Airworthiness Directives; Enstrom Helicopter Corporation Model F-28A, F-28C, F-28F, TH-28, 280, 280C, 280F, 280FX, 480, and 480B Helicopters, 669-672 [E7-43]

Download as PDF Federal Register / Vol. 72, No. 4 / Monday, January 8, 2007 / Proposed Rules Note 1: For the Model 369D, 369E, 369F, 369FF, and 500N helicopters, the Handbook of Maintenance Instruction, Servicing and Maintenance, HMI, CSP–HMI–2, Chapter 32, Section 32–10–00, ‘‘Landing Gear Strut Inspection’’ pertains to the subject of this AD. Note 2: For the Model 369(A) (OH–6A), 369H, 369HE, 369HS, and 369HM helicopters, the Basic Handbook of Maintenance Instructions CSP–H–2, Section 6, ‘‘Landing Gear’’ pertains to the subject of this AD. (d) To request a different method of compliance or a different compliance time for this AD, follow the procedures in 14 CFR 39.19. Contact the Los Angeles Aircraft Certification Office, Transport Airplane Directorate, FAA, for information about previously approved alternative methods of compliance. Issued in Fort Worth, Texas, on December 26, 2006. David A. Downey, Manager, Rotorcraft Directorate, Aircraft Certification Service. [FR Doc. E7–41 Filed 1–5–07; 8:45 am] BILLING CODE 4910–13–P DEPARTMENT OF TRANSPORTATION Federal Aviation Administration 14 CFR Part 39 [Docket No. FAA–2006–26771; Directorate Identifier 2005–SW–07–AD] RIN 2120–AA64 Airworthiness Directives; Enstrom Helicopter Corporation Model F–28A, F–28C, F–28F, TH–28, 280, 280C, 280F, 280FX, 480, and 480B Helicopters Federal Aviation Administration, DOT. ACTION: Notice of proposed rulemaking (NPRM). sroberts on PROD1PC70 with PROPOSALS AGENCY: SUMMARY: This document proposes adopting a new airworthiness directive (AD) for Enstrom Helicopter Corporation (Enstrom) Model F–28A, F– 28C, F–28F, TH–28, 280, 280C, 280F, 280FX, 480, and 480B helicopters. The AD would require determining the installation dates for each main rotor push-pull control rod (push-pull rod), inspecting the push-pull rods for corrosion, replacing any push-pull rod which has corrosion that is severe enough to cause pitting, or has visible moisture inside the rod, and repairing each push-pull rod that has corrosion but no pitting. This proposal is prompted by one reported incident in which the helicopter pilot encountered severe in flight vibration due to the failure of a push-pull rod, requiring an VerDate Aug<31>2005 16:21 Jan 05, 2007 Jkt 211001 emergency landing. The actions specified by the proposed AD are intended to detect corrosion and prevent failure of a push-pull rod, and subsequent loss of control of the helicopter. Comments must be received on or before March 9, 2007. ADDRESSES: Use one of the following addresses to submit comments on this proposed AD: • DOT Docket Web site: Go to https:// dms.dot.gov and follow the instructions for sending your comments electronically; • Government-wide rulemaking Web site: Go to https://www.regulations.gov and follow the instructions for sending your comments electronically; • Mail: Docket Management Facility; U.S. Department of Transportation, 400 Seventh Street, SW., Nassif Building, Room PL–401, Washington, DC 20590; • Fax: 202–493–2251; or • Hand Delivery: Room PL–401 on the plaza level of the Nassif Building, 400 Seventh Street, SW., Washington, DC, between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays. You may get the service information identified in this proposed AD from The Enstrom Helicopter Corporation, Twin County Airport, P.O. Box 490, Menominee, Michigan 49858. You may examine the comments to this proposed AD in the AD docket on the Internet at https://dms.dot.gov. FOR FURTHER INFORMATION CONTACT: Shawn Malekpour, Aviation Safety Engineer, FAA, Chicago Aircraft Certification Office, 2300 East Devon Ave., Des Plaines, Illinois 60018, telephone (847) 294–7837, fax (847) 294–7834. SUPPLEMENTARY INFORMATION: DATES: Comments Invited We invite you to submit any written data, views, or arguments regarding this proposed AD. Send your comments to the address listed under the caption ADDRESSES. Include the docket number ‘‘FAA–2006–26771, Directorate Identifier 2005–SW–07–AD’’ at the beginning of your comments. We specifically invite comments on the overall regulatory, economic, environmental, and energy aspects of the proposed AD. We will consider all comments received by the closing date and may amend the proposed AD in light of those comments. We will post all comments we receive, without change, to https:// dms.dot.gov, including any personal information you provide. We will also PO 00000 Frm 00010 Fmt 4702 Sfmt 4702 669 post a report summarizing each substantive verbal contact with FAA personnel concerning this proposed rulemaking. Using the search function of our docket Web site, you can find and read the comments to any of our dockets, including the name of the individual who sent or signed the comment. You may review the DOT’s complete Privacy Act Statement in the Federal Register published on April 11, 2000 (65 FR 19477–78) or you may visit https://dms.dot.gov. Examining the Docket You may examine the docket that contains the proposed AD, any comments, and other information in person at the Docket Management System (DMS) Docket Office between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays. The Docket Office (telephone 1–800–647– 5227) is located at the plaza level of the Department of Transportation NASSIF Building in Room PL–401 at 400 Seventh Street, SW., Washington, DC. Comments will be available in the AD docket shortly after the DMS receives them. Discussion This document proposes adopting a new AD for Enstrom Model F–28A, F– 28C, F–28F, TH–28, 280, 280C, 280F, 280FX, 480, and 480B helicopters. The proposed AD would require reviewing the helicopter maintenance records and determining the installation dates for the push-pull rods. If the dates cannot be determined from the maintenance records, using the ‘‘Date MFD’’, which is located on the helicopter data plate, would be used as the installation date for the push-pull rods. The proposed AD would also require a visual inspection for corrosion on the exterior and interior of the three push-pull rods, part number (P/N) 28–16253-all dash numbers (for Model F–28A, F–28C, F– 28F, 280, 280C, 280F, and 280FX helicopters) or P/N 4140532-all dash numbers (for Model TH–28, 480, and 480B helicopters), using the compliance times stated in the following table. Replacing any push-pull rod that has corrosion that is severe enough to cause pitting or has moisture inside the rod, and repairing any push-pull rod that has corrosion but no pitting, would be required before further flight. Repairing a push-pull rod consists of cleaning the push-pull rod, applying a protective coating, and sealing the push-pull rod before reinstalling it on a helicopter. E:\FR\FM\08JAP1.SGM 08JAP1 670 Federal Register / Vol. 72, No. 4 / Monday, January 8, 2007 / Proposed Rules Helicopter models Push-pull rod service life Compliance times Model F–28A, F–28C, F–28F, 280, 280C, 280F, and 280FX helicopters. Push-pull rod that has been installed for 20 or more years. Model F–28A, F–28C, F–28F, 280, 280C, 280F, and 280FX helicopters. Model F–28A, F–28C, F–28F, 280, 280C, 280F, and 280FX helicopters. Push-pull rod that has been installed for 10 or more years, but less than 20 years. Push-pull rod that has been installed for less than 10 years. Model TH–28, 480, and 480B helicopters ......... Push-pull rod that has been installed for 10 or more years. Push-pull rod that has been installed for less than 10 years. Inspect within 10 hours time-in-service (TIS) or at next annual inspection, whichever occurs first. Inspect within 50 hours TIS or at the next annual inspection, whichever occurs first. Inspect before the service life of the push-pull rod reaches 10 years since initial installation. Inspect within 50 hours TIS or at the next annual inspection, whichever occurs first. Inspect before the service life of the push-pull rod reaches 10 years since initial installation. sroberts on PROD1PC70 with PROPOSALS Model TH–28, 480, and 480B helicopters ......... This proposal is prompted by one reported incident in which severe inflight vibrations required an emergency landing. Upon landing, the tail rotor, tail rotor gearbox, and horizontal stabilizer separated from the helicopter. A subsequent investigation revealed a rupture of the lower end of one of the three push-pull rods. The actions specified by the proposed AD are intended to detect corrosion on a pushpull rod and prevent failure of a pushpull rod, and subsequent loss of control of the helicopter. We have reviewed the following service information: • Enstrom Helicopter Corporation Service Directive Bulletin No. 0096, dated September 10, 2003, which describes visually inspecting the pushpull rods for corrosion and internal moisture, provides for repairing light corrosion, and is applicable to Model F– 28A, F–28C, F–28F, 280, 280C, 280F, and 280FX helicopters. • Enstrom Helicopter Corporation Service Directive Bulletin No. T–019, dated September 10, 2003, which describes visually inspecting the pushpull rods for corrosion and internal moisture, provides for repairing light corrosion, and is applicable to Model TH–28, 480, and 480B helicopters. • Enstrom Helicopter Corporation Service Information Letter (SIL) No. T– 019, dated December 9, 2003, applicable to Model TH–28, 480, and 480B helicopters, which describes visually inspecting each push-pull rod for a crack, nick, scratch, dent, corrosion, damaged threads, bending, and contact wear. We are not proposing to require the inspections specified in the SIL. • Enstrom Helicopter Corporation Service Information Letter No. 0156, dated December 9, 2005, applicable to Model F–28A, F–28C, F–28F, 280, 280C, 280F, and 280FX helicopters, which describes visually inspecting each pushpull rod for a crack, nick, scratch, dent, corrosion, damaged threads, bending, and contact wear. We are not proposing VerDate Aug<31>2005 16:21 Jan 05, 2007 Jkt 211001 to require the inspections specified in the SIL. This unsafe condition is likely to exist or develop on other helicopters of the same type designs. Therefore, the proposed AD would require determining the installation date for the push-pull rods and inspecting each of the three push-pull rods for corrosion. If corrosion that is severe enough to cause pitting is found, or if moisture is visible on the inside of a push-pull rod, the AD would require replacing the push-pull rod. If there is corrosion without pitting on a push-pull rod, that push-pull rod may be repaired. Repairing a push-pull rod consists of cleaning the push-pull rod, applying a protective coating, and sealing the push-pull rod before remarking it and reinstalling it on a helicopter. The actions would be required to be accomplished in accordance with the specified portions of the Enstrom service directive bulletins described previously. We estimate that this proposed AD would affect 378 helicopters of U.S. registry, and that the required actions would take the following numbers of work hours to accomplish on each helicopter at an average labor rate of $80 per work hour: • 8 work hours to remove, disassemble, and inspect the 3 pushpull rods; • 9 work hours to repair corrosion without pitting, remark each push-pull rod, and reassemble each push-pull rod; and • 3 work hours to reinstall 3 pushpull rods on the helicopter. Required parts would cost approximately $900 per helicopter. Based on these figures, the total cost impact of the proposed AD on U.S. operators would be $945,000 ($2,500 per helicopter), assuming 3 push-pull rods are replaced on each helicopter. Regulatory Findings We have determined that this proposed AD would not have federalism implications under Executive Order PO 00000 Frm 00011 Fmt 4702 Sfmt 4702 13132. Additionally, 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. For the reasons discussed above, I certify that the proposed regulation: 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 draft economic evaluation of the estimated costs to comply with this proposed AD. See the DMS to examine the draft economic evaluation. 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. List of Subjects in 14 CFR Part 39 Air transportation, Aircraft, Aviation safety, Safety. E:\FR\FM\08JAP1.SGM 08JAP1 Federal Register / Vol. 72, No. 4 / Monday, January 8, 2007 / Proposed Rules The Proposed Amendment Accordingly, pursuant to the authority delegated to me by the Administrator, the Federal Aviation Administration proposes to amend 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. Section 39.13 is amended by adding a new airworthiness directive to read as follows: Enstrom Helicopter Company: Docket No. FAA–2006–26771; Directorate Identifier 2005–SW–07–AD. Applicability: Model F–28A, F–28C, and F–28F helicopters, excluding serial number (S/N) 816 and subsequent; Model 280, 280C, 280F, and 280FX helicopters, excluding S/N 2100 and subsequent; and Model TH–28, 480, and 480B helicopters, excluding S/N 5058 and subsequent, certificated in any category. Compliance: Required as indicated, unless accomplished previously. To detect corrosion and prevent failure of a main rotor push-pull control rod (push-pull rod), and subsequent loss of control of the helicopter, accomplish the following: (a) Within 10 hours time-in-service (TIS) or at the next annual inspection, whichever occurs first, review the helicopter maintenance records and determine the date that each push-pull rod, part number (P/N) 671 28–16253-all dash numbers (for Model F– 28A, F–28C, F–28F, 280, 280C, 280F, and 280FX helicopters) and P/N 4140532-all dash numbers (for Model TH–28, 480, and 480B helicopters), was installed. If the date cannot be determined from the maintenance records, use the ‘‘Date MFD’’, which is located on the helicopter data plate, as the installation date for the push-pull rod. (b) For Model F–28A, F–28C, F–28F, 280, 280C, 280F, and 280FX helicopters, using the compliance times stated in Table 1 of this AD, visually inspect the exterior and interior of each of the three push-pull rods for corrosion severe enough to cause pitting or any moisture, paying special attention to the area of the lower fitting, in accordance with section 5.1., INSPECTION, in Enstrom Helicopter Corporation Service Directive Bulletin No. 0096, dated September 10, 2003 (SDB 0096). TABLE 1 Helicopter models Push-pull rod service life Compliance times Model F–28A, F–28C, F–28F, 280, 280C, 280F, and 280FX helicopters. Push-pull rod that has been installed for 20 or more years. Model F–28A, F–28C, F–28F, 280, 280C, 280F, and 280FX helicopters. Model F–28A, F–28C, F–28F, 280, 280C, 280F, and 280FX helicopters. Push-pull rod that has been installed for 10 or more years, but less than 20 years. Push-pull rod that has been installed for less than 10 years. Inspect within 10 hours time-in-service (TIS) or at next annual inspection, whichever occurs first. Inspect within 50 hours TIS or at the next annual inspection, whichever occurs first. Inspect before the service life of the push-pull rod reaches 10 years since initial installation. (1) Before further flight, if corrosion without pitting is found on a push-pull rod, then repair, reassemble, remark, and reinstall it in accordance with section 5.2., REPAIR/ REASSEMBLY, in SDB 0096. (2) Before further flight, if corrosion is found that is severe enough to cause pitting, or if any moisture is visible on the inside of a push-pull rod, replace it with an airworthy push-pull rod. Note 1: Determining continued serviceability of the push-pull rods by inspecting the exterior only of each push-pull rod is described in Enstrom Helicopter Corporation Service Information Letter No. 0156, dated December 9, 2003. (c) For Model TH–28, 480 and 480B helicopters, using the compliance times stated in Table 2 of this AD, visually inspect the exterior and interior of each of the three push-pull rods for corrosion severe enough to cause pitting or any moisture, paying special attention to the area of the lower fitting, in accordance with section 5.1., INSPECTION, in Enstrom Helicopter Corporation Service Directive Bulletin No. T–019, dated September 10, 2003 (SDB T–019). TABLE 2 Helicopter models Push-pull rod service life Compliance times Model TH–28, 480, and 480B helicopters ......... Push-pull rod that has been installed for 10 or more years. Push-pull rod that has been installed for less than 10 years. Inspect within 50 hours TIS or at the next annual inspection, whichever occurs first. Inspect before the service life of the push-pull rod reaches 10 years since initial installation. sroberts on PROD1PC70 with PROPOSALS Model TH–28, 480, and 480B helicopters ......... VerDate Aug<31>2005 16:21 Jan 05, 2007 Jkt 211001 PO 00000 Frm 00012 Fmt 4702 Sfmt 4702 E:\FR\FM\08JAP1.SGM 08JAP1 672 Federal Register / Vol. 72, No. 4 / Monday, January 8, 2007 / Proposed Rules (1) Before further flight, if corrosion without pitting is found on a push-pull rod, then repair, reassemble, remark, and reinstall it in accordance with section 5.2., REPAIR/ REASSEMBLY, in SDB T–019. (2) Before further flight, if corrosion is found that is severe enough to cause pitting, or if any moisture is visible on the inside of a push-pull rod, replace it with an airworthy push-pull rod. Note 2: Determining continued serviceability of the push-pull rods by inspecting the exterior only of each push-pull rod is described in Enstrom Helicopter Corporation Service Information Letter No. T–019, dated December 9, 2003. (d) To request a different method of compliance or a different compliance time for this AD, follow the procedures in 14 CFR 39.19. Contact Chicago Aircraft Certification Office, Small Airplane Directorate, FAA, for information about previously approved alternative methods of compliance. Issued in Fort Worth, Texas, on December 26, 2006. David A. Downey, Manager, Rotorcraft Directorate, Aircraft Certification Service. [FR Doc. E7–43 Filed 1–5–07; 8:45 am] BILLING CODE 4910–13–P DEPARTMENT OF TRANSPORTATION Federal Aviation Administration 14 CFR Part 39 [Docket No. FAA–2006–26693; Directorate Identifier 2006–CE–90–AD] RIN 2120–AA64 Airworthiness Directives; Reims Aviation S.A. F406 Airplanes Federal Aviation Administration (FAA), Department of Transportation (DOT). ACTION: Notice of proposed rulemaking (NPRM). AGENCY: sroberts on PROD1PC70 with PROPOSALS SUMMARY: We propose to adopt a new airworthiness directive (AD) for the products listed above. This proposed AD results from mandatory continuing airworthiness information (MCAI) issued by an aviation authority of another country to identify and correct an unsafe condition on an aviation product. The MCAI describes the unsafe condition as: This AD is issued following a nose landing gear collapse during takeoff roll. Several expertises proved that the locking device of the Nose Landing Gear (NLG) actuator rod was on several F406 airplanes not conforming with the installation approved by the manufacturer. There were two different landing gear actuator designs installed on the F406 airplanes. The actuators used different VerDate Aug<31>2005 16:21 Jan 05, 2007 Jkt 211001 locking devices to retain the spherical rod-end to the actuator rod. Use of the incorrect locking device could allow the spherical rod-end to disconnect from the actuator rod. The proposed AD would require actions that are intended to address the unsafe condition described in the MCAI. DATES: We must receive comments on this proposed AD by February 7, 2007. ADDRESSES: You may send comments by any of the following methods: • DOT Docket Web site: Go to https:// dms.dot.gov and follow the instructions for sending your comments electronically. • Fax: (202) 493–2251. • Mail: Docket Management Facility, U.S. Department of Transportation, 400 Seventh Street, SW., Nassif Building, Room PL–401, Washington, DC 20590– 0001. • Hand Delivery: Room PL–401 on the plaza level of the Nassif Building, 400 Seventh Street, SW., Washington, DC, between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays. • Federal eRulemaking Portal: https:// www.regulations.gov. Follow the instructions for submitting comments. Examining the AD Docket You may examine the AD docket on the Internet at https://dms.dot.gov; 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 proposed AD, the regulatory evaluation, any comments received, and other information. The street address for the Docket Office (telephone (800) 647– 5227) is in the ADDRESSES section. Comments will be available in the AD docket shortly after receipt. FOR FURTHER INFORMATION CONTACT: Mike Kiesov, Aerospace Engineer, FAA, Small Airplane Directorate, 901 Locust, Room 301, Kansas City, Missouri 64106; telephone (816) 329–4144; fax (816) 329–4090. SUPPLEMENTARY INFORMATION: Streamlined Issuance of AD The FAA is implementing a new process for streamlining the issuance of ADs related to MCAI. The streamlined process will allow us to adopt MCAI safety requirements in a more efficient manner and will reduce safety risks to the public. This process continues to follow all FAA AD issuance processes to meet legal, economic, Administrative Procedure Act, and Federal Register requirements. We also continue to meet our technical decision-making responsibilities to identify and correct unsafe conditions on U.S.-certificated products. PO 00000 Frm 00013 Fmt 4702 Sfmt 4702 This proposed AD references the MCAI and related service information that we considered in forming the engineering basis to correct the unsafe condition. The proposed AD contains text copied from the MCAI and for this reason might not follow our plain language principles. Comments Invited We invite you to send any written relevant data, views, or arguments about this proposed AD. Send your comments to an address listed under the ADDRESSES section. Include ‘‘Docket No. FAA–2006–26693; Directorate Identifier 2006–CE–90–AD’’ at the beginning of your comments. We specifically invite comments on the overall regulatory, economic, environmental, and energy aspects of this proposed AD. We will consider all comments received by the closing date and may amend this proposed AD because of those comments. We will post all comments we receive, without change, to https:// dms.dot.gov, including any personal information you provide. We will also post a report summarizing each substantive verbal contact we receive about this proposed AD. Discussion ´ ´ The Direction Generale de L’Aviation Civile (DGAC), which is the aviation authority for France, has issued AD No. F–2005–065, dated April 27, 2005 (referred to after this as ‘‘the MCAI’’), to correct an unsafe condition for the specified products. The MCAI states: This AD is issued following a nose landing gear collapse during takeoff roll. Several expertises proved that the locking device of the Nose Landing Gear (NLG) actuator rod was on several F406 airplanes not conforming with the installation approved by the manufacturer. As Main Landing Gear (MLG) actuator rod locking devices are similar to the NLG ones, then MLG actuator locking devices shall also be inspected. This AD requires inspection of the NLG and MLG locking devices and as requested their replacement to comply with the manufacturer’s approved design. There were two different landing gear actuator designs installed on the F406 airplanes. The actuators used different locking devices to retain the spherical rod-end to the actuator rod. Use of the incorrect locking device could allow the spherical rod-end to disconnect from the actuator rod and consequently the landing gear could collapse. This AD requires you to do a one time inspection of the landing gear actuators and, if an incorrect locking device is found, replace it with the correct locking device. E:\FR\FM\08JAP1.SGM 08JAP1

Agencies

[Federal Register Volume 72, Number 4 (Monday, January 8, 2007)]
[Proposed Rules]
[Pages 669-672]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: E7-43]


-----------------------------------------------------------------------

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2006-26771; Directorate Identifier 2005-SW-07-AD]
RIN 2120-AA64


Airworthiness Directives; Enstrom Helicopter Corporation Model F-
28A, F-28C, F-28F, TH-28, 280, 280C, 280F, 280FX, 480, and 480B 
Helicopters

AGENCY: Federal Aviation Administration, DOT.

ACTION: Notice of proposed rulemaking (NPRM).

-----------------------------------------------------------------------

SUMMARY: This document proposes adopting a new airworthiness directive 
(AD) for Enstrom Helicopter Corporation (Enstrom) Model F-28A, F-28C, 
F-28F, TH-28, 280, 280C, 280F, 280FX, 480, and 480B helicopters. The AD 
would require determining the installation dates for each main rotor 
push-pull control rod (push-pull rod), inspecting the push-pull rods 
for corrosion, replacing any push-pull rod which has corrosion that is 
severe enough to cause pitting, or has visible moisture inside the rod, 
and repairing each push-pull rod that has corrosion but no pitting. 
This proposal is prompted by one reported incident in which the 
helicopter pilot encountered severe in flight vibration due to the 
failure of a push-pull rod, requiring an emergency landing. The actions 
specified by the proposed AD are intended to detect corrosion and 
prevent failure of a push-pull rod, and subsequent loss of control of 
the helicopter.

DATES: Comments must be received on or before March 9, 2007.

ADDRESSES: Use one of the following addresses to submit comments on 
this proposed AD:
     DOT Docket Web site: Go to https://dms.dot.gov and follow 
the instructions for sending your comments electronically;
     Government-wide rulemaking Web site: Go to https://
www.regulations.gov and follow the instructions for sending your 
comments electronically;
     Mail: Docket Management Facility; U.S. Department of 
Transportation, 400 Seventh Street, SW., Nassif Building, Room PL-401, 
Washington, DC 20590;
     Fax: 202-493-2251; or
     Hand Delivery: Room PL-401 on the plaza level of the 
Nassif Building, 400 Seventh Street, SW., Washington, DC, between 9 
a.m. and 5 p.m., Monday through Friday, except Federal holidays.
    You may get the service information identified in this proposed AD 
from The Enstrom Helicopter Corporation, Twin County Airport, P.O. Box 
490, Menominee, Michigan 49858.
    You may examine the comments to this proposed AD in the AD docket 
on the Internet at https://dms.dot.gov.

FOR FURTHER INFORMATION CONTACT: Shawn Malekpour, Aviation Safety 
Engineer, FAA, Chicago Aircraft Certification Office, 2300 East Devon 
Ave., Des Plaines, Illinois 60018, telephone (847) 294-7837, fax (847) 
294-7834.

SUPPLEMENTARY INFORMATION: 

Comments Invited

    We invite you to submit any written data, views, or arguments 
regarding this proposed AD. Send your comments to the address listed 
under the caption ADDRESSES. Include the docket number ``FAA-2006-
26771, Directorate Identifier 2005-SW-07-AD'' at the beginning of your 
comments. We specifically invite comments on the overall regulatory, 
economic, environmental, and energy aspects of the proposed AD. We will 
consider all comments received by the closing date and may amend the 
proposed AD in light of those comments.
    We will post all comments we receive, without change, to https://
dms.dot.gov, including any personal information you provide. We will 
also post a report summarizing each substantive verbal contact with FAA 
personnel concerning this proposed rulemaking. Using the search 
function of our docket Web site, you can find and read the comments to 
any of our dockets, including the name of the individual who sent or 
signed the comment. You may review the DOT's complete Privacy Act 
Statement in the Federal Register published on April 11, 2000 (65 FR 
19477-78) or you may visit https://dms.dot.gov.

Examining the Docket

    You may examine the docket that contains the proposed AD, any 
comments, and other information in person at the Docket Management 
System (DMS) Docket Office between 9 a.m. and 5 p.m., Monday through 
Friday, except Federal holidays. The Docket Office (telephone 1-800-
647-5227) is located at the plaza level of the Department of 
Transportation NASSIF Building in Room PL-401 at 400 Seventh Street, 
SW., Washington, DC. Comments will be available in the AD docket 
shortly after the DMS receives them.

Discussion

    This document proposes adopting a new AD for Enstrom Model F-28A, 
F-28C, F-28F, TH-28, 280, 280C, 280F, 280FX, 480, and 480B helicopters. 
The proposed AD would require reviewing the helicopter maintenance 
records and determining the installation dates for the push-pull rods. 
If the dates cannot be determined from the maintenance records, using 
the ``Date MFD'', which is located on the helicopter data plate, would 
be used as the installation date for the push-pull rods. The proposed 
AD would also require a visual inspection for corrosion on the exterior 
and interior of the three push-pull rods, part number (P/N) 28-16253-
all dash numbers (for Model F-28A, F-28C, F-28F, 280, 280C, 280F, and 
280FX helicopters) or P/N 4140532-all dash numbers (for Model TH-28, 
480, and 480B helicopters), using the compliance times stated in the 
following table. Replacing any push-pull rod that has corrosion that is 
severe enough to cause pitting or has moisture inside the rod, and 
repairing any push-pull rod that has corrosion but no pitting, would be 
required before further flight. Repairing a push-pull rod consists of 
cleaning the push-pull rod, applying a protective coating, and sealing 
the push-pull rod before reinstalling it on a helicopter.

[[Page 670]]



------------------------------------------------------------------------
                                  Push-pull rod
      Helicopter models           service life        Compliance times
------------------------------------------------------------------------
Model F-28A, F-28C, F-28F,    Push-pull rod that    Inspect within 10
 280, 280C, 280F, and 280FX    has been installed    hours time-in-
 helicopters.                  for 20 or more        service (TIS) or at
                               years.                next annual
                                                     inspection,
                                                     whichever occurs
                                                     first.
Model F-28A, F-28C, F-28F,    Push-pull rod that    Inspect within 50
 280, 280C, 280F, and 280FX    has been installed    hours TIS or at the
 helicopters.                  for 10 or more        next annual
                               years, but less       inspection,
                               than 20 years.        whichever occurs
                                                     first.
Model F-28A, F-28C, F-28F,    Push-pull rod that    Inspect before the
 280, 280C, 280F, and 280FX    has been installed    service life of the
 helicopters.                  for less than 10      push-pull rod
                               years.                reaches 10 years
                                                     since initial
                                                     installation.
Model TH-28, 480, and 480B    Push-pull rod that    Inspect within 50
 helicopters.                  has been installed    hours TIS or at the
                               for 10 or more        next annual
                               years.                inspection,
                                                     whichever occurs
                                                     first.
Model TH-28, 480, and 480B    Push-pull rod that    Inspect before the
 helicopters.                  has been installed    service life of the
                               for less than 10      push-pull rod
                               years.                reaches 10 years
                                                     since initial
                                                     installation.
------------------------------------------------------------------------

    This proposal is prompted by one reported incident in which severe 
in-flight vibrations required an emergency landing. Upon landing, the 
tail rotor, tail rotor gearbox, and horizontal stabilizer separated 
from the helicopter. A subsequent investigation revealed a rupture of 
the lower end of one of the three push-pull rods. The actions specified 
by the proposed AD are intended to detect corrosion on a push-pull rod 
and prevent failure of a push-pull rod, and subsequent loss of control 
of the helicopter.
    We have reviewed the following service information:
     Enstrom Helicopter Corporation Service Directive Bulletin 
No. 0096, dated September 10, 2003, which describes visually inspecting 
the push-pull rods for corrosion and internal moisture, provides for 
repairing light corrosion, and is applicable to Model F-28A, F-28C, F-
28F, 280, 280C, 280F, and 280FX helicopters.
     Enstrom Helicopter Corporation Service Directive Bulletin 
No. T-019, dated September 10, 2003, which describes visually 
inspecting the push-pull rods for corrosion and internal moisture, 
provides for repairing light corrosion, and is applicable to Model TH-
28, 480, and 480B helicopters.
     Enstrom Helicopter Corporation Service Information Letter 
(SIL) No. T-019, dated December 9, 2003, applicable to Model TH-28, 
480, and 480B helicopters, which describes visually inspecting each 
push-pull rod for a crack, nick, scratch, dent, corrosion, damaged 
threads, bending, and contact wear. We are not proposing to require the 
inspections specified in the SIL.
     Enstrom Helicopter Corporation Service Information Letter 
No. 0156, dated December 9, 2005, applicable to Model F-28A, F-28C, F-
28F, 280, 280C, 280F, and 280FX helicopters, which describes visually 
inspecting each push-pull rod for a crack, nick, scratch, dent, 
corrosion, damaged threads, bending, and contact wear. We are not 
proposing to require the inspections specified in the SIL.
    This unsafe condition is likely to exist or develop on other 
helicopters of the same type designs. Therefore, the proposed AD would 
require determining the installation date for the push-pull rods and 
inspecting each of the three push-pull rods for corrosion. If corrosion 
that is severe enough to cause pitting is found, or if moisture is 
visible on the inside of a push-pull rod, the AD would require 
replacing the push-pull rod. If there is corrosion without pitting on a 
push-pull rod, that push-pull rod may be repaired. Repairing a push-
pull rod consists of cleaning the push-pull rod, applying a protective 
coating, and sealing the push-pull rod before remarking it and 
reinstalling it on a helicopter. The actions would be required to be 
accomplished in accordance with the specified portions of the Enstrom 
service directive bulletins described previously.
    We estimate that this proposed AD would affect 378 helicopters of 
U.S. registry, and that the required actions would take the following 
numbers of work hours to accomplish on each helicopter at an average 
labor rate of $80 per work hour:
     8 work hours to remove, disassemble, and inspect the 3 
push-pull rods;
     9 work hours to repair corrosion without pitting, remark 
each push-pull rod, and reassemble each push-pull rod; and
     3 work hours to reinstall 3 push-pull rods on the 
helicopter. Required parts would cost approximately $900 per 
helicopter. Based on these figures, the total cost impact of the 
proposed AD on U.S. operators would be $945,000 ($2,500 per 
helicopter), assuming 3 push-pull rods are replaced on each helicopter.

Regulatory Findings

    We have determined that this proposed AD would not have federalism 
implications under Executive Order 13132. Additionally, 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.
    For the reasons discussed above, I certify that the proposed 
regulation:
    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 draft economic evaluation of the estimated costs to 
comply with this proposed AD. See the DMS to examine the draft economic 
evaluation.

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.

List of Subjects in 14 CFR Part 39

    Air transportation, Aircraft, Aviation safety, Safety.

[[Page 671]]

The Proposed Amendment

    Accordingly, pursuant to the authority delegated to me by the 
Administrator, the Federal Aviation Administration proposes to amend 
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.


Sec.  39.13  [Amended]

    2. Section 39.13 is amended by adding a new airworthiness directive 
to read as follows:

Enstrom Helicopter Company: Docket No. FAA-2006-26771; Directorate 
Identifier 2005-SW-07-AD.

    Applicability: Model F-28A, F-28C, and F-28F helicopters, 
excluding serial number (S/N) 816 and subsequent; Model 280, 280C, 
280F, and 280FX helicopters, excluding S/N 2100 and subsequent; and 
Model TH-28, 480, and 480B helicopters, excluding S/N 5058 and 
subsequent, certificated in any category.
    Compliance: Required as indicated, unless accomplished 
previously.
    To detect corrosion and prevent failure of a main rotor push-
pull control rod (push-pull rod), and subsequent loss of control of 
the helicopter, accomplish the following:
    (a) Within 10 hours time-in-service (TIS) or at the next annual 
inspection, whichever occurs first, review the helicopter 
maintenance records and determine the date that each push-pull rod, 
part number (P/N) 28-16253-all dash numbers (for Model F-28A, F-28C, 
F-28F, 280, 280C, 280F, and 280FX helicopters) and P/N 4140532-all 
dash numbers (for Model TH-28, 480, and 480B helicopters), was 
installed. If the date cannot be determined from the maintenance 
records, use the ``Date MFD'', which is located on the helicopter 
data plate, as the installation date for the push-pull rod.
    (b) For Model F-28A, F-28C, F-28F, 280, 280C, 280F, and 280FX 
helicopters, using the compliance times stated in Table 1 of this 
AD, visually inspect the exterior and interior of each of the three 
push-pull rods for corrosion severe enough to cause pitting or any 
moisture, paying special attention to the area of the lower fitting, 
in accordance with section 5.1., INSPECTION, in Enstrom Helicopter 
Corporation Service Directive Bulletin No. 0096, dated September 10, 
2003 (SDB 0096).

                                 Table 1
------------------------------------------------------------------------
                                  Push-pull rod
      Helicopter models           service life        Compliance times
------------------------------------------------------------------------
Model F-28A, F-28C, F-28F,    Push-pull rod that    Inspect within 10
 280, 280C, 280F, and 280FX    has been installed    hours time-in-
 helicopters.                  for 20 or more        service (TIS) or at
                               years.                next annual
                                                     inspection,
                                                     whichever occurs
                                                     first.
Model F-28A, F-28C, F-28F,    Push-pull rod that    Inspect within 50
 280, 280C, 280F, and 280FX    has been installed    hours TIS or at the
 helicopters.                  for 10 or more        next annual
                               years, but less       inspection,
                               than 20 years.        whichever occurs
                                                     first.
Model F-28A, F-28C, F-28F,    Push-pull rod that    Inspect before the
 280, 280C, 280F, and 280FX    has been installed    service life of the
 helicopters.                  for less than 10      push-pull rod
                               years.                reaches 10 years
                                                     since initial
                                                     installation.
------------------------------------------------------------------------

    (1) Before further flight, if corrosion without pitting is found 
on a push-pull rod, then repair, reassemble, remark, and reinstall 
it in accordance with section 5.2., REPAIR/REASSEMBLY, in SDB 0096.
    (2) Before further flight, if corrosion is found that is severe 
enough to cause pitting, or if any moisture is visible on the inside 
of a push-pull rod, replace it with an airworthy push-pull rod.

    Note 1: Determining continued serviceability of the push-pull 
rods by inspecting the exterior only of each push-pull rod is 
described in Enstrom Helicopter Corporation Service Information 
Letter No. 0156, dated December 9, 2003.

    (c) For Model TH-28, 480 and 480B helicopters, using the 
compliance times stated in Table 2 of this AD, visually inspect the 
exterior and interior of each of the three push-pull rods for 
corrosion severe enough to cause pitting or any moisture, paying 
special attention to the area of the lower fitting, in accordance 
with section 5.1., INSPECTION, in Enstrom Helicopter Corporation 
Service Directive Bulletin No. T-019, dated September 10, 2003 (SDB 
T-019).

                                 Table 2
------------------------------------------------------------------------
                                  Push-pull rod
      Helicopter models           service life        Compliance times
------------------------------------------------------------------------
Model TH-28, 480, and 480B    Push-pull rod that    Inspect within 50
 helicopters.                  has been installed    hours TIS or at the
                               for 10 or more        next annual
                               years.                inspection,
                                                     whichever occurs
                                                     first.
Model TH-28, 480, and 480B    Push-pull rod that    Inspect before the
 helicopters.                  has been installed    service life of the
                               for less than 10      push-pull rod
                               years.                reaches 10 years
                                                     since initial
                                                     installation.
------------------------------------------------------------------------


[[Page 672]]

    (1) Before further flight, if corrosion without pitting is found 
on a push-pull rod, then repair, reassemble, remark, and reinstall 
it in accordance with section 5.2., REPAIR/REASSEMBLY, in SDB T-019.
    (2) Before further flight, if corrosion is found that is severe 
enough to cause pitting, or if any moisture is visible on the inside 
of a push-pull rod, replace it with an airworthy push-pull rod.

    Note 2: Determining continued serviceability of the push-pull 
rods by inspecting the exterior only of each push-pull rod is 
described in Enstrom Helicopter Corporation Service Information 
Letter No. T-019, dated December 9, 2003.

    (d) To request a different method of compliance or a different 
compliance time for this AD, follow the procedures in 14 CFR 39.19. 
Contact Chicago Aircraft Certification Office, Small Airplane 
Directorate, FAA, for information about previously approved 
alternative methods of compliance.

    Issued in Fort Worth, Texas, on December 26, 2006.
David A. Downey,
Manager, Rotorcraft Directorate, Aircraft Certification Service.
[FR Doc. E7-43 Filed 1-5-07; 8:45 am]
BILLING CODE 4910-13-P
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