April 26, 2023 - No. 017 In This Issue : FAA issues AD for Pilatus PC-12 after corrosion concern : 3 years after Ligado decision, criticism mounts over interference concerns : FAA approves use of off-the-shelf parts for older certificated aircraft : Repair Parts Running Out For GNS 430/530 : FAA proposes revisions for helicopter radio altimeter 5G interference AD : Diamond Aircraft Announces Dedicated Engine Testing Program For SAF : Dutch investigators recommend changes to Boeing 747 engines following failure : American Airlines to upgrade cockpit displays on more than 100 Airbus A320s FAA issues AD for Pilatus PC-12 after corrosion concern Aviation News Posted By: Haley Davoren, GlobalAir.com Published: Apr. 17, 2023 at 04:48 PM EST Updated: Apr. 17, 2023 at 04:54 PM EST Note: See important photos in the original article. The FAA has issued a new airworthiness directive (AD) for some Pilatus PC-12/47E airplanes, prompted by mandatory continuing airworthiness information (MCAI) by an aviation authority internationally, which identified a potential safety risk involving corrosion that can decrease the effectivity of surface protection. The AD will require the replacement of some MLG and NLG electro-mechanical actuators. This AD will be effective May 19. This applies to certain serial-numbered PC-12/47E, otherwise known as the PC-12 NG. An AD sent out by the European Union Aviation Safety Agency (EASA) from Aug. 4, 2022 prompted the FAA to send out its notice to proposed rule-making. The EASA sent out the AD after occurrences of corrosion of the actuator attachment lug areas underneath the anti-rotation pads of the main landing gear (MLG) and nose landing gear (NLG). This corrosion can decrease the effectiveness of surface protection and allow for more corrosion on the attachment lugs, which can lead to cracking and failure of the attachment lugs. If this concern is not addressed properly, it can lead to a loss of functionality of the MLF and NLG, potentially leading to damage on the airplane or injury for the passengers. The MCAI would require an inspection and possible replacement for the MLG and NLG electro-mechanical actuators with serviceable actuators, prohibiting the installation of an affected actuator unless it has previously been reworked to a serviceable actuator. The EASA’s AD was superseded on Nov. 9. This included a revision from the Pilatus service bulletin. Investigations revealed the parts were installed on other airplanes, addressed in the second AD from the EASA. The service bulletin from Pilatus was mandatory, listing different time tables for different serial numbers. The bulletin lists groups of serial numbers and the different requirements for each, MSN 1300 and 1451 through 1663, 1664 through 1719, 1721 through 1942, 1720, 2001 through 2202 and 2204 and 2206. FAA projected cost of replacements/work The Airline Pilots Association, International (ALPA) supported the NPRM without change. Pilatus also commented on the publication, noting that revised service information had been issued and requesting a few changes to references of outdated service bulletin, to the most recent, dated Oct. 7. A revision was requested for the three-month compliance time, which Pilatus felt should only be applicable to older aircraft on which the actuators were installed and initial failures were identified, to which the FAA agreed. There are few differences between the MCAI and the AD. The MCAI bases compliance time for the replacement of the parts on the corrosion environment for the plane. The FAA regulations do not require operators to track operations in different environmental conditions, rendering this ineffective as a verifiable factor for the AD. The FAA estimates this will impact 440 planes in the U.S. and is applicable to any Model PC-12/47E plane with a serial number 1300 and 1451 and higher in any category. FAA issues AD for Pilatus PC-12 after corrosion concern 3 years after Ligado decision, criticism mounts over interference concerns Aviation News Posted By: Haley Davoren, GlobalAir.com Published: Apr. 25, 2023 at 05:00 PM EST Updated: Apr. 25, 2023 at 05:07 PM EST The NBAA has joined with 90 trade associations and agricultural aviation groups in urging the FCC to revoke its approval of the high-speed broadband cellular network that has been shown to interfere with GPS and satellite communications networks. The ruling, known as the Ligado Order, came in on April 20, 2020. It announced that the FCC had approved with conditions the Ligado application to deploy a “low-power terrestrial nationwide network in the L-Band that will support 5G and Internet of Things and services. This ruling swept in when global aviation traffic had declined in the wake of the COVID-19 pandemic. The opponents to this controversial ruling have maintained that the FCC made the decision despite a lack of evidence on the potential interference from the L-band signals near the frequencies used by GPS. RELATED STORY: NBAA, Coalition Petition FCC to Reconsider Approval of Ligado 5G Network NBAA, Coalition Petition FCC to Reconsider Approval of Ligado 5G Network “We greatly appreciate your administration’s opposition to the Ligado Order and commitment that the National Telecommunications and Information Administration (NTIA), on behalf of the executive branch, will continue to actively pursue its petition for reconsideration of the order,” the industry letter said. The call to vacate the decision follows an independent technical review that was mandated by bipartisan action in Congress, started by the National Academies of Sciences, Engineering and Medicine. This study confirmed that the Ligado network would notably “cause harmful interference at significant ranges to incumbent L-band services across a broad range of deployment scenarios.” The letter sent to President Biden outlined the concerns over the FCC’s decision, sent by organizations like the NBAA, Helicopter Association International, American Road & Transportation Builders Association and countless other organizations from transportation to agriculture, whose work would be impacted by the interference. Read the full letter sent to President Biden here. NBAA President and CEO Ed Bolen urged the President to take action and revoke the Ligado decision. “GPS forms the backbone of our National Aviation System, which is the safest in the world,” Bolen said. “With numerous studies now reaffirming our industries’ concerns about dangerous interference to these vital systems from the Ligado network, it’s long past time for the FCC to do the right thing and rethink its ill-considered decision.” The expansion of 5G is imminent and agencies like the FAA have been working extensively with companies to ensure that the expansion does not impact the safety of the national airspace. The decision made at a time when the sky was clearer than normal, may have a serious impact on aviation, agriculture and other modes of transportation. The NBAA and other impacted organizations call for a quick response and the removal of the ruling. RELATED STORIES: FAA airworthiness directive on 5G interference 'falls short', NBAA responds with aviation coalition FAA gives 5G deployment updates FAA airworthiness directive on 5G interference 'falls short', NBAA responds with aviation coalition FAA gives 5G deployment updates “The unequivocal conclusions of the NAS Report constitute the exact type of previously unavailable information that the FCC’s rules dictate must be addressed on reconsideration,” the letter said. “We therefore urge you to work with the FCC to address the harm from Ligado’s proposed terrestrial network to critical GPS, satellite communications, and weather forecasting services by staying the Order, addressing the previously unavailable information contained in the NAS Report, and resolving the pending petitions for reconsideration.” 3 years after Ligado decision, criticism mounts over interference concerns FAA approves use of off-the-shelf parts for older certificated aircraft By General Aviation News Staff · April 12, 2023 The FAA has unveiled a new program for the use of off-the-shelf parts in type-certificated aircraft. The new Vintage Aircraft Replacement and Modification Article (VARMA) program is the “next big step in keeping vintage aircraft flying,” according to officials with the Experimental Aircraft Association (EAA). “Anyone who owns and operates vintage aircraft knows that finding parts can be a major challenge. This situation is especially frustrating when perfectly safe and functional alternatives are readily available, but can’t be used because there’s been no legal way to install them in a type-certificated aircraft,” association officials said. “With VARMA in place, some aspects of vintage aircraft ownership and operation are about to get a lot simpler.” VARMA uses several existing FAA policies to create a program that requires no new regulations, orders, or advisory circulars, EAA officials continued. VARMA applies to small (less than 12,500 pounds) type-certificated aircraft built before 1980. It allows ordinary maintenance personnel to validate that certain low-risk replacement parts are suitable for installation on aircraft, without the need for extensive engineering analysis or complex and time-consuming design and production approvals from the FAA, EAA officials explained. “This is great news for those of us who own and fly vintage aircraft,” said Jack Pelton, EAA’s CEO and chairman of the board. “There could easily come a time when a classic airplane that would otherwise be grounded for want of a part that’s no longer available will fly again thanks to the parts substitution enabled by VARMA.” The program applies to parts whose failure would not “prevent continued safe flight and landing.” While this means that safety-critical components are not subject to this program, there are plenty of hard-to-find parts that meet VARMA’s criteria, EAA officials said. For the first approval under VARMA, EAA used the same Cessna 150 it used as a testbed for its auto fuel STC. For VARMA it applied for an off-the-shelf starter solenoid as the failure of the starter system is generally irrelevant to flight safety. The FAA granted the first Form 337 approval under the program several weeks later. Since that time, the association also been granted approval for alternators and voltage regulators in VFR aircraft. “There are many more parts that are eligible under VARMA,” EAA officials said. Initially, the FAA will be managing the program through its Chicago Aircraft Certification Office, which can be reached at 847-294-7357. For now, approvals will be considered on an individual basis, although type clubs and ownership groups are encouraged to keep track of substitute parts that have gained approval, EAA officials advised. “EAA has had a longstanding commitment to maintainability and modernization in the legacy aircraft community,” said Tom Charpentier, EAA’s government relations director. “Our EFIS and autopilot STCs broke new ground in affordable avionics, and it is our hope that VARMA opens many new doors for easily found replacement parts. As with the STC programs, we blazed the trail with the first FAA approves use of off-the-shelf parts for older certificated aircraft Repair Parts Running Out For GNS 430/530 By Russ Niles Published: March 15, 2023 Updated: March 16, 2023 Garmin says those who still rely on its early generation navigation products should start planning a panel upgrade. The company says “multiple component availability limitations” mean the parts needed to fix the devices that heralded a revolution in aviation navigation and in-flight information are fading away. “First introduced in 1998, Garmin has offered repair service for the GNS 430/530 series for 25 years,” the company said in a brief service advisory issued March 14. “Garmin plans to continue offering repair service when the components required for a specific repair remain available. Database updates and technical support will also remain available.” But the company said that starting in 2024, it will no longer be able to fix some issues with the early devices, which include “all WAAS and Non-WAAS GNC® 420, GNS 430, GNS 530, GPS 400, and GPS 500.” The company said now is the time to think about an upgrade. “We encourage GNS 430(W)/530(W) series owners to begin considering their transition strategy to newer generation products,” the advisory said. Repair Parts Running Out For GNS 430/530 FAA proposes revisions for helicopter radio altimeter 5G interference AD Aviation News Posted By: Haley Davoren, GlobalAir.com Published: Apr. 17, 2023 at 03:49 PM EST Updated: Apr. 17, 2023 at 03:50 PM EST The FAA has proposed to replace the Airworthiness Directive for helicopters equipped with a radio altimeter flying in areas impacted by 5G C-Band interference. The new notice of proposed rulemaking (NPRM) states that additional limitations are needed ahead of the continued deployment of 5G C-Band base stations, with signals covering most of the U.S. The FAA proposed the changes to the previous AD was issued on Dec. 7, 2021 in response to the U.S. Federal Communications Commission (FCC) adopting final rules in March 2020 that authorized flexible use of 3.7-3.98 GHz band for newer services, like 5G. The new NPRM proposes a revision of the existing AD and incorporates new limitations that prohibit certain operations that require radio altimeter data. The FAA proposed the revision to address any potentially unsafe conditions for helicopters using these products. The FAA invites relevant data, views, comments or arguments by May 12. All submitted comments will be considered and the FAA may amend the proposal in response if it sees fit. The FAA feels the radio altimeter is not a reliable tool when faced with interference from wireless broadband operations. The AD requests a revision for any existing rotorcraft flight manual (RFM) to add in limitations, set by the FAA. The original AD was issued since anomalies in the radio altimeter often go undetected by the automation or the pilot. These irregularities most often go unnoticed close to the ground, which can result in a loss of continued safe flight and landing. The same day the FAA proposed the initial AD, it issued an AD to correct the same unsafe condition and require similar limitations for all transport and commuter category planes with a radio altimeter. Since the initial AD was proposed, the FAA has reviewed data from alternative method of compliance (AMOC) requests to demonstrate that the radio altimeters can be used for the intended purpose when operating outside of a protection radius around the 5G C-Band transmitters. The AMOC process gave the FAA more accurate insight into how 5G transmissions can impact flight operations. During the initial analysis, the FAA sought to protect against interference during critical operations when a pilot relies on radio altimeters. The FAA hoped to prohibit operations within these vicinities, known as 5G C-Band emitters. With a new understanding of the interference and potential risk, the FAA has reduced the protected areas around the 5G C-Band emitters, protecting rotorcraft. Since the second AD applied to transport and commuter category planes, comments given gave the FAA a broader range of ideas for most of the radio altimeters on the market, for helicopters and other types of aircraft. The FAA now has a better understanding of how specific radio altimeters can react to interference and perform in protected radiuses, subsequently proposing to retain existing prohibitions in the initial AD with an option to upgrade to a different, more tolerant radio altimeter rotorcraft to avoid the limitations. RELATED STORIES: FAA issues exemption for helicopter air ambulances from 5G restrictions FAA airworthiness directive on 5G interference 'falls short', NBAA responds with aviation coalition FAA gives 5G deployment updates The FAA has done extensive collaborative work with 5G operators like AT&T and Verizon, as well as the government and FCC. As 5G expands across the country, so does the work being done to prevent possible interference and safety concerns. Safety zones are tailored to where critical phases of flight take place. The measures being taken, like the revised AD, are being pushed out ahead of the continued deployment of 5G C-Band services. As more 5G C-Band base stations pop up near airports in the national airspace system (NAS), the FAA will continue to monitor the impact. The use of 5G services will continue to roll out across the country and the FAA and other aviation organizations will continue to ensure that aviation operations can run smoothly and safely, without interference causing concern. FAA proposes revisions for helicopter radio altimeter 5G interference AD Diamond Aircraft Announces Dedicated Engine Testing Program For SAF By Mark Phelps Published: April 18, 2023 So far, at least, sustainable aviation fuel (SAF) is limited to the jet fuel set, which has kept most piston-powered aircraft out of the conversation. A notable exception is the fleet of Austro-Engine-powered Diamond Aircraft models, which burn jet fuel rather than aviation gasoline (avgas). Diamond has just announced a dedicated SAF development program for its aircraft powered by jet-fuel-burning (aka “diesel”) engines from sister company Austro Engine. To this end, the company has developed a dedicated engine-test bench. It has the unique capability to measure “cylinder pressures in real time with crank angle resolution, the emission components of unburned hydrocarbons (HC), nitrogen oxides (NOx), GHG [greenhouse gas] carbon dioxide and carbon monoxide (CO2, CO).” Diamond clarified, “To validate and approve sustainable aviation fuels that will be available at airports in the future, turbocharged compression-ignition piston engines require not only chemical and calorific analyses but also investigations on component test stands, engine test stands and flight tests.” The company expects to receive its first batch of certified SAF to start the testing next month. With electric-powered aircraft also in the planning stages for Diamond, Robert Kremnitzer, Diamond’s head of design organization, said, “Next to the all-electric eDA40, SAF will become a near-term available solution for sustainable aviation. In the piston engine segment, we have the big advantage that most of our existing fleet is already using jet fuel. With this program, we ensure that sustainable alternatives to these fuel types may be used as soon as they become available at airports with General Aviation fuel stations—with no, or only minor, adaptions to the aircraft.” Diamond Aircraft said it expects to see D7566 SAF blends become increasingly available at GA airports as a seamless “drop-in” fuel. The company targets approval for the fuel mix across its entire fleet by year-end of 2025. Diamond said, “Significant market penetration of SAFs is expected by 2030 and availability of 100 percent pure SAFs without blending for 2050.” Diamond Aircraft Announces Dedicated Engine Testing Program For SAF Dutch investigators recommend changes to Boeing 747 engines following failure BY RYTIS BERESNEVICIUS 2023-04-19 Note: See photos in the original article. The Onderzoeksraad voor Veiligheid (Dutch Safety Board, OVV) has issued several recommendations in its final accident report into a contained engine failure on a converted Boeing 747-400 freighter (B747-400BCF) in which engine parts dropped on a village in the Netherlands. The incident took place on February 20, 2021, when the Boeing 747-400BCF, registered as VQ-BWT, suffered a contained engine failure shortly after its departure from Maastricht Aachen Airport (MST) to New York John F. Kennedy International Airport (JFK). The aircraft, operated by Longtail Aviation, suffered damage to engine 1 (outer wing left-hand side engine). While none of the crew onboard the 747 were not hurt, two people on the ground suffered injuries. Further damage was recorded to cars and houses in the village of Meerssen located approximately two kilometers (1.2 miles) south of runway 21 at MST. Following the contained engine failure, the aircraft diverted to Liege Airport (LGG) in Belgium, where the Boeing 747-400F landed without further incident. The freighter was powered by four Pratt & Whitney PW4000 family turbofan engines that accumulated 73,995 flight hours (FH) and 9,964 flight cycles (FC) since they entered service in January 1993. Since their last overhaul in 2010, the four turbofans had 11,516 FHs and 1,998 FCs at the time of the incident. Contained engine failure of the Boeing 747-400BCF Throughout its investigation, the OVV focused on finding the cause of the contained engine failure and whether the risks to the people on the ground had been properly managed. According to the Dutch investigators, the risks were looked into because the OVV “received e-mail messages and letters from residents who expressed their safety concerns and that injuries to residents and damage to property had occurred as a result of this occurrence”. The final report depicted that apart from the auxiliary power unit (APU) being unserviceable due to the inlet door being stuck in a partially open position, resulting in the crew compensating for the additional drag during the takeoff performance calculation, the aircraft was in normal operating condition. The operator’s Minimal Equipment List (MEL) allowed the Boeing 747-400BCF to be operated in such a condition. The OVV noted in its final report that as the aircraft began to taxi to runway 21, “the flight crew started the engines; the start up times were within limits and all engine indications were normal”. Investigators added that the taxi time “provided sufficient time for the engines to comply with the minimum warm-up time, as recommended by the engine manufacturer”. While the take-off roll was uneventful, at an altitude of 1,150 feet (350 meters) above mean sea level (AMSL), the pilots of the aircraft heard a banging noise and the 747 began to roll and yaw slightly to the left. Furthermore, the exhaust gas temperature of engine no 1 was above the maximum temperature, with the power plant failing and losing thrust shortly after. The first officer, who was pilot flying (PF), corrected for the asymmetric trust and performed the first item of the “engine limit or surge or stall” procedure, investigators noted, reducing the number 1 engine’s thrust to flight idle. At the same time, “the runway controller informed the flight crew that flames were observed from the number 1 engine”. The captain, who was pilot monitoring (PM) declared an emergency, telling Air Traffic Control (ATC) that they were shutting down the engine. Even though there was no engine fire indication in the cockpit, the report claimed that “the crew decided to treat the event as an engine fire and performed the memory items for the ‘engine fire’ procedure”. Subsequently, the pilots switched “the number 1 fuel control switch to cutoff, pulled the engine 1 fire switch and rotated it to its stop to exert a fire suppressing agent into the engine”, isolating the engine from the hydraulic system and cutting off the flow of fuel into the now-failed turbofan. Since the aircraft was above its maximum landing weight, the flight crew and ATC coordinated to dump fuel and reduce weight. At this point, the captain became the PF, while the first officer was now the PM. Less than an hour after taking off from MST, the crew dumped over three tons of fuel and landed uneventfully at LGG. Notably, the report found that “the fire brigade reported to the flight crew that there were no signs of fire from engine number 1, nor that there was external damage visible”. Prior to landing, ATC informed the flight crew that there were already reports about debris on the ground from the engine, which is why the pilots “took into consideration that possible damage to the wing or flaps might have happened”, the report added. Damage to the high pressure and low-pressure turbines of the P&W PW4000 Following a post-landing inspection, the OVV pointed out there was “significant damage was visible to the aft stages of the low pressure turbine when looking forward into the tail pipe”. Further inspections showed that the number 1 engine “encountered a contained failure and sustained internal damage of among others the high pressure turbine and low pressure turbine”. No other parts of the aircraft were harmed during the event. The Dutch investigators found “that the second stage blade outer air seal of the high pressure turbine (HPT), as well as the HPT itself had deteriorated”, resulting in the outer transition ducts being exposed to elevated temperatures. As a result, these two factors contributed to the slow deformation of the ducts. “The outer transition duct panels distorted, the attachment hooks deformed and backed away from the case, which led to liberation of one panel and one being fractured,” the OVV continued. The panels damaged the turbine blades, fragments of which left the engine via the exhaust pipe and rained down on the Dutch village. The report noted: “The investigation ruled out that runway foreign object debris or a bird strike or drone strike had led to the engine failure. The meteorological conditions played no part in this failure either.” Pratt & Whitney, the manufacturer of the PW4000 engine, was aware that such a failure could occur, and issued two Service Bulletins (SB) in 1993. Furthermore, the Federal Aviation Administration (FAA) issued two airworthiness directives (AD) to the power plant. The OVV highlighted that while the engine had the SB 74-488 incorporated, SB 72-462, which is meant to add additional HPT cooling features, did not. While one AD was not applicable due to the incorporation of SB 72-488, the other AD, requiring operators to inspect LPT vanes, had not been incorporated because the engine’s last shop visit had been in 2009, before the publishing date of the directive. “According to Pratt & Whitney’s analytical modelling, the outer transition ducts failure would not have occurred if SB 72-462 had been incorporated. “This claim seems credible, as the investigation did not find similar failure modes with engines that had been modified with the additional cooling features,” the Dutch investigators stated. “Despite the fact that the engine was equipped with the redesigned outer transition ducts, the temperature could rise to a level that it caused damage over a long period of time, which led to liberation of outer transition duct panels and finally failure of the engine, whereas the lacking additional cooling features were supposed to prevent this from happening,” the OVV added. However, while the SB was published in 1993, it was not incorporated during the engine’s visit to the shop in 1999 and 2009, when the engine was disassembled. Longtail Aviation was also not the operator of the aircraft at the time, rather it was Singapore Airlines (operated between 1991 and 2004), and Martinair, a subsidiary of KLM (between 2007 and 2010). As a result, investigators found that “the content of the service bulletin was not considered an urgent safety issue” and operation of the engine is allowed without the incorporation of SB 72-462. Reconsider whether SB should be a mandatory AD The Dutch investigators issued three recommendations to various parties. First, the OVV recommended that Longtail Aviation “keep the record keeping of the (non-)implementation of service bulletins for leased engines of your fleet of commercial air transport aeroplanes complete and accessible”. Second, the Dutch investigators advised the FAA to reconsider whether SB 72-462 should be made mandatory through an AD. And finally, the institution recommended that the Dutch Minister of Infrastructure and Water Management “perform and publish an assessment for residential areas around Maastricht Aachen Airport of the risks of parts departing the aircraft, such as departing engine debris”. The report noted that while the failure caused no risk to the safe operation of the aircraft, the fragments that exited the engine “caused a hazard to persons and property on the ground”. “The engine failure showed that the hazard of departing engine parts is real, resulting in injured people and damaged property,” the OVV said, adding that “residents around airports are at least exposed to two types of risks: first, parts departing the aircraft, and second an accident with an aircraft”. At the time of the report, no study had been conducted to assess the residential areas around MST for the two risks. “Based on the results of such an assessment, an informed decision about the acceptability of these local risks should be made,” the OVV concluded. The OVV marked the event as a serious incident due to the “potential for an accident, as the departing engine debris that came down in a village could have seriously injured people, besides the injuries that had taken place”. Dutch investigators recommend changes to Boeing 747 engines following failure American Airlines to upgrade cockpit displays on more than 100 Airbus A320s BY RYTIS BERESNEVICIUS 2023-04-20 American Airlines and Airbus entered into a partnership to upgrade the cockpit displays on more than 100 of the carrier’s Airbus A320s. According to an announcement made by Airbus on April 19, 2023, the two companies will partner to “install Enhanced Electronic Instrument System (EEIS2) LCD flight deck displays and new display computers” on American Airlines aircraft in a multi-year retrofit program. The EEIS2 will replace the current cathode ray tube displays and Display Management Computers (DMC) found in the airline’s cockpits. According to Airbus, “each A320 family aircraft has six flight deck displays and three DMCs located in the avionics bay”. The EEIS is built by Thales, a French aerospace, defense, and transportation electrical systems manufacturer, and will be integrated by Airbus. The Original Equipment Manufacturer (OEM) of the A320 family noted that it “will provide the necessary service bulletins and installation kits as well as on-site engineering support”. Compared to the current displays, the new system improves “information displays for pilots thanks to its high resolution LCD screen and offers new system capabilities and features for American’s A320ceo fleet,” per the OEM’s estimates. Additionally, Airbus said that the retrofit program will maximize fleet commonality, reduce maintenance costs, and save 50 kilograms (110.2 lbs) of weight per aircraft. Currently, American Airlines has 399 A320 current engine option (ceo) and 124 new engine option (neo) aircraft in its fleet, according to ch-aviation.com data. It also has four A321neo and 50 Airbus A321XLR on order, per ch-aviation.com data. American Airlines to upgrade cockpit displays on more than 100 Airbus A320s Curt Lewis