AD 2018-20-08

This AD is effective October 17, 2018.

We must receive comments on this AD by November 16, 2018.

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

• Federal eRulemaking Portal: Go to http://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, between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays.

For service information identified in this final rule, contact Airbus SAS, Airworthiness Office—EIAS, Rond-Point Emile Dewoitine No: 2, 31700 Blagnac Cedex, France; telephone +33 5 61 93 36 96; fax +33 5 61 93 44 51; email account.airworth-eas@airbus.com; internet http://www.airbus.com. You may view this referenced service information at the FAA, Transport Standards Branch, 2200 South 216th St., Des Moines, WA. For information on the availability of this material at the FAA, call 206-231-3195. It is also available on the internet at http://www.regulations.gov by searching for and locating Docket No. FAA-2018-0804.

Sanjay Ralhan, Aerospace Engineer, International Section, Transport Standards Branch, FAA, 2200 South 216th St., Des Moines, WA 98351; telephone and fax 206-231-3223.

We issued AD 2018-02-18, Amendment 39-19171 (83 FR 5182, February 6, 2018) (“AD 2018-02-18”), which applied to certain Airbus SAS Model A318, A319, and A320 series airplanes and Model A321-111, -112, -131, -211, -212, -213, -231, and -232 airplanes. AD 2018-02-18 was prompted by a determination that when two AoA sensors are adversely affected by icing conditions at the same time, data displayed on the BUSS could be erroneous. AD 2018-02-18 required revising the AFM to provide guidance to the flightcrew for emergency procedures when erroneous airspeed indications are displayed on the BUSS. We issued AD 2018-02-18 to address erroneous airspeed data displays, which could lead to an increased flightcrew workload, possibly resulting in reduced control of the airplane.

Since we issued AD 2018-02-18, we have determined that airplanes on which Airbus Service Bulletin A320-34-1543 was embodied in service are also subject to the unsafe condition, and that the AFM may have been erroneously revised on certain airplanes not equipped with a BUSS function.

The European Aviation Safety Agency (EASA), which is the Technical Agent for the Member States of the European Union, has issued EASA AD 2018-0189, dated August 30, 2018 (referred to after this as the Mandatory Continuing Airworthiness Information, or “the MCAI”), to correct an unsafe condition for all Airbus SAS Model A318, A319, and A320 series airplanes and Model A321-111, -112, -131, -211, -212, -213, -231, and -232 airplanes. The MCAI states:

In extreme icing conditions, pitot probes may induce erroneous airspeed indications. To provide flight crews with reliable information on airspeed, Airbus developed a Back-up Speed Scale (BUSS and reversible BUSS, based on angle of attack (AoA) value) displayed on the Primary Flight Display (PFD), together with a PFD Back-Up Altitude Scale based on Global Positioning System (GPS) altitude. This BUSS function is intended to be used below flight level (FL) 250 only. Following new investigation related to AoA probes blockages, it was identified that, when two AoA sensors are adversely affected by icing conditions at the same time, data displayed on the BUSS could be erroneous.

This condition, if not corrected, could lead to an increased flight crew workload, possibly resulting in reduced control of the aeroplane.

To address this potential unsafe condition, Airbus established specific operational instructions to be applied by the flight crew under certain defined conditions. The relevant procedure was incorporated into the applicable A320 family AFM [airplane flight manual] since 07 March 2017 (publication date). Consequently, EASA issued AD 2017-0257 (later revised) to require a one-time AFM amendment to introduce the additional operational procedure.

Since EASA AD 2017-0257R1 [which corresponds to FAA AD 2018-02-18] was issued, it was determined that aeroplanes on which Airbus SB [service bulletin] A320-34-1543 (mod 154033) was embodied in service were inadvertently missing from the Applicability of the [EASA] AD.

For the reason described above, this [EASA] AD retains the requirements of EASA AD 2017-0257R1, which is superseded, and extends the Applicability to aeroplanes that embody Airbus SB A320-34-1543. This AD also requires removal of the AFM amendment, where it was mistakenly inserted in the AFM of an aeroplane not equipped with the BUSS function, prompted by the Applicability definition and requirements of EASA AD 2017-0257 at original issue.

You may examine the MCAI on the internet at http://www.regulations.gov by searching for and locating Docket No. FAA-2018-0804.

This product has been approved by the aviation authority of another country, and is approved for operation in the United States. Pursuant to our bilateral agreement with the State of Design Authority, we have been notified of the unsafe condition described in the MCAI and service information referenced above. We are issuing this AD because we evaluated all pertinent information and determined the unsafe condition exists and is likely to exist or develop on other products of the same type design.

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 when two AoA sensors are adversely affected by icing conditions at the same time, data displayed on the BUSS could be erroneous, leading to an increased flightcrew workload that could ultimately result in reduced control of the airplane. Therefore, we find good cause that notice and opportunity for prior public comment are impracticable. In addition, for the reason(s) stated above, we find that good cause exists for making this amendment effective in less than 30 days.

This AD is a final rule that involves requirements affecting flight safety, and we did not precede it by notice and opportunity for public comment. We invite you to send any written relevant data, views, or arguments about this AD. Send your comments to an address listed under the ADDRESSES section. Include “Docket No. FAA-2018-0804; Product Identifier 2018-NM-129-AD” at the beginning of your comments. We specifically invite comments on the overall regulatory, economic, environmental, and energy aspects of this AD. We will consider all comments received by the closing date and may amend this AD because of those comments.

We will post all comments we receive, without change, to http://www.regulations.gov, including any personal information you provide. We will also post a report summarizing each substantive verbal contact we receive about this AD.

We estimate that this AD affects 1,250 airplanes of U.S. registry.

We estimate the following costs to comply with this AD:

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.

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 transport category airplanes and associated appliances to the Director of the System Oversight Division.

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 that 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);

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.

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

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

2. The FAA amends § 39.13 by removing airworthiness directive (AD) 2018-02-18, Amendment 39-19171 (83 FR 5182, February 6, 2018), and adding the following new AD: