May 3, 2023 - No. 018 In This Issue : Air Force Working on Fuel-Saving, 3D-Printed ‘Microvanes’ for C-17 : Air New Zealand grounds two Airbus A321neos over global engine shortages : Sustainable Aviation Fuel approved for Piper turboprops : FAA issues new AD addressing missing shims on more than 1,900 Boeing 737s : FAA looks to address potential fuel leaks from Boeing 737’s APU : Continental Jet-A piston engines achieve milestones, including increased TBR By General Aviation News Staff · April 27, 2023 · 8 Comments : Five Hawaiian Airlines Planes Grounded Confounding Multiple Problems Photo-US Air Force C-17 With "Microvanes" Air Force Working on Fuel-Saving, 3D-Printed ‘Microvanes’ for C-17 Dec. 6, 2022 | By Chris Gordon The Air Force is considering making aerodynamic retrofits to one of its flagship cargo planes in an effort to save on fuel and be kinder to the environment. As part of a project that has been in the works for years, the Air Force Research Laboratory (AFRL) and Air Force Life Cycle Management Center are in the process of airworthiness certification to fit microvanes on C-17s. Microvanes are small fin-like additions that attach to the fuselage to reduce drag. The Air Force says fitting the parts to the existing fleet could save millions of dollars per year in fuel. “This is a great step forward on an existing aircraft for fuel efficiency and mission enhancement,” Ed Clark, an AFRL engineer, told Air & Space Forces Magazine in an email. The microvanes are a prime example of “bringing modern technologies forward on an older aircraft,” said Clark, a member of the Future Force Energy office at AFRL’s Materials and Manufacturing Directorate. Clark said AFRL first began working on the technology in 2014 and that work to fit microvanes to C-17s began in 2015. Microvanes were originally developed by Lockheed Martin in collaboration with the Air Force. They are commercially available for C-130 and have already been installed on some Canadian Armed Forces aircraft of the type. In 2021, the Department of Defense awarded a contract to Metro Aerospace, which holds the license to Lockheed Martin’s patent on the technology, to explore putting microvanes on Air Force’s C-130s and “help validate drag-reduction concepts that can be developed and applied to commercial aircraft, other aircraft such as the C-17, KC-135, and future vertical lift.” The C-17 microvanes are fin-shaped structures that attach to the aft of the fuselage. Cargo planes have historically had high drag in that area because of upsweep in the fuselage required for the rear cargo door, which microvanes can help reduce, according to a Lockheed Martin study. The Air Force Research Laboratory says it took several new steps in the development of the microvanes so they could be tested with limited interruption in the service’s fleet of around 220 aircraft. C-17s have been sometimes been stretched thin and required to conduct massive airlift operations on little notice. The AFRL team sought to minimize disruption to the fleet. The team used Computational Flow Dynamics (CFD) to help design, test, and evaluate the efficiency of the parts. The microvanes are 3D-printed from DuraForm GF/DuraForm ProX GF composite material, reducing the complexity required when producing and fitting them to the aircraft. Modern design tools allowed the the team to make “a safe and integral gain to the aircraft while not impacting operations,” Clark said. “This is a 3D-printed device which can be installed in a short amount of time utilizing Air Force aircraft maintenance personnel.” By reducing drag, the Air Force can save fuel by reducing the workload of the engines. C-17s with microvanes installed save around one percent in fuel over regular C-17s, according to the service. The Air Force says those savings are significant if added up over the fleet. “When installed across the C-17 fleet, including Air National Guard and Air Force Reserve aircraft, the Air Force estimates the microvanes will pay for themselves in fuel savings in seven months and save over $10 million per year,” according to a release from the office of the Assistant Secretary of Air Force for Energy, Installations, and Environment. Clark said the microvanes program has cost approximately $5 million so far to develop. AFRL hopes to complete airworthiness certification soon on C-17s. “Our goal is calendar year 2023 with added flight verification and in service testing in the first half of the year,” Clark said. In 2023, “the Air Force will determine the best option for production of the microvanes for the C-17 fleet,” he added. Air Force Working on Fuel-Saving, 3D-Printed ‘Microvanes’ for C-17 Air New Zealand grounds two Airbus A321neos over global engine shortages BY IAN MOLYNEAUX 2023-04-21 Air New Zealand has grounded two of its Airbus jets over a global engine supply shortage now affecting 28 airlines worldwide. Two Airbus A321neos were taken out of service. including one aircraft which was only introduced in 2022 and is the carrier’s biggest-ever jet dedicated to domestic flying. “Essentially, we don’t have enough engines,” group general manager of engineering and maintenance, Brett Daley told Stuff Travel. “The scheduled removal of engines and usual non-scheduled removals are all coming together at the same time for every operator around the world.” According to flightradar24.com data, the two A321neo aircraft have not flown for the past few weeks, with ch-aviation.com data also showing that they have been in maintenance at Auckland International Airport (AKL). ZK-OYA’s last flight was on March 10, 2023, while ZK-OYC last flew on April 1, 2023, with both landing at AKL on their respective last flights. Air New Zealand’s fleet of A320 and A321s are powered by engines made by manufacturer Pratt & Whitney, which has experience supply issues this year. Air New Zealand currently has 32 engines on its planes, four spares, and three lease options, but executives at the carrier are still concerned about its ability to operate. According to Stuff Travel, the engines will be removed from the grounded domestic planes and used on aircrafts that fly internationally. 150,000 passengers will have their flights affected, with most customers facing a 90-minute alteration to their original departure time. In February 2023, more than 50 IndiGo and Go First planes were grounded in India due to Pratt & Whitney’s engine issues and persisting supply chain woes. Executives at US-based Raytheon Technologies, the parent company of Pratt & Whitney, warned during the firm’s earnings call in January 2023 that material shortages related to engine castings would continue throughout the year. For additional information: More than 50 IndiGo and Go First aircraft grounded due to P&W engine issues Air New Zealand grounds two Airbus A321neos over global engine shortages Sustainable Aviation Fuel approved for Piper turboprops By General Aviation News Staff · April 24, 2023 Piper Aircraft reports that all PA-46 based, single-engine turbine-powered aircraft, including the M600/SLS, M500, and Meridian, can now use Sustainable Aviation Fuel (SAF). SAF is not only FAA approved via Special Airworthiness Information Bulletin NE-11-56R4, but is available for use in every country where turbine M-Class aircraft operate, Piper officials added. All jet fuel that meets the requirements of the American Society for Testing and Materials (ASTM) D7566 Standard Specification for Aviation Turbine Fuel Containing Synthesized Hydrocarbons can be used in Piper turbine-powered aircraft. Typically, this fuel is made from fatty acids or other synthetic components, and is acceptable for use in aircraft and engines certified for use with D1655 fuel, more commonly known as traditional Jet A and Jet A-1 fuel, company officials explained. Using SAF in a Piper turboprop will not require a change in aircraft placarding or Pilot’s Operating Handbooks. The use of SAF in Piper turboprops follows another recent commitment by the company to promote sustainability in general aviation, initially revealed at EAA AirVenture Oshkosh 2022, Piper officials noted. Piper Aircraft and CAE are collaborating on an electrically powered conversion kit via a Supplemental Type Certificate (STC) for in-service Archer TX aircraft. Upon certification, CAE plans to convert two-thirds of its existing Piper Archer TX training fleet, and will be the first to develop a curriculum for new pilots to conduct training in an electric airplane. Sustainable Aviation Fuel approved for Piper turboprops FAA issues new AD addressing missing shims on more than 1,900 Boeing 737s BY RYTIS BERESNEVICIUS 2023-04-24 Thiago B Trevisan / Shutterstock.com The United States (US) Federal Aviation Administration (FAA) has issued an Airworthiness Directive (AD) that addresses missing shims on Boeing 737 NextGeneration (NG) aircraft, namely the -600, -700, -700C, -800, -900, and -900ER. According to the FAA, the AD was prompted by “reports of missing shims, a wrong type of shim, shanked fasteners, fastener head gaps, and incorrect hole sizes common to the left and right sides at a certain station (STA) frame inner chord and web”. To comply with the directive airlines will have to inspect for existing repairs as well as cracking and, if required, perform on-condition actions. “The FAA is issuing this AD to address cracking in the left and right sides of STA 727 frame inner chord and S–18A web before the cracking reaches a critical length,” the agency continued, adding that the cracking could result “in fatigue critical baseline structure (FCBS) and the inability of a principal structural element (PSE) to sustain limit load, which could adversely affect the structural integrity of the airplane”. This is a final rule AD with an effective date of May 30, 2023. The authority estimated that the directive will affect 1,925 Boeing 737 NGs registered in the US, estimating and calculating that a general visual inspection and inspection of the high frequency eddy current (HFEC) and shim installation will cost $170 and $425 per operator, respectively. Meanwhile, “on-condition actions include installation of a new shim, a surface HFEC inspection of the STA 727 frame inner chord at S–18A for cracking, and repair,” and is estimated to cost $225 per aircraft. The STA 727 frame inner chord is located just behind the wings of the Boeing 737 in section 46 of the fuselage. Several parties, including American Airlines, Aviation Partners Boeing (APB), Boeing, Southwest Airlines, and United Airlines, as well as one individual, commented on the AD. Of note, APB and Southwest Airlines requested the FAA add that the installation of blended or split scimitar winglets with the Supplemental Type Certificate (STC) ST00830SE will not affect compliance with the AD, with the agency agreeing to the request. In addition, Southwest Airlines requested that general visual inspections would be optional for aircraft on which the Boeing Alert Requirements Bulletin 737–53A1385 RB has already been completed. The FAA partially agreed, noting that the RB “specifies inspecting for existing repairs, contacting Boeing if any repair is found, and checking for a gap if no repair is found”. Furthermore, the agency agrees that there is no need to repeat reports for Boeing Alert Requirements Bulletin 737–53A1402 RB if an inspection was carried out according to the Boeing Alert Requirements Bulletin 737–53A1385 RB. Rather than making the action optional, the FAA instead added a paragraph that gives credit to operators who have completed the task before the effective date of this AD. The FAA noted that “rather than making this required action option” a paragraph had been added to the AD “giving operators credit for completing that task” before the effective date. FAA issues new AD addressing missing shims on more than 1,900 Boeing 737s FAA issues final rule AD to prevent potential 737 MAX fuel tank explosions BY RYTIS BERESNEVICIUS 2023-04-06 The United States (US) Federal Aviation Administration (FAA) issued a final rule Airworthiness Directive (AD) for the Boeing 737 MAX, including the 737 MAX-8, MAX-9, and the high-density MAX-8-200, with the aim of preventing fuel tank explosions. The final rule AD was published on April 5, 2023, and will come into effect on May 10, 2023. In the AD, the FAA stated that the directive “was prompted by a determination that a new airworthiness limitation is necessary to require periodic replacement of the oxygen sensor of the nitrogen generation system (NGS)”. The notice of proposed rulemaking (NPRM) for the directive included a proposal to revise the current maintenance program and include the new airworthiness limitation. “The FAA is issuing this AD to prevent increasing the flammability exposure of the center fuel tank, which together with an ignition source in the fuel tank, could lead to a fuel tank explosion and consequent loss of the airplane,” the agency said. The AD affects 62 aircraft registered in the US, and the work to comply with the directive is expected to take airlines an average of 90 hours. However, the FAA said it “recognizes that this number may vary from operator to operator” and, as such, provided a per-operator cost estimate of $7,650, which will be comprised of 90 work hours at $85 per hour. FAA looks to address potential fuel leaks from Boeing 737’s APU Continental Jet-A piston engines achieve milestones, including increased TBR By General Aviation News Staff · April 27, 2023 Continental reports two milestones for its Jet-A piston engine series: The jet-fuel burning piston engine family has accumulated more than 10 million flight hours, while the CD-170 engine has received a Time Between Replacement (TBR) extension from 1,200 to 1,800 hours from the European Aviation Safety Agency (EASA). When the CD-170 launched in 2020 with a TBR of 1,200 hours, Continental officials committed to increasing the TBR. Continental prioritized this development project, knowing it would provide additional value to owners, officials noted. Continental Jet-A piston engines are available in select new certified aircraft from Tecnam, Diamond, and Piper. In addition, the CD-100 series is also available in a Standard Type Certificate (STC) retrofit kit for various aircraft, such as Cessna 172 and older Piper PA-28s, where it only takes 21 days to upgrade your standard engine to a new Jet-A engine, company officials said. Continental Jet-A piston engines achieve milestones, including increased TBR By General Aviation News Staff · April 27, 2023 · 8 Comments Five Hawaiian Airlines Planes Grounded Confounding Multiple Problems APRIL 25, 2023 by BEAT OF HAWAII Hawaiian Airlines reported Wednesday on their first quarter results, which are, at best mixed. There are big issues the carrier is still grappling with, including a fleet of planes with engine problems and a runway gone missing at their primary airport. But there are bright spots, too, like travel bookings ahead of last year, more demand for international travel, and four 787 Dreamliners scheduled to arrive by 2024. Five A321neo aircraft are out of service and awaiting new engines. Hawaiian hopes to resolve these problems by the end of this quarter, which would be by June. But clearly, the situation has gotten worse, not better, since last they spoke about it. In February, HA spokesperson Alex Da Silva told us, “Yes, we’ve had supply chain issues – many companies – during the pandemic. We’ve been working with our suppliers to prevent disruptions to our operations.” But disrupted, they are. When we previously wrote about the Hawaiian A321 engine problems, just two planes had gone out of service and were awaiting new engines. Peter Ingram had said that parts availability issues resulted in the “A321s being grounded for an extended period, awaiting available serviceable engines.” We were aware several weeks ago that the problem had since gotten worse, and at that time, four planes were already down. Now, however, five out of the eighteen narrowbody planes are disabled and awaiting engine repair/replacement. It has been suggested that more of the aircraft could be at risk of going out of service, which we hope is, in fact, not the case. Others have commented that the issues are supply chain limitations and overall engine reliability problems. We were told the Pratt engines have multiple issues, including heat causing unexpected wear and engine vibration problems. When one of the two engines has a problem, the plane can no longer be dispatched. Five Hawaiian Airlines Planes Grounded Confounding Multiple Problems Curt Lewis