FAA Issues Three Airworthiness Directives; FERC Opens Comment on Hydroelectric and Pipeline Filings

FAA Airworthiness Directives — Effective September 3, 2026

The Federal Aviation Administration is adopting three new airworthiness directives (ADs), each effective September 3, 2026, targeting separate unsafe conditions across commercial, general-aviation, and glider fleets.

Airbus A330 freighter conversions — oxygen supply for ETOPS-180. The FAA is issuing an AD for certain Airbus SAS Model A330-200 and A330-300 series airplanes modified by supplemental type certificate (STC) ST04038NY — aircraft converted from passenger to freighter configuration in accordance with EASA STC S10063798, issued to Elbe Flugzeugwerke GmbH (EFW). The AD was prompted by a finding that, for airplanes with a flightcrew oxygen system supplied by a single oxygen cylinder, the oxygen supply would not be sufficient under all circumstances for extended operations (ETOPS) with a maximum diversion time of 180 minutes (ETOPS-180) with four flightcrew members. The agency explains that this condition, if not corrected, could lead to insufficient oxygen supply in emergency situations during ETOPS-180 operation with four flightcrew members. It was also identified that minimum oxygen dispatch pressure information in the Flight Crew Operating Manual Supplement was not properly referenced by the Airplane Flight Manual Supplement (AFM-S). The AD requires revising the existing AFM-S to limit ETOPS-180 operations to three flightcrew members, as applicable, and to correct minimum oxygen dispatch pressure information. The FAA estimates the AD affects 11 airplanes of U.S. registry. The agency estimates compliance costs at 1 work-hour at $85 per hour, for a labor cost of $85 per airplane and $0 in parts cost, yielding a cost per product of $85 and a total cost on U.S. operators of $935. The Air Line Pilots Association, International (ALPA) supported the proposed rule without change. The underlying NPRM was published in the Federal Register on April 29, 2026.

Stemme S 12 gliders — fuel system leakage. The FAA is adopting an AD for all Stemme GmbH Model Stemme S 12 gliders, prompted by reports of fuel leaking around certain copper sealing rings within the fuel system. The AD requires repetitive visual checks of the fuel system for fuel leakage and replacement of the affected copper sealing ring. The AD also prohibits the installation of affected parts.

Pilatus PC-12/47E — engine-start avionics shutdown. The FAA is adopting an AD for certain Pilatus Aircraft Ltd. Model PC-12/47E airplanes, prompted by a reported occurrence in which, during an engine start on the ground, the airplane battery voltage dropped to a value that resulted in an avionic system shutdown. The agency explains that as a result, engine parameters including interstage turbine temperature (ITT) indications were undetectable, and ITT exceedance protection during the engine ground start procedure was deactivated. The agency states that under these conditions an ITT exceedance could occur with the aircrew having no means to detect it, and that this condition, if not addressed, could result in reduced turbine blade structural integrity with possible engine failure and loss of thrust. The AD requires incorporating a temporary revision (TR) into the existing pilot's operating handbook (POH) to provide operators with instructions for an enhanced engine start procedure. The underlying NPRM was published in the Federal Register on January 21, 2026. ALPA and an individual commenter supported the NPRM without change; a separate individual commenter requested changes to the location and emphasis level of the TR within the POH, both of which the FAA declined to make in the final rule. The agency determined that the actions required by the AD adequately address the identified unsafe condition by ensuring that the revised procedures are incorporated and followed, thereby preventing operation of the airplane with a compromised engine condition.

All three ADs amend 14 CFR part 39 and were issued pursuant to the FAA's authority under Title 49 of the United States Code.

FERC: Hydroelectric License Amendment — Domtar Paper, Wisconsin River

The Federal Energy Regulatory Commission (FERC) has accepted for filing a non-capacity amendment of license application from Domtar Paper Company, LLC for its Rothschild Hydroelectric Project, located on the Wisconsin River in Marathon County, Wisconsin (Project No. 2212-062). The project does not occupy any federal lands. The application was filed April 30, 2026, and supplemented on June 30, 2026.

According to the notice, in 2022 the licensee retired in place five inoperable turbine-generator units (Units 1, 2, 4, 5, and 6); the other two turbine-generating units at the project (Units 3 and 7) remain in service. The licensee now proposes to return Unit 5 to service by repairing the unit and reconnecting the generator leads, citing newly available energy incentives from the Focus on Energy program in the State of Wisconsin. The notice states the proposed upgrades would not result in any ground disturbance. The Commission is also inviting federal, state, local, and Tribal agencies with jurisdiction and/or special expertise with respect to environmental issues to cooperate in the preparation of any applicable environmental document, noting that agencies that cooperate in such preparation cannot also intervene.

FERC: Pipeline Pressure Uprate — Southern Star, Kansas

Southern Star Central Gas Pipeline, Inc. filed a prior notice request on July 15, 2026, seeking authorization to increase the maximum allowable operating pressure (MAOP) on a 13,100 foot segment of its 8-inch-diameter Line EU from 150 pounds per square inch gauge (psig) to 333 psig, located in Leavenworth County, Kansas (Line EU MAOP Uprate Project). The request was filed pursuant to sections 157.205 and 157.208 of the Commission's regulations under the Natural Gas Act and Southern Star's blanket certificate issued in Docket No. CP82-479-000. The notice states that no increased capacity is expected to occur from the MAOP uprate of Line EU, and that the uprate will support the planned installation of facilities under automatic authorization authority.

What to Watch

• August 26, 2026, 5:00 p.m. ET — Deadline for comments, motions to intervene, and protests on the Domtar Paper Rothschild Hydroelectric Project license amendment (FERC Project No. 2212-062).
• September 3, 2026 — Effective date for all three FAA airworthiness directives: Airbus A330 freighter ETOPS-180 oxygen limit, Stemme S 12 fuel system inspection and repair, and Pilatus PC-12/47E enhanced engine-start procedure.
• September 25, 2026, 5:00 p.m. ET — Deadline for protests, motions to intervene, and comments on Southern Star's Line EU MAOP Uprate Project (FERC Docket No. CP26-554-000).

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