Airworthiness Directives; Cirrus Design Corporation

[Federal Register Volume 84, Number 116 (Monday, June 17, 2019)]
[Rules and Regulations]
[Pages 27932-27935]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2019-12622]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2019-0392; Product Identifier 2019-CE-020-AD; Amendment 
39-19639; AD 2019-08-51]
RIN 2120-AA64


Airworthiness Directives; Cirrus Design Corporation

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Final rule; request for comments.

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SUMMARY: The FAA is adopting a new airworthiness directive (AD) for all 
Cirrus Design Corporation (Cirrus) Model SF50 airplanes. This AD was 
sent previously as an emergency AD to all known U.S. owners and 
operators of

[[Page 27933]]

these airplanes. This AD requires replacing the angle of attack (AOA) 
sensors with improved AOA sensors. This AD was prompted by three 
incidents on Cirrus Model SF50 airplanes of the stall warning and 
protection system (SWPS) or Electronic Stability & Protection (ESP) 
System engaging when not appropriate. The FAA is issuing this AD to 
address the unsafe condition on these products.

DATES: This AD is effective June 17, 2019 to all persons except those 
persons to whom it was made immediately effective by Emergency AD 2019-
08-51, issued on April 18, 2019, which contained the requirements of 
this amendment.
    The Director of the Federal Register approved the incorporation by 
reference of a certain publication identified in this AD as of June 17, 
2019.
    The FAA must receive comments on this AD by August 1, 2019.

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 http://www.regulations.gov. 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: Deliver to Mail address above between 9 
a.m. and 5 p.m., Monday through Friday, except Federal holidays.
    For service information identified in this final rule, contact 
Cirrus Worldwide Headquarters, 4515 Taylor Circle, Duluth, Minnesota 
55811; telephone: (800) 921-2737 or after hours (800) 921-2737; fax: 
(218) 788-3500; email: [email protected]; internet: 
https://cirrusaircraft.com/service-support/. You may view this 
referenced service information at the FAA, Policy and Innovation, 901 
Locust, Kansas City, Missouri 64106. For information on the 
availability of this material at the FAA, call (816) 329-4148. It is 
also available on the internet at http://www.regulations.gov by 
searching for locating Docket No. FAA-2019-0392.

Examining the AD Docket

    You may examine the AD docket on the internet at http://www.regulations.gov by searching for and locating Docket No. FAA-2019-
0392; 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, the regulatory evaluation, any comments received, and 
other information. The street address for Docket Operations (phone: 
800-647-5527) is listed above. Comments will be available in the AD 
docket shortly after receipt.

FOR FURTHER INFORMATION CONTACT: Wess Rouse, Small Airplane Program 
Manager, 2300 East Devon Avenue, Room 107, Des Plaines, Illinois 60018; 
telephone: (847) 294-8113; fax: (847) 294-7834; email: 
[email protected].

SUPPLEMENTARY INFORMATION:

Discussion

    On April 18, 2019, we issued Emergency AD 2019-08-51, which 
requires replacing the AOA sensors with improved AOA sensors. Emergency 
AD 2019-08-51 was sent previously to all known U.S. owners and 
operators of Cirrus Model SF50 airplanes. This action was prompted by 
reports of three incidents on Cirrus Model SF50 airplanes of the SWPS 
or ESP System engaging when not appropriate. The SWPS or ESP systems 
may engage even when sufficient airspeed and proper angle of AOA exists 
for normal flight. The SWPS includes the stall warning alarm, stick 
shaker, and stick pusher. The ESP includes under speed protection 
(USP). The SWPS or the ESP systems engaging inappropriately could 
potentially result in a stall warning crew alert (CAS) message 
activation, accompanied by an audio alarm and stick shaker activation, 
followed possibly by either low speed ESP/USP engaging, and the stick 
pusher engaging. The pilot will also observe the dynamic and color-
coded (Red) airspeed awareness ranges displaying the stall band, 
regardless of actual indicated airspeed.
    The information below presents detailed information on the three 
incidents.
    1. While the airplane was under manual pilot control, the airplane 
activated several downward pitch commands coincident with stall 
warning, stick shaker, and several associated alerts. The pilot 
reported ``AOA FAIL'' and ``STICK PUSHER FAIL CAS'' messages preceding 
the pitch command. The pilot was able to stop the automatic pitch 
commands by pressing and holding the autopilot disconnect button in 
accordance with the emergency procedure in the airplane flight manual 
and safely landed at his destination.
    2. The operator reported stall warning and stick pusher failure in 
flight.
    3. The airspeed indicator went red and the stall warning and stick 
shaker were heard and felt while on descent. The autopilot was 
disengaged with the same results. The system settled with stick pusher 
fail, stall warning fail, and LSA fail under the airspeed. The pilot 
hand flew the approach and had no V<INF>REF</INF> indicator but AOA 
appeared to be operating normally.
    Cirrus and Aerosonic (manufacturer of the technical standard order 
AOA sensor) have identified the probable root cause as an AOA sensor 
malfunction due to a quality escape in the assembly of the AOA sensor 
at Aerosonic. Two set screws that secure the potentiometer shaft to the 
AOA vane shaft may have improper torqueing and no application of thread 
locker (Loctite) to secure the two set screws. The AOA sensor with this 
quality escape is labeled with part number 4677-03.
    Potential erroneous AOA derived indications may occur before, 
during, and after unintended automatic control system engagement. These 
indications include an abnormal appearing low speed red band or VREF 
green donut presented on the airspeed tape. Failed indications or 
intermittent indication may result in one or more of the following:
    <bullet> Unintended automatic flight control activations;
    <bullet> The flight crew having difficulty controlling the 
airplane;
    <bullet> Excessive nose-down attitude; and/or
    <bullet> Possible impact with terrain.
    We are issuing this AD to address the unsafe condition on these 
products.

Related Service Information Under 1 CFR Part 51

    The FAA reviewed Cirrus Design Corporation SF50 Service Bulletin 
Number: SB5X-34-03, dated April 16, 2019 (SB5X-34-03). The service 
information provides instructions for replacing the AOA sensor with an 
improved flight sensor. The FAA also reviewed Cirrus SF50 Alert Service 
Advisory SA19-08, dated April 8, 2019. This service information 
provides instructions for the pilot to follow in the event the AOA 
sensor fails in flight.his 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.

FAA's Determination

    The FAA is issuing this AD because we evaluated all the relevant 
information and determined the unsafe condition described previously is 
likely to exist or develop in other products of these same type 
designs.

[[Page 27934]]

FAA's Justification and Determination of the Effective Date

    An unsafe condition exists that required the immediate adoption of 
Emergency AD 2019-08-51, issued on April 18, 2019, to all known U.S. 
owners and operators of these airplanes. The FAA found that the risk to 
the flying public justified waiving notice and comment prior to 
adoption of this rule because the noted condition presents an immediate 
danger to pilots and passengers of Cirrus Model SF50 airplanes. An 
uncommanded pitch down may be difficult to recover from in some flight 
regimes with potential fatal consequences. The before further flight 
compliance time to replace the AOA sensors due to the potential fatal 
consequences does not allow for prior notice and opportunity to comment 
for the public.
    These conditions still exist and the AD is hereby published in the 
Federal Register as an amendment to section 39.13 of the Federal 
Aviation Regulations (14 CFR 39.13) to make it effective to all 
persons. Therefore, the FAA finds good cause that notice and 
opportunity for prior public comment are impracticable. In addition, 
for the reason(s) stated above, the FAA finds that good cause exists 
for making this amendment effective in less than 30 days.

Differences Between This AD and the Service Information

    SB5X-34-03 specifies 5 hours time-in-service (TIS) before replacing 
the AOA sensors. The FAA determined that allowing 5 hours TIS to 
replace the AOA sensors does not mitigate the unsafe condition; thus, 
this AD requires such replacement before further flight.

Comments Invited

    This AD is a final rule that involves requirements affecting flight 
safety and was not preceded by notice and an opportunity for public 
comment. However, the FAA invites you to send any written data, views, 
or arguments about this final rule. Send your comments to an address 
listed under the ADDRESSES section. Include the docket number FAA-2019-
0392 and Product Identifier 2019-CE-020-AD at the beginning of your 
comments. The FAA specifically invites comments on the overall 
regulatory, economic, environmental, and energy aspects of this final 
rule. The FAA will consider all comments received by the closing date 
and may amend this final rule because of those comments.
    The FAA will post all comments we receive, without change, to 
http://www.regulations.gov, including any personal information you 
provide. The FAA will also post a report summarizing each substantive 
verbal contact we receive about this final rule.

Costs of Compliance

    The FAA estimates that this AD affects 99 airplanes of U.S. 
registry.
    The FAA estimates the following costs to comply with this AD:

                                                 Estimated Costs
----------------------------------------------------------------------------------------------------------------
                                                                                     Cost per      Cost on U.S.
                Action                         Labor cost           Parts cost        product        operators
----------------------------------------------------------------------------------------------------------------
Replace the AOA sensor................  1.25 work-hours x $85            $16,250      $16,356.25   $1,619,268.75
                                         per hour = $106.25.
----------------------------------------------------------------------------------------------------------------

    According to the manufacturer, all of the costs of this AD may be 
covered under warranty, thereby reducing the cost impact on affected 
individuals. The FAA does not control warranty coverage for affected 
individuals. As a result, the FAA has included all costs in our cost 
estimate.

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.
    This AD is issued in accordance with authority delegated by the 
Executive Director, Aircraft Certification Service, as authorized by 
FAA Order 8000.51C. In accordance with that order, issuance of ADs is 
normally a function of the Compliance and Airworthiness Division, but 
during this transition period, the Executive Director has delegated the 
authority to issue ADs applicable to small airplanes, gliders, 
balloons, airships, domestic business jet transport airplanes, and 
associated appliances to the Director of the Policy and Innovation 
Division.

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,
    (2) Is not a ``significant rule'' under DOT Regulatory Policies and 
Procedures (44 FR 11034, February 26, 1979),
    (3) Will not affect intrastate aviation in Alaska, and
    (4) 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.

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 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 adding the following new airworthiness 
directive (AD):

2019-08-51 Cirrus Design Corporation: Amendment 39-19639; Docket No. 
FAA-2019-0392; Product Identifier 2019-CE-020-AD.

[[Page 27935]]

 (a) Effective Date

    This AD is effective June 17, 2019 to all persons except those 
persons to whom it was made immediately effective by Emergency AD 
2019-08-51, issued on April 18, 2019, which contained the 
requirements of this amendment.

(b) Affected ADs

    None.

(c) Applicability

    This AD applies to Cirrus Design Corporation Model SF50 
airplanes, all serial numbers, certificated in standard category.

(d) Subject

    Joint Aircraft System Component (JASC)/Air Transport Association 
(ATA) of America Code 27; Flight Controls.

(e) Unsafe Condition

    This AD was prompted by Cirrus reporting three incidents of the 
stall warning and protection system (SWPS) or Electronic Stability & 
Protection (ESP) System engaging when not appropriate. The SWPS and 
ESP may engage even when sufficient airspeed and proper angle of 
attack (AOA) exists for normal flight. SWPS includes the stall 
warning alarm, stick shaker and stick pusher. ESP includes under 
speed protection (USP). The SWPS and ESP engaging could potentially 
result in a STALL WARNING crew alert (CAS) message activation, 
accompanied by an audio alarm and stick shaker activation, followed 
possibly by either low speed ESP/USP engaging and/or the stick 
pusher engaging. The pilot will also observe the dynamic and color-
coded (Red) airspeed awareness ranges displaying the stall band, 
regardless of actual indicated airspeed. These conditions, if not 
addressed, could result in the flight crew having difficulty 
controlling the airplane, lead to excessive nose-down attitude, 
significant altitude loss, and possible impact with terrain.

(f) Compliance

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

(g) Corrective Action

    (1) Before further flight after the effective date of this AD, 
replace the AOA sensor with an improved AOA sensor, Aerosonic part 
number 4677-03 Mod 1 or Cirrus part number 32159-004 in accordance 
with section 11. ACCOMPLISHMENT INSTRUCTIONS, paragraphs A, B, and C 
of Cirrus Design Corporation SF50 Service Bulletin Number: SB5X-34-
03, dated April 16, 2019.
    (2) Before further flight after replacement of the AOA sensor 
per paragraph (g)(1) of this AD, perform final installation checkout 
procedures and flight tests in accordance with a method approved by 
the Manager, FAA, Chicago ACO Branch. For the checkout procedures 
and flight test to be approved by the Manager, FAA, Chicago ACO 
Branch as required by this paragraph, the Manager's approval letter 
must specifically refer to this AD.
    (3) As of the effective date of this AD, do not install any AOA 
sensor on any affected airplane unless it is an improved AOA sensor 
as identified in paragraph (g)(1) of this AD.

(h) Special Flight Permit

    A special flight permit is allowed with the following 
limitation: Operators may fly the airplane to a location where the 
modification/corrective action can be incorporated. However, the 
pilot must follow the procedures listed in section 4., Pilot Actions 
Required, in Cirrus SF50 Alert Service Advisory SA19-08, dated April 
8, 2019.

(i) Alternative Methods of Compliance (AMOCs)

    (1) The Manager, Chicago 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 (j)(1) of this AD.
    (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.

(j) Related Information

    (1) For further information about this AD, contact: Wess Rouse, 
Small Airplane Program Manager, 2300 East Devon Avenue, Room 107, 
Des Plaines, Illinois 60018; telephone: (847) 294-8113; fax: (847) 
294-7834; email: [email protected].
    (2) For additional information related to this AD, you may refer 
to Cirrus SF50 Alert Service Advisory SA19-08, dated April 8, 2019.

 (k) Material Incorporated by Reference

    (1) The Director of the Federal Register approved the 
incorporation by reference (IBR) of the service information listed 
in this paragraph under 5 U.S.C. 552(a) and 1 CFR part 51.
    (2) You must use this service information as applicable to do 
the actions required by this AD, unless the AD specifies otherwise.
    (i) Cirrus Design Corporation SF50 Service Bulletin Number: 
SB5X-34-03, dated April 16, 2019.
    (ii) Cirrus SF50 Alert Service Advisory SA19-08, dated April 8, 
2019.
    (3) For service information identified in this AD, contact 
Cirrus Worldwide Headquarters, 4515 Taylor Circle, Duluth, 
Minnesota, 55811; telephone: (800) 921-2737 or after hours (800) 
921-2737; fax: (218) 788-3500; email: 
[email protected]; internet: https://cirrusaircraft.com/service-support/.
    (4) You may view this service information at FAA, Small Airplane 
Standards Branch, 901 Locust, Kansas City, Missouri 64106. For 
information on the availability of this material at the FAA, call 
(816) 329-4148. For information on the availability of this material 
at the FAA, call (816) 329-4148.
    (5) You may view this service information that is incorporated 
by reference at the National Archives and Records Administration 
(NARA). For information on the availability of this material at 
NARA, call 202-741-6030, or go to: http://www.archives.gov/federal-register/cfr/ibr-locations.html.

    Issued in Kansas City, Missouri, on June 10, 2019.
Melvin J. Johnson,
Aircraft Certification Service, Deputy Director, Policy and Innovation 
Division, AIR-601.
[FR Doc. 2019-12622 Filed 6-14-19; 8:45 am]
 BILLING CODE 4910-13-P

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