# AD 2011-16-03: Hydraulic power

- Type: Airworthiness directive
- Status: Current
- Products: Airbus A300 B4-601, A300 B4-603, A300 B4-605R, A300 B4-620, A300 B4-622, A300 B4-622R, A300 C4-605R Variant F, A300 F4-605R, A300 F4-622R, A310-203, A310-204, A310-221 and 53 more
- Effective: September 9, 2011
- Published: August 5, 2011, 76 FR 47430–47435
- Issued: July 20, 2011
- Issued as: Final rule
- Superseded by: Nothing supersedes this AD
- Product type: Aircraft, Large airplane
- ATA chapter: 29 · Hydraulic power
- Amendment: 39-16761
- Docket: FAA-2011-0388 (https://www.regulations.gov/docket/FAA-2011-0388)
- Project: 2010-NM-004-AD
- Registered aircraft: 1,608 may be affected, by airframe or engine model (OpenAirDocs)
- Official PDF: https://openairdocs.org/files/sha256/d9/4c/d94c7a7258d8aca68fbc0d393acbbb6782d58ebe49a24c6003b25cd55756a09d (from https://www.govinfo.gov/content/pkg/FR-2011-08-05/pdf/2011-19433.pdf)
- Federal Register: https://www.federalregister.gov/documents/2011/08/05/2011-19433/airworthiness-directives-airbus-model-a300-b4-600-a300-b4-600r-and-a300-f4-600r-series-airplanes-and
- FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/001EB66C0575BF65862578E3004A9B90.0001
- DRS record last changed: May 30, 2024
- Page: https://openairdocs.org/ad/2011-16-03

## Summary

We are adopting a new airworthiness directive (AD) for the products listed above. This AD results from mandatory continuing airworthiness information (MCAI) originated by an aviation authority of another country to identify and correct an unsafe condition on an aviation product. For Model A310 and A300-600 series airplanes, the MCAI describes the unsafe condition as:

Hamilton Sundstrand (HS), the manufacturer of the RAT [ram air turbine], reported the failure during a wind tunnel test of a balance weight fastening screw on the RAT turbine cover. After investigation, it has been discovered that a batch of screws, which are used to attach the balance washers of the HS RAT Turbine Assembly, has not been subject to the correct heat treatment and are consequently exposed to potential fracture.

This condition, if not corrected, might lead to the ejection of screw heads and consequently to the detachment of the associated balance washers. The loss of balance washers could increase RAT vibrations, which might lead to a possible detachment of RAT parts and consequent loss of RAT functionality. The loss of the RAT, in combination with a total engine flame out, could result in loss of control of the aeroplane.

For Model A318, A319, A320, and A321 series airplanes, the MCAI describes the unsafe condition as:

Hamilton Sundstrand (HS) reported the failure of a balance weight fastening screw on the RAT turbine cover during a wind tunnel test. After investigation, it has been discovered that a batch of screws, used to attach the balance washers of the RAT Turbine assembly, has not received the correct heat treatment, making them more subject to a potential failure.

This condition, if left uncorrected, could lead to the ejection of screw heads and detachment of the associated balance washers. The loss of balance washers would increase RAT vibrations, which could lead to a possible detachment of RAT parts and loss of RAT functionality. The loss of the RAT, in combination with a double engine failure, or a total loss of normal electrical power generation, could result in loss of control of the aeroplane.

For Model A330 and A340 series airplanes, the MCAI describes the unsafe condition as:

Hamilton Sundstrand (HS), the manufacturer of the RAT, reported the failure of a balance weight fastening screw on the RAT cover during a wind tunnel test. After investigation, it has been discovered that a batch of screws, which are used to attach the balance washers of the HS RAT turbine lower gear box assembly, has not been subject to the correct heat treatment and the screws are consequently exposed to potential fracture.

This condition, if not corrected, might lead to the ejection of screw heads and consequently to the detachment of the associated balance washers. The loss of balance washers could increase RAT vibrations, which might lead to a possible detachment of RAT parts, and thus to damage to the aeroplane and risk of injury to persons on the ground.

We are issuing this AD to require actions to correct the unsafe condition on these products.

## The airworthiness directive

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

2. The FAA amends § 39.13 by adding the following new AD:

2011-16-03 Airbus: Amendment 39-16761. Docket No. FAA-2011-0388; Directorate Identifier 2010-NM-004-AD.

### (a) Effective Date

  (a) This airworthiness directive (AD) becomes effective September 9, 2011.

### (b) Affected ADs

  (b) None.

### (c) Applicability

  (c) This AD applies to the Airbus airplanes listed in paragraphs (c)(1), (c)(2), (c)(3), (c)(4), and (c)(5) of this AD, certificated in any category.

  (1) Airbus Model A300 B4-601, B4-603, B4-620, B4-622, B4-605R, B4-622R, F4-605R, F4-622R, and C4-605R Variant F airplanes; and Model A310-203, -204, -221, -222, -304, -322, -324, and -325 airplanes; all certified models, all manufacturer serial numbers, if equipped with a Hamilton Sundstrand ram air turbine (RAT) turbine assembly, as identified by part number (P/N) in Hamilton Sundstrand Service Bulletin 730816-29-15, dated August 4, 2009 (for Model A310 airplanes), and Hamilton Sundstrand Service Bulletin 732365-29-7, dated August 4, 2009 (for Model A300-600 series airplanes); or equipped with a Hamilton Sundstrand RAT turbine lower gear box assembly on which the part number cannot be determined.

  (2) Airbus Model A318-111, -112, -121, and -122 airplanes; Model A319-111, -112, -113, -114, -115, -131, -132, and -133 airplanes; Model A320-211, -212, -214, -231, -232, and -233 airplanes; and Model A321-111, -112, -131, -211, -212, -213, -231, and -232 airplanes; all manufacturer serial numbers, if equipped with a Hamilton Sundstrand RAT turbine assembly Model ERPS08M, as identified by part number in Hamilton Sundstrand Service Bulletin ERPS08M-29-8, dated June 17, 2009; or equipped with a Hamilton Sundstrand RAT turbine lower gear box assembly on which the part number cannot be determined.

  (3) Airbus Model A330-201, -202, -203, -223, -243, -301, -302, -303, -321, -322, -323, -341, -342, and -343 airplanes; all manufacturer serial numbers, if equipped with a Hamilton Sundstrand RAT turbine lower gearbox assembly, as identified by part number in Hamilton Sundstrand Service Bulletin ERPS06G-29-6, dated July 20, 2009; or equipped with a Hamilton Sundstrand RAT turbine lower gear box assembly on which the part number cannot be determined.

  (4) Model A340-211, -212, -213, -311, -312, and -313 airplanes; all manufacturer serial numbers, if equipped with a Hamilton Sundstrand RAT turbine lower gearbox assembly, as identified by part number in Hamilton Sundstrand Service Bulletin ERPS06G-29-6, dated July 20, 2009; or equipped with a Hamilton Sundstrand RAT turbine lower gear box assembly on which the part number cannot be determined.

  (5) Model A340-541 and -642 airplanes, all manufacturer serial numbers, if equipped with a Hamilton Sundstrand RAT turbine lower gearbox assembly, as identified by part number in Hamilton Sundstrand Service Bulletin ERPS33G-29-1, dated July 20, 2009; or equipped with a Hamilton Sundstrand RAT turbine lower gear box assembly on which the part number cannot be determined.

### (d) Subject

  (d) Air Transport Association (ATA) of America Code 29: Hydraulic power.

### (e) Reason

  (e) For Model A310 and A300-600 series airplanes, the MCAI describes the unsafe condition as:

Hamilton Sundstrand (HS), the manufacturer of the RAT, reported the failure during a wind tunnel test of a balance weight fastening screw on the RAT turbine cover. After investigation, it has been discovered that a batch of screws, which are used to attach the balance washers of the HS RAT Turbine Assembly, has not been subject to the correct heat treatment and are consequently exposed to potential fracture.

This condition, if not corrected, might lead to the ejection of screw heads and consequently to the detachment of the associated balance washers. The loss of balance washers could increase RAT vibrations, which might lead to a possible detachment of RAT parts and consequent loss of RAT functionality. The loss of the RAT, in combination with a total engine flame out, could result in loss of control of the aeroplane.

For Model A318, A319, A320, and A321 series airplanes, the MCAI describes the unsafe condition as:

Hamilton Sundstrand (HS) reported the failure of a balance weight fastening screw on the RAT turbine cover during a wind tunnel test. After investigation, it has been discovered that a batch of screws, used to attach the balance washers of the RAT Turbine assembly, has not received the correct heat treatment, making them more subject to a potential failure.

This condition, if left uncorrected, could lead to the ejection of screw heads and detachment of the associated balance washers. The loss of balance washers would increase RAT vibrations, which could lead to a possible detachment of RAT parts and loss of RAT functionality. The loss of the RAT, in combination with a double engine failure, or a total loss of normal electrical power generation, could result in loss of control of the aeroplane.

For Model A330 and A340 series airplanes, the MCAI describes the unsafe condition as:

Hamilton Sundstrand (HS), the manufacturer of the RAT, reported the failure of a balance weight fastening screw on the RAT cover during a wind tunnel test. After investigation, it has been discovered that a batch of screws, which are used to attach the balance washers of the HS RAT turbine lower gear box assembly, has not been subject to the correct heat treatment and the screws are consequently exposed to potential fracture.

This condition, if not corrected, might lead to the ejection of screw heads and consequently to the detachment of the associated balance washers. The loss of balance washers could increase RAT vibrations, which might lead to a possible detachment of RAT parts, and thus to damage to the aeroplane and risk of injury to persons on the ground.

### (f) Compliance

  (f) You are responsible for having the actions required by this AD performed within the compliance times specified, unless the actions have already been done.

### (g) Actions

  (g) At the applicable time specified in paragraph (g)(1), (g)(2), or (g)(3) of this AD: Inspect to determine the part number and serial number of the RAT turbine lower gear box assembly, in accordance with the applicable Airbus all operator telex (AOT) identified in table 1 of this AD. If the RAT turbine lower gear box assembly has a part number and a serial number that are not listed in the applicable Hamilton Sundstrand service bulletin identified in table 2 of this AD, no further action is required by this AD, except as required by paragraph (k) of this AD. A review of airplane maintenance records is acceptable in lieu of this inspection if the part and serial numbers of the RAT turbine lower gear box assembly can be conclusively determined from that review.

*Table 1—Airbus AOTs*

| Model | Document | Date |
| --- | --- | --- |
| Model A300-600 series airplanes | Airbus AOT A300-29A6062 | September 1, 2009. |
| Model A310 series airplanes | Airbus AOT A310-29A2098 | September 1, 2009. |
| Model A318 series airplanes; Model A319 series airplanes; Model A320-211, -212, -214, -231, -232, and -233 airplanes; Model A321 series airplanes | Airbus AOT A320-29A1150 | June 24, 2009. |
| Model A330-200 and A330-300 series airplanes | Airbus AOT A330-29A3110 | September 1, 2009. |
| Model A340-200 and A340n-300 series airplanes | Airbus AOT A340-29A4085 | September 1, 2009. |
| Model A340-500 and A340-600 series airplanes | Airbus AOT A340-500/600-29A5015 | September 1, 2009. |

  (1) For airplanes identified in paragraph (c)(1) of this AD: Before the next RAT spin test, or within 1,500 flight hours or 9 months after the effective date of this AD, whichever occurs first.

  (2) For airplanes identified in paragraph (c)(2) of this AD: Before the next RAT spin test, or within 3,000 flight hours or 12 months after the effective date of this AD, whichever occurs first.

  (3) For airplanes identified in paragraph (c)(3), (c)(4), and (c)(5) of this AD: Before the next RAT spin test, or within 3,000 flight hours or 8 months after the effective date of this AD, whichever occurs first.

  (h) If, during the inspection required by paragraph (g) of this AD, the RAT turbine lower gear box assembly has a part number and a serial number identified in the applicable Hamilton Sundstrand service bulletin specified in table 2 of this AD; or if the part number or serial number of the RAT turbine lower gear box assembly cannot be determined: Before further flight, inspect the RAT turbine lower gear box assembly to determine if the nameplate is identified with the applicable symbol specified in table 3 of this AD, in accordance with the applicable Airbus AOT specified in table 1 of this AD. If the RAT turbine lower gear box assembly nameplate has the applicable symbol that is identified in table 3 of this AD, no further action is required by this AD except as required by paragraph (k) of this AD. A review of airplane maintenance records is acceptable in lieu of this inspection if the symbol identified on the nameplate can be conclusively determined from that review.

*Table 2—Applicable Hamilton Sundstrand Service Bulletins*

| Model | Document | Date |
| --- | --- | --- |
| Model A300-600 series airplanes | Hamilton Sundstrand Service Bulletin 732365-29-7 | August 4, 2009. |
| Model A310 series airplanes | Hamilton Sundstrand Service Bulletin 730816-29-15 | August 4, 2009. |
| Model A318 series airplanes; Model A319 series airplanes; Model A320-211, -212, -214, -231, -232, and -233 airplanes; Model A321 series airplanes | Hamilton Sundstrand Service Bulletin ERPS08M-29-8 | June 17, 2009. |
| Model A330-200 and A330-300 series airplanes and Model A340-200 and A340-300 series airplanes | Hamilton Sundstrand Service Bulletin ERPS06G-29-6 | July 20, 2009. |
| Model A340-500 and A340-600 series airplanes | Hamilton Sundstrand Service Bulletin ERPS33G-29-1 | July 20, 2009. |

*Table 3—Nameplate Identification*

| Model | Symbol |
| --- | --- |
| Model A300-600 series airplanes | 29-7 |
| Model A310 series airplanes | 29-15 |
| Model A318 series airplanes; Model A319 series airplanes; Model A320-211, -212, -214, -231, -232, and -233 airplanes; Model A321 series airplanes | 29-8 |
| Model A330-200 and A330-300 series airplanes | 29-6 |
| Model A340-200 and A340-300 series airplanes | 29-6 |
| Model A340-500 and A340-600 series airplanes | 29-1 |

    (i) If, during the inspection required by paragraph (h) of this AD, the RAT turbine lower gear box assembly does not have the applicable symbol specified in table 3 of this AD: Before further flight, do a general visual inspection for the missing and fractured balance screws and for missing washers in accordance with the applicable Airbus AOT specified in table 1 of this AD.

  (1) If all balance screws are fitted on the turbine and are not fractured or missing, at the applicable time specified in paragraph (i)(1)(i), (i)(1)(ii), or (i)(1)(iii) of this AD: Replace the RAT turbine lower gear box assembly with a new or serviceable RAT turbine lower gear box assembly, or replace all balance screws on the RAT turbine lower gear box assembly with new or serviceable balance screws, in accordance with the applicable Airbus AOT specified in table 1 of this AD.

    (i) For airplanes identified in paragraph (c)(1) of this AD: Within 1,500 flight hours or 9 months after the effective date of this AD, whichever occurs first.

    (ii) For airplanes identified in paragraph (c)(2) of this AD: Within 3,000 flight hours or 12 months after the effective date of this AD, whichever occurs first.

    (iii) For airplanes identified in paragraphs (c)(3), (c)(4), and (c)(5) of this AD: Within 3,000 flight hours or 8 months after the effective date of this AD, whichever occurs first.

  (2) If one or more screws are fractured but the associated balance washers are still fitted on the RAT turbine lower gear box assembly, before further flight, do the actions specified in paragraph (i)(2)(i) or (i)(2)(ii) of this AD, in accordance with the applicable Airbus AOT specified in table 1 of this AD.

    (i) Replace the RAT turbine lower gear box assembly with a new or serviceable RAT turbine lower gear box assembly.

    (ii) Replace all balance screws on the RAT turbine lower gear box assembly with new or serviceable balance screws, including replacing any missing washers.

  (3) If one or more screws are fractured and any balance washer is missing, before further flight, replace the RAT turbine lower gear box assembly with new or serviceable RAT turbine lower gear box assembly, in accordance with the applicable Airbus AOT specified in table 1 of this AD.

### (j) Reporting Requirement

  (j) At the applicable time specified in paragraph (j)(1) or (j)(2) of this AD, submit a report of the findings (both positive and negative) of the inspection required by paragraph (i) of this AD to Airbus, as specified in Paragraph 7 of the applicable AOT specified in table 1 of this AD. The report must include the inspection results, a description of any discrepancies found, the airplane serial number, and the number of landings and flight hours on the airplane.

  (1) If the inspection was done on or after the effective date of this AD: Submit the report within 30 days after the inspection.

  (2) If the inspection was done before the effective date of this AD: Submit the report within 30 days after the effective date of this AD.

### (k) Parts Installation

  (k) As of the effective date of this AD, no person may install, on any airplane, a RAT turbine lower gear box assembly, as identified by part number in the applicable Hamilton Sundstrand service bulletin specified in table 2 of this AD, unless it has been inspected and all applicable corrective actions have been done, in accordance with the requirements of this AD.

### FAA AD Differences

Note 1: This AD differs from the MCAI and/or service information as follows: No differences.

### (l) Other FAA AD Provisions

    (l) The following provisions also apply to this AD:

  (1) Alternative Methods of Compliance (AMOCs): The Manager, International Branch, ANM-116, Transport Airplane Directorate, FAA, has the authority to approve AMOCs for this AD, if requested using the procedures found in 14 CFR 39.19. In accordance with 14 CFR 39.19, send your request to your principal inspector or local Flight Standards District Office, as appropriate. If sending information directly to the International Branch, send it to Attn: Dan Rodina, Aerospace Engineer, International Branch, ANM-116, Transport Airplane Directorate, FAA, 1601 Lind Avenue, SW., Renton, Washington 98057-3356; telephone (425) 227-2125; fax (425) 227-1149. Before using any approved AMOC, notify your appropriate principal inspector, or lacking a principal inspector, the manager of the local flight standards district office/certificate holding district office. The AMOC approval letter must specifically reference this AD.

  (2) Airworthy Product: For any requirement in this AD to obtain corrective actions from a manufacturer or other source, use these actions if they are FAA-approved. Corrective actions are considered FAA-approved if they are approved by the State of Design Authority (or their delegated agent). You are required to assure the product is airworthy before it is returned to service.

  (3) Reporting Requirements: A Federal agency may not conduct or sponsor, and a person is not required to respond to, nor shall a person be subject to a penalty for failure to comply with a collection of information subject to the requirements of the Paperwork Reduction Act unless that collection of information displays a current valid OMB Control Number. The OMB Control Number for this information collection is 2120-0056. Public reporting for this collection of information is estimated to be approximately 5 minutes per response, including the time for reviewing instructions, completing and reviewing the collection of information. All responses to this collection of information are mandatory. Comments concerning the accuracy of this burden and suggestions for reducing the burden should be directed to the FAA at: 800 Independence Ave., SW., Washington, DC 20591, Attn: Information Collection Clearance Officer, AES-200.

### (m) Related Information

  (m) Refer to the applicable MCAI European Aviation Safety Agency (EASA) AD specified in table 4 of this AD, the Airbus AOTs specified in table 1 of this AD, and the Hamilton Sundstrand service bulletins specified in table 2 of this AD, for related information.

*Table 4—EASA ADs*

| For model— | EASA AD— | Dated— |
| --- | --- | --- |
| A300-600 and A310 series airplanes | 2009-0258 | December 10, 2009. |
| A318, A319, A320, and A321 series airplanes | 2010-0120 | June 21, 2010. |
| A330 and A340 series airplanes | 2009-0260 | December 10, 2009 (corrected December 14, 2009). |

### (n) Material Incorporated by Reference

  (n) You must use the service information contained in table 5 of this AD, as applicable, to do the actions required by this AD, unless the AD specifies otherwise.

*Table 5—Material Incorporated by Reference*

| Document | Date |
| --- | --- |
| Airbus All Operator Telex A300-29A6062 | September 1, 2009. |
| Airbus All Operator Telex A310-29A2098 | September 1, 2009. |
| Airbus All Operator Telex A320-29A1150 | June 24, 2009. |
| Airbus All Operator Telex A330-29A3110 | September 1, 2009. |
| Airbus All Operator Telex A340-29A4085 | September 1, 2009. |
| Airbus All Operator Telex A340-500/600-29A5015 | September 1, 2009. |
| Hamilton Sundstrand Service Bulletin 732365-29-7 | August 4, 2009. |
| Hamilton Sundstrand Service Bulletin 730816-29-15 | August 4, 2009. |
| Hamilton Sundstrand Service Bulletin ERPS08M-29-8 | June 17, 2009. |
| Hamilton Sundstrand Service Bulletin ERPS06G-29-6 | July 20, 2009. |
| Hamilton Sundstrand Service Bulletin ERPS33G-29-1 | July 20, 2009. |

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

  (2) For Airbus service information identified in this AD, contact the appropriate office listed below.

    (i) For Model A300-600 and A310 series airplanes: Airbus SAS—EAW (Airworthiness Office), 1 Rond Point Maurice Bellonte, 31707 Blagnac Cedex, France; telephone +33 5 61 93 36 96; fax +33 5 61 93 44 51; e-mail: account.airworth-eas@airbus.com; Internet http://www.airbus.com.

    (ii) For Model A318, A319, A320, and A321 series airplanes: Airbus, Airworthiness Office—EAS, 1 Rond Point Maurice Bellonte, 31707 Blagnac Cedex, France; telephone +33 5 61 93 36 96; fax +33 5 61 93 44 51; e-mail: account.airworth-eas@airbus.com; Internet http://www.airbus.com.

    (iii) For Model A330 and A340 series airplanes: Airbus SAS—Airworthiness Office—EAL, 1 Rond Point Maurice Bellonte, 31707 Blagnac Cedex, France; telephone +33 5 61 93 36 96; fax +33 5 61 93 45 80; e-mail airworthiness.A330-A340@airbus.com; Internet http://www.airbus.com.

  (3) For Hamilton Sundstrand service information identified in this AD, contact Hamilton Sundstrand, Technical Publications, Mail Stop 302-9, 4747 Harrison Avenue, P.O. Box 7002, Rockford, Illinois 61125-7002; telephone 860-654-3575; fax 860-998-4564; e-mail tech.solutions@hs.utc.com; Internet http://www.hamiltonsundstrand.com.

  (4) You may review copies of the service information at the FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington. For information on the availability of this material at the FAA, call 425-227-1221.

  (5) You may also review copies of the 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/code_of_federal_regulations/ibr_locations.html.

## Rule preamble

### Dates

This AD becomes effective September 9, 2011.

The Director of the Federal Register approved the incorporation by reference of certain publications listed in this AD as of September 9, 2011.

### Addresses

You may examine the AD docket on the Internet at http://www.regulations.gov or in person at the U.S. Department of Transportation, Docket Operations, M-30, West Building Ground Floor, Room W12-140, 1200 New Jersey Avenue, SE., Washington, DC.

### For further information contact

Dan Rodina, Aerospace Engineer, International Branch, ANM-116, Transport Airplane Directorate, FAA, 1601 Lind Avenue, SW., Renton, Washington 98057-3356; telephone (425) 227-2125; fax (425) 227-1149.

### Discussion

We issued a notice of proposed rulemaking (NPRM) to amend 14 CFR part 39 to include an AD that would apply to the specified products. That NPRM was published in the Federal Register on May 4, 2011 (76 FR 25259). That NPRM proposed to correct an unsafe condition for the specified products.

The MCAI for Model A300-600 and A310 series airplanes states:

Hamilton Sundstrand (HS), the manufacturer of the RAT [ram air turbine], reported the failure during a wind tunnel test of a balance weight fastening screw on the RAT turbine cover. After investigation, it has been discovered that a batch of screws, which are used to attach the balance washers of the HS RAT Turbine Assembly, has not been subject to the correct heat treatment and are consequently exposed to potential fracture.

This condition, if not corrected, might lead to the ejection of screw heads and consequently to the detachment of the associated balance washers. The loss of balance washers could increase RAT vibrations, which might lead to a possible detachment of RAT parts and consequent loss of RAT functionality. The loss of the RAT, in combination with a total engine flame out, could result in loss of control of the aeroplane.

For the reasons described above, this AD requires the identification of the affected RAT turbine assemblies and replacement of all balance weight screws or, in case balance washer detachment is found, replacement of the RAT turbine assembly.

The MCAI for Model A318, A319, A320, and A321 series airplanes states:

Hamilton Sundstrand (HS) reported the failure of a balance weight fastening screw on the RAT turbine cover during a wind tunnel test. After investigation, it has been discovered that a batch of screws, used to attach the balance washers of the RAT Turbine assembly, has not received the correct heat treatment, making them more subject to a potential failure.

This condition, if left uncorrected, could lead to the ejection of screw heads and detachment of the associated balance washers. The loss of balance washers would increase RAT vibrations, which could lead to a possible detachment of RAT parts and loss of RAT functionality. The loss of the RAT, in combination with a double engine failure, or a total loss of normal electrical power generation, could result in loss of control of the aeroplane.

For the reasons described above, EASA AD 2009-0259 was issued in December 2009 to require the replacement of all balance weight screws on the affected RAT turbine assemblies, or replacement of the RAT, if any balancing washer was found missing.

This AD retains some of the requirements of AD 2009-0259, which is superseded, and corrects its applicability by adding Airbus model A320-215 and A320-216 aeroplanes which were inadvertently omitted. Also, this AD requires the replacement of the set of balancing weights screws before the next operational or functional check of the RAT assembly.

The MCAI for Model A330 and A340 series airplanes states:

Hamilton Sundstrand (HS), the manufacturer of the RAT, reported the failure of a balance weight fastening screw on the RAT cover during a wind tunnel test. After investigation, it has been discovered that a batch of screws, which are used to attach the balance washers of the HS RAT turbine lower gear box assembly, has not been subject to the correct heat treatment and the screws are consequently exposed to potential fracture.

This condition, if not corrected, might lead to the ejection of screw heads and consequently to the detachment of the associated balance washers. The loss of balance washers could increase RAT vibrations, which might lead to a possible detachment of RAT parts, and thus to damage to the aeroplane and risk of injury to persons on the ground.

For the reasons described above, this AD requires the identification of the affected RAT turbine lower gear box assemblies and replacement of all balance screws or, in case balance washer detachment is found, replacement of the RAT turbine lower gear box assembly. * * *

You may obtain further information by examining the MCAI in the AD docket.

### Comments

We gave the public the opportunity to participate in developing this AD. We received no comments on the NPRM or on the determination of the cost to the public.

### Conclusion

We reviewed the available data and determined that air safety and the public interest require adopting the AD as proposed.

### Differences Between This AD and the MCAI or Service Information

We have reviewed the MCAI and related service information and, in general, agree with their substance. But we might have found it necessary to use different words from those in the MCAI to ensure the AD is clear for U.S. operators and is enforceable. In making these changes, we do not intend to differ substantively from the information provided in the MCAI and related service information.

We might also have required different actions in this AD from those in the MCAI in order to follow our FAA policies. Any such differences are highlighted in a NOTE within the AD.

### Costs of Compliance

Based on the service information, we estimate that this AD will affect about 1,004 products of U.S. registry. We also estimate that it will take about 2 work-hours per product to comply with the basic requirements of this AD. The average labor rate is $85 per work-hour. Required parts will cost about $100 per product. Where the service information lists required parts costs that are covered under warranty, we have assumed that there will be no charge for these costs. As we do not control warranty coverage for affected parties, some parties may incur costs higher than estimated here. Based on these figures, we estimate the cost of the AD on U.S. operators to be $271,080, or $270 per product.

### 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 products identified in this rulemaking action.

### Regulatory Findings

We determined that 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 this 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 regulatory evaluation of the estimated costs to comply with this AD and placed it in the AD docket.

### Examining the AD Docket

You may examine the AD docket on the Internet at http://www.regulations.gov; 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 the NPRM, the regulatory evaluation, any comments received, and other information. The street address for the Docket Operations office (telephone (800) 647-5527) is in the ADDRESSES section. Comments will be available in the AD docket shortly after receipt.

### Adoption of the Amendment

Accordingly, under the authority delegated to me by the Administrator, the FAA amends 14 CFR part 39 as follows:

## Affected data sheets (4) (OpenAirDocs)

The type certificate data sheets whose models the AD names.

- [TCDS A28NM](https://openairdocs.org/tcds/A28NM): Airbus SAS; names 26 of 50 models: A318-111, A318-112, A318-121, A318-122, A319-111, A319-112, A319-113, A319-114…
- [TCDS A35EU](https://openairdocs.org/tcds/A35EU): Airbus SAS; names 17 of 17 models: A310-203, A300 B4-622R, A300 F4-605R, A300 B4-601, A310-204, A310-221, A300 B4-603, A300 B4-622…
- [TCDS A46NM](https://openairdocs.org/tcds/A46NM): Airbus SAS; names 14 of 18 models: A330-201, A330-341, A330-342, A330-223, A330-301, A330-321, A330-302, A330-322…
- [TCDS A43NM](https://openairdocs.org/tcds/A43NM): Airbus SAS; names 8 of 8 models: A340-541, A340-311, A340-313, A340-211, A340-312, A340-213, A340-642, A340-212

## Registered aircraft it may apply to (OpenAirDocs)

Matched by airframe and engine model; the AD's applicability may narrow it by serial number, part number or equipment.

- Aircraft: 1,608 (1,608 by airframe model, 0 by engine model)
- Makers: Airbus 1,122, Airbus Industrie 483, Airbus S A S 3

Models with the most aircraft:

- [Airbus A321-231](https://openairdocs.org/model/airbus-a321-231): 248 aircraft (airframe model)
- [Airbus A320-232](https://openairdocs.org/model/airbus-a320-232): 189 aircraft (airframe model)
- [Airbus A320-214](https://openairdocs.org/model/airbus-a320-214): 160 aircraft (airframe model)
- [Airbus Industrie A320-232](https://openairdocs.org/model/airbus-industrie-a320-232): 109 aircraft (airframe model)
- [Airbus A321-211](https://openairdocs.org/model/airbus-a321-211): 106 aircraft (airframe model)
- [Airbus A321-213](https://openairdocs.org/model/airbus-a321-213): 65 aircraft (airframe model)
- [Airbus Industrie A319-112](https://openairdocs.org/model/airbus-industrie-a319-112): 54 aircraft (airframe model)
- [Airbus Industrie A319-131](https://openairdocs.org/model/airbus-industrie-a319-131): 50 aircraft (airframe model)
- [Airbus A319-115](https://openairdocs.org/model/airbus-a319-115): 42 aircraft (airframe model)
- [Airbus A330-243](https://openairdocs.org/model/airbus-a330-243): 40 aircraft (airframe model)
- [Airbus Industrie A320-212](https://openairdocs.org/model/airbus-industrie-a320-212): 39 aircraft (airframe model)
- [Airbus A319-132](https://openairdocs.org/model/airbus-a319-132): 37 aircraft (airframe model)
- [Airbus Industrie A300 F4-605R](https://openairdocs.org/model/airbus-industrie-a300-f4-605r): 36 aircraft (airframe model)
- [Airbus Industrie A321-231](https://openairdocs.org/model/airbus-industrie-a321-231): 31 aircraft (airframe model)
- [Airbus A319-114](https://openairdocs.org/model/airbus-a319-114): 31 aircraft (airframe model)
- [Airbus A300 F4-622R](https://openairdocs.org/model/airbus-a300-f4-622r): 31 aircraft (airframe model)
- [Airbus Industrie A319-132](https://openairdocs.org/model/airbus-industrie-a319-132): 30 aircraft (airframe model)
- [Airbus Industrie A319-114](https://openairdocs.org/model/airbus-industrie-a319-114): 27 aircraft (airframe model)
- [Airbus A319-112](https://openairdocs.org/model/airbus-a319-112): 27 aircraft (airframe model)
- [Airbus Industrie A320-214](https://openairdocs.org/model/airbus-industrie-a320-214): 26 aircraft (airframe model)

All 58 models: https://openairdocs.org/ad/2011-16-03/models.md
Every aircraft: https://openairdocs.org/ad/2011-16-03/aircraft.md

## Related documents

- [Proposed rule FAA-2011-0388](https://openairdocs.org/proposed/FAA-2011-0388): Notice of proposed rulemaking (NPRM), published May 4, 2011

Its text cites no advisory circulars or STCs.

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