Airworthiness Directives; Bell Helicopter Textron Model 204B, 205A, 205A-1, 205B, 210, 212, 412, 412CF, and 412EP Helicopters, 24858-24864 [E8-9790]
Download as PDF
<![CDATA[
24858
Federal Register / Vol. 73, No. 88 / Tuesday, May 6, 2008 / Rules and Regulations
Regulatory Findings
We determined that this AD will not
have federalism implications under
Executive Order 13132. This AD will
not have a substantial direct effect on
the States, on the relationship between
the national government and the States,
or on the distribution of power and
responsibilities among the various
levels of government.
For the reasons discussed above, I
certify this AD:
1. Is not a ‘‘significant regulatory
action’’ under Executive Order 12866;
2. Is not a ‘‘significant rule’’ under the
DOT Regulatory Policies and Procedures
(44 FR 11034, February 26, 1979); and
3. Will not have a significant
economic impact, positive or negative,
on a substantial number of small entities
under the criteria of the Regulatory
Flexibility Act.
We prepared an economic evaluation
of the estimated costs to comply with
this AD and placed it in the AD docket.
List of Subjects in 14 CFR Part 39
Air transportation, Aircraft, Aviation
safety, Safety.
Adoption of the Amendment
Accordingly, under the authority
delegated to me by the Administrator,
the FAA amends 14 CFR part 39 as
follows:
I
PART 39—AIRWORTHINESS
DIRECTIVES
1. The authority citation for part 39
continues to read as follows:
I
Authority: 49 U.S.C. 106(g), 40113, 44701.
§ 39.13
[Amended]
2. The FAA amends § 39.13 by adding
the following new AD:
I
2008–10–01 Eurocopter France:
Amendment 39–15507. Docket No.
FAA–2008–0489; Directorate Identifier
2007–SW–59–AD.
Effective Date
(a) This airworthiness directive (AD)
becomes effective on May 21, 2008.
Other Affected ADs
(b) None.
PWALKER on PROD1PC71 with RULES
(e) Before further flight, remove any
spherical thrust bearing, part number
7050A3622036, serial numbers LK0130,
LK0142, LK0155, or LK0158, and replace it
with an airworthy spherical thrust bearing.
Differences Between the FAA AD and the
MCAI
(f) None.
Subject
(g) Air Transport Association of America
(ATA) Code 6220, Main Rotor Hub.
Other FAA AD Provisions
(h) The following information also applies
to this AD:
(1) Alternative Methods of Compliance
(AMOCs): The Manager, Safety Management
Group, Rotorcraft Directorate, FAA, has the
authority to approve AMOCs for this AD, if
requested using the procedures found in 14
CFR 39.19. Send information to ATTN: Gary
Roach, Aviation Safety Engineer, FAA,
Rotorcraft Directorate, Regulations and
Guidance Group, Fort Worth, Texas 76193–
0111, telephone (817) 222–5130, fax (817)
222–5961.
(2) Airworthy Product: Use only FAAapproved corrective actions. Corrective
actions are considered FAA-approved if they
are approved by the State of Design Authority
(or their delegated agent) if the State of
Design has an appropriate bilateral agreement
with the United States. You are required to
ensure the helicopter is airworthy before it is
returned to service.
(3) Reporting Requirements: For any
reporting requirement in this AD, under the
provisions of the Paperwork Reduction Act,
the Office of Management and Budget (OMB)
has approved the information collection
requirements and has assigned OMB Control
Number 2120–0056.
(i) Mandatory Continuing Airworthiness
Information Direction generale de l’aviation
civile Airworthiness Directive No. F–2006–
040, dated February 15, 2006, contains
related information.
Reason
(d) The mandatory continued
airworthiness information (MCAI) states:
This Airworthiness Directive (AD) follows
upon the discovery of a batch of spherical
thrust bearings which prove to be unfit for
flight.
16:31 May 05, 2008
Actions and Compliance
Related Information
Applicability
(c) This AD applies to Model EC120B
helicopters, with spherical thrust bearings,
part number 7050A3622036, serial number
LK0130, LK0142, LK0155, and LK0158,
installed, certificated in any category.
VerDate Aug<31>2005
This AD requires actions that are intended to
address the unsafe condition caused by the
manufacture of a batch of spherical thrust
bearings that are not airworthy because they
were not manufactured in accordance with
approved type design. Failure of a spherical
thrust bearing during flight could cause the
main rotor (M/R) system to separate from the
helicopter, which would be catastrophic.
Jkt 214001
Issued in Fort Worth, Texas, on April 23,
2008.
David A. Downey,
Manager, Rotorcraft Directorate, Aircraft
Certification Service.
[FR Doc. E8–9799 Filed 5–5–08; 8:45 am]
BILLING CODE 4910–13–P
PO 00000
Frm 00008
Fmt 4700
Sfmt 4700
DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. FAA–2008–0490; Directorate
Identifier 2008–SW–26–AD; Amendment 39–
15509; AD 2008–10–03]
RIN 2120–AA64
Airworthiness Directives; Bell
Helicopter Textron Model 204B, 205A,
205A–1, 205B, 210, 212, 412, 412CF,
and 412EP Helicopters
Federal Aviation
Administration, DOT.
ACTION: Final rule; request for
comments.
AGENCY:
SUMMARY: This amendment adopts a
new airworthiness directive (AD) for the
specified Bell Helicopter Textron (Bell)
model helicopters. This action requires
certain checks and inspections of each
tail rotor blade assembly (T/R blade) at
specified intervals and repairing or
replacing, as applicable, any
unairworthy T/R blade. This
amendment is prompted by three
failures of a T/R blade occurring during
flight and a recent incident of a cracked
T/R blade discovered during a
scheduled visual inspection. The
actions specified in this AD are
intended to detect damage to a T/R
blade that could lead to cracking of a T/
R blade and subsequent loss of control
of the helicopter.
DATES: Effective May 21, 2008.
Comments for inclusion in the Rules
Docket must be received on or before
July 7, 2008.
ADDRESSES: Use one of the following
addresses to submit comments on this
AD:
• Federal eRulemaking Portal: Go to
https://www.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: U.S. Department of
Transportation, Docket Operations, M–
30, West Building Ground Floor, Room
W12–140, 1200 New Jersey Avenue, SE.,
Washington, DC 20590, between 9 a.m.
and 5 p.m., Monday through Friday,
except Federal holidays.
You may get the service information
identified in this AD from Bell
Helicopter Textron, Inc., P.O. Box 482,
Fort Worth, Texas 76101, telephone
(817) 280–3391, fax (817) 280–6466.
Examining the Docket: You may
examine the docket that contains the
E:\FR\FM\06MYR1.SGM
06MYR1
Federal Register / Vol. 73, No. 88 / Tuesday, May 6, 2008 / Rules and Regulations
AD, any comments, and other
information on the Internet at https://
www.regulations.gov, or in person at the
Docket Operations office between 9 a.m.
and 5 p.m., Monday through Friday,
except Federal holidays. The Docket
Operations office (telephone (800) 647–
5527) is located in Room W12–140 on
the ground floor of the West Building at
the street address stated in the
ADDRESSES section. Comments will be
available in the AD docket shortly after
receipt.
FOR FURTHER INFORMATION CONTACT:
Michael Kohner, Aviation Safety
Engineer, FAA, Rotorcraft Directorate,
Rotorcraft Certification Office, Fort
Worth, Texas 76193–0170, telephone
(817) 222–5447, fax (817) 222–5783.
SUPPLEMENTARY INFORMATION: A
proposal to amend 14 CFR part 39 to
include an AD for the specified model
helicopters was published in the
Federal Register as Docket No. FAA–
Model
Year
P/N 212–
010–750–
Blade
station
(in.)
Crack
length
(in.)
Initial damage part
and type
1973
1985
¥009
¥009
3,224
279
32.2
31.5
6.5
13.0
212 .................
412 .................
412 .................
PWALKER on PROD1PC71 with RULES
212 .................
212 .................
1991
1990
1996
¥105
¥009
¥105
423
3,876
1,235
30.8
27.6
30.0
8.0
8.0
8.3
The NPRM proposed to require the
following interim actions until either a
more rigorous inspection is developed
or a new blade that is more damage
tolerant is designed:
• Before each start of the engines,
visually checking each T/R blade for a
crack;
• Within 25 hours TIS or 15 days,
whichever occurs first, and thereafter at
intervals not to exceed 25 hours TIS or
15 days, whichever occurs first,
cleaning and visually inspecting each
T/R blade for a crack, corrosion, nick,
scratch, or dent using a 3-power or
higher magnifying glass and a bright
light;
• If certain damage is found,
inspecting for a crack or corrosion using
a 10-power or higher magnifying glass
and measuring the depth of any damage;
and
• Before further flight, replacing any
cracked T/R blade and repairing or
replacing any otherwise unairworthy
T/R blade.
Since the issuance of that NPRM, we
were notified that a crack was found on
another T/R blade, P/N 212–010–750–
105 FM, installed on a Bell Model
412EP helicopter. The crack was
VerDate Aug<31>2005
18:08 May 05, 2008
Jkt 214001
provided in the maintenance manual.
That failed blade had accumulated
1,478 hours time-in-service (TIS). In
another in-flight failure, a section of the
T/R blade separated from the helicopter
during cruise flight at 5,500 feet. The
helicopter was reported to have
violently turned down and to the left.
The helicopter ‘‘leveled out’’ at
approximately 1,000 feet before setting
down in the water. The blade failed due
to a cracked stainless steel leading edge
spar that originated from a corrosion pit
.001 inches deep. The corrosion area
extended .003 inches along the surface
of the origin location. That blade had
accumulated 4,643 hours TIS. In the
third in-flight failure, sanding on the
spar and chem-milling was found
during a post-accident investigation.
The crack had initiated at blade station
21.9 and the blade had accumulated
1,232 hours TIS. Also, the following
blades were found cracked:
2006–26219, Directorate Identifier
2004–SW–49–AD on November 2, 2006
(71 FR 64484). That Notice of Proposed
Rulemaking (NPRM) was prompted by
eight reports of fatigue cracking of T/R
blades installed on Bell Model 212 and
412 helicopters (three failures on the
Bell Model 212 and five failures on the
Bell Model 412) with a blade assembly,
part number (P/N) 212–010–750–009,
–105, and –107. Six of the cracks
initiated between blade stations 30 to
33.5; one crack initiated at blade station
21.9; and one crack initiated at blade
station 27.6. Three of these T/R blades
failed during flight and all were
installed on Bell Model 412 series
helicopters. In one of the in-flight
failures, the T/R blade failed due to a
fatigue crack that initiated in the blade
skin from a nick .060 inches long by
.008 inches deep. The initial damage
was above the maximum allowable
damage limit for the blade skin
Hours TIS
Skin—Corrosion .............
Spar—Manufacturing
Notch.
Skin—Non Sharp Dent ...
Skin—Corrosion .............
Skin—Scratch .................
discovered while the helicopter was on
the ground during a scheduled visual
inspection. The T/R blade is now being
examined at the manufacturer’s field
investigation lab. The crack is located
approximately in the center of the TR
blade span and extends across the
majority of the chord. The T/R blade
had accumulated 2,076 hours TIS.
Because P/N 212–010–750–105 FM was
not included in the applicability of the
NPRM, and because a crack growth
analysis using the striation count data
from one of the failed T/R blades
predicted a crack propagation rate of
approximately 77 hours TIS from
damage initiation to blade failure, we
will withdraw that NPRM and issue this
AD as a Final rule; request for
comments. This AD contains the
proposed requirements from the NPRM;
however, we’ve included additional
P/Ned blades and made other changes
based on the comments to the NPRM. In
response to the NPRM we received
several comments from 4 commenters;
the manufacturer, the Canadian
National Defence Headquarters, and 2
individuals.
Two commenters suggest changing
the compliance time for the proposed
PO 00000
Frm 00009
Fmt 4700
Sfmt 4700
24859
Initial damage size
.030 in. wide.
.090 in. wide.
.75 in. long.
Unknown.
.45 in. long by .005 in.
deep.
actions. One of the commenters suggests
changing the proposed initial inspection
from 25 hours TIS or 15 days to 25
hours TIS or 30 days and changing the
recurring inspection from 25 hours TIS
or 15 days to 25 hours TIS or 30 days.
The other commenter believes that a
visual inspection before the first flight
of each day would be adequate and that
a limit of 10 hours between visual
inspections in any one day could be
added. The same commenter states that
it is not always practical (e.g. carrying
a suitable safe ladder for conducting an
adequate inspection and carry
passengers) and might also be hazardous
(e.g. doing an inspection from an
offshore oil field platform where there is
no ladder or stand available or where
there is restricted space and the
possibility of high wind speeds) to do a
visual inspection before each engine
start. Finally, one commenter, the
manufacturer, states that it is
impractical to require inspection of the
T/R blades before each flight or engine
start unless we are referring to a groundlevel visual inspection because a ladder,
which is not available in the field,
would be required for a hands-on
inspection. It recommends an
E:\FR\FM\06MYR1.SGM
06MYR1
24860
Federal Register / Vol. 73, No. 88 / Tuesday, May 6, 2008 / Rules and Regulations
inspection in accordance with the
maintenance manual. The manufacturer
further recommends an inspection for
more than just ‘‘cracks’’, that is, any
damage beyond limits in accordance
with the published schedule and
requirements in the maintenance
manual.
We concur with the recommendation
to change the initial and recurring
inspections from 25 hours TIS or 15
days to 25 hours TIS or 30 days. The 15day interval was originally proposed
because a corrosion pit was the
initiation point for one of the failures
and that interval is consistent with FAA
advisory material relating to the
detection of corrosion. Since the
proposal was published, we have
reevaluated the need for the interval and
determined that a 30-day interval is
adequate for this inspection and the AD
is revised accordingly. We do not
concur that a visual inspection before
the first flight of each day would be
adequate and that a limit of 10 hours
between visual inspections in any one
day should be added. Additionally, we
do not agree with the manufacturer that
a 60-day interval would be appropriate
because of the quick degradation in the
T/R blade strength. However, we do
agree that it is not always practical to
require a detailed visual inspection of
the T/R blades using a ladder before
each flight or engine start. The proposed
owner/operator (pilot) check was only
intended to be a ‘‘walk around’’ check
to detect any large cracks. Although the
Canadian commenter states that their
inspection from the ground is not
considered effective, we have received
reports that two cracked blades were
discovered during checks performed
from the ground. The initial and
recurring inspections performed by a
mechanic are detailed, up-close
inspections.
One commenter also suggests that
instead of requiring a mandatory daily
log book entry stating compliance with
the AD that ‘‘the blade inspection be
made a required preflight checklist item
with no daily log book entry required.’’
If a logbook entry is required, the
commenter suggests that it be a separate
entry made at the time the 25 hour is
signed off. We have determined that this
critical check needs to be mandated.
This determination is based on the
critical nature of this failure and that the
length of a crack is predicted to grow
quickly once it is detectable based on
the service history of these T/R blades.
All required inspections, including the
pilot checks specifically approved by
this AD, must be recorded at the time
they are performed. That recording
evidences that the required AD actions
have been performed. If it is not
recorded, the aircraft is not in
compliance with the AD and is
unairworthy.
In addition to comments regarding the
inspection times and types, the
manufacturer provided other comments
to the NPRM. Those comments and our
responses follow:
Comment
Response
The AD lists a 1991 Model 212 with a .75″ crack * * * that Bell questions since they have no conclusive technical data on it. They also
question our references to a 77 hour crack propagation from striation
count and state that the 77 hour value is actually from a crack
growth analysis that simply includes striation count data. Bell also
states that they are aware of only 4, not 8, existing M205Bs that are
of FAA certified configuration.
The cracked T/R blade in question is found in the FAA service difficulty
database. An approximate 8-inch crack was found in the T/R blade
installed on a Bell Model 212 helicopter during a daily inspection.
The crack was located 20.25 inches inboard from the tip of the T/R
blade running through a .75 inch long smooth dent. The part number
of the T/R blade was 212–010–750–105 with a total time of 423
hours.
We agree with the comment about the reference to the 77 hour crack
propagation and the number of existing M205B helicopters and have
revised this AD accordingly.
While the standard Model 204B helicopter may not use this particular
T/R blade, the 212–010–750 T/R blade may be on a modified Model
204B helicopter that does use this blade. To assure that we have
covered all affected blades, the applicability now encompasses all affected dash-numbered T/R blades.
Agree with this change and have revised this AD accordingly.
The listed tail rotor dash numbers appear to be incorrect. The Model
204B does not use the 212–010–750 tail rotor blade and there also
appears to be several of the later dash numbers missing from various models.
PWALKER on PROD1PC71 with RULES
Recommend changing areas called out for special attention to Stations
25.0 to 35.0 (both sides) for damage/corrosion and include inboard
blade butt area surrounding balance weights/screws for cracks.
There have not been eight reported failures, there have been three. All
others are reported cracks in the blade skin, not ‘‘failures.’’ The term
‘‘failure’’ can be misleading.
Bell objects to our statement in the NPRM that ‘‘The requirements of
the proposed AD would be interim actions until either a more rigorous inspection is developed or a new blade that is more damage
tolerant is designed.’’ Bell states ‘‘Although we are in concept discussions with DND, completion and certification of this blade is many
months away and could be misleading to the commercial community.’’
Another commenter, the Canadian
National Defence Headquarters, views
the proposed actions as a ‘‘good first
VerDate Aug<31>2005
18:08 May 05, 2008
Jkt 214001
A crack in a blade makes that blade unable to safely perform its intended function. Thus, there are now 9 T/R blades that meet that criteria.
As we understand this objection by the manufacturer, it believes that a
redesigned blade is unnecessary and that the current inspections are
adequate. We do not agree. Based on the fracture analysis, once
the crack reaches a size that is detectable by inspection, it is predicted to grow quickly. Therefore, for the affected T/R blades, it is
critical to find a crack or damage that could lead to a crack at the
earliest opportunity. The service history of these affected T/R blades
has shown that the current inspections are inadequate to reveal
these cracks before blade failure. One T/R blade failed and another
one cracked because of manufacturing damage on the inside of the
T/R blade. That damage was not initially detectable by external inspection. Another T/R blade failed during flight due to cracking that
initiated from a corrosion pit in the leading edge spar that was too
small to be readily detected. Therefore, replacing the affected T/R
blades with a redesigned, more damage-tolerant T/R blade is anticipated as terminating action for the requirements of this AD.
step’’ but offers several
recommendations. Those
PO 00000
Frm 00010
Fmt 4700
Sfmt 4700
recommendations and our responses
follow:
E:\FR\FM\06MYR1.SGM
06MYR1
Federal Register / Vol. 73, No. 88 / Tuesday, May 6, 2008 / Rules and Regulations
24861
Recommendation
Response
‘‘Promulgate to other aviation regulation agencies worldwide because
there are many more airframes affected than the ‘388 helicopters of
U.S. registry’.’’
Adjust the inspection frequency as a function of the operations environment, e.g., a 12.5 hours inspection frequency using the 10x magnification (noting that deployments of small numbers of aircraft take
the minimum support equipment required) visual inspection for operations using ‘‘harsh & rough’’ landing fields and an interval of 25
hours inspection for paved landing fields.
Our standard practice is to send our ADs to aviation authorities with
which we have a bilateral agreement. In turn, it is then at their discretion whether or not to follow up with similar action.
We agree that the risk of incurring damage in the T/R blade would be
less for those helicopters operated on paved landing fields versus
‘‘harsh & rough’’ landing fields. Defining and enforcing such an inspection interval, however, would be difficult because helicopters operate in so many varied environments. We believe the commet to
use a 10-power magnifying glass may be a typographical error because the Canadian National Defense uses a 2-power magnifying
glass and a good source of light every 12.5 hours TIS for the visual
inspection of the T/R blades on their Model 412CF helicopters. Regardless, we have determined that a 25-hour TIS inspection using a
3x or higher magnifying glass is best for the overall safe operation of
these helicopters in the U.S.
We do not believe that further information regarding who can carry out
this visual check is necessary. The visual check is only intended to
detect a large-scale crack and we believe an owner/operator (pilot) is
qualified to perform this ‘‘walk-around’’ function.
The illumination levels are historically not given for visual inspections
that are mandated by an AD. We believe what constitutes a bright
light can be adequately determined by the individuals who are qualified to do the inspection. We also did not want to create additional
calibration and recordkeeping requirements.
Inspection of the T/R blade records and recording any damage found
within the repair limits are in the maintenance instructions for the T/R
blade inspection on the applicable helicopters. These steps are currently in the applicable maintenance procedures. Operators are free
to implement such mapping if they believe it will reduce their maintenance burden.
We believe the requirement to use of a 10-power magnifying glass is
adequate.
Specify that the visual check be carried out by an appropriately qualified person.
Define what constitutes a ‘‘bright light’’ ....................................................
Implement damage mapping as a means to increase detectability of
new damage and decrease the maintenance burden.
PWALKER on PROD1PC71 with RULES
Carry out a Type 1, Method C, Level III dye-penetrant inspection in
cases where difficulties are encountered in determining the presence
of a crack by visual inspection.
We have reviewed the following Bell
documents:
• Operations Safety Notice OSN 205–
02–37, OSN 205B–02–10, OSN 212–02–
39, OSN 412–02–25, OSN 412CF–02–05,
and OSN UH–1H–II–02–3, dated August
27, 2002. These Operations Safety
Notices apply to all owners and
operators of Bell 205, 205B, 212, 412,
412CF, and UH–1H–II helicopters and
were written to remind operators of the
following:
• The importance of accomplishing a
complete inspection of the T/R blades at
specified inspection intervals;
• That the blades must be cleaned in
order to perform an adequate visual
inspection to determine their condition;
and
• That maintenance manuals and
component repair and overhaul manuals
are to be consulted for damage limits
and repair criteria as required.
• Alert Service Bulletin No. 412CF–
03–20, dated February 6, 2003, which
applies to Model 412CF helicopters and
provides instructions for doing a visual
inspection of certain T/R blades
immediately and every 25 hours TIS in
accordance with the Model 412CF
maintenance manual and instructions
for sending the affected tail rotor blade
to DND ‘‘Calgary Supply Center’’ for
refinishing and reidentification.
VerDate Aug<31>2005
18:08 May 05, 2008
Jkt 214001
• Bell Maintenance Document C–12–
146–000/MF–001, Mod 4, dated
February 12, 2004, which applies to
Model 412CF helicopters and specifies
a tail rotor blade damage records check
and a visual inspection for dents, nicks,
cracks, paint chips, or blisters using a
2-power magnifying glass and a good
source of light in specified areas of the
tail rotor blades (reference 64–00–00,
section 64–38, page 42).
This unsafe condition is likely to exist
or develop on other helicopters of these
same type designs. Therefore, this AD is
being issued to detect damage to a T/R
blade that could lead to cracking of a
T/R blade and subsequent loss of
control of the helicopter. This AD
requires:
• Before each start of the engines,
visually checking each T/R blade for a
crack. An owner/operator (pilot)
holding at least a private pilot certificate
may perform this visual check and must
enter compliance with paragraph (a) of
this AD into the aircraft maintenance
records in accordance with 14 CFR
43.11 and 91.417(a)(2)(v). A pilot may
do this check because it requires no
special tools and can be performed
equally well by a pilot or a mechanic.
• Within 25 hours TIS or 30 days,
whichever occurs first, unless
accomplished previously, and thereafter
PO 00000
Frm 00011
Fmt 4700
Sfmt 4700
at intervals not to exceed 25 hours TIS
or 30 days, whichever occurs first,
cleaning and visually inspecting the
T/R blade skins, leading edge spar,
doublers, grip plates, and trailing edge
for a crack, corrosion (may be indicated
by blistering, peeling, flaking, bubbling,
or cracked paint) and any other damage
(including a nick, scratch, or dent) using
a 3x or higher magnifying glass.
• If certain damage is found,
inspecting the affected area using a 10power or higher magnifying glass and
measuring the depth of the damage.
• Before further flight, repairing or
replacing, as applicable, any
unairworthy T/R blade. The short
compliance time involved is required
because a cracked or damaged T/R blade
creates an unsafe condition that can
adversely affect the structural integrity
and controllability of the helicopter.
Therefore the required actions within
the specified short time intervals require
that this AD be issued immediately.
Since a situation exists that requires
the immediate adoption of this
regulation, it is found that notice and
opportunity for prior public comment
hereon are impracticable, and that good
cause exists for making this amendment
effective in less than 30 days.
We estimate that this AD will affect
384 helicopters of U.S. registry. There
E:\FR\FM\06MYR1.SGM
06MYR1
24862
Federal Register / Vol. 73, No. 88 / Tuesday, May 6, 2008 / Rules and Regulations
are approximately 184 Model 205A and
205A–1 helicopters, 4 Model 205B
helicopters, 101 Model 212 helicopters,
80 Model 412, 412CF, and 412EP
helicopters, and 15 modified Model
204B helicopters. Each visual check will
take .125 hours, each visual inspection
will take .5 hours, and 6 hours to
remove and replace each T/R blade
assembly, if necessary. The average
labor rate is $80. Replacement parts will
cost $11,243 for each T/R blade
assembly. Based on these figures, the
estimated cost impact of the AD for all
of the affected models will be
$1,828,855 assuming an average of 600
hours TIS per year for each helicopter
resulting in 365 visual checks, 24
inspections, and 5 T/R blade assembly
replacements for the total fleet.
Comments Invited
This AD is a final rule that involves
requirements that affect flight safety and
was not preceded by notice and an
opportunity for public comment;
however, we invite you to submit any
written data, views, or arguments
regarding this AD. Send your comments
to an address listed under ADDRESSES.
Include ‘‘Docket No. FAA–2008–0490;
Directorate Identifier 2008–SW–26–AD’’
at the beginning of your comments. We
specifically invite comments on the
overall regulatory, economic,
environmental, and energy aspects of
the AD. We will consider all comments
received by the closing date and may
amend the AD in light of those
comments.
We will post all comments we
receive, without change, to https://
www.regulations.gov, including any
personal information you provide. We
will also post a report summarizing each
substantive verbal contact with FAA
personnel concerning this AD. 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 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).
Regulatory Findings
We have determined that this AD will
not have federalism implications under
Executive Order 13132. This AD will
not have a substantial direct effect on
the States, on the relationship between
the national Government and the States,
or on the distribution of power and
responsibilities among the various
levels of government.
For the reasons discussed above, I
certify that the 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 an economic evaluation
of the estimated costs to comply with
this AD. See the AD docket to examine
the 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.
Helicopter model
210 ............................................................................................................
PWALKER on PROD1PC71 with RULES
Required as indicated.
To detect any damage in a T/R blade,
prevent cracking of a T/R blade leading to
failure from static overload, and subsequent
loss of control of the helicopter, accomplish
the following:
(a) Before each start of the engines, visually
check both sides of each T/R blade for a
crack. An owner/operator (pilot) holding at
least a private pilot certificate may perform
this visual check and must enter compliance
with this paragraph into the aircraft
VerDate Aug<31>2005
16:31 May 05, 2008
Jkt 214001
List of Subjects in 14 CFR Part 39
Air transportation, Aircraft, Aviation
safety, Safety.
Adoption of the Amendment
Accordingly, pursuant to the authority
delegated to me by the Administrator,
the Federal Aviation Administration
amends part 39 of the Federal Aviation
Regulations (14 CFR part 39) as follows:
I
PART 39—AIRWORTHINESS
DIRECTIVES
1. The authority citation for part 39
continues to read as follows:
I
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:
I
2008–10–03 Bell Helicopter Textron:
Amendment 39–15509. Docket No.
FAA–2008–0490; Directorate Identifier
2008–SW–26–AD.
Applicability
The following model helicopters, with the
specified tail rotor blade assembly (T/R
blade) installed, certificated in any category:
With T/R blade, part number (P/N)
204B, 205A, 205A–1, 212, 412, 412CF, and 412EP ...............................
205B .........................................................................................................
Compliance
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.
212–010–750–(all
212–010–750–(all
212–015–501–(all
210–010–001–(all
212–010–750–(all
dash
dash
dash
dash
dash
maintenance records in accordance with 14
CFR 43.11 and 91.417(a)(2)(v).
(b) Within 25 hours time-in-service (TIS) or
30 days, whichever occurs first, unless
accomplished previously, and thereafter at
intervals not to exceed 25 hours TIS or 30
days, whichever occurs first:
(1) Clean each T/R blade by hand using a
mild degreaser and water to remove soot and
grime on both sides of the blade using a
coarse, loosely woven cotton cloth in a
spanwise direction. Use a cloth with a color
that contrasts with the color of the T/R blade
so that a snag will be visible.
PO 00000
Frm 00012
Fmt 4700
Sfmt 4700
numbers).
numbers).
numbers).
numbers).
numbers).
(2) Using a 3-power or higher magnifying
glass and a bright light, visually inspect the
T/R blade skins, leading edge spar, doublers,
grip plates, and trailing edge for a crack,
corrosion (may be indicated by blistering,
peeling, flaking, bubbling, or cracked paint)
and any other damage (including a nick,
scratch, or dent). See Figure 1 of this AD. Pay
particular attention to both sides of the T/R
blade in the area located 16 to 26 inches from
the T/R blade tip (blade station 25 to 35—the
T/R blade tip is located at blade station 51)
and to the inboard blade butt area near the
attachment of the external balance weights
E:\FR\FM\06MYR1.SGM
06MYR1
Federal Register / Vol. 73, No. 88 / Tuesday, May 6, 2008 / Rules and Regulations
and screws. Also pay particular attention to
any blade surface that was snagged by the
24863
cloth, as that may be an indication of a crack
or paint chip that could lead to corrosion.
BILLING CODE 4910–13–C
VerDate Aug<31>2005
16:31 May 05, 2008
Jkt 214001
PO 00000
Frm 00013
Fmt 4700
Sfmt 4700
E:\FR\FM\06MYR1.SGM
06MYR1
ER06MY08.182</GPH>
PWALKER on PROD1PC71 with RULES
BILLING CODE 4910–13–P
24864
Federal Register / Vol. 73, No. 88 / Tuesday, May 6, 2008 / Rules and Regulations
(3) If any blistering, peeling, flaking,
bubbling, or cracked paint is detected,
remove the paint from the affected area and
visually inspect the affected area for
corrosion or a crack using a 10-power or
higher magnifying glass. If any corrosion is
found, measure the depth of the corrosion (a
digital optical micrometer is one tool that can
be used for this measurement).
(4) If a nick, scratch, or dent is found,
visually inspect for a crack using a 10-power
or higher magnifying glass and measure the
depth of the damage (a digital optical
micrometer is one tool that can be used for
this measurement).
(c) Before further flight:
(1) Replace any T/R blade that has a crack
with an airworthy blade.
(2) Replace any T/R blade that has any
corrosion, nick, scratch, dent, or other
damage that exceeds any maximum repair
limit with an airworthy blade.
Note 1: The maximum repair limits are
specified in the applicable maintenance
manual.
(3) Repair or replace with an airworthy
blade any T/R blade that has any corrosion,
nick, scratch, dent or other damage that is
within the maximum repair limits.
Note 2: The repair procedures are specified
in the applicable maintenance manual and
component repair and overhaul manuals.
(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 Manager, Rotorcraft
Certification Office, Rotorcraft Directorate,
FAA, ATTN: Michael Kohner, Aviation
Safety Engineer, Fort Worth, Texas 76193–
0170, telephone (817) 222–5447, fax (817)
222–5783, for information about previously
approved alternative methods of compliance.
(e) This amendment becomes effective on
May 21, 2008.
Issued in Fort Worth, Texas, on April 22,
2008.
Mark R. Schilling,
Acting Manager, Rotorcraft Directorate,
Aircraft Certification Service.
[FR Doc. E8–9790 Filed 5–5–08; 8:45 am]
BILLING CODE 4910–13–P
SUMMARY: We are adopting a new
airworthiness directive (AD) for the
products listed above. This AD results
from service history of incidents and
accidents involving transport category
turbojet airplanes without leading edge
high lift devices. This service history
shows that even small amounts of frost,
ice, snow, or slush on the wing leading
edges or forward upper wing surfaces
can cause an adverse change in the stall
speeds and stall characteristics, and can
negate the protection provided by a stall
protection system. While there have
been no accidents or incidents related to
wing contamination associated with the
BAE Systems (Operations) Limited
Model BAe 146 and Model Avro 146–
RJ airplanes, these airplanes are also
transport category turbojet airplanes
without leading edge high lift devices,
and therefore may be similarly sensitive
to small amounts of wing
contamination. This AD requires
revising the airplane flight manual to
include a new cold weather operations
limitation. We are issuing this AD to
prevent possible loss of control on
takeoff resulting from even small
amounts of frost, ice, snow, or slush on
the wing leading edges or forward upper
wing surfaces. We are issuing this AD to
require actions to correct the unsafe
condition on these products.
This AD becomes effective June
10, 2008.
DATES:
You may examine the AD
docket on the Internet at https://
www.regulations.gov or in person at the
U.S. Department of Transportation,
Docket Operations, M–30, West
Building Ground Floor, Room W12–140,
1200 New Jersey Avenue, SE.,
Washington, DC.
ADDRESSES:
FOR FURTHER INFORMATION CONTACT:
DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. FAA–2007–0371; Directorate
Identifier 2007–NM–269–AD; Amendment
39–15511; AD 2008–10–05]
PWALKER on PROD1PC71 with RULES
RIN 2120–AA64
Airworthiness Directives; BAE
Systems (Operations) Limited Model
BAe 146 and Model Avro 146–RJ
Airplanes
Federal Aviation
Administration (FAA), Department of
Transportation (DOT).
ACTION: Final rule.
AGENCY:
VerDate Aug<31>2005
16:31 May 05, 2008
Jkt 214001
Todd Thompson, Aerospace Engineer,
International Branch, ANM–116,
Transport Airplane Directorate, FAA,
1601 Lind Avenue, SW., Renton,
Washington 98057–3356; telephone
(425) 227–1175; fax (425) 227–1149.
SUPPLEMENTARY INFORMATION:
Discussion
We issued a notice of proposed
rulemaking (NPRM) to amend 14 CFR
part 39 to include an AD that would
apply to the specified products. That
NPRM was published in the Federal
Register on December 26, 2007 (72 FR
72968). That NPRM proposed to require
revising the airplane flight manual to
include a new cold weather operations
limitation.
PO 00000
Frm 00014
Fmt 4700
Sfmt 4700
Comments
We gave the public the opportunity to
participate in developing this AD. We
have considered the comment received.
Request to Withdraw NPRM or Revise
Paragraph (e)
BAE Systems (Operations) Limited,
type certificate holder for Model BAe
146 and Model Avro 146–RJ airplanes,
states that it has reviewed the NPRM
and is preparing advice in an expanded
flight crew operations manual (FCOM)
to explain the importance of a ‘‘clean
wing’’ prior to takeoff. The information
in that manual, including the use of
tactile checks, permits operators and de/anti-icing service providers to develop
procedures to suit local arrangements.
BAE Systems states that this approach is
consistent with other regional aircraft
types for which airplane flight manual
(AFM) revisions have not been
mandated. While BAE Systems fully
supports safety initiatives aimed at
minimizing wing contamination, BAE
Systems asserts that a safety concern
does not exist on the Model BAe 146
and Model Avro 146–RJ airplanes for
the following reasons:
• No accidents or incidents due to
upper surface contamination have
occurred on Model BAe 146 and Model
Avro 146–RJ airplanes (this information
was not included in the Summary of the
NPRM).
• The different wing shape on Model
BAe 146 and Model Avro 146–RJ
airplanes make them less susceptible to
the effects of leading edge and upper
surface contamination.
• There is no evidence that small/
visually imperceptible amounts of ice
on the wing of these airplanes would
lead to loss of control during takeoff.
BAE Systems asks that if we amend
14 CFR part 39 to require the additional
limitations in the AFM, we revise
paragraph (e) ‘‘Reason’’ of the NPRM to
include the words: ‘‘Whilst there is no
service history that indicates the
BAe146 and Avro 146–RJ will be
similarly affected. * * *’’
We acknowledge BAE Systems’
concerns, and partially agree with its
requests. We agree that no accidents or
incidents due to upper surface
contamination have occurred on Model
BAe 146 and Model Avro 146–RJ
airplanes. We have revised the AD to
include that acknowledgement in the
Summary and in paragraph (e).
However, we disagree that a safety
concern does not exist on the Model
BAe 146 and Model Avro 146–RJ
airplanes and therefore, by implication,
that we should withdraw the NPRM.
Section 39.1 of the Federal Aviation
Regulations (14 CFR 39.1) states:
E:\FR\FM\06MYR1.SGM
06MYR1
]]>Agencies
[Federal Register Volume 73, Number 88 (Tuesday, May 6, 2008)]
[Rules and Regulations]
[Pages 24858-24864]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: E8-9790]
-----------------------------------------------------------------------
DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. FAA-2008-0490; Directorate Identifier 2008-SW-26-AD;
Amendment 39-15509; AD 2008-10-03]
RIN 2120-AA64
Airworthiness Directives; Bell Helicopter Textron Model 204B,
205A, 205A-1, 205B, 210, 212, 412, 412CF, and 412EP Helicopters
AGENCY: Federal Aviation Administration, DOT.
ACTION: Final rule; request for comments.
-----------------------------------------------------------------------
SUMMARY: This amendment adopts a new airworthiness directive (AD) for
the specified Bell Helicopter Textron (Bell) model helicopters. This
action requires certain checks and inspections of each tail rotor blade
assembly (T/R blade) at specified intervals and repairing or replacing,
as applicable, any unairworthy T/R blade. This amendment is prompted by
three failures of a T/R blade occurring during flight and a recent
incident of a cracked T/R blade discovered during a scheduled visual
inspection. The actions specified in this AD are intended to detect
damage to a T/R blade that could lead to cracking of a T/R blade and
subsequent loss of control of the helicopter.
DATES: Effective May 21, 2008.
Comments for inclusion in the Rules Docket must be received on or
before July 7, 2008.
ADDRESSES: Use one of the following addresses to submit comments on
this AD:
Federal eRulemaking Portal: Go to https://
www.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: U.S. Department of Transportation, Docket
Operations, M-30, West Building Ground Floor, Room W12-140, 1200 New
Jersey Avenue, SE., Washington, DC 20590, between 9 a.m. and 5 p.m.,
Monday through Friday, except Federal holidays.
You may get the service information identified in this AD from Bell
Helicopter Textron, Inc., P.O. Box 482, Fort Worth, Texas 76101,
telephone (817) 280-3391, fax (817) 280-6466.
Examining the Docket: You may examine the docket that contains the
[[Page 24859]]
AD, any comments, and other information on the Internet at https://
www.regulations.gov, or in person at the Docket Operations office
between 9 a.m. and 5 p.m., Monday through Friday, except Federal
holidays. The Docket Operations office (telephone (800) 647-5527) is
located in Room W12-140 on the ground floor of the West Building at the
street address stated in the ADDRESSES section. Comments will be
available in the AD docket shortly after receipt.
FOR FURTHER INFORMATION CONTACT: Michael Kohner, Aviation Safety
Engineer, FAA, Rotorcraft Directorate, Rotorcraft Certification Office,
Fort Worth, Texas 76193-0170, telephone (817) 222-5447, fax (817) 222-
5783.
SUPPLEMENTARY INFORMATION: A proposal to amend 14 CFR part 39 to
include an AD for the specified model helicopters was published in the
Federal Register as Docket No. FAA-2006-26219, Directorate Identifier
2004-SW-49-AD on November 2, 2006 (71 FR 64484). That Notice of
Proposed Rulemaking (NPRM) was prompted by eight reports of fatigue
cracking of T/R blades installed on Bell Model 212 and 412 helicopters
(three failures on the Bell Model 212 and five failures on the Bell
Model 412) with a blade assembly, part number (P/N) 212-010-750-009, -
105, and -107. Six of the cracks initiated between blade stations 30 to
33.5; one crack initiated at blade station 21.9; and one crack
initiated at blade station 27.6. Three of these T/R blades failed
during flight and all were installed on Bell Model 412 series
helicopters. In one of the in-flight failures, the T/R blade failed due
to a fatigue crack that initiated in the blade skin from a nick .060
inches long by .008 inches deep. The initial damage was above the
maximum allowable damage limit for the blade skin provided in the
maintenance manual. That failed blade had accumulated 1,478 hours time-
in-service (TIS). In another in-flight failure, a section of the T/R
blade separated from the helicopter during cruise flight at 5,500 feet.
The helicopter was reported to have violently turned down and to the
left. The helicopter ``leveled out'' at approximately 1,000 feet before
setting down in the water. The blade failed due to a cracked stainless
steel leading edge spar that originated from a corrosion pit .001
inches deep. The corrosion area extended .003 inches along the surface
of the origin location. That blade had accumulated 4,643 hours TIS. In
the third in-flight failure, sanding on the spar and chem-milling was
found during a post-accident investigation. The crack had initiated at
blade station 21.9 and the blade had accumulated 1,232 hours TIS. Also,
the following blades were found cracked:
--------------------------------------------------------------------------------------------------------------------------------------------------------
Blade Crack
Model Year P/N 212-010- Hours TIS station length Initial damage part Initial damage size
750- (in.) (in.) and type
--------------------------------------------------------------------------------------------------------------------------------------------------------
212................................. 1973 -009 3,224 32.2 6.5 Skin--Corrosion........ .030 in. wide.
212................................. 1985 -009 279 31.5 13.0 Spar--Manufacturing .090 in. wide.
Notch.
212................................. 1991 -105 423 30.8 8.0 Skin--Non Sharp Dent... .75 in. long.
412................................. 1990 -009 3,876 27.6 8.0 Skin--Corrosion........ Unknown.
412................................. 1996 -105 1,235 30.0 8.3 Skin--Scratch.......... .45 in. long by .005
in. deep.
--------------------------------------------------------------------------------------------------------------------------------------------------------
The NPRM proposed to require the following interim actions until
either a more rigorous inspection is developed or a new blade that is
more damage tolerant is designed:
Before each start of the engines, visually checking each
T/R blade for a crack;
Within 25 hours TIS or 15 days, whichever occurs first,
and thereafter at intervals not to exceed 25 hours TIS or 15 days,
whichever occurs first, cleaning and visually inspecting each T/R blade
for a crack, corrosion, nick, scratch, or dent using a 3-power or
higher magnifying glass and a bright light;
If certain damage is found, inspecting for a crack or
corrosion using a 10-power or higher magnifying glass and measuring the
depth of any damage; and
Before further flight, replacing any cracked T/R blade and
repairing or replacing any otherwise unairworthy T/R blade.
Since the issuance of that NPRM, we were notified that a crack was
found on another T/R blade, P/N 212-010-750-105 FM, installed on a Bell
Model 412EP helicopter. The crack was discovered while the helicopter
was on the ground during a scheduled visual inspection. The T/R blade
is now being examined at the manufacturer's field investigation lab.
The crack is located approximately in the center of the TR blade span
and extends across the majority of the chord. The T/R blade had
accumulated 2,076 hours TIS. Because P/N 212-010-750-105 FM was not
included in the applicability of the NPRM, and because a crack growth
analysis using the striation count data from one of the failed T/R
blades predicted a crack propagation rate of approximately 77 hours TIS
from damage initiation to blade failure, we will withdraw that NPRM and
issue this AD as a Final rule; request for comments. This AD contains
the proposed requirements from the NPRM; however, we've included
additional P/Ned blades and made other changes based on the comments to
the NPRM. In response to the NPRM we received several comments from 4
commenters; the manufacturer, the Canadian National Defence
Headquarters, and 2 individuals.
Two commenters suggest changing the compliance time for the
proposed actions. One of the commenters suggests changing the proposed
initial inspection from 25 hours TIS or 15 days to 25 hours TIS or 30
days and changing the recurring inspection from 25 hours TIS or 15 days
to 25 hours TIS or 30 days. The other commenter believes that a visual
inspection before the first flight of each day would be adequate and
that a limit of 10 hours between visual inspections in any one day
could be added. The same commenter states that it is not always
practical (e.g. carrying a suitable safe ladder for conducting an
adequate inspection and carry passengers) and might also be hazardous
(e.g. doing an inspection from an offshore oil field platform where
there is no ladder or stand available or where there is restricted
space and the possibility of high wind speeds) to do a visual
inspection before each engine start. Finally, one commenter, the
manufacturer, states that it is impractical to require inspection of
the T/R blades before each flight or engine start unless we are
referring to a ground-level visual inspection because a ladder, which
is not available in the field, would be required for a hands-on
inspection. It recommends an
[[Page 24860]]
inspection in accordance with the maintenance manual. The manufacturer
further recommends an inspection for more than just ``cracks'', that
is, any damage beyond limits in accordance with the published schedule
and requirements in the maintenance manual.
We concur with the recommendation to change the initial and
recurring inspections from 25 hours TIS or 15 days to 25 hours TIS or
30 days. The 15-day interval was originally proposed because a
corrosion pit was the initiation point for one of the failures and that
interval is consistent with FAA advisory material relating to the
detection of corrosion. Since the proposal was published, we have
reevaluated the need for the interval and determined that a 30-day
interval is adequate for this inspection and the AD is revised
accordingly. We do not concur that a visual inspection before the first
flight of each day would be adequate and that a limit of 10 hours
between visual inspections in any one day should be added.
Additionally, we do not agree with the manufacturer that a 60-day
interval would be appropriate because of the quick degradation in the
T/R blade strength. However, we do agree that it is not always
practical to require a detailed visual inspection of the T/R blades
using a ladder before each flight or engine start. The proposed owner/
operator (pilot) check was only intended to be a ``walk around'' check
to detect any large cracks. Although the Canadian commenter states that
their inspection from the ground is not considered effective, we have
received reports that two cracked blades were discovered during checks
performed from the ground. The initial and recurring inspections
performed by a mechanic are detailed, up-close inspections.
One commenter also suggests that instead of requiring a mandatory
daily log book entry stating compliance with the AD that ``the blade
inspection be made a required preflight checklist item with no daily
log book entry required.'' If a logbook entry is required, the
commenter suggests that it be a separate entry made at the time the 25
hour is signed off. We have determined that this critical check needs
to be mandated. This determination is based on the critical nature of
this failure and that the length of a crack is predicted to grow
quickly once it is detectable based on the service history of these T/R
blades. All required inspections, including the pilot checks
specifically approved by this AD, must be recorded at the time they are
performed. That recording evidences that the required AD actions have
been performed. If it is not recorded, the aircraft is not in
compliance with the AD and is unairworthy.
In addition to comments regarding the inspection times and types,
the manufacturer provided other comments to the NPRM. Those comments
and our responses follow:
------------------------------------------------------------------------
Comment Response
------------------------------------------------------------------------
The AD lists a 1991 Model 212 with a The cracked T/R blade in
.75'' crack * * * that Bell questions question is found in the FAA
since they have no conclusive service difficulty database.
technical data on it. They also An approximate 8-inch crack
question our references to a 77 hour was found in the T/R blade
crack propagation from striation count installed on a Bell Model 212
and state that the 77 hour value is helicopter during a daily
actually from a crack growth analysis inspection. The crack was
that simply includes striation count located 20.25 inches inboard
data. Bell also states that they are from the tip of the T/R blade
aware of only 4, not 8, existing running through a .75 inch
M205Bs that are of FAA certified long smooth dent. The part
configuration. number of the T/R blade was
212-010-750-105 with a total
time of 423 hours.
We agree with the comment about
the reference to the 77 hour
crack propagation and the
number of existing M205B
helicopters and have revised
this AD accordingly.
The listed tail rotor dash numbers While the standard Model 204B
appear to be incorrect. The Model 204B helicopter may not use this
does not use the 212-010-750 tail particular T/R blade, the 212-
rotor blade and there also appears to 010-750 T/R blade may be on a
be several of the later dash numbers modified Model 204B helicopter
missing from various models. that does use this blade. To
assure that we have covered
all affected blades, the
applicability now encompasses
all affected dash-numbered T/R
blades.
Recommend changing areas called out for Agree with this change and have
special attention to Stations 25.0 to revised this AD accordingly.
35.0 (both sides) for damage/corrosion
and include inboard blade butt area
surrounding balance weights/screws for
cracks.
There have not been eight reported A crack in a blade makes that
failures, there have been three. All blade unable to safely perform
others are reported cracks in the its intended function. Thus,
blade skin, not ``failures.'' The term there are now 9 T/R blades
``failure'' can be misleading. that meet that criteria.
Bell objects to our statement in the As we understand this objection
NPRM that ``The requirements of the by the manufacturer, it
proposed AD would be interim actions believes that a redesigned
until either a more rigorous blade is unnecessary and that
inspection is developed or a new blade the current inspections are
that is more damage tolerant is adequate. We do not agree.
designed.'' Bell states ``Although we Based on the fracture
are in concept discussions with DND, analysis, once the crack
completion and certification of this reaches a size that is
blade is many months away and could be detectable by inspection, it
misleading to the commercial is predicted to grow quickly.
community.'' Therefore, for the affected T/
R blades, it is critical to
find a crack or damage that
could lead to a crack at the
earliest opportunity. The
service history of these
affected T/R blades has shown
that the current inspections
are inadequate to reveal these
cracks before blade failure.
One T/R blade failed and
another one cracked because of
manufacturing damage on the
inside of the T/R blade. That
damage was not initially
detectable by external
inspection. Another T/R blade
failed during flight due to
cracking that initiated from a
corrosion pit in the leading
edge spar that was too small
to be readily detected.
Therefore, replacing the
affected T/R blades with a
redesigned, more damage-
tolerant T/R blade is
anticipated as terminating
action for the requirements of
this AD.
------------------------------------------------------------------------
Another commenter, the Canadian National Defence Headquarters,
views the proposed actions as a ``good first step'' but offers several
recommendations. Those recommendations and our responses follow:
[[Page 24861]]
------------------------------------------------------------------------
Recommendation Response
------------------------------------------------------------------------
``Promulgate to other aviation Our standard practice is to
regulation agencies worldwide because send our ADs to aviation
there are many more airframes affected authorities with which we have
than the `388 helicopters of U.S. a bilateral agreement. In
registry'.'' turn, it is then at their
discretion whether or not to
follow up with similar action.
Adjust the inspection frequency as a We agree that the risk of
function of the operations incurring damage in the T/R
environment, e.g., a 12.5 hours blade would be less for those
inspection frequency using the 10x helicopters operated on paved
magnification (noting that deployments landing fields versus ``harsh
of small numbers of aircraft take the & rough'' landing fields.
minimum support equipment required) Defining and enforcing such an
visual inspection for operations using inspection interval, however,
``harsh & rough'' landing fields and would be difficult because
an interval of 25 hours inspection for helicopters operate in so many
paved landing fields. varied environments. We
believe the commet to use a 10-
power magnifying glass may be
a typographical error because
the Canadian National Defense
uses a 2-power magnifying
glass and a good source of
light every 12.5 hours TIS for
the visual inspection of the T/
R blades on their Model 412CF
helicopters. Regardless, we
have determined that a 25-hour
TIS inspection using a 3x or
higher magnifying glass is
best for the overall safe
operation of these helicopters
in the U.S.
Specify that the visual check be We do not believe that further
carried out by an appropriately information regarding who can
qualified person. carry out this visual check is
necessary. The visual check is
only intended to detect a
large-scale crack and we
believe an owner/operator
(pilot) is qualified to
perform this ``walk-around''
function.
Define what constitutes a ``bright The illumination levels are
light''. historically not given for
visual inspections that are
mandated by an AD. We believe
what constitutes a bright
light can be adequately
determined by the individuals
who are qualified to do the
inspection. We also did not
want to create additional
calibration and recordkeeping
requirements.
Implement damage mapping as a means to Inspection of the T/R blade
increase detectability of new damage records and recording any
and decrease the maintenance burden. damage found within the repair
limits are in the maintenance
instructions for the T/R blade
inspection on the applicable
helicopters. These steps are
currently in the applicable
maintenance procedures.
Operators are free to
implement such mapping if they
believe it will reduce their
maintenance burden.
Carry out a Type 1, Method C, Level III We believe the requirement to
dye-penetrant inspection in cases use of a 10-power magnifying
where difficulties are encountered in glass is adequate.
determining the presence of a crack by
visual inspection.
------------------------------------------------------------------------
We have reviewed the following Bell documents:
Operations Safety Notice OSN 205-02-37, OSN 205B-02-10,
OSN 212-02-39, OSN 412-02-25, OSN 412CF-02-05, and OSN UH-1H-II-02-3,
dated August 27, 2002. These Operations Safety Notices apply to all
owners and operators of Bell 205, 205B, 212, 412, 412CF, and UH-1H-II
helicopters and were written to remind operators of the following:
The importance of accomplishing a complete inspection of
the T/R blades at specified inspection intervals;
That the blades must be cleaned in order to perform an
adequate visual inspection to determine their condition; and
That maintenance manuals and component repair and overhaul
manuals are to be consulted for damage limits and repair criteria as
required.
Alert Service Bulletin No. 412CF-03-20, dated February 6,
2003, which applies to Model 412CF helicopters and provides
instructions for doing a visual inspection of certain T/R blades
immediately and every 25 hours TIS in accordance with the Model 412CF
maintenance manual and instructions for sending the affected tail rotor
blade to DND ``Calgary Supply Center'' for refinishing and
reidentification.
Bell Maintenance Document C-12-146-000/MF-001, Mod 4,
dated February 12, 2004, which applies to Model 412CF helicopters and
specifies a tail rotor blade damage records check and a visual
inspection for dents, nicks, cracks, paint chips, or blisters using a
2-power magnifying glass and a good source of light in specified areas
of the tail rotor blades (reference 64-00-00, section 64-38, page 42).
This unsafe condition is likely to exist or develop on other
helicopters of these same type designs. Therefore, this AD is being
issued to detect damage to a T/R blade that could lead to cracking of a
T/R blade and subsequent loss of control of the helicopter. This AD
requires:
Before each start of the engines, visually checking each
T/R blade for a crack. An owner/operator (pilot) holding at least a
private pilot certificate may perform this visual check and must enter
compliance with paragraph (a) of this AD into the aircraft maintenance
records in accordance with 14 CFR 43.11 and 91.417(a)(2)(v). A pilot
may do this check because it requires no special tools and can be
performed equally well by a pilot or a mechanic.
Within 25 hours TIS or 30 days, whichever occurs first,
unless accomplished previously, and thereafter at intervals not to
exceed 25 hours TIS or 30 days, whichever occurs first, cleaning and
visually inspecting the T/R blade skins, leading edge spar, doublers,
grip plates, and trailing edge for a crack, corrosion (may be indicated
by blistering, peeling, flaking, bubbling, or cracked paint) and any
other damage (including a nick, scratch, or dent) using a 3x or higher
magnifying glass.
If certain damage is found, inspecting the affected area
using a 10-power or higher magnifying glass and measuring the depth of
the damage.
Before further flight, repairing or replacing, as
applicable, any unairworthy T/R blade. The short compliance time
involved is required because a cracked or damaged T/R blade creates an
unsafe condition that can adversely affect the structural integrity and
controllability of the helicopter. Therefore the required actions
within the specified short time intervals require that this AD be
issued immediately.
Since a situation exists that requires the immediate adoption of
this regulation, it is found that notice and opportunity for prior
public comment hereon are impracticable, and that good cause exists for
making this amendment effective in less than 30 days.
We estimate that this AD will affect 384 helicopters of U.S.
registry. There
[[Page 24862]]
are approximately 184 Model 205A and 205A-1 helicopters, 4 Model 205B
helicopters, 101 Model 212 helicopters, 80 Model 412, 412CF, and 412EP
helicopters, and 15 modified Model 204B helicopters. Each visual check
will take .125 hours, each visual inspection will take .5 hours, and 6
hours to remove and replace each T/R blade assembly, if necessary. The
average labor rate is $80. Replacement parts will cost $11,243 for each
T/R blade assembly. Based on these figures, the estimated cost impact
of the AD for all of the affected models will be $1,828,855 assuming an
average of 600 hours TIS per year for each helicopter resulting in 365
visual checks, 24 inspections, and 5 T/R blade assembly replacements
for the total fleet.
Comments Invited
This AD is a final rule that involves requirements that affect
flight safety and was not preceded by notice and an opportunity for
public comment; however, we invite you to submit any written data,
views, or arguments regarding this AD. Send your comments to an address
listed under ADDRESSES. Include ``Docket No. FAA-2008-0490; Directorate
Identifier 2008-SW-26-AD'' at the beginning of your comments. We
specifically invite comments on the overall regulatory, economic,
environmental, and energy aspects of the AD. We will consider all
comments received by the closing date and may amend the AD in light of
those comments.
We will post all comments we receive, without change, to https://
www.regulations.gov, including any personal information you provide. We
will also post a report summarizing each substantive verbal contact
with FAA personnel concerning this AD. 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 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).
Regulatory Findings
We have determined that this AD will not have federalism
implications under Executive Order 13132. This AD will not have a
substantial direct effect on the States, on the relationship between
the national Government and the States, or on the distribution of power
and responsibilities among the various levels of government.
For the reasons discussed above, I certify that the 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 an economic evaluation of the estimated costs to comply
with this AD. See the AD docket to examine the 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.
Adoption of the Amendment
0
Accordingly, pursuant to the authority delegated to me by the
Administrator, the Federal Aviation Administration amends part 39 of
the Federal Aviation Regulations (14 CFR part 39) as follows:
PART 39--AIRWORTHINESS DIRECTIVES
0
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]
0
2. Section 39.13 is amended by adding a new airworthiness directive to
read as follows:
2008-10-03 Bell Helicopter Textron: Amendment 39-15509. Docket No.
FAA-2008-0490; Directorate Identifier 2008-SW-26-AD.
Applicability
The following model helicopters, with the specified tail rotor
blade assembly (T/R blade) installed, certificated in any category:
------------------------------------------------------------------------
With T/R blade, part number (P/
Helicopter model N)
------------------------------------------------------------------------
204B, 205A, 205A-1, 212, 412, 412CF, 212-010-750-(all dash numbers).
and 412EP.
205B................................... 212-010-750-(all dash numbers).
212-015-501-(all dash numbers).
210.................................... 210-010-001-(all dash numbers).
212-010-750-(all dash numbers).
------------------------------------------------------------------------
Compliance
Required as indicated.
To detect any damage in a T/R blade, prevent cracking of a T/R
blade leading to failure from static overload, and subsequent loss
of control of the helicopter, accomplish the following:
(a) Before each start of the engines, visually check both sides
of each T/R blade for a crack. An owner/operator (pilot) holding at
least a private pilot certificate may perform this visual check and
must enter compliance with this paragraph into the aircraft
maintenance records in accordance with 14 CFR 43.11 and
91.417(a)(2)(v).
(b) Within 25 hours time-in-service (TIS) or 30 days, whichever
occurs first, unless accomplished previously, and thereafter at
intervals not to exceed 25 hours TIS or 30 days, whichever occurs
first:
(1) Clean each T/R blade by hand using a mild degreaser and
water to remove soot and grime on both sides of the blade using a
coarse, loosely woven cotton cloth in a spanwise direction. Use a
cloth with a color that contrasts with the color of the T/R blade so
that a snag will be visible.
(2) Using a 3-power or higher magnifying glass and a bright
light, visually inspect the T/R blade skins, leading edge spar,
doublers, grip plates, and trailing edge for a crack, corrosion (may
be indicated by blistering, peeling, flaking, bubbling, or cracked
paint) and any other damage (including a nick, scratch, or dent).
See Figure 1 of this AD. Pay particular attention to both sides of
the T/R blade in the area located 16 to 26 inches from the T/R blade
tip (blade station 25 to 35--the T/R blade tip is located at blade
station 51) and to the inboard blade butt area near the attachment
of the external balance weights
[[Page 24863]]
and screws. Also pay particular attention to any blade surface that
was snagged by the cloth, as that may be an indication of a crack or
paint chip that could lead to corrosion.
BILLING CODE 4910-13-P
[GRAPHIC] [TIFF OMITTED] TR06MY08.182
BILLING CODE 4910-13-C
[[Page 24864]]
(3) If any blistering, peeling, flaking, bubbling, or cracked
paint is detected, remove the paint from the affected area and
visually inspect the affected area for corrosion or a crack using a
10-power or higher magnifying glass. If any corrosion is found,
measure the depth of the corrosion (a digital optical micrometer is
one tool that can be used for this measurement).
(4) If a nick, scratch, or dent is found, visually inspect for a
crack using a 10-power or higher magnifying glass and measure the
depth of the damage (a digital optical micrometer is one tool that
can be used for this measurement).
(c) Before further flight:
(1) Replace any T/R blade that has a crack with an airworthy
blade.
(2) Replace any T/R blade that has any corrosion, nick, scratch,
dent, or other damage that exceeds any maximum repair limit with an
airworthy blade.
Note 1: The maximum repair limits are specified in the
applicable maintenance manual.
(3) Repair or replace with an airworthy blade any T/R blade that
has any corrosion, nick, scratch, dent or other damage that is
within the maximum repair limits.
Note 2: The repair procedures are specified in the applicable
maintenance manual and component repair and overhaul manuals.
(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 Manager, Rotorcraft Certification Office, Rotorcraft
Directorate, FAA, ATTN: Michael Kohner, Aviation Safety Engineer,
Fort Worth, Texas 76193-0170, telephone (817) 222-5447, fax (817)
222-5783, for information about previously approved alternative
methods of compliance.
(e) This amendment becomes effective on May 21, 2008.
Issued in Fort Worth, Texas, on April 22, 2008.
Mark R. Schilling,
Acting Manager, Rotorcraft Directorate, Aircraft Certification Service.
[FR Doc. E8-9790 Filed 5-5-08; 8:45 am]
BILLING CODE 4910-13-P
