Je veux savoir à propos de…

53016

Federal Register / Vol. 86, No. 183 / Friday, September 24, 2021 / Proposed Rules
telephone 303 3421080; email 9Denver-Aircraft-Cert@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 ADDRESSES. Include Docket No.
FAA20210830; Project Identifier AD
202000257R 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 amend 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 https
www.regulations.gov, including any personal information you provide. The agency will also post a report summarizing each substantive verbal contact received about this NPRM.
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 NPRM
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 NPRM, 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 NPRM. Submissions containing CBI
should be sent to Matthew Bryant, Aerospace Engineer, Denver ACO
Branch, FAA, 26805 East 68th Avenue, Denver, CO 80249; telephone 303 342
1080; email 9-Denver-Aircraft-Cert@
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 Special Airworthiness Information Bulletin SW1905 on April 4, 2019 SAIB SW
1905 to alert owners and operators of Bell Textron Canada Limited Model
VerDate Sep<11>2014

16:14 Sep 23, 2021

Jkt 253001

206L1, 206L3, and 206L4 helicopters with Air Comms Supplemental Type Certificate STC SH2750NM installed.
SAIB SW1905 was prompted by reports of the air conditioner pulleys locking system, which is installed on the oil cooler drive shafts splined quill, causing excessive spline tooth wear to the drive ring spline teeth and the mating spline teeth on the oil cooler blower shaft. SAIB SW1905
recommends following the inspection instructions of certain Air Comm service information and routinely inspecting the air conditioner pulley lock ring.
At the time SAIB SW1905 was issued, the airworthiness concern was not determined to be an unsafe condition that would warrant AD action under 14 CFR part 39. However, subsequent investigations were not able to determine whether the limited damaged observed on several oil cooler blower shafts would remain localized or progress to a point where the shaft is no longer safe for continued use. The FAA
also later determined that operators may have difficulty aligning the air conditioning systems drive ring holes with the air conditioning condenser drive pulley without leaving the condenser drive pulley under-torqued.
Accordingly, the FAA proposes to adopt a new AD for certain Bell Textron Canada Limited Model 206L1 and 206L3 helicopters with Bell Model 206L1/L3 Service Instruction for Increased Gross Weight Upgrade Kit BHT206SI2052, Revision 1, dated October 14, 2010, installed and Bell Model 206L4 helicopters equipped with one of the following Air Comm STC SH2750NM air conditioning systems part number 206EC2041, 206EC2042, 206EC2081, 206EC
2082, 206EC2101, 206EC2102, 206EC2103, 206EC2123 or 206EC
2124. Helicopters with a 206L1+
designation are Model 206L1
helicopters and helicopters with a 206L3+ designation are Model 206L3
helicopters.
FAAs Determination The FAA is issuing this NPRM after determining that the unsafe condition described previously is likely to exist or develop on other products of the same type design.
Related Service Information Under 1
CFR Part 51
The FAA reviewed ACC Air Comm Corporation Service Bulletin SB 206EC
091119, Rev B, dated May 26, 2021 SB
206EC091119 Rev B, which specifies procedures for visually inspecting the drive ring spline teeth and the mating spline teeth on the tail rotor drives oil
PO 00000

Frm 00004

Fmt 4702

Sfmt 4702

cooler blower shaft for deformation or fretting.
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.
Proposed AD Requirements in This NPRM
This proposed AD would require, within 300 hours time-in-service TIS, and thereafter at intervals not to exceed 300 hours TIS, gaining access to the drive ring spline teeth and the mating area spline teeth on the oil cooler blower shaft, repetitively inspecting the drive ring spline teeth and the mating spline teeth on the tail rotor drives oil cooler blower shaft for deformation and fretting, and depending on the results of each inspection, removing certain parts from service before further flight. This proposed AD would also require reinstalling certain parts, and if required, reinstalling the drive pulley by torqueing and aligning the drive pulley bolt holes.
Differences Between This Proposed AD
and the Service Bulletin SB 206EC091119 Rev B requires inspecting the air conditioning compressor drive belt tension and the general condition of the drive belt, drive pulley and surrounding components, whereas this proposed AD would not.
SB 206EC091119 Rev B requires reporting any deformation or fretting to Air Comm Service Department, whereas this proposed AD would not. SB 206EC
091119 Rev B provides an option to deactivate the air conditioning system if deformation of fretting is found on the drive ring or the oil cooler blower shaft assembly, whereas this proposed AD
would require removing these parts from service instead.
Costs of Compliance The FAA estimates that this proposed AD would affect up to 100 helicopters of U.S. Registry. The FAA estimates that operators may incur the following costs in order to comply with this proposed AD. Labor costs are estimated at $85 per work-hour.
Removing the tail rotor drive systems forward short shaft, spline adaptor, and drive ring and visually inspecting the drive ring spline teeth and the mating area spline teeth would take about 1
work-hour for an estimated cost of $85
per helicopter and $8,500 for the U.S.
fleet per inspection cycle.
Replacing the drive ring would take about 3 work-hours and parts would cost about $300 for an estimated cost of $555 per replacement.

E:FRFM24SEP1.SGM

24SEP1