AD 2020-18-08

final rule

Airworthiness Directives; Robinson Helicopter Company

AD Number
2020-18-08
Status
final_rule
Effective Date
Product Category
engine
Docket
Docket No. FAA-2020-0786
FR Citation
85 FR 52890

Applicability

TypeManufacturerModelDetails
aircraft Robinson Helicopter Company R44 II Airworthiness Directives; Robinson Helicopter Company

Unsafe Condition

Separation between the outer and inner layers of the orange silicone hose P/N A785-31, which can result in blockage of air flow to the engine, engine stoppage, and subsequent loss of control of the helicopter.

AI-generated summary from the source AD text. Verify against the official source before acting.

Required Actions

Inspect the inside of the hose for separation between the outer and inner layers, and flex the hose in all directions while listening for a crinkling sound. If there is any separation or a crinkling sound, remove the hose from service before further flight. If there is no separation and no crinkling sound, and the hose is marked with code 3Q17 or 1Q18 or the code marking is illegible, remove the hose from service within 50 hours TIS. Perform the inspection of the inside of the hose at intervals not to exceed 100 hours TIS or at each annual inspection after the effective date of this AD, whichever occurs first. If there is any separation or a crinkling sound, remove the hose from service before further flight.

AI-generated summary from the source AD text. Verify against the official source before acting.

Compliance Time

Within 10 hours TIS after the effective date of this AD, or within 100 hours TIS or at each annual inspection after the effective date of this AD, whichever occurs first.

AI-generated summary from the source AD text. Verify against the official source before acting.

Affected Aircraft

Robinson Model R44 II helicopters with S/Ns 14168 through 14314 inclusive (except S/Ns 14269, 14287, 14299, and 14304), or with an orange silicone hose P/N A785-31 installed after October 1, 2017, and before the effective date of this AD.

AI-generated summary from the source AD text. Verify against the official source before acting.

Federal Register Abstract

The FAA is superseding Airworthiness Directive (AD) 2019-12-18 for Robinson Helicopter Company (Robinson) Model R44 II helicopters. AD 2019-12-18 required inspecting certain engine air induction hoses (hoses) and replacing any hose that was not airworthy. AD 2019-12-18 also prohibited the installation of certain hoses. This AD continues to require inspecting those previously affected hoses and amends the applicability, clarifies an inspection requirement, adds a requirement to repeat the inspection, and expands the installation prohibition. This AD was prompted by an additional report of separation between the outer and inner hose layers. The FAA is issuing this AD to address the unsafe condition on these products.

Applicability Source Text

Show captured applicability text from the source AD
(c) Applicability

    This AD applies to Robinson Helicopter Company Model R44 II 
helicopters, certificated in any category, with an orange silicone 
engine air induction hose (hose) part number (P/N) A785-31 
installed. This AD does not apply to helicopters with a black 
neoprene hose P/N A785-31 installed.

Document Text

Show stored source text (verify against official source)
[Federal Register Volume 85, Number 167 (Thursday, August 27, 2020)]
[Rules and Regulations]
[Pages 52890-52893]
From the Federal Register Online via the Government Publishing Office [<a href="http://www.gpo.gov">www.gpo.gov</a>]
[FR Doc No: 2020-18829]


=======================================================================
-----------------------------------------------------------------------

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2020-0786; Project Identifier AD-2020-00914-R; 
Amendment 39-21229; AD 2020-18-08]
RIN 2120-AA64


Airworthiness Directives; Robinson Helicopter Company

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Final rule; request for comments.

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

SUMMARY: The FAA is superseding Airworthiness Directive (AD) 2019-12-18 
for Robinson Helicopter Company (Robinson) Model R44 II helicopters. AD 
2019-12-18 required inspecting certain engine air induction hoses 
(hoses) and replacing any hose that was not airworthy. AD 2019-12-18 
also prohibited the installation of certain hoses. This AD continues to 
require inspecting those previously affected hoses and amends the 
applicability, clarifies an inspection requirement, adds a requirement 
to repeat the inspection, and expands the installation prohibition. 
This AD was prompted by an additional report of separation between the 
outer and inner hose layers. The FAA is issuing this AD to address the 
unsafe condition on these products.

DATES: This AD is effective August 27, 2020.
    The FAA must receive any comments on this AD by October 13, 2020.

ADDRESSES: You may send comments, using the procedures found in 14 CFR 
11.43 and 11.45, by any of the following methods:
    <bullet> Federal eRulemaking Portal: Go to <a href="https://www.regulations.gov">https://www.regulations.gov</a>. Follow the instructions for submitting comments.
    <bullet> Fax: 202-493-2251.
    <bullet> 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.
    <bullet> 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.
    For service information identified in this final rule, contact 
Robinson Helicopter Company, 2901 Airport Drive, Torrance, CA 90505; 
telephone 310-539-0508; fax 310-539-5198; or at <a href="https://robinsonheli.com/">https://robinsonheli.com/</a>. 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.

Examining the AD Docket

    You may examine the AD docket on the internet at <a href="https://www.regulations.gov">https://www.regulations.gov</a> by searching for and locating Docket No. FAA-2020-
0786; or in person at Docket Operations between 9 a.m. and 5 p.m., 
Monday through Friday, except Federal holidays. The AD docket contains 
this final rule, any comments received, and other information. The 
street address for Docket Operations is listed above. Comments will be 
available in the AD docket shortly after receipt.

FOR FURTHER INFORMATION CONTACT: Roger Gretler, Aerospace Engineer, Los 
Angeles ACO Branch, Compliance & Airworthiness Division, FAA, 3960 
Paramount Blvd., Lakewood, CA 90712; phone 562-627-5251; email 
<a href="/cdn-cgi/l/email-protection#51233e3634237f362334253d3423113730307f363e27"><span class="__cf_email__" data-cfemail="4e3c21292b3c60293c2b3a222b3c0e282f2f60292138">[email&#160;protected]</span></a>.

SUPPLEMENTARY INFORMATION:

Discussion

    The FAA issued AD 2019-12-18, Amendment 39-19673 (84 FR 32028, July 
5, 2019) (``AD 2019-12-18''), for Robinson Model R44 II helicopters. AD 
2019-12-18 required, for helicopter serial numbers (S/Ns) 14248 through 
14268 and 14270 through 14286 and helicopters with a hose part number 
(P/N) A785-31 installed after April 30, 2018, inspecting the inside of 
the hose for separation between the outer and inner layers and flexing 
the hose in all directions while listening for a crinkling sound, which 
is an indication of separation. If there was any separation or a 
crinkling sound, AD 2019-12-18 required replacing the hose before 
further flight. If there was no separation and no crinkling sound, AD 
2019-12-18 required replacing the hose within 50 hours time-in-service 
(TIS). Finally, AD 2019-12-18 prohibited installing hose P/N A785-31 
marked with code 1Q18 on any helicopter.
    AD 2019-12-18 resulted from 12 reports, including an accident on 
April 4, 2019, of separation between the outer and inner layers of the 
orange silicone hose out of a suspected population of 100 hoses traced 
to a specific manufacturing batch marked by code 1Q18 (1st quarter of 
2018). The separation of the silicone layers, if not addressed, could 
result in blockage of air flow to the engine, engine stoppage, and 
subsequent loss of control of the helicopter. Accordingly, the FAA 
issued AD 2019-12-18 to address the unsafe condition on these products.

Actions Since AD 2019-12-18 Was Issued

    Since the FAA issued AD 2019-12-18, an NTSB report of October 2019 
concluded from the accident aircraft's orange silicone hose marked by 
code 1Q18, that contamination was introduced during the manufacturing 
process between the silicone layers that prevented a satisfactory bond.
    In addition, a helicopter accident occurred on April 6, 2020, and 
preliminary investigation indicated that separation between the outer 
and inner layers of the orange silicone hose P/N A785-31 occurred. This 
hose was traced to the manufacturing batch marked by code 3Q17 (3rd 
quarter of 2017).
    Subsequently, the FAA determined that any helicopter with an 
improved black neoprene hose P/N A785-31 installed should not be 
affected by this AD. The FAA has also determined that, for helicopters 
with an orange silicone hose, repeating the inspection is necessary. 
Accordingly, the FAA is superseding AD 2019-12-18 to amend the 
applicability from all Robinson Model R44 II helicopters to Model R44 
II helicopters with an orange silicone hose P/N A785-31 installed. This 
AD also clarifies that the hose must be removed to perform the 
inspection, adds a requirement to repeat the inspection, and expands 
the installation prohibition

[[Page 52891]]

to include any orange silicone hose P/N A785-31 marked with code 3Q17 
or with an illegible code marking.

Comments to AD 2019-12-18

    After AD 2019-12-18 was published, the FAA received a comment from 
one commenter.

Request

    An anonymous commenter requested the FAA clarify which hose P/N 
A785-31 must be replaced within 50 hours TIS. The commenter stated 
that, as written, AD 2019-12-18 requires that any hose P/N A785-31 
installed after April 30, 2018, must be replaced within 50 hours TIS 
regardless of its code. The commenter asked whether this is correct, or 
if instead whether only P/N A785-31 hoses with code 1Q18 need to be 
replaced.
    The commenter is correct that AD 2019-12-18 required replacement of 
any hose P/N A785-31 installed after April 30, 2018, regardless of its 
code. The FAA intended this requirement in the event the manufacturing 
code becomes illegible during service. However, the FAA agrees that 
instead only P/N A785-31 hoses marked with code 1Q18 (with no 
separation and no crinkling sound) must be replaced within 50 hours 
TIS. The FAA has changed this final rule accordingly.

Related Service Information

    The FAA reviewed Robinson Helicopter Company R44 Service Bulletin 
SB-97, dated April 11, 2019 (SB-97). This service information applies 
to Robinson Model R44 II helicopters S/Ns 14248 through 14286, except 
14269, and to any P/N A785-31 hoses shipped as spares from May through 
November 2018. This service information specifies, within 1 flight hour 
or prior to further flight if engine roughness or power loss is, or has 
been encountered, visually inspecting the hose for separation, flexing 
the hose to listen for a crinkling sound, which is an indication of 
separation, and replacing any hose that shows indication of separation. 
This service information also specifies replacing or discarding all 
affected hoses by June 30, 2019.
    The FAA also reviewed Robinson Helicopter Company R44 Service 
Bulletin SB-100, dated July 3, 2019 (SB-100). This service information 
applies to Robinson Model R44 II helicopters S/Ns 10001 through 14314, 
except 14269, 14287, 14299, and 14304, and to any P/N A785-31 hoses 
shipped as spares through March 2019. This service information 
specifies the same inspection procedures as SB-97, except with a 
compliance time of within 100 hours TIS or by August 31, 2019, 
whichever occurs first, and replacing the hose only if there is any 
indication of separation. This service information also specifies 
returning the hose to Robinson or discarding a hose with any indication 
of separation.

FAA's Determination

    The FAA is issuing this AD after evaluating all the relevant 
information and determining the unsafe condition described previously 
is likely to exist or develop in other products of the same type 
design.

AD Requirements

    This AD requires:
    <bullet> For Robinson Model R44 II helicopters with S/Ns 14168 
through 14314 inclusive (except S/Ns 14269, 14287, 14299, and 14304), 
or with an orange silicone hose P/N A785-31 installed after October 1, 
2017, and before the effective date of this AD, within 10 hours TIS 
after the effective date of this AD, inspecting the inside of the hose 
for separation between the outer and inner layers, and flexing the hose 
in all directions while listening for a crinkling sound. This 
inspection must be done with the hose removed.
    <bullet> If there is any separation or a crinkling sound, removing 
the hose from service before further flight.
    <bullet> If there is no separation and no crinkling sound, and the 
hose is marked with code 3Q17 or 1Q18 or the code marking is illegible, 
removing the hose from service within 50 hours TIS.
    <bullet> For all Robinson Model R44 II helicopters with an orange 
silicone hose P/N A785-31 installed, performing the inspection of the 
inside of the hose at intervals not to exceed 100 hours TIS or at each 
annual inspection after the effective date of this AD, whichever occurs 
first. If there is any separation or a crinkling sound, removing the 
hose from service before further flight.
    This AD prohibits installing an orange silicone hose P/N A785-31 
marked with code 1Q18 or 3Q17, or with an illegible code marking, on 
any helicopter.
    Because this AD only applies to Model R44 II helicopters with an 
orange silicone hose P/N A785-31 installed, operators do not have to 
comply with this AD if they have replaced the orange silicone hose 
installed on their helicopter with a black neoprene hose P/N A785-31.

Differences Between This AD and the Service Information

    SB-97 and SB-100 apply to Robinson Model R44 II helicopters with 
certain S/Ns and certain spare hoses. This AD applies to Robinson Model 
R44 II helicopters with an orange silicone hose P/N A785-31 installed 
instead. SB-97 specifies inspecting the hose within one flight hour or 
prior to further flight if engine roughness or power loss has been 
encountered, and SB-100 specifies inspecting the hose within 100 hours 
TIS or by August 31, 2019, whichever occurs first. For certain 
helicopters, this AD requires inspecting the hose within 10 hours TIS, 
and for all other helicopters, within 100 hours TIS or at the next 
annual inspection, whichever occurs first. This AD requires repeating 
the inspection, whereas SB-97 and SB-100 do not. SB-97 specifies 
replacing all affected hoses, even if they pass the inspection, by June 
30, 2019, and SB-100 specifies only replacing a hose if the hose has 
any indication of separation. This AD requires removing from service 
all hoses with any separation or a crinkling sound, as well as hoses 
marked with code 3Q17, 1Q18, or an illegible code, even if they pass 
the inspection.

FAA's Justification and Determination of the Effective Date

    Section 553(b)(3)(B) of the Administrative Procedure Act (5 U.S.C.) 
authorizes agencies to dispense with notice and comment procedures for 
rules when the agency, for ``good cause'' finds that those procedures 
are ``impracticable, unnecessary, or contrary to the public interest.'' 
Under this section, an agency, upon finding good cause, may issue a 
final rule without seeking comment prior to the rulemaking.
    An unsafe condition exists that requires the immediate adoption of 
this AD without providing an opportunity for public comments prior to 
adoption. The FAA has found that the risk to the flying public 
justifies waiving notice and comment prior to adoption of this rule 
because the corrective actions must be completed within 10 hours TIS 
and within 100 hours TIS, a time period of up to four months based on 
the average flight-hour utilization rates of these helicopters. 
Therefore, notice and opportunity for prior public comment are 
impracticable and contrary to public interest pursuant to 5 U.S.C. 
553(b)(3)(B). In addition, for the reasons stated above, the FAA finds 
that good cause exists pursuant to 5 U.S.C. 553(d) for making this 
amendment effective in less than 30 days.

Comments Invited

    This AD is a final rule that involves requirements affecting flight 
safety, and the FAA did not provide you with notice and an opportunity 
to provide your comments prior to it becoming

[[Page 52892]]

effective. However, the FAA invites you to participate in this 
rulemaking by submitting written comments, data, or views. The most 
helpful comments reference a specific portion of the AD, explain the 
reason for any recommended change, and include supporting data. To 
ensure the docket does not contain duplicate comments, commenters 
should send only one copy of written comments, or if comments are filed 
electronically, commenters should submit them only one time.
    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 file in the docket all comments received, as well 
as a report summarizing each substantive public contact with FAA 
personnel concerning this rulemaking during the comment period. The FAA 
will consider all the comments received and may conduct additional 
rulemaking based on those comments.

Confidential Business Information

    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 final rule 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 final rule, 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 final rule. Submissions 
containing CBI should be sent to Roger Gretler, Aerospace Engineer, Los 
Angeles ACO Branch, Compliance & Airworthiness Division, FAA, 3960 
Paramount Blvd., Lakewood, CA 90712; phone 562-627-5251; email 
<a href="/cdn-cgi/l/email-protection#1c6e737b796e327b6e796870796e5c7a7d7d327b736a"><span class="__cf_email__" data-cfemail="ddafb2bab8aff3baafb8a9b1b8af9dbbbcbcf3bab2ab">[email&#160;protected]</span></a>. Any commentary that the FAA receives which is 
not specifically designated as CBI will be placed in the public docket 
for this rulemaking.

Regulatory Flexibility Act

    The requirements of the Regulatory Flexibility Act (RFA) do not 
apply when an agency finds good cause pursuant to 5 U.S.C. 553 to adopt 
a rule without prior notice and comment. Because the FAA has determined 
that it has good cause to adopt this rule without notice and comment, 
RFA analysis is not required.

Costs of Compliance

    The FAA estimates that this AD affects up to 187 helicopters of 
U.S. registry. Labor rates are estimated at $85 per work-hour. Based on 
these numbers, the FAA estimates the following costs to comply with 
this AD.
    Inspecting a hose takes about 0.5 work-hour for an estimated cost 
of $43 per helicopter and $8,041 for the U.S. fleet per inspection 
cycle. Replacing a hose takes about 0.5 work-hour and parts cost about 
$151 for an estimated cost of $194 per helicopter.

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

    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 this AD:
    (1) Is not a ``significant regulatory action'' under Executive 
Order 12866, and
    (2) Will not affect intrastate aviation in Alaska.

List of Subjects in 14 CFR Part 39

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

Adoption of the Amendment

    Accordingly, under the authority delegated to me by the 
Administrator, the FAA 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. The FAA amends Sec.  39.13 by:
0
a. Removing Airworthiness Directive (AD) 2019-12-18, Amendment 39-19673 
(84 FR 32028, July 5, 2019); and
0
b. Adding the following new AD:

 2020-18-08 Robinson Helicopter Company: Amendment 39-21229; Docket 
No. FAA-2020-0786; Project Identifier AD-2020-00914-R.

(a) Effective Date

    This AD is effective August 27, 2020.

(b) Affected ADs

    This AD replaces AD 2019-12-18, Amendment 39-19673 (84 FR 32028, 
July 5, 2019) (``AD 2019-12-18'').

(c) Applicability

    This AD applies to Robinson Helicopter Company Model R44 II 
helicopters, certificated in any category, with an orange silicone 
engine air induction hose (hose) part number (P/N) A785-31 
installed. This AD does not apply to helicopters with a black 
neoprene hose P/N A785-31 installed.

(d) Subject

    Joint Aircraft System Component (JASC): 7160, Engine Air Intake 
System.

(e) Unsafe Condition

    This AD was prompted by reports of separation between the outer 
and inner layers of a hose. The FAA is issuing this AD to prevent 
blockage of air flow to the engine, engine stoppage, and subsequent 
loss of control of the helicopter.

(f) Compliance

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

(g) Required Actions

    (1) For helicopters with serial numbers (S/Ns) 14168 through 
14314 inclusive (except S/Ns 14269, 14287, 14299, and 14304), or 
with an orange silicone hose P/N A785-31 installed after October 1, 
2017, and before the effective date of this AD, within 10 hours 
time-in-service (TIS) after the effective date of this AD:
    (i) With the hose removed, inspect the inside of the hose for 
separation between the outer and inner layers, and flex the hose in 
all directions while listening for a crinkling sound, which is an 
indication of separation.
    (ii) If there is any separation or a crinkling sound, before 
further flight, remove the hose from service.
    (iii) If there is no separation and no crinkling sound, and the 
hose is marked with

[[Page 52893]]

code 3Q17 or 1Q18 or an illegible code, within 50 hours TIS, remove 
the hose from service.
    (2) For all helicopters identified in paragraph (c) of this AD, 
accomplish the inspection required by paragraph (g)(1)(i) of this AD 
within 100 hours TIS after the effective date of this AD or at the 
next annual inspection after the effective date of this AD, 
whichever occurs first, and thereafter at intervals not to exceed 
100 hours TIS or at each annual inspection, whichever occurs first. 
If there is any separation or a crinkling sound, before further 
flight, remove the hose from service.
    (3) As of July 5, 2019 (the effective date of AD 2019-12-18), do 
not install on any helicopter an orange silicone hose P/N A785-31 
marked with code 1Q18.
    (4) As of the effective date of this AD, do not install on any 
helicopter an orange silicone hose P/N A785-31 marked with code 3Q17 
or an illegible code.

(h) Alternative Methods of Compliance (AMOCs)

    (1) The Manager, Los Angeles ACO 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 (i) of this AD. Information may 
be emailed to: <a href="/cdn-cgi/l/email-protection#cef7e38f8083e3828f8f8d81e38f83818de39c8b9f9b8b9d9a9d8ea8afafe0a9a1b8"><span class="__cf_email__" data-cfemail="a0998de1eeed8dece1e1e3ef8de1edefe38df2e5f1f5e5f3f4f3e0c6c1c18ec7cfd6">[email&#160;protected]</span></a>.
    (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.
    (3) AMOCs approved for AD 2019-12-18 are approved as AMOCs for 
the corresponding provisions of this AD.

(i) Related Information

    For more information about this AD, contact Roger Gretler, 
Aerospace Engineer, Los Angeles ACO Branch, Compliance & 
Airworthiness Division, FAA, 3960 Paramount Blvd., Lakewood, CA 
90712; phone 562-627-5251; email <a href="/cdn-cgi/l/email-protection#57253830322579302532233b32251731363679303821"><span class="__cf_email__" data-cfemail="1e6c71797b6c30796c7b6a727b6c5e787f7f30797168">[email&#160;protected]</span></a>.

    Issued on August 21, 2020.
Lance T. Gant,
Director, Compliance & Airworthiness Division, Aircraft Certification 
Service.
[FR Doc. 2020-18829 Filed 8-26-20; 8:45 am]
BILLING CODE 4910-13-P

Source: Official FAA Source ↗

Retrieved: Apr 4, 2026

Rights: U.S. Government Public Domain

This site is not affiliated with or endorsed by the FAA. Always verify with official sources.