2) Remove any affected IRU from the airplane.	If found to not function properly during the inspection required by paragraph (d)(1) of this AD, remove prior to further flight after the inspection. If found to function properly, remove within 200 hours time-in-service (TIS) after the inspection required by paragraph (d)(1) of this AD.	In accordance with the instructions in Honeywell Alert Service Bulletin HG1075AB-34-A0013, dated May 21, 2001; or Honeywell Alert Service Bulletin HG1075GB-34-A0005, dated May 21, 2001, as applicable.
(3) Do not install, on any aircraft, one of the IRU's identified in paragraphs (a)(1) and (a)(2) of this AD, unless it has been modified at Honeywell, Inc. and updated to one of the following:	As of August 9, 2002 (the effective date of this AD)	Not Applicable.
(i) IRU P/N HG1075AB05 IRU Mod 7; or
(ii) IRU P/N HG1075GB05 IRU Mod 6.

(e) Can I comply with this AD in any other way? You may use an alternative method of compliance or adjust the compliance time if:

(1) Your alternative method of compliance provides an equivalent level of safety; and

(2) The Manager, Chicago Aircraft Certification Office (ACO), approves your alternative. Submit your request through an FAA Principal Maintenance Inspector, who may add comments and then send it to the Manager, Chicago ACO.

Note 2:

This AD applies to each airplane identified in paragraph (a) of this AD, regardless of whether it has been modified, altered, or repaired in the area subject to the requirements of this AD. For airplanes that have been modified, altered, or repaired so that the performance of the requirements of this AD is affected, the owner/operator must request approval for an alternative method of compliance in accordance with paragraph (e) of this AD. The request should include an assessment of the effect of the modification, alteration, or repair on the unsafe condition addressed by this AD; and, if you have not eliminated the unsafe condition, specific actions you propose to address it.

(f) Where can I get information about any already-approved alternative methods of compliance? Contact Wesley Rouse, Aerospace Engineer, FAA, Chicago Aircraft Certification Office, 2300 E. Devon Avenue, Des Plaines, Illinois 60018; telephone: [phone]; facsimile: [phone].

(g) What if I need to fly the airplane to another location to comply with this AD? The FAA can issue a special flight permit under sections 21.197 and 21.199 of the Federal Aviation Regulations (14 CFR 21.197 and 21.199) to operate your airplane to a location where you can accomplish the requirements of this AD.

(h) Are any service bulletins incorporated into this AD by reference? Actions required by this AD must be done in accordance with Honeywell Alert Service Bulletin HG1075AB-34-A0013, dated May 21, 2001 or Honeywell Alert Service Bulletin HG1075GB-34-A0005, dated May 21, 2001, as applicable. The Director of the Federal Register approved this incorporation by reference under 5 U.S.C. 552(a) and 1 CFR part 51. You may get copies from Honeywell, Inc., Customer Response Center at 1-877-436-2005. You may view copies at the FAA, Central Region, Office of the Regional Counsel, 901 Locust, Room 506, Kansas City, Missouri, or at the Office of the Federal Register, 800 North Capitol Street, NW, suite 700, Washington, DC.

(i) When does this amendment become effective? This amendment becomes effective on August 9, 2002.

Issued in Kansas City, Missouri, on June 20, 2002.

Michael Gallagher,

Manager, Small Airplane Directorate, Aircraft Certification Service.