### 94946 Federal Register / Vol. 81, No. 248 / Tuesday, December 27, 2016 / Rules and Regulations

or the component history card or equivalent record do not specify a life limit for the TT strap, or if they specify a different life limit than in paragraph (e)(1), do the following:

(i) Revise the Airworthiness Limitations section of the applicable maintenance manual or ICA by establishing a life limit of 25,000 flights or 10 years since date of manufacture, whichever occurs first, for each TT strap P/N 2604067 and P/N 117–14110 by making pen-and-ink changes or by inserting a copy of this AD into the Airworthiness
Limitations section of the maintenance manual or the ICA. For purposes of this AD, a flight would be counted anytime the helicopter lifts off into the air and then lands again regardless of the duration of the landing and regardless of whether the engine
is shut down.

(ii) Create a component history card or equivalent record for each TT strap P/N 2604067 and P/N 117–14110, if one does not exist, and record a life limit of 25,000 flights or 10 years since date of manufacture,
whichever occurs first.

(3) Remove from service each TT strap that
has reached or exceeded its life limit.

(f) Special Flight Permits

Special flight permits are prohibited.

(g) Alternative Methods of Compliance (AMOCs)

(1) The Manager, Safety Management Group, FAA, may approve AMOCs for this AD. Send your proposal to: Matt Fuller, Senior Aviation Safety Engineer, Safety Management Group, Rotorcraft Directorate, FAA, 10101 Hillwood Pkwy, Fort Worth, Texas 76177; telephone (817) 222–5110;
email 9-ASW-FTW-AMOC-Requests@faa.gov.

(2) For operations conducted under a 14 CFR part 119 operating certificate or under 14 CFR part 91, subpart K, we suggest that you notify your principal inspector, or lacking a principal inspector, the manager of the local flight standards district office or certificate holding district office, before operating any aircraft complying with this AD through an AMOC.

(h) Additional Information

(1) Airbus Helicopters Alert Service Bulletin ASB BO105LS–10A–013, Revision 0, dated March 9, 2015, which is not incorporated by reference, contains additional information about the subject of
this AD. For service information identified in this AD, contact Airbus Helicopters, 2701 N. Forum Drive, Grand Prairie, TX 75052; telephone (972) 641–0000 or (800) 232–0323; fax (972) 641–3775; or at http:// www.airbushelicopters.com/techpub. You may review the referenced service information at the FAA, Office of the Regional Counsel, Southwest Region, 10101 Hillwood Pkwy, Room 6N–321, Fort Worth,

TX 76177.

(2) The subject of this AD is addressed in European Aviation Safety Agency (EASA) AD No. 2015–0042, dated March 9, 2015. You may view the EASA AD on the Internet at http://www.regulations.gov in Docket No.

FAA–2016–5247. (i) Subject
Joint Aircraft Service Component (JASC) Code: 6200 Main Rotor System.

Issued in Fort Worth, Texas, on December
1, 2016.
Lance T. Gant, Manager, Rotorcraft Directorate, Aircraft Certification Service.

[FR Doc. 2016–30053 Filed 12–23–16; 8:45 am]

**BILLING CODE 4910–13–P**

**DEPARTMENT OF TRANSPORTATION**

**Federal Aviation Administration**

**14 CFR Part 39**

**[Docket No. FAA–2016–4278; Directorate Identifier 2012–SW–022–AD; Amendment**  **39–18758; AD 2016–26–01]**

**RIN 2120–AA64**

**Airworthiness Directives; AgustaWestland S.p.A. (Agusta)**  **Helicopters**

**AGENCY :**  Federal Aviation Administration (FAA), DOT.

**ACTION :**  Final rule.

**SUMMARY :**  We are adopting a new airworthiness directive (AD) for certain Agusta Model AB139 and AW139 helicopters. This AD requires performing operational checks of both hydraulic systems. This AD was prompted by an assessment of the hydraulic systems of the helicopter following an accident. These actions are intended to prevent the unsafe condition on these products.

**DATES :**  This AD is effective January 31,

2017.

The Director of the Federal Register approved the incorporation by reference of a certain document listed in this AD as of January 31, 2017.

**ADDRESSES :**  For service information identified in this final rule, contact AgustaWestland, Product Support Engineering, Via del Gregge, 100, 21015 Lonate Pozzolo (VA) Italy, ATTN: Maurizio D’Angelo; telephone 39–0331– 664757; fax 39 0331–664680; or at http://www.agustawestland.com/ technical-bulletins. You may review the referenced service information at the FAA, Office of the Regional Counsel, Southwest Region, 10101 Hillwood Pkwy, Room 6N–321, Fort Worth, TX

76177.
Examining the AD Docket

You may examine the AD docket on the Internet at http:// www.regulations.gov by searching for and locating Docket No. FAA–2016– 4278; or in person at the Docket Operations Office between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays. The AD docket contains this AD, the European Aviation Safety Agency (EASA) AD, theeconomic evaluation, any incorporatedby-reference service information, any comments received, and other information. The street address for the Docket Operations Office (phone: 800– 647–5527) is U.S. Department of Transportation, Docket Operations Office, M–30, West Building Ground Floor, Room W12–140, 1200 New Jersey Avenue SE., Washington, DC 20590.

**FOR FURTHER INFORMATION CONTACT :**  Matt Wilbanks, Aviation Safety Engineer, Safety Management Group, Rotorcraft Directorate, FAA, 10101 Hillwood Parkway, Fort Worth, Texas 76177; telephone (817) 222–5110; email matt.wilbanks@faa.gov.

**SUPPLEMENTARY INFORMATION :** 

Discussion

On March 11, 2016, at 81 FR 12838, the Federal Register published our notice of proposed rulemaking (NPRM), which proposed to amend 14 CFR part 39 by adding an AD that would apply to certain serial-numbered Agusta Model AB139 and AW139 helicopters. The NPRM proposed to require, within 50 hours time-in-service (TIS), performing operational tests of the Number 1 and Number 2 hydraulic systems power control modules (PCMs), the tail shut-off valve, the PCM1 and PCM2 flight control shut-off valves, and the emergency landing gear shut-off valve for correct functionality. Depending on the results of the operational checks, the NPRM proposedto require replacing a PCM, the tail shutoff valve, a flight control shut-off valve, the number 2 hydraulic control panel, the number 1 hydraulic module, the number 1 or number 2 PCM pressure switch, or repairing the electrical wiring. The proposed requirements were intended to prevent loss of hydraulic power to the flight controls and subsequent loss of control of the helicopter.

The NPRM was prompted by AD No. 2011–0207, dated October 20, 2011 (AD No. 2011–0207), issued by EASA, which is the Technical Agent for the Member States of the European Union, to correctan unsafe condition for certain serialnumbered Agusta Model AB139 and AW139 helicopters. EASA advises that an accident involving a Model AW139 helicopter caused the tail rotor (T/R), the T/R gearbox, and part of the fin to detach from the aircraft, rupturing the hydraulic lines and draining all of the hydraulic fluid. According to EASA, an


### 94947 Federal Register / Vol. 81, No. 248 / Tuesday, December 27, 2016 / Rules and Regulations

assessment of the helicopter’s hydraulic systems following the accident revealed that an operational check of the hydraulic systems is necessary to ensure its functionality. EASA advises that this condition, if not corrected, could lead, in the case of multiple failures, to loss of hydraulic power and subsequent loss of control of the helicopter. To address this, EASA AD No. 2011–0207 requires, within 50 flight hours or 2 months, operational checks of the power control modules and shutoff valves and reporting the results to the manufacturer.

Comments

After our NPRM (81 FR 12838, March 11, 2016) was published, we received comments from one commenter.

Request

The commenter requested we not adopt the proposed AD, as it is unnecessary. The commenter stated that following the release of EASA AD No. 2011–0207 and Agusta Bollettino Tecnico No. 139–269, dated September 30, 2011 (BT 139–269), they already have a 600 hour/12 month inspection and operational check of the hydraulic systems as part of their maintenance program that covers all of the proposed actions in the NPRM. Finally, the commenter stated that the proposed AD would not change any of their maintenance procedures, but it would add an additional burden of required paper work for the same results.

We disagree. EASA AD No. 2011– 0207 is not mandatory for U.S. operators. Additionally, while an operator may incorporate the procedures described in BT 139–269 into its maintenance program, not all operators are required to do so. In order for the corrective actions in BT 139–269 to become mandatory, and to correct the unsafe condition identified in the NPRM, the FAA must issue an AD.

FAA’s Determination

These helicopters have been approved by the aviation authority of Italy and are approved for operation in the United States. Pursuant to our bilateral agreement with Italy, EASA, its technical representative, has notified us of the unsafe condition described in the EASA AD. We are issuing this AD because we evaluated all information provided by EASA, reviewed the relevant information, considered the comment received, and determined the unsafe condition exists and is likely to exist or develop on other helicopters of these same type designs and that air safety and the public interest require adopting the AD requirements as proposed.

Differences Between This AD and the
EASA AD

The EASA AD requires reporting the results of the operational checks to Agusta, while this AD does not. The EASA AD also requires compliance within 50 flight-hours or 2 months, while this AD requires compliance within 50 hours TIS.

Related Service Information Under 1
CFR Part 51

We reviewed BT 139–269 for Model AB139 and AW139 helicopters. BT 139– 269 contains procedures for conducting operational checks of both hydraulic systems to confirm correct functionality.

This service information is reasonably available because the interested parties have access to it through their normal course of business or by the means identified in the **ADDRESSES** section.
Costs of Compliance

We estimate this AD will affect 102 helicopters of U.S. Registry.

Based on an average labor rate of $85 per hour, we estimate that operators may incur the following costs in order to comply with this AD. Performing the operational checks of the hydraulic systems requires about 2 work-hours for a total cost per helicopter of $170 and a total cost to U.S. operators of $17,340.

If required, replacing a PCM will require about 3 work-hours and required parts will cost about $87,136, for a cost per helicopter of $87,391.

If required, replacing a tail or flight control shut-off valve will require about 2 work-hours, and required parts will cost about $7,512, for a cost per helicopter of $7,682. If required, replacing the number 2 hydrauliccontrol panel will require about 2 workhours, and required parts will cost about $8,165, for a cost per helicopter of $8,335.

If required, replacing the number 1 hydraulic module will require about 4 work-hours, and required parts will cost about $87,137, for a cost per helicopter of $87,477.

If required, replacing a PCM pressure switch will require about 2 work-hours, and required parts will cost about $6,974, for a cost per helicopter of $7,144.

If required, repairing the electrical wiring will require about 2 work-hours, and required parts will cost about $45, for a cost per helicopter of $215.

Authority for This Rulemaking

Title 49 of the United States Code specifies the FAA’s authority to issue rules on aviation safety. Subtitle I, section 106, describes the authority of the FAA Administrator. Subtitle VII: Aviation Programs, describes in more detail the scope of the Agency’s authority.

We are issuing this rulemaking under the authority described in Subtitle VII, Part A, Subpart III, Section 44701: ‘‘General requirements.’’ Under that section, Congress charges the FAA with promoting safe flight of civil aircraft in air commerce by prescribing regulations for practices, methods, and procedures the Administrator finds necessary for safety in air commerce. This regulation is within the scope of that authority because it addresses an unsafe condition that is likely to exist or develop on helicopters identified in this rulemaking
action.
Regulatory Findings

This AD will not have federalism implications under Executive Order 13132. This AD 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.

For the reasons discussed above, I certify that this AD:

(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);

(3) Will not affect intrastate aviation in Alaska to the extent that it justifies making a regulatory distinction; and

(4) 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 an economic evaluation of the estimated costs to comply with this AD and placed it in the AD docket.

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 FAA amends 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.


### 94948 Federal Register / Vol. 81, No. 248 / Tuesday, December 27, 2016 / Rules and Regulations

**§ 39.13 [Amended]**

■ 2. The FAA amends § 39.13 by adding the following new airworthiness directive (AD):

2016–26–01 AGUSTAWESTLAND S.P.A. (AGUSTA): Amendment 39–18758; Docket No. FAA–2016–4278; Directorate Identifier 2012–SW–022–AD.

(a) Applicability

This AD applies to Agusta Model AB139 and AW139 helicopters, all serial numbers except serial number 31007, 31094, 31293, 31301, 31303, 31313, and 31329, certificated in any category.

(b) Unsafe Condition

This AD defines the unsafe condition as an inoperative hydraulic shut-off valve, which could result in loss of hydraulic power and subsequent loss of control of the helicopter.

(c) Effective Date

This AD becomes effective January 31,

2017.
(d) Compliance

You are responsible for performing each action required by this AD within the specified compliance time unless it has already been accomplished prior to that time.

(e) Required Actions

Within 50 hours time-in service: (1) Perform an operational test of each Number 1 and Number 2 power control module (PCM). If the fluid level in the reservoir changes more than 5mm (0.196 in) in an hour, replace the affected PCM.

(2) Perform an operational test of each tail shut-off valve. If the 2 SERVO caution message is not illuminated and the UTIL SOV2 and TR SOV indications are in the open position:

(i) Disconnect the Tail Shutoff valve connector, HP4P1.

(ii) Disconnect the PCM2 connectors, A44P3 and A44P12.

(iii) Disconnect the TB38 terminal board connector, TB38P1.

(iv) Perform a continuity test from HP4P1– 1 to A44P12–16, from HP4P1–2 to TB38P1– D, and from HP4P1–4 to A44P3–6.

(v) If there is no continuity, repair or replace the defective wiring.

(vi) If there is continuity, release the test lever of the PCM2 to the DOWN NORM position.

(vii) If the TRSVO indication stays in the closed position, replace the tail shutoff valve.

(3) Perform an operational test of the PCM 2 flight control shut-off valve as described in the Compliance Instructions, paragraphs 5.1. through 5.5., of Agusta Bollettino Tecnico No. 139–269, dated September 30, 2011 (BT 139–269).

(i) If the 2 SERVO caution message is illuminated:

(A) On the hydraulic control panel, lift the guard of the SOV1/SOV2 switch and set it to SOV2 (closed position). Make sure that the 2 HYD PRESS caution message and the HYD 2 PRESS warning light on the hydraulic control panel are illuminated.

(B) Reset the SOV1/SOV2 switch to the open position. (C) If the 2 HYD PRESS and 2 SERVO caution messages remain illuminated:

( 1 ) Disconnect the PL14P1 and PL14P2 connectors from the hydraulic control panel.

( 2 ) Disconnect the A1–1P4 connector from the MAU1.

( 3 ) Disconnect the A2–1P3 connector from the MAU2.

( 4 ) Disconnect the A44P3 connector from the Number 2 PCM.

( 5) Disconnect the PL1P3 connector from the circuit breaker panel.

( 6) Perform a continuity test from PL14P1– J to A1–1P4–18, from PL14P1–D to PL1P3– q, from PL14P2–J to A44P3–5, and from PL14P2–T to A2–1P3–34. If there is no continuity, repair or replace the defective wiring.

( 7) If the HYD PRESS and 2 SERVO caution messages remain illuminated, replace the number 2 hydraulic power module.

(ii) If the 2 HYD PRESS caution message is illuminated, the HYD 2 pressure indication is more than 190 bar (2,755 lbf/sq in), and the SOV2 shutoff valve is in the open position, replace the pressure switch on the Number
2 PCM.

(iii) If the closure of SOV 2 is indicated on the MFD hydraulic synoptic page, before further flight, replace the Number 2 PCM.

(4) Perform an operational test of the PCM 1 flight control shut-off valve as described in the Compliance Instructions, paragraphs 6.1. through 6.4., of BT 139–269.

(i) If the 1 SERVO caution message is
illuminated:

(A) On the hydraulic control panel, lift the guard of the SOV1/SOV2 switch and set it to SOV1 (closed position). Make sure that the 1 HYD PRESS caution message and the HYD 1 PRESS warning light on the hydraulic control panel are illuminated.

(B) Reset the SOV1/SOV2 switch to the open position. If the 1 HYD PRESS and 1 SERVO caution messages remain illuminated:

( 1 ) Disconnect the PL14P1 and PL14P2 connectors from the hydraulic control panel.

( 2 ) Disconnect the A1–1P4 connector from
the MAU1.

( 3 ) Disconnect the A2–1P3 connector from
the MAU2.

( 4 ) Disconnect the A45P3 connector from
the Number 1 PCM.

( 5) Disconnect the PL1P3 connector from the circuit breaker panel.

( 6) Perform a continuity test from PL14P1– J to A1–1P4–18, from PL14P1–E to A45P3– 5, from PL14P1–D to PL1P3-q, and from
PL14P2–T to A2–1P3–34. If there is no continuity, repair or replace the defective wiring.

( 7) If the HYD PRESS and 1 SERVO caution messages remain illuminated, replace the Number 1 hydraulic control panel.

(ii) If the 1 HYD PRESS caution message is illuminated, the HYD 1 pressure indication is more than 190 bar (2,755 lbf/sq in), and the SOV1 shutoff valve is in the open position, replace the pressure switch on the Number
1 PCM.

(iii) If the closure of SOV 1 is indicated on the MFD hydraulic synoptic page, before further flight, replace the Number 1 PCM.

(4) Perform an operational test of the emergency landing gear shutoff valve as described in the Compliance Instructions, paragraphs 7.1. through 7.4., of BT 139–269.

(i) If the EMERG L/G PRESS caution message is illuminated, the HYD 1 pressure indication is more than 190 bar (2,755 lbf/sq in), and the UTIL SOV1 (LDG GEAR EMER) shutoff valve is in the open position, replace the pressure switch on the Number 1 PCM.

(ii) If the 1 HYD MIN caution message is illuminated, inspect the fluid level on the Number 1 PCM and inspect the Number 1 main hydraulic system for leaks.

(A) If the fluid level is between the FULL and ADD marks, or if there are no hydraulic fluid leaks, perform an operational test of the level switches. If the 1 HYD MIN caution message is illuminated, replace the Number
1 PCM.

(B) If there is a hydraulic fluid leak: ( 1 ) Replace all leaking parts and lines or repair the leak.

(2) If the 1 HYD MIN caution message remains illuminated, perform an operational test of the level switches.

(3) If the 1 HYD MIN caution message remains illuminated, replace the Number 1
PCM.

(f) Alternative Methods of Compliance (AMOCs)

(1) The Manager, Safety Management Group, FAA, may approve AMOCs for this AD. Send your proposal to: Matt Wilbanks, Aviation Safety Engineer, Safety Management Group, Rotorcraft Directorate, FAA, 10101 Hillwood Parkway, Fort Worth, Texas 76177; telephone (817) 222–5110; email 9-ASWFTW-AMOC-Requests@faa.gov.

(2) For operations conducted under a 14 CFR part 119 operating certificate or under 14 CFR part 91, subpart K, we suggest that you notify your principal inspector, or lacking a principal inspector, the manager of the local flight standards district office or certificate holding district office, before operating any aircraft complying with this AD through an AMOC.

(g) Additional Information

The subject of this AD is addressed in European Aviation Safety Agency (EASA) AD No. 2011–0207, dated October 20, 2011. You may view the EASA AD on the Internet at http://www.regulations.gov in Docket No.

FAA-2016–4278.

(h) Subject

Joint Aircraft Service Component (JASC) Code: 2900: Hydraulic Power.

(i) Material Incorporated by Reference

(1) The Director of the Federal Register approved the incorporation by reference of the service information listed in this paragraph under 5 U.S.C. 552(a) and 1 CFR part 51.

(2) You must use this service information as applicable to do the actions required by this AD, unless the AD specifies otherwise.

(i) Agusta Bollettino Tecnico No. 139–269, dated September 30, 2011.

(ii) Reserved. (3) For Agusta service information identified in this final rule, contact AgustaWestland, Product Support Engineering, Via del Gregge, 100, 21015 Lonate Pozzolo (VA) Italy, ATTN: Maurizio


### 94949 Federal Register / Vol. 81, No. 248 / Tuesday, December 27, 2016 / Rules and Regulations

D’Angelo; telephone 39–0331–664757; fax 39
0331–664680; or at http://www.agustawestland.com/technicalbulletins.

(4) You may view this service information at FAA, Office of the Regional Counsel, Southwest Region, 10101 Hillwood Pkwy, Room 6N–321, Fort Worth, TX 76177. For information on the availability of this material at the FAA, call (817) 222–5110.

(5) You may view this service information that is incorporated by reference at the
National Archives and Records Administration (NARA). For information on the availability of this material at NARA, call (202) 741–6030, or go to: http://www.archives.gov/federal-register/cfr/ibrlocations.html.

Issued in Fort Worth, Texas, on December
9, 2016.
Scott A. Horn, Acting Manager, Rotorcraft Directorate, Aircraft Certification Service.

[FR Doc. 2016–30285 Filed 12–23–16; 8:45 am]

**BILLING CODE 4910–13–P**

**DEPARTMENT OF TRANSPORTATION**

**Federal Aviation Administration**

**14 CFR Part 39**

**[Docket No. FAA–2015–7525; Directorate Identifier 2015–NM–064–AD; Amendment**  **39–18727; AD 2016–25–01]**

**RIN 2120–AA64**

**Airworthiness Directives; The Boeing Company Airplanes** 

**AGENCY :**  Federal Aviation Administration (FAA), DOT.

**ACTION :**  Final rule.

**SUMMARY :**  We are adopting a new airworthiness directive (AD) for certain The Boeing Company Model 747–400, 747–400D, and 747–400F series airplanes; Model 757 airplanes; and Model 767–200, –300, –300F, and –400ER series airplanes. This AD was prompted by reports of uncommanded autopilot engagement events resulting in incorrect stabilizer trim adjustment during takeoff. This AD requires, depending on the model/configuration, installing an on-ground stabilizer autotrim inhibit system, relays and related wiring to open and close the flight control computer (FCC) analog output, and new operational program software (OPS) into the FCCs. We are issuing this AD to address the unsafe condition on these products.

**DATES :**  This AD is effective January 31,

2017.

The Director of the Federal Register approved the incorporation by reference of certain publications listed in this AD as of January 31, 2017. **ADDRESSES :**  For service information identified in this final rule, contact Boeing Commercial Airplanes, Attention: Data & Services Management, P. O. Box 3707, MC 2H–65, Seattle, WA 98124–2207; telephone: 206–544–5000, extension 1; fax: 206–766–5680; Internet https://www.myboeingfleet.com. You may view this referenced service information at the FAA, Transport Airplane Directorate, 1601 Lind Avenue SW., Renton, WA. For information on the availability of this material at the FAA, call 425–227–1221. It is also available on the Internet at http:// www.regulations.gov by searching for and locating Docket No. FAA–2015–

7525.
Examining the AD Docket

You may examine the AD docket on the Internet at http:// www.regulations.gov by searching for and locating Docket No. FAA–2015– 7525; or in person at the Docket Management Facility between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays. The AD docket contains this AD, the regulatory evaluation, any comments received, and other information. The address for the Docket Office (phone: 800–647–5527) is Docket Management Facility, U.S. Department of Transportation, Docket Operations, M–30, West Building Ground Floor, Room W12–140, 1200 New Jersey Avenue SE., Washington,
DC 20590.

**FOR FURTHER INFORMATION CONTACT :**  Fnu Winarto, Aerospace Engineer, Systems and Equipment Branch, ANM–130S, FAA, Seattle Aircraft Certification Office (ACO), 1601 Lind Avenue SW., Renton, WA 98057–3356; phone: 425– 917–6659; fax: 425–917–6590; email: fnu.winarto@faa.gov.

**SUPPLEMENTARY INFORMATION :** 

Discussion

We issued a notice of proposed rulemaking (NPRM) to amend 14 CFR part 39 by adding an AD that would apply to certain The Boeing Company Model 747–400, 747–400D, and 747– 400F series airplanes; Model 757 airplanes; and Model 767–200, –300, –300F, and –400ER series airplanes. The NPRM published in the Federal Register on December 23, 2015 (80 FR 79735) (‘‘the NPRM’’). The NPRM was prompted by reports of uncommanded autopilot engagement events resulting in incorrect stabilizer trim adjustment during takeoff. The NPRM proposed to require, depending on the model/ configuration for Model 747 airplanes, installing an on-ground stabilizer autotrim inhibit system, doing routine functional testing of the system, and doing corrective actions if necessary; for Model 757 airplanes and Model 767 airplanes, installing relays and related wiring to open and close the FCC analog output that controls the stabilizer trim adjustment, doing routine functional testing of the on-ground auto stabilizer trim inhibit system, and doing corrective actions if necessary; and for Model 767–300, and –300F series airplanes, installing new OPS into the FCCs. We are issuing this AD to prevent stabilizer mistrim, which could result in a high-speed rejected takeoff and runway overrun, or reduced controllability of the airplane after takeoff due to insufficient pitch control.

Comments

We gave the public the opportunity to participate in developing this AD. The following presents the comments received on the NPRM and the FAA’s response to each comment.

Support for the NPRM

The Airline Pilots Association, International stated that it fully supports the intent of the NPRM.

Requests To Withdraw the NPRM

United Parcel Service (UPS) requested that the NPRM be withdrawn until the actual root cause of the unsafe condition can be determined and a validated and confirmed solution is developed.

FedEx Express (FedEx) requested that we withdraw the NPRM. FedEx stated that the burden of the actions proposed in the NPRM is not justified based on data presented in Boeing Fleet Team Digest 757–FTD–22–12001 or its operational experience. FedEx believes this is an extremely isolated and unlikely anomaly on the Model 757 fleet. FedEx stated that it operates over 100 Model 757 aircraft and has completed over 210,000 flight cycles with no reports of uncommanded autopilot engagement.

We disagree with the commenters’ request to withdraw the NPRM. The quantitative and qualitative risks analyzed for this identified unsafe condition present an unacceptable risk that must be addressed on both passenger and freighter models. The manufacturer also considers the condition a safety issue and has developed an on-ground stabilizer autotrim inhibit system that addresses the unsafe condition. We have determined that it is necessary to proceed with issuance of this AD.

Requests To Clarify Root Cause

Boeing requested that we revise the Discussion section of the NPRM. Boeing