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ADs updated daily at www.Tdata.com
PROPOSED AD BELL TEXTRON INC.: Docket No. FAA-2022-0600; Project Identifier AD-2021-01160-R. 
(a) COMMENTS DUE DATE

    The FAA must receive comments on this  airworthiness directive (AD) by
    June 24, 2024.

(b) AFFECTED ADS

    None.

(c) APPLICABILITY

    This AD applies to Bell Textron Inc., Model  204B, 205A, 205A-1, 205B,
    and 210 helicopters, certificated in any category.

(d) SUBJECT

    Joint Aircraft System Component (JASC) 5302, Rotorcraft Tail Boom.

(e) UNSAFE CONDITION

    This AD was prompted by an accident and incidents involving failure of
    the tail  boom attachment  structure. The  FAA is  issuing this  AD to
    address fatigue cracking of tail boom attachment fittings, cap angles,
    longerons, and bolts.  The unsafe condition,  if not addressed,  could
    result  in  separation  of  the  tail  boom  from  the  helicopter and
    subsequent loss of control of the helicopter.

(f) COMPLIANCE

    Comply  with this  AD within  the compliance  times  specified, unless
    already done.

(g) ALLOWABLE TORQUE VALUES (IN-LBS)

         TAIL BOOM                     MODEL 205A/
      ATTACHMENT POINT     MODEL 204B    205A-1     MODEL 205B   MODEL 210
    Upper left-hand bolt     570-610    1000-1200    1000-1200   1300-1600
    Upper right-hand bolt    360-380    1000-1200    1000-1200   1000-1200
    Lower left-hand bolt     360-380      400-430      400-430     400-430
    Lower right-hand bolt    360-380      400-430      400-430     400-430

(h) REQUIRED ACTIONS

(1) Within 300 hours time-in-service (TIS) or 90 days after the  effective
    date  of  this  AD, whichever  occurs  first,  accomplish the  actions
    required  by  paragraphs  (h)(1)(i),  (ii), or  (iii)  of  this  AD as
    applicable to your model helicopter. For purposes of this AD, the word
    "new" is defined as having zero total hours TIS.

(i) For  Model  204B  helicopters,  accomplish  the  actions  required  by
    paragraphs (h)(1)(i)(A) through (C) of this AD.

(A) With the tail boom assembly removed, remove the upper left- hand  (LH)
    tail  boom  attachment  bolt  (bolt)  from  service  and  inspect  its
    associated  tail  boom  attachment nut  (nut)  for  mechanical damage,
    corrosion,  a  crack,  damaged threads,  and  wear,  and to  determine
    whether it  is a  steel alloy  part number  (P/N) NAS679A, NAS1291, or
    MS21042. If  there is  any mechanical  damage, corrosion,  a crack,  a
    damaged thread, or wear, or if nut P/N NAS679A, NAS1291, or MS21042 is
    installed, before further flight, remove the nut from service.

(B) Visually inspect each bulkhead (FS 195.00 and FS 195.03) and the  bolt
    holes for mechanical damage,  corrosion, and cracks; visually  inspect
    each attachment fitting for mechanical damage, corrosion, cracks,  and
    loose fasteners; determine if any of the three other nuts are a  steel
    alloy P/N NAS679A, NAS1291, or MS21042; and visually inspect the other
    three nuts, the  upper right-hand (RH)  bolt, and two  lower bolts for
    mechanical  damage,  corrosion,  cracks,  damaged  threads,  and wear,
    including the bolt  shank and head  radii of the  bolts for a  damaged
    thread, wear, and mechanical damage.

(1) If  there is  any  mechanical  damage,  corrosion,  or cracks  on  any
    bulkhead  (FS  195.00  or  FS  195.03),  or  any  mechanical   damage,
    corrosion, or cracks on any bolt holes, or if there is any  mechanical
    damage,  corrosion,  cracks,  or  loose  fasteners  on  any attachment
    fitting,  before  further  flight,  repair  or  replace  the  affected
    bulkhead  or  the  affected  attachment  fitting,  as  appropriate, in
    accordance with FAA-approved procedures.

(2) If there  is any  mechanical  damage,  corrosion, a  crack, a  damaged
    thread, or wear on any nut, or if nut P/N NAS679A, NAS1291, or MS21042
    is  installed, before  further flight,  remove the  affected nut  from
    service. If there is a crack  on any nut, before further flight,  also
    remove its associated bolt from service.

(3) If there  is any  mechanical  damage,  corrosion, a  crack, a  damaged
    thread, or wear on the on the upper RH bolt or two lower bolts,  which
    includes the bolt shank or  head radii, before further flight,  remove
    the affected bolt from service.

(C) Apply a coating of Aeriol ThixO #2 (3810-0) or Aeriol ThixO SYN  (3820
    -0) aviation grease to each bolt shank only. Install the hardware  set
    of each tail boom attachment point (nickel alloy nut P/ N 90-132L7  or
    90-132L6, as applicable  to the affected  tail boom attachment  point,
    new upper  LH bolt  P/N NAS627-21,  upper RH  and two  lower bolts P/N
    NAS626-20, countersunk washer, and plain washers). Torque each bolt by
    using the torque value information identified in paragraph (g) of this
    AD.

(ii) For Model 205A, 205A-1, and 205B helicopters, accomplish the  actions
     required by paragraphs (h)(1)(ii)(A) through (C) of this AD.

(A) With the  tail boom assembly  removed, remove the  upper LH bolt  from
    service and  inspect its  associated tail  boom attachment  barrel nut
    (barrel nut) and retainer  for mechanical damage, corrosion,  a crack,
    damaged threads,  and wear,  and to  determine whether  it is  a steel
    alloy barrel  nut P/N  NAS577B8A. If  there is  any mechanical damage,
    corrosion, a crack, a  damaged thread, or wear,  or if barrel nut  P/N
    NAS577B8A is installed, before  further flight, remove the  barrel nut
    and its associated retainer from service.

(B) Visually inspect each bulkhead (BS  17.31 and FS 243.89) and the  bolt
    holes for mechanical damage,  corrosion, and cracks; visually  inspect
    each attachment fitting for mechanical damage, corrosion, cracks,  and
    loose fasteners; determine if any  of the three other barrel  nuts are
    steel alloy P/N NAS577B8A or  P/N NAS577B6A; and visually inspect  the
    other three  barrel nuts  and the  associated retainers,  the upper RH
    bolt, and two  lower bolts for  mechanical damage, corrosion,  cracks,
    damaged threads, and wear, including the bolt shank and head radii  of
    the bolts for a damaged thread, wear, and mechanical damage.

(1) If  there is  any  mechanical  damage,  corrosion,  or cracks  on  any
    bulkhead (BS 17.31 or FS 243.89), or any mechanical damage, corrosion,
    or cracks on  any bolt holes,  or if there  is any mechanical  damage,
    corrosion,  cracks,  or  loose fasteners  on  any  attachment fitting,
    before further flight, repair or replace the affected bulkhead or  the
    affected attachment  fitting, as  appropriate, in  accordance with FAA
    -approved procedures.

(2) If there  is any  mechanical  damage,  corrosion, a  crack, a  damaged
    thread, or wear on  any barrel nut or  retainer, or if barrel  nut P/N
    NAS577B8A or NAS577B6A is installed, before further flight, remove the
    affected barrel nut and retainer (as a pair) from service. If there is
    a crack on any nut, before further flight, also remove its  associated
    bolt from service.

(3) If there  is any  mechanical  damage,  corrosion, a  crack, a  damaged
    thread,  or  wear on  the  upper RH  bolt  or two  lower  bolts, which
    includes the bolt shank or  head radii, before further flight,  remove
    the affected bolt from service.

(C) Apply a coating of Aeriol ThixO #2 (3810-0) or Aeriol ThixO SYN  (3820
    -0) aviation grease to each bolt shank only. Install the hardware  set
    of  each  tail boom  attachment  point (nickel  alloy  barrel nut  P/N
    NAS577C6A  or  P/N  NAS577C8A  and  retainer  P/N  NAS578C6A  or   P/N
    NAS578C8A, as applicable to  the affected tail boom  attachment point,
    new upper  LH bolt  P/N NAS628-22,  upper RH  and two  lower bolts P/N
    NAS628-22  or  NAS626-18,  as applicable  to  the  affected tail  boom
    attachment point, countersunk washer, and plain washers). Torque  each
    bolt by using the torque value information identified in paragraph (g)
    of this AD.

(iii) For  Model  210  helicopters,  accomplish  the  actions  required by
      paragraphs (h)(1)(iii)(A) through (C) of this AD.

(A) With the tail boom supported, remove the upper LH bolt, and the  steel
    alloy barrel nut P/N NAS577B9A, including the retainer, from  service.
    Remove  the countersunk  washer, and  plain washers,  and install  new
    nickel alloy  barrel nut  P/N NAS577C9A,  new retainer  P/N NAS578C9A,
    airworthy countersunk washer, airworthy plain washers, and a new  bolt
    in accordance with the Accomplishment Instructions, Part I, paragraphs
    5 through 7 of Bell  Alert Service Bulletin (ASB) 210-21-15,  Revision
    A, dated February 23, 2022 (ASB 210-21-15, Rev A).

(B) Remove  the  upper RH  bolt, steel  alloy  barrel  nut P/N  NAS577B8A,
    countersunk washer, and plain  washers. Visually inspect the  upper RH
    bolt for any corrosion,  damaged threads, wear, and  fatigue cracking.
    If the  upper RH  bolt has  any corrosion,  damaged threads,  wear, or
    fatigue cracking, before further flight, remove the upper RH bolt from
    service.  Visually inspect  the removed  barrel nut  for cracking.  If
    there is any cracking in the barrel nut, before further flight, remove
    the upper RH bolt from service. Regardless of the result of the  upper
    RH steel alloy  barrel nut inspection,  replace the barrel  nut with a
    new  nickel  alloy  barrel  nut P/N  NAS577C8A  and  new  retainer P/N
    NAS578C8A. Install a new upper RH bolt or reinstall the existing upper
    RH bolt (if  no cracks in  the barrel nut,  and no corrosion,  damaged
    threads, wear, or  fatigue cracking in  the bolt were  identified), by
    following the Accomplishment Instructions,  part I, paragraphs 11  and
    12, including the caution above paragraph 11, of ASB 210-21-15, Rev A.

(C) Remove one of  the lower bolts, its  lower steel alloy barrel  nut P/N
    NAS577B6A,  countersunk washer,  and plain  washers. Visually  inspect
    that lower bolt for any corrosion, damaged threads, wear, and  fatigue
    cracking. If the lower bolt has any corrosion, damaged threads,  wear,
    or fatigue cracking, before further flight, remove the lower bolt from
    service. Visually inspect the  removed lower barrel nut  for cracking.
    If  there is  any cracking  in the  lower barrel  nut, before  further
    flight, remove the lower bolt  from service. Regardless of the  result
    of that lower  steel alloy barrel  nut inspection, replace  the barrel
    nut with a new nickel alloy barrel nut P/N NAS577C6A and new  retainer
    P/N NAS578C6A.  Install a  new lower  bolt or  reinstall the  existing
    lower bolt (if no cracks in the barrel nut, and no corrosion,  damaged
    threads, wear, or  fatigue cracking in  the bolt were  identified), by
    following  the  Accomplishment  Instructions,  part  I,  paragraphs 16
    through 17, including  the caution above  paragraph 16, of  ASB 210-21
    -15, Rev  A. Repeat  the actions  required by  this paragraph  for the
    other lower attachment point.

(2) For  helicopters  identified  in  paragraph  (c)  of  this  AD,  after
    accumulating  1  hour  TIS,  but not  to  exceed  5  hours TIS,  after
    accomplishing the  actions required  by paragraph  (h)(1) of  this AD,
    using the torque value information identified in paragraph (g) of this
    AD, as applicable to your model helicopter, inspect the torque applied
    on each bolt.  Thereafter, repeat the  torque inspection of  each bolt
    after accumulating  1 hour  TIS, but  not to  exceed 5  hours TIS,  to
    determine if  the torque  has stabilized.  Do not  exceed three torque
    inspections total for each  bolt, and accomplish the  actions required
    by paragraphs (h)(2)(i) and (ii) of this AD.

(i) If the torque on a bolt is below the minimum allowable torque limit as
    a result of any  instance of the torque  inspection or if after  three
    torque inspection attempts, the torque on any bolt has not stabilized,
    before further flight, accomplish  the actions required by  paragraphs
    (h)(2)(i)(A) and (B) of this AD.

(A) Remove the hardware set of one failed tail boom attachment point (nut,
    bolt,  countersunk   washer,  and   plain  washers   for  Model   204B
    helicopters, and barrel nut,  bolt, retainer, countersunk washer,  and
    plain washers for Model 205A, 205A-1, 205B, and 210 helicopters).  For
    Model 204 helicopters, remove the nut from service and for Model 205A,
    205A-1, 205B, and 210 helicopters  remove the barrel nut and  retainer
    from service as applicable to the affected tail boom attachment point.
    Visually inspect the removed bolt for any corrosion, damaged  threads,
    wear, and fatigue cracking. If  the bolt has any corrosion,  a damaged
    thread, wear, or fatigue  cracking, before further flight,  remove the
    bolt from service.

(B) Apply a coating of Aeriol ThixO #2 (3810-0) or Aeriol ThixO SYN  (3820
    -0) aviation  grease to  the bolt  shank only.  Install a  new bolt or
    reinstall the existing bolt  (if no corrosion, damaged  threads, wear,
    or fatigue cracking in the bolt were identified), and the hardware set
    of the affected  tail boom attachment  point (new nut  P/N 90-132L6 or
    90-132L7,  countersunk  washer,  and  plain  washers  for  Model  204B
    helicopters, and new nickel alloy barrel nut P/N NAS577C6A,  NAS577C8A
    or P/N  NAS577C9A and  new retainer  P/N NAS578C6A,  NAS578C8A, or P/N
    NAS577C9A, countersunk washer, and plain washers for Model 205A,  205A
    -1, 205B, and 210 helicopters) as applicable to the affected tail boom
    attachment  point.  Torque  the   bolt  by  using  the   torque  value
    information identified in paragraph (g) of this AD. Repeat the actions
    required  by paragraphs  (h)(2)(i)(A) and  (B) of  this AD,  for  each
    failed tail boom  attachment point, one  hardware set at  a time. Then
    repeat the actions  required by paragraph  (h)(2) of this  AD just for
    each newly installed or reinstalled bolt until the torque for all four
    tail boom attachment points stabilize.

(ii) If  the  torque  for  all  four  tail  boom   attachment  points  has
     stabilized, before further flight, apply a torque stripe to all  four
     bolts.

(3) For  helicopters identified  in paragraph  (c) of  this AD, within 600
    hours TIS or 12 months, whichever occurs first, after applying  torque
    stripes to all four bolts as required by paragraph (h)(2)(ii) of  this
    AD, and thereafter within intervals not to exceed 600 hours TIS or  12
    months, whichever  occurs first,  inspect the  torque applied  on each
    bolt using the torque value information identified in paragraph (g) of
    this AD, as applicable to your model helicopter. If the torque on  any
    bolt  is  below the  minimum  allowable torque  limit,  accomplish the
    actions required by paragraphs (h)(3)(i) and (ii) of this AD.

(i) Before further flight, remove the hardware set of one failed tail boom
    attachment point (nut, bolt, countersunk washer, and plain washers for
    Model 204B  helicopters, and  barrel nut,  retainer, bolt, countersunk
    washer,  and  plain washers  for  Model 205A,  205A-1,  205B, and  210
    helicopters) and  then accomplish  the actions  required by paragraphs
    (h)(3)(i)(A),  (B), or  (C) of  this AD  as applicable  to your  model
    helicopter.

(A) For Model  204B  helicopters,  visually inspect  the  removed  nut for
    cracking,  corrosion, and  loss of  tare torque.  If the  nut has  any
    cracking, corrosion,  or loss  of tare  toque, before  further flight,
    remove the nut from service and replace with a new nut P/N 90-132L7 or
    90-132L6 as applicable to  the tail boom attachment  point. Regardless
    of the result of the nut inspection, remove the bolt from service  and
    replace it with a  new bolt by applying  a coating of Aeriol  ThixO #2
    (3810-0) or  Aeriol ThixO  SYN (3820-0)  aviation grease  to the  bolt
    shank only, and install the  hardware set of the tail  boom attachment
    point (nut, bolt, and  countersunk washer, and plain  washers). Torque
    each  bolt  by  using  the  torque  value  information  identified  in
    paragraph  (g)  of  this  AD.  Repeat  the  actions  required  by this
    paragraph for each failed tail boom attachment point, one hardware set
    at a time.

(B) For Model  205A, 205A-1, and  205B, helicopters, visually  inspect the
    removed barrel nut for cracking,  corrosion, and loss of tare  torque.
    If the barrel nut has any cracking, corrosion, or loss of tare  toque,
    before further flight, remove the barrel nut and retainer from service
    and replace them with a new nickel alloy barrel nut P/N NAS577C6A,  or
    NAS577C8A, and new retainer P/N NAS578C6A, or NAS578C8A, with the  P/N
    of the new  nickel alloy barrel  nut and the  P/N of the  new retainer
    being  as  applicable  to the  affected  tail  boom attachment  point.
    Regardless of the result of the barrel nut inspection, remove the bolt
    from service and replace it with a new bolt. Apply a coating of Aeriol
    ThixO #2 (3810-0) or Aeriol ThixO SYN (3820-0) aviation grease to each
    bolt shank only. Install the hardware set of each tail boom attachment
    point (nickel  alloy barrel  nut, retainer,  bolt, countersunk washer,
    and  plain  washers).  Torque  each bolt  by  using  the  torque value
    information identified in paragraph (g) of this AD. Repeat the actions
    required by this paragraph for each failed tail boom attachment point,
    one hardware set at a time.

(C) For Model 210 helicopters, visually inspect the removed barrel nut for
    cracking, corrosion, and  loss of tare  torque. If the  barrel nut has
    any cracking, corrosion, or loss of tare toque, before further flight,
    remove the barrel nut and retainer from service and replace them  with
    a new nickel alloy barrel nut P/N NAS577C6A, NAS577C8A, or  NAS577C9A,
    and new retainer P/N NAS578C6A, NAS578C8A, or NAS578C9A, with the  P/N
    of the new  nickel alloy barrel  nut and the  P/N of the  new retainer
    being  as  applicable  to the  affected  tail  boom attachment  point.
    Regardless of the result of the barrel nut inspection, remove the bolt
    from service and replace it with a new bolt, apply a coating of Aeriol
    ThixO #2 (3810-0) or Aeriol ThixO SYN (3820-0) aviation grease to each
    bolt  shank only,  and torque  each bolt  by using  the  torque  value
    information identified in paragraph (g) of this AD. Repeat the actions
    required by this paragraph for each failed tail boom attachment point,
    one hardware set at a time.

(ii) After accumulating 1  hour TIS, but not  to exceed 5 hours  TIS after
     accomplishing the actions required by paragraph (h)(3)(i) of this AD,
     using the  torque value  information identified  in paragraph  (g) of
     this AD as  applicable to your  model helicopter, inspect  the torque
     applied on each newly  installed bolt. Thereafter, repeat  the torque
     inspection of those bolts after  accumulating 1 hour TIS, but  not to
     exceed 5 hours TIS, to determine if the torque has stabilized. Do not
     exceed three torque inspections total for those bolts and  accomplish
     the actions required by paragraphs (h)(2)(i) and (ii) of this AD.

(4) For helicopters identified in  paragraph (c) of this AD,  within 5,000
    hours  TIS or  5 years  after  accomplishing  the actions  required by
    paragraph (h)(1) of this  AD, whichever occurs first,  and thereafter,
    within intervals not to exceed  5,000 hours TIS or 5  years, whichever
    occurs first, accomplish the actions required by paragraphs  (h)(4)(i)
    and (ii) of this AD.

(i) Accomplish  the  actions  required  by paragraphs  (h)(1)(i), (ii), or
    (iii) of this AD, as applicable to your model helicopter.

(ii) After accumulating 1  hour TIS, but not  to exceed 5 hours  TIS after
     accomplishing  the actions  required by  paragraph (h)(4)(i)  of this
     AD, using the torque value information identified in paragraph (g) of
     this AD as  applicable to your  model helicopter, inspect  the torque
     applied on  each bolt.  Thereafter, repeat  the torque  inspection of
     those bolts after accumulating 1 hour TIS, but not to exceed 5  hours
     TIS, to determine if the  torque has stabilized. Do not  exceed three
     torque inspections total for  those bolts and accomplish  the actions
     required by paragraphs (h)(2)(i) and (ii) of this AD.

(5) As  of the  effective date  of this  AD, do  not install the following
    parts identified in  paragraphs (h)(5)(i) and  (ii) of this  AD on any
    helicopter.

(i) For Model 204B helicopters;  steel alloy nut P/N NAS679A,  NAS1291, or
    MS21042.

(ii) For Model 205A, 205A-1, 205B, and 210 helicopters; steel alloy barrel
     nut P/N NAS577B9A, P/N NAS577B8A, or P/N NAS577B6A.

(i) SPECIAL FLIGHT PERMIT

    A one-time special flight permit  may be issued in accordance  with 14
    CFR 21.197 and 21.199 in order to fly to a maintenance area to perform
    the required actions in this AD.

(j) ALTERNATIVE METHODS OF COMPLIANCE (AMOCS)

(1) The Manager, Central Certification  Branch, 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 manager  of the
    certification  office,  send  it  to  the  attention  of  the   person
    identified in paragraph (k) of this AD. Information may be emailed  to
    fwaco@faa.gov.

(2) 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.

(k) RELATED INFORMATION

    For more information about  this AD, contact Michael  Perrin, Aviation
    Safety Engineer, FAA, 1801 S  Airport Road, Wichita, KS 67209;  phone:
    (562) 627-5362; email: Michael.j.perrin@faa.gov.

(l) MATERIAL INCORPORATED BY REFERENCE

(1) The  Director of  the Federal  Register approved  the incorporation by
    reference (IBR) 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) Bell Alert Service Bulletin 210-21-15, Revision A, dated February  23,
    2022.

(ii) [Reserved]

(3) For service  information identified in  this AD, contact  Bell Textron
    Inc., P.O. Box  482,  Fort Worth,  TX 76101;  phone  (450) 437-2862 or
    (800) 363-8023; fax  (450) 433-0272; email  productsupport@bellflight.
    com; or website: bellflight.com/support/contact-support.

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

(5) You may view this material at the National Archives and Records Admin-
    istration (NARA). For information on the availability of this material
    at NARA, visit www.archives.gov/federal-register/cfr/ibr-locations  or
    email fr.inspection@nara.gov.

Issued on April  26, 2024. James  D. Foltz, Deputy  Director, Compliance &
Airworthiness Division, Aircraft Certification Service.

DATES: The FAA must receive comments on this SNPRM by June 24, 2024.
PREAMBLE 

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2022-0600; Project Identifier AD-2021-01160-R]
RIN 2120-AA64

Airworthiness Directives; Bell Textron Inc., Helicopters

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Supplemental notice of proposed rulemaking (SNPRM).

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

SUMMARY: The FAA is revising a notice of proposed rulemaking (NPRM)
that would have applied to all Bell Textron Inc., Model 204B, 205A,
205A-1, 205B, and 210 helicopters. This AD was prompted by an accident
and incidents involving failure of the tail boom attachment structure.
This action revises the NPRM by changing the proposed required actions
and adding a special flight permit limitation. The FAA is proposing
this airworthiness directive (AD) to address the unsafe condition on
these products. Since these actions would impose an additional burden
over those in the NPRM, the agency is requesting comments on this SNPRM.

DATES: The FAA must receive comments on this SNPRM by June 24, 2024.

ADDRESSES: You may send comments, using the procedures found in 14 CFR
11.43 and 11.45, by any of the following methods:

Federal eRulemaking Portal: Go to regulations.gov. Follow
the instructions for submitting comments.

Fax: 202-493-2251.

Mail: U.S. Department of Transportation, Docket
Operations, M-30, West Building Ground Floor, Room W12-140, 1200 New
Jersey Avenue SE, Washington, DC 20590.

Hand Delivery: Deliver to Mail address above between 9
a.m. and 5 p.m., Monday through Friday, except Federal holidays.

AD Docket: You may examine the AD docket at regulations.gov by
searching for and locating Docket No. FAA-2022-0600; or in person at
Docket Operations between 9 a.m. and 5 p.m., Monday through Friday,
except Federal holidays. The AD docket contains the NPRM, this SNPRM,
any comments received, and other information. The street address for
Docket Operations is listed above.

Material Incorporated by Reference:

For Bell material, contact Bell Textron Inc., P.O. Box
482, Fort Worth, TX 76101; phone (450) 437-2862 or (800) 363-8023; fax
(450) 433-0272; email productsupport@bellflight.com; website:
bellflight.com/support/contact-support.

You may view this service information at the 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.

Other Related Service Information: For other service information
identified in this SNPRM, contact Bell Textron Inc., P.O. Box 482, Fort
Worth, TX 76101; phone (450) 437-2862 or (800) 363-8023; fax (450) 433-
0272; email productsupport@bellflight.com; website: bellflight.com/support/contact-support.

FOR FURTHER INFORMATION CONTACT: Michael Perrin, Aviation Safety
Engineer, FAA, 1801 S Airport Road, Wichita, KS 67209; phone: (562)
627-5362; email: Michael.j.perrin@faa.gov.

SUPPLEMENTARY INFORMATION:

Comments Invited

The FAA invites you to send any written relevant data, views, or
arguments about this proposal. Send your comments to an address listed
under the ADDRESSES section. Include "Docket No. FAA-2022-0600;
Project Identifier AD-2021-01160-R" at the beginning of your comments.
The most helpful comments reference a specific portion of the proposal,
explain the reason for any recommended change, and include supporting
data. The FAA will consider all comments received by the closing date
and may again revise this proposal because of those comments.

Except for Confidential Business Information (CBI) as described in
the following paragraph, and other information as described in 14 CFR
11.35, the FAA will post all comments received, without change, to
regulations.gov, including any personal information you provide. The
agency will also post a report summarizing each substantive verbal
contact received about this SNPRM.

Confidential Business Information

CBI is commercial or financial information that is both customarily
and actually treated as private by its owner. Under the Freedom of
Information Act (FOIA) (5 U.S.C. 552), CBI is exempt from public
disclosure. If your comments responsive to this SNPRM contain
commercial or financial information that is customarily treated as
private, that you actually treat as private, and that is relevant or
responsive to this SNPRM, it is important that you clearly designate
the submitted comments as CBI. Please mark each page of your submission
containing CBI as "PROPIN." The FAA will treat such marked
submissions as confidential under the FOIA, and they will not be placed
in the public docket of this SNPRM. Submissions containing CBI should
be sent to Michael Perrin, Aviation Safety Engineer, FAA, 1801 S
Airport Road, Wichita, KS 67209; phone: (562) 627-5362; email:
Michael.j.perrin@faa.gov. Any commentary that the FAA receives which is
not specifically designated as CBI will be placed in the public docket
for this rulemaking.

Background

The FAA issued AD 2021-15-14, Amendment 39-21661 (86 FR 39942, July
26, 2021) (AD 2021-15-14) for various restricted category helicopters.
AD 2021-15-14 was prompted by an accident involving a Model UH-1B
helicopter and two forced landings involving Model UH-1H and UH-1F
helicopters, due to tail boom attachment structure failures. Each of
the three events involved a failure of the upper left-hand (LH) tail
boom attachment fitting, which is the most heavily loaded at the four
tail boom attach points. The FAA issued AD 2021-15-14 to address
fatigue cracking of tail boom attachment fittings, cap angles,
longerons, and bolts.

Due to their similarity to the Model UH-1B, UH-1H, and UH-1F
helicopters, the FAA determined that Bell Textron Inc., Model 204B,
205A, 205A-1, 205B, and 210 helicopters are also affected by the same
unsafe condition and issued an NPRM to propose the same actions as
those required in AD 2021-15-14. The NPRM published in the Federal
Register on June 7, 2022 (87 FR 34587) to amend 14 CFR part 39, and
would have applied to Bell Textron Inc., Model 204B, 205A, 205A-1,
205B, and 210 helicopters. The NPRM proposed to require revising the
helicopter's existing rotorcraft flight manual (RFM) to incorporate
pre-flight checks; removing excess paint and sealant, and cleaning
certain parts; and repetitive inspections of structural components that
attach the tail boom to the fuselage. Depending on the inspection
results, the NPRM proposed to require repairing or replacing
components, or re-bonding the structure.

Actions Since the NPRM Was Issued

Since the FAA issued the NPRM, the FAA has determined changes to
the proposed required actions are necessary, primarily based on
comments received from several commenters and additional review. The
FAA has also determined to require a special flight permit limitation
as proposed in this SNPRM.

Comments

The FAA received comments from four commenters. The following
discussion presents the comments received on the NPRM and the FAA's
response.

Requests To Withdraw the NPRM

Request: Delta Helicopters Ltd. (DHL) and Remote Helicopters Ltd.
(RHL) stated that because Bell service information and established
maintenance programs already provide the needed requirements to address
the unsafe condition, the proposed AD is not necessary. Additionally,
an individual commenter stated the proposed requirements will not
prevent a sudden failure and stated that daily nut and bolt
inspections, replacement of bolts and nuts at scheduled intervals, and
maintaining proper torque would be just as effective as the
requirements proposed in the NPRM.

DHL stated that although damage does occur, sudden failures will
not occur unless the helicopter is being operated outside of its
capabilities and not being inspected properly as already prescribed by
Bell in related alert service bulletins (ASBs). RHL stated that the
proposed requirements in the NPRM are not necessary because properly
accomplishing the service information from Bell and operating the
helicopter within the appropriate parameters are sufficient. The FAA
infers that these commenters are requesting that the FAA withdraw the
NPRM.

FAA Response: The FAA disagrees. While an operator may incorporate
into its maintenance program the inspections in the manufacturer's
service bulletins referenced by the commenters, not all operators are
required to do so. In order for these inspections to become mandatory,
and to correct the unsafe conditions identified in the NPRM, the FAA
must issue an AD.

Request: DHL, RHL, and one individual commenter each stated that
the restricted category helicopters and the Bell Textron Inc., Model
204 and 205 helicopters have significant dissimilarities. DHL stated
that the comparison between restricted category and Bell Textron Inc.,
Model 204B and 205A-1 helicopters is not accurate, and the Model 205
structure has more in common with the structure of a Model 212
helicopter.

RHL stated that the tail boom inspection for the Model UH-1
helicopter is more difficult because of lack of access to the
inspection areas. Accordingly, RHL stated that lack of access to the
inspection areas is not a problem for Bell Textron Inc., Model 205
helicopters, and because of this, the inspection areas for these
helicopters are inspected on a regular basis.

Additionally, one individual commenter stated the structural design
of the tail boom and the fuselage attachment structure is different
when comparing Model UH helicopters to Bell Textron Inc., Model 205A,
205A-1, 205B, and 210 helicopters, and that these helicopters are more
robust than the Model UH helicopter. The individual commenter also
stated the failures mentioned in the NPRM occurred only on Model UH
helicopters used during heli-logging, and heavy lift activities, but
that commenter has never seen these failures during heavy lift
activities in the Bell Textron Inc., Model 205A-1 helicopter. Finally,
the individual commenter stated the proposed AD is unwarranted and
without basis to include the Bell Textron Inc., Model 205A, 205A-1,
205B, and 210 helicopters in the applicability as they are closer in
similarity to the Bell Textron Inc., Model 212 helicopter. The FAA
infers that these commenters are requesting that the FAA withdraw the NPRM.

FAA Response: The FAA disagrees. An examination of the structures
of both the Model UH-1 helicopters and the Bell Textron Inc., Model 204
and 205 helicopters indicated no significant differences between the
commercial and military model helicopters. Furthermore, there have been
reported tail boom attachment failures involving the Bell Textron Inc.,
Model 205 helicopter. Additionally, performing heavy lift operations
such as logging could accelerate failures in the tail boom attachment
region. The FAA expects that the number of tail boom attachment
failures will increase over time and will also include those aircraft
not involved in heavy lift operations.

Request for Changes to the Required Actions

Request: DHL commenter stated that stripping paint is not necessary
to detect damage during routine maintenance.

FAA Response: The FAA agrees and has revised this SNPRM accordingly.

Request: One individual commenter stated inspection requirements
are part of the Instructions for Continued Airworthiness and should not
be included in a flight manual. The individual commenter stated a
mandatory inspection is a stand-alone inspection and is not related to
the operation of an aircraft, which is the main reason for a flight
manual. Furthermore, the commenter stated maintenance personnel
would not review or reference a flight manual for inspection requirements.

FAA Response: The FAA agrees and has revised this proposed AD
accordingly by removing the requirement of revising the rotorcraft
flight manual from the required actions.

Comment Regarding an Alternative Method of Compliance (AMOC) Request

Request: One individual commenter requested the ability to submit a
request for an AMOC for the tail boom sensor supplemental type
certificate.

FAA Response: The FAA agrees that operators may request approval of
an AMOC under the provisions of paragraph (j) of this SNPRM.

FAA's Determination

The FAA is proposing this AD after determining the unsafe condition
described previously is likely to exist or develop in other products of
the same type design. Certain changes described above expand the scope
of the NPRM. As a result, it is necessary to reopen the comment period
to provide additional opportunity for the public to comment on this
SNPRM.

Related Service Information Under 1 CFR Part 51

The FAA reviewed Bell Alert Service Bulletin (ASB) 210-21-15,
Revision A, dated February 23, 2022 (ASB 210-21-15, Rev A). This
service information specifies procedures for replacing the steel alloy
barrel nuts with nickel alloy barrel nuts, inspecting, and replacing
the tail boom attachment hardware, stabilizing the tail boom attachment
hardware torque, applying torque seals, and subsequently checking the
torque.

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.

Other Related Service Information

The FAA reviewed Bell ASB 205-21-118, Bell ASB 204B-21-75, and Bell
ASB 205B-21-72, each Revision A and dated February 23, 2022. This
service information specifies the same procedures as ASB 210-21-15, Rev A.

Proposed AD Requirements in This SNPRM

This proposed AD would require for Bell Textron Inc., Model 204B
helicopters, with the tailboom assembly removed, removing the upper
left-hand (LH) bolt from service and inspecting the bolt's associated
attachment hardware, and depending on the inspection results, removing
the associated nut from service. This proposed AD would also require
visually inspecting each bulkhead, bolt hole, attachment fitting, the
three other nuts, the upper right-hand bolt, and two lower bolts,
including the bolt shank and head radii. Depending on inspection
results, this proposed AD would require repairing or replacing an
affected bulkhead or affected fitting, removing certain part-numbered
nuts, removing any affected nut and its associated bolt from service,
and removing any affected bolt from service.

This proposed AD would require for Bell Textron Inc., Model 205A,
205A-1, and 205B helicopters, with the tail boom assembly removed,
removing the upper LH bolt from service, and inspecting its associated
barrel nut and retainer, and depending on the inspection results,
removing barrel nut and retainer from service. This proposed AD would
also require visually inspecting each bulkhead, bolt hole, attachment
fitting, the three other barrel nuts, associated retainers, the upper
right-hand bolt, and two lower bolts, including the bolt shank and head
radii. Depending on inspection results, this proposed AD would require
repairing or replacing an affected bulkhead or affected fitting,
removing certain part-numbered barrel nuts and retainers, removing any
affected barrel nuts and its associated bolt from service, and removing
any affected bolt from service.

This proposed AD would require for Bell Textron Inc., Model 210
helicopters, with the tail boom supported, removing the upper LH steel
alloy barrel nut, retainer, and bolt from service. This proposed AD
would also require removing the countersunk washer and plain washers,
and replacing them with a new certain part-numbered nickel alloy barrel
nut, new retainer, new bolt, an airworthy countersunk washer, and
airworthy plain washers. This proposed AD would also require visually
inspecting the upper RH bolt and its associated hardware, and depending
on the inspection results, removing the upper RH bolt and barrel nut
from service. Additionally, this proposed AD would require visually
inspecting the two lower bolts and the associated barrel nuts, and
depending on the inspection results, removing any affected barrel nut
and its associated bolt from service, and removing any affected bolt
from service.

Additionally, this proposed AD would require for all applicable
helicopters, after the initial inspections have been completed,
applying a coating of grease to each bolt shank only, installing the
applicable hardware, and torquing each bolt by using the torque value
information identified in this proposed AD or identified in ASB 210-21-
15, Rev A as applicable.

Thereafter, for all applicable helicopters, this proposed AD would
require inspecting the torque applied on each bolt to determine if the
torque has stabilized and, depending on the results, replacing and
inspecting certain tail boom attachment point hardware and repeating
the torque inspections, or applying torque stripes.

Lastly, this proposed AD would prohibit installing certain part-
numbered steel alloy nuts on any Model 204B helicopters; and would
prohibit installing certain part-numbered steel alloy barrel nuts on
any Model 205A, 205A-1, 205B, and 210 helicopters.

Differences Between This SNPRM and the Service Information

The service information specifies checking torque, whereas this
proposed AD would require inspecting torque because that action must be
accomplished by persons authorized under 14 CFR 43.3.

When stabilizing the tail boom attachment hardware torque, the
service information does not specify what to do if the torque on a tail
boom attachment bolt is below the minimum allowable torque limit,
whereas this proposed AD would require replacing and inspecting certain
tail boom attachment point hardware, stabilizing the torque of the
replaced hardware set, and applying torque stripes.

Costs of Compliance

The FAA estimates that this proposed AD would affect 62 (five Model
204B helicopters, fifty-three Model 205A, 205A-1, and 205B helicopters,
and four Model 210 helicopters) of U.S. registry. Labor costs are
estimated at $85 per work-hour. Based on these numbers, the FAA
estimates the following costs to comply with this proposed AD.

For the initial requirements for Model 204B helicopters, inspecting
or replacing up to four bolts (which includes applying a coating of
grease), inspecting each bulkhead, inspecting each fitting and bolt
hole, inspecting and stabilizing the torque, and applying torque
stripes would take up to approximately 8.5 work-hours for an estimated
labor cost of up to $723. The parts cost for an upper LH bolt would be
approximately $196 and the parts cost for the other bolts would be
approximately $89 per bolt. The parts cost for four new nuts would be
approximately $680. The parts cost to apply torque stripes would be a
nominal amount. The estimated cost for these actions would be up to
approximately $1,866 per helicopter and $9,330 for the U.S. fleet.

For the initial requirements for Model 205A, 205A-1, and 205B
helicopters, replacing the four steel alloy barrel nuts with new nickel
alloy barrel nuts, inspecting or replacing up to four bolts (which
includes applying a coating of grease), inspecting each bulkhead,
inspecting and stabilizing the torque, and applying torque stripes
would take up to approximately 8.5 work-hours for an estimated labor
cost of up to $723. The parts cost for the four new nickel alloy barrel
nuts (including retainers) would be approximately $680. The parts cost
for an upper LH bolt would be approximately $196 and the parts cost for
the other bolts would be approximately $89 per bolt. The parts cost to
apply torque stripes would be a nominal amount. The estimated cost for
these actions would be up to approximately $1,866 per helicopter and
$98,898 for the U.S. fleet.

For the intital requirements for Model 210 helicopters, replacing
the four steel alloy barrel nuts with new nickel alloy barrel nuts,
inspecting or replacing up to four bolts (which includes applying a
coating of grease), inspecting and stabilizing the torque, and applying
torque stripes would take up to approximately 8.5 work-hours for an
estimated labor cost of up to $723. The parts cost for the four new
nickel alloy barrel nuts (including retainers) would be approximately
$680. The parts cost for an upper LH bolt would be approximately $196
and the parts cost for the other bolts would be approximately $89 per
bolt. The parts cost to apply torque stripes would be a nominal amount.
The estimated cost for these actions would be up to approximately
$1,866 per helicopter and $7,464 for the U.S. fleet.

For all applicable helicopters, inspecting the torque applied on
each bolt would take approximately 1 work-hour for an estimated cost of
$85 per helicopter and $5,270 for the U.S. fleet, per inspection cycle.

For all applicable helicopters, replacing an upper LH bolt,
stabilizing the torque, and applying a torque stripe would take up to
approximately 5 work-hours. The parts cost for an upper LH bolt would
be approximately $196 and the parts cost to apply a torque stripe would
be a nominal amount. The estimated cost for these actions would be up
to approximately $621 per helicopter and $38,502 for the U.S. fleet,
per replacement cycle. Inspecting one of the other bolts, stabilizing
the torque, and applying a torque stripe would take up to approximately
3.5 work-hours for an estimated cost of $298 per other bolt and $18,476
for the U.S. fleet per other bolt per inspection cycle. If required,
replacing a bolt following that inspection would take a minimal amount
of additional time and the parts cost would be approximately $89.

If required as a result of failing any torque inspection required
by this proposed AD, visually inspecting a nut or a barrel nut,
replacing a bolt, stabilizing the torque, and applying a torque stripe
would take up to approximately 5.5 work-hours per failed hardware set.
The parts cost for an upper LH bolt would be approximately $196 and the
parts cost for the other bolts would be approximately $89 per bolt. The
parts cost to apply a torque stripe would be a nominal amount. The
estimated cost for these actions would be $664 (upper LH bolt) or $557
(other bolts), per failed hardware set. If required, replacing a nut
following that inspection would take a minimal amount of additional
time and the parts cost for a nut would be approximately $89 per nut,
and if required, replacing a barrel nut following that inspection would
take a minimal amount of additional time and the parts cost for a
barrel nut (including retainer) would be approximately $173 per barrel nut.

The corrective action that may be needed as a result of the
bulkhead inspection could vary significantly from helicopter to
helicopter. The FAA has no data to determine the costs to accomplish
the corrective action or the number of helicopters that may require
corrective action.

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.

The FAA is 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

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

For the reasons discussed above, I certify this proposed regulation:

(1) Is not a "significant regulatory action" under Executive Order 12866,

(2) Would not affect intrastate aviation in Alaska, and

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

List of Subjects in 14 CFR Part 39

Air transportation, Aircraft, Aviation safety, Incorporation by
reference, Safety.

The Proposed Amendment

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

PART 39--AIRWORTHINESS DIRECTIVES

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

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

Sec. 39.13 [Amended]

2. The FAA amends Sec. 39.13 by adding the following new airworthiness
directive: