Aviation Maintenance & Technology Exchange April 17, 2024 - No. 16 In This Issue : FAA Proposes Directive For Boeing 747-400F To Address Risks Of Fuel Tank Explosions ; Airworthiness Directives: The Most Important Ones Of 2023 : Aircraft Cabin Air International Conference - 17 & 18 September - London : Ural Airlines admits no plans to return stranded Airbus A320 back to service : Boeing Quality Standdowns Extend Across MRO Segment : A Boeing supplier says it tried using Vaseline, cornstarch, and talcum powder to lubricate a door seal before settling on Dawn dish soap: NYT : Enhanced Cessna High-Wing Piston Aircraft Enter into Service Following First Deliveries : CFM Delivering Leap-1As With Reverse Bleed System : NTSB Urges Better Prop Inspections : Boeing claims no findings of fatigue on older 787 jets ahead of whistleblower testimony : Air Force’s costliest accidents, maintainer injuries rose in 2023 FAA Proposes Directive For Boeing 747-400F To Address Risks Of Fuel Tank Explosions BY RYTIS BERESNEVIČIUS The requirements to ensure fuel tank safety stemmed from the TWA Flight 800 accident in 1996. SUMMARY • The FAA is addressing potential fuel tank explosions on Boeing 747-400F aircraft. • The regulator received reports about improperly applied cap seals to certain fasteners on specific 747-400Fs. • The FAA warned that improperly applied cap seals could fail to prevent arcing within the fuel tanks in case of a lightning strike or a short circuit. The Federal Aviation Administration (FAA) has published a notice of proposed rulemaking (NPRM) to address potential Boeing 747-400F fuel tank explosions after receiving reports of improperly applied cap seals to certain fasteners on aircraft of the type. This reduced their electrical insulation and increased the risk of a fuel tank explosion. Changes following the TWA Flight 800 accident Providing more background on the issue, the FAA said that it has examined the underlying safety issues involved in fuel tank explosions on several large commercial aircraft and whether the then-existing regulations were adequate enough to alleviate safety risks. The regulator presented its findings in May 2001, issuing a final rule document titled ‘Transport Airplane Fuel Tank System Design Review, Flammability Reduction, and Maintenance and Inspection Requirements.’ The document was published several years after a Trans World Airlines (TWA) Boeing 747-100, operating flight TWA 800, exploded several minutes after it had taken off from New York John F. Kennedy International Airport (JFK). Following the National Transportation Safety Board’s (NTSB) report, the FAA was prompted to address these issues, where the investigators concluded that the center wing fuel tank exploded due to an unknown ignition source. The NTSB also provided three safety recommendations, including calls to reduce fuel heating in the center wing fuel tanks, reduce or eliminate operations with flammable vapors in the fuel tanks, and reevaluate the fuel system design and maintenance practices. RELATED What Caused TWA Flight 800 To Explode In Mid-Air? Following a June 2022 directive The report, prompted by the NTSB’s recommendations, resulted in new airworthiness standards for commercial aircraft and maintenance requirements for already-delivered airframes, which the FAA published and later amended twice in 2002. As such, the Special Federal Aviation Regulation No. 88 (SFAR 88) was included in the Code of Federal Regulations (CFR). Essentially, the rule requires type certificate (TC) and supplemental TC (STC) holders, namely aircraft manufacturers, to ensure that their fuel tank systems can prevent ignition sources within the fuel tanks. Thus, the FAA established four principles that defined unsafe conditions associated with fuel tank systems, with one being the percentage of operating time during which fuel tanks are exposed to flammable conditions. “The other three criteria address the failure types under evaluation: Single failures, combination of failures, and unacceptable (failure) experience.” In June 2022, after the FAA had received reports about some cap seals not being applied to certain fasteners in the fuel tank during production, the regulator issued an airworthiness directive (AD). The directive required operators to apply cap seals to certain fasteners in the fuel tank on Boeing 747 aircraft from line number (LN) 645 to LN 1363 inclusive. The manufacturer intended to incorporate the change in future aircraft, namely airframes between LN 1365 and LN 1419 inclusive. “However, Boeing discovered that the design change omitted application of the cap seals on eight fasteners (four each on the left and right wings in the inboard main fuel tanks).” RELATED How An Aircraft's Fuel System Works Explosion or fire leading to loss of an aircraft The FAA warned that without these cap seals, the ends of the fasteners do not have sufficient electrical insulation to prevent arcing in case of a lightning strike or high-powered short circuit, which could create an ignition source within the inboard main fuel tanks. A failure to prevent an ignition source in the fuel tank, combined with flammable fuel vapors, could result in an explosion or fire, resulting in a complete airframe loss, the regulator added. As such, the NPRM, which would be finalized with an AD, applies to certain Boeing 747-400F aircraft, with the FAA inviting stakeholders to comment on the proposed rule until May 28. The affected aircraft were identified in Boeing Alert Requirements Bulletin (RB) 747-57A2371 RB, published on September 29, 2023. The FAA estimated that only 15 Boeing 747-400F would be affected in the US, with the only compliance requirement being the application of cap seals on eight fasteners located on the left and right wings in the inboard main fuel tanks, four per side. Airworthiness Directives: The Most Important Ones Of 2023 BY RYTIS BERESNEVIČIUS PUBLISHED JAN 2, 2024 While regulators have published hundreds of airworthiness directives (AD) throughout the year, some addressed major safety issues. SUMMARY • Throughout the year, regulators have published hundreds of airworthiness directives (AD), addressing various safety issues on commercial aircraft. • This included directives for Airbus, Boeing, and other aircraft. • ADs were also published for engines, including the Pratt & Whitney PW1100G, also known as the Geared Turbofan (GTF), which has had manufacturing quality defects for older engines, powering the Airbus A320neo aircraft family. Throughout the year, aviation regulators, whether it would be the United States (US) Federal Aviation Administration, European Union Aviation Safety Agency (EASA), Transport Canada (TC), or any other authority, publish hundreds of directives addressing minor and major safety issues. These airworthiness directives (AD) can apply to aircraft, engines, and helicopters, ranging from fuselage cracking issues to preventing mid-air engine failures. During 2023, some of them were more important than others, including addressing the Pratt & Whitney PW1100G, also known as the Geared Turbofan (GTF), inspections based on the manufacturer’s service bulletins (SB). The Pratt & Whitney PW1100G issues In August 2023, the FAA published the first AD addressing the Pratt & Whitney PW1100G manufacturing quality defects. RTX, the parent company of Pratt & Whitney, first disclosed the problems in July 2023, saying that the engine manufacturer had determined “that a rare condition in powder metal used to manufacture certain engine parts will require accelerated fleet inspection.” Subsequently, the US-based regulator issued the AD, saying that while initially, a failure of the International Aero Engines (IAE) V2500 engine, used on the Airbus A320ceo aircraft family, was due to “a material anomaly attributed to deficiencies in the manufacturing process,” the same anomaly was also found in PW1100G engines. While the initial AD was issued in September 2021, two subsequent directives superseded the first, with a December 2022 engine failure on an A320neo prompting P&W to conduct “a records review of production and field-returned parts, and re-evaluated their engineering analysis methodology.” Read the latest Airbus news here. As a result, the manufacturer determined that the engine’s high-pressure turbine (HPT) stage 1 and 2 hubs “are susceptible to failure much earlier than previously determined.” The FAA mandated airlines to perform an ultrasonic inspection (USI) of both hubs for cracks per the P&W SB. In December 2023, prompted by another engine failure, where the high-pressure compressor (HPC) 7th-stage integrally bladed rotor (IBR–7) broke down, the FAA issued an AD Notice of Proposed Rulemaking (AD NPRM), requiring “accelerated replacement of the HPC IBR–7, HPC IBR–8, HPC rear hub, HPT 1st-stage hub, HPT 1st-stage air seal, HPT 1st-stage blade retaining plate, HPT 2nd-stage hub, HPT 2nd-stage blade retaining plate, and HPT 2nd-stage rear seal.” RELATED FAA To Require Inspection Of Some Pratt & Whitney GTF Engines Anti-ice system on the Boeing 737 MAX In April 2023, the FAA warned that the usage of the engine anti-ice (EAI) system in dry air for more than five minutes during certain weather conditions could “cause overheating of the engine inlet inner barrel beyond the material design limit, resulting in failure of the engine inlet inner barrel and severe engine inlet cowl damage.” The directive applied to all Boeing 737 MAX aircraft powered exclusively by the CFM International LEAP-1B engine. Notably, the inlet is manufactured by Boeing rather than the engine maker, which is a joint venture between General Electric (GE) and Safran Aircraft Engines. At the time, the FAA said that changes would have to be made to the aircraft’s existing airplane flight manual (AFM), limiting the usage of the EAI system in certain weather conditions. Furthermore, aircraft operators must amend the minimum equipment list (MEL) to prohibit flights when the EAI valve is locked open. RELATED Transport Canada Directive: Boeing 737 MAX Operators Must Limit Anti-Icing System Airbus A380 storage-related cracks In 2019, Airbus issued an SB to address potential cracks in the Airbus A380 wing outer rear spar (ORS) area, prompting EASA to issue an interim action AD, requiring repetitive special detailed inspections (SDI) of the affected wing ORS with ultrasonic testing methods. However, throughout the years, the issue has continued, including the European warning that additional areas could be affected by the same cracks. As a result, all Airbus A380 had to be inspected according to an EASA AD published in January 2022. Between 2019 and 2022, a lot has changed in the aviation industry, including the pandemic, which resulted in the majority of Airbus A380s being stored for more extended periods due to the lackluster demand for air travel. While the aircraft has seemingly experienced a resurgence since, EASA warned that the severity of the cracks “showed a clear relationship with the amount of time an aeroplane has spent on ground, parked or stored, in severe environmental conditions.” EASA’s last AD addressing the problem was published in December 20223. The regulator said that following an assessment of more initial inspections, there were more findings of higher severity, no longer justifying the inspection criteria as defined by Airbus. As a result, the manufacturer redefined the parameters for the threshold of the inspections, replacing factored time on ground (FTOG) with storage FTOG (SFTOG), which focuses more on the time that the aircraft has spent on the ground. RELATED Airbus To Repair A380s With Wing-Spar Cracking Boeing 777 fuel tank lightning protection In August 2023, the FAA superseded an AD for all Boeing 777 aircraft, ranging from the 777F to the 777-300ER. The previous directive required airlines to check for potential cracks in “the left- and right-side ring chords, repair angles, front spar lower chords, and front spar webs (depending on configuration) common to a certain underwing longeron; modification of the front spar lower chord for some airplanes; repetitive post-modification inspections; and applicable on-condition actions.” The actions mandated by the directive introduced “a new unsafe condition related to the application of certain fastener cap seals,” which could result in a fuel tank explosion. The regulator detailed that the initial AD contained errors “relating to the application of cap seals to fasteners penetrating the center wing fuel tank which introduce a second, urgent unsafe condition.” The fastener cap seals are a critical lightning protection feature, which are located inside the fuel tank. The front spar lower chord and underwing longeron work mandated by the initial AD required operators to remove the cap seals to ensure the aircraft’s airworthiness, yet in the case that the seals are not appropriately replaced, while the associated fastener has poor electrical bonding, it could result in a fuel tank explosion. Read the latest Boeing news here. Similarly, Boeing recently discovered that the bonding jumper outside of the fuel tank of the 747-8 “is failing at an excessive rate in addition to the known degradation of the primary electrical bonding path through the spar fitting.” The condition could also result in a potential fuel tank explosion, with the FAA issuing an AD for all Boeing 747 aircraft in December 2023. Related: Boeing 747 Lightning Protection Must Be Inspected Due To Fast Degradation Ural Airlines admits no plans to return stranded Airbus A320 back to service BY IAN MOLYNEAUX 2024-04-11 Ural Airlines has admitted that it has no plans to return an Airbus A320 that became stranded in a Russian wheat field just outside Novosibirsk, in southern Siberia, back into service. On September 12, 2023, the Airbus A320 with 167 people onboard was forced to land in a Russian wheat field after the aircraft ran out of fuel while diverting to Novosibirsk Airport (OVB). For months following the accident rumors swelled that the A320 would take off once the ground had frozen in winter temperatures or that it would be cut into pieces and airlifted from the field by helicopters. On April 11, 2024, news outlet TASS reported that Ural Airlines said it had spent “9.27 million rubles” ($99,000) on payments to the farmer that owned the field, security, fencing and containers since the aircraft became stranded. Ural Airlines also told TASS that it did not have a plan to return the Airbus A320 aircraft to flights, something that was also widely reported on other Russian news websites. In an additional statement to URA.RU, Ural Airlines said: “We are assessing all the risks and are inclined to not use this aircraft in commercial operation, taking into account the fact that in the current conditions there is no support from the manufacturer Airbus.” On April 11, 2024, the Russian Federal Agency for Air Transport (Rosaviatsiya) also published an investigation report that said the incident arose out of multiple violations and errors made by the crew. Part of the report seen by AeroTime said that the pilots diverted to OVB as they knew the hydraulic system affecting the aircraft could be repaired there. The report said that the crew were concerned that if they landed at their designated destination at Omsk Tsentralny Airport (OMS) it would go against company advice to try and land at airports where there are trained technical personnel to perform troubleshooting work. The report also said that the Ural Airlines board will decide whether two deputy general directors responsible for safety on flights should remain in their positions. AeroTime first reported in November 2023, that the Ural Airline Airbus A320 would be dismantled. At the time Ural Airlines said, “no decisions will be made until the end of the investigation”. Boeing Quality Standdowns Extend Across MRO Segment Christine Boynton April 11, 2024 CHICAGO—Quality standdowns that began within Boeing Commercial Airplanes (BCA) are also extending across the OEM’s Global Services (BGS) segment, a senior company executive said. “Whether that’s in our MRO facilities or in our digital software development teams, we’re doing it across the entire enterprise,” Dan Abraham, BGS VP-Commercial Sales and Marketing, told Aviation Week Network’s MRO Americas conference attendees here. “We’re stopping, we’re pausing, we’re asking questions, we’re meeting with employees, we’re looking at what we’re doing every day and how we do it, so we can get better.” The sessions come as the OEM faces scrutiny from the Jan. 5 Alaska Airlines 737-9 door plug blowout. Focused on quality and improvement, the first of Boeing’s series of work pauses was held Jan. 25 at the 737 MAX production facilities in Renton, Seattle, and Moses Lake, Washington. Boeing’s enhanced surveillance on its own facilities joins an FAA review of all three 737 MAX production lines as well as fuselage supplier Spirit AeroSystems’ work in Wichita. A six-week audit by the agency found “noncompliance issues in Boeing’s manufacturing process control, parts handling and storage, and product control,” FAA said in early March. Describing an “enterprise refocus on safety” Abraham noted, “whether it’s the Alaska incident or any other incident, we’ve been reminded recently that it’s a continual process and effort. It’s something that we have to remain committed to every day, and when you have something like that Alaska incident, it just reminds all of us that we can never stop.” BCA has described the standdown sessions as including “hands-on learning, reflection, and collaboration to identify where quality and compliance can be improved and create actionable plans that will be tracked to closure." A Boeing supplier says it tried using Vaseline, cornstarch, and talcum powder to lubricate a door seal before settling on Dawn dish soap: NYT Kwan Wei Kevin Tan Apr 12, 2024, 12:22 AM CDT The Spirit AeroSystems logo is pictured on an unpainted 737 fuselage as Boeing's 737 factory teams hold the first day of a "Quality Stand Down" for the 737 program at Boeing's factory in Renton, Washington on January 25, 2024. Jason Redmond/AFP via Getty Images • Boeing supplier Spirit AeroSystems said it was being innovative when it used soap as a lubricant. • Besides the soap, FAA auditors say they saw Spirit mechanics use a hotel key card to check a door seal. • Spirit said both practices were approved by Boeing and the FAA. A supplier for Boeing said it tried using other household products like Vaseline and cornstarch as a lubricant before it settled on using liquid Dawn soap, The New York Times reported on Thursday. In March, The Times reported that Federal Aviation Administration's (FAA) auditors saw Spirit AeroSystems' mechanics applying soap to a door seal. The mechanics were also seen using a hotel key card to check a door seal, per an audit report obtained by The Times. "People look at the hotel key card or Dawn soap and think this is sloppy. This is actually an innovative approach to solving for an efficient shop aid," Spirit spokesperson Joe Buccino told The Times. According to Buccino, Spirit also tried using other household products such as Vaseline, cornstarch, and talcum powder as a lubricant before settling on liquid Dawn soap. Buccino said the Dawn soap became their top choice because it didn't cause the door seal to degrade over time. "The employment of nonstandard shop aides demonstrates the kind of innovation we have throughout this company," Buccino told BI. Enhanced Cessna High-Wing Piston Aircraft Enter into Service Following First Deliveries Textron Aviation introduces enhanced Cessna piston aircraft models with modern design features and improved functionality. The new interior designs offer increased comfort and convenience, catering to both student pilots and experienced aviators. Textron's investment in the Cessna lineup showcases a commitment to innovation and customer satisfaction. 04/09/2024 - 10:00 AMWICHITA, Kan.--(BUSINESS WIRE)-- Textron Aviation today announced the entry into service of its enhanced Cessna Skyhawk, Cessna Skylane, Turbo Skylane and Turbo Stationair HD following first deliveries for each aircraft. These latest product investments aim to provide a modern and stylish tone that aligns with the newest Cessna Citation jets, while maintaining the renowned comfort, durability and performance of the iconic Cessna piston lineup. This press release features multimedia. View the full release here: https://www.businesswire.com/news/home/20240408350310/en/ Cessna SEHW Piston Enhancements (Photo: Business Wire) The Cessna Skyhawk, Skylane, Turbo Skylane and Turbo Stationair HD are designed and manufactured by Textron Aviation Inc., a Textron Inc. (NYSE: TXT) company. "These enhancements to the iconic Cessna piston family offer improved comfort, functionality and style,” said Chris Crow, vice president, Piston Sales. “Whether you're a student pilot or an experienced aviator, the extensive product lineup offers something to meet your needs, elevate your flying adventures and inspire the journey of flight." With new features and design elements, the Cessna aircraft continue to be versatile and reliable tools that enable customers to fulfill a wide range of missions. The new interior designs include: • All-new comfortable seats with additional support and padding • Power headset jacks at every seat • A and C USB charging ports at every seat • Sleek, black instrument panels • Thoughtfully placed side and cell phone pockets throughout the aircraft • Integrated overhead air conditioning on equipped aircraft • A new center armrest available on certain models • When it comes to the exterior, owners can select from a variety of new modern exterior schemes to match their preferences. Textron Aviation's investment in the Cessna piston aircraft lineup demonstrates the company’s continued enthusiasm and support for pilots worldwide, whether they are pursuing training ambitions or planning their next adventure. The company remains dedicated to delivering cutting-edge technology and exceptional craftsmanship to the aviation community. The new interior designs will be unveiled at the highly anticipated 2024 SUN ‘n FUN event in Lakeland, Florida. About Textron Aviation We inspire the journey of flight. For more than 95 years, Textron Aviation Inc., a Textron Inc. company, has empowered our collective talent across the Beechcraft, Cessna and Hawker brands to design and deliver the best aviation experience for our customers. With a range that includes everything from business jets, turboprops and high-performance pistons, to special mission, military trainer and defense products, Textron Aviation has the most versatile and comprehensive aviation product portfolio in the world and a workforce that has produced more than half of all general aviation aircraft worldwide. Customers in more than 170 countries rely on our legendary performance, reliability and versatility, along with our trusted global customer service network, for affordable and flexible flight. Enhanced Cessna High-Wing Piston Aircraft Enter into Service Following First Deliveries CFM Delivering Leap-1As With Reverse Bleed System Sean Broderick April 09, 2024 CHICAGO—CFM International has begun delivering Leap-1A new-production engines with its new reverse bleed system (RBS) designed to prevent a fuel nozzle problem linked to carbon deposits and expects to have retrofits available by mid-year. The problem, known as coking, occurs when core engine hardware releases heat, or soaks back, after shutdown. The RBS is designed to eliminate the issue as well as related maintenance inspections and nozzle swaps in place now to mitigate risk. CFM earned certification for the Leap-1A RBS from the FAA and European Union Aviation Safety Agency (EASA) in 2023. The first new-delivery engines with RBSs are expected to enter service around mid-year, on Airbus A320neo-family variants, CFM announced at Aviation Week’s MRO Americas April 9. CFM is working on an RBS for the Leap-1B, which powers the entire Boeing 737 MAX fleet. Both will be available as retrofits as well, with the Leap-1A becoming available by mid-summer. Installation can be done on-wing “in as few as 10 hours,” CFM said. RBS installation training for airlines and MRO shops is available at the GE Customer Technical Education Center in Springdale, Ohio; Safran Aircraft Engines Customer Training Center in Montereau, France; Aero Engine Maintenance Training Center in Guanghan, China; and CFM Aircraft Engine Support South Asia in Hyderabad, India. Coking occurs when residual heat soaks back and heats fuel nozzles’ certain thresholds. If the nozzles get hot enough, unburned fuel around the nozzles is hardened into solid carbon, which affects fuel flow and causes uneven internal combustor temperatures. This leads to reduced on-wing life and in the most extreme cases, in-service issues. The RBS’s main elements are a valve and a blower. After engine shutdown, the valve activates and the blower directs air, in reverse, through the engine bleed duct system into the flow path. This keeps fuel nozzles cool enough to prevent coking. CFM identified the issue several years ago and issued service bulletins with recommended engine inspection and nozzle replacement procedures. Regulators mandated some of them. “This RBS is part of a broader plan to improve engine durability, that will see additional upgrades introduced throughout the year,” CFM President Gaël Méheust said. CFM, a 50-50 GE Aerospace/Safran joint venture, also is introducing redesigned turbine blades to improve durability. New Leap-1A blades are expected to enter service in 2024, while -1B blade testing is just getting started. NTSB Urges Better Prop Inspections By Russ Niles Published: April 16, 2024 After investigating a few aluminum propeller failures, the NTSB has issued a Safety Alert and it’s particularly addressing backcountry pilots. “Aluminum propeller blades can be susceptible to fatigue cracking and fracture if a small nick, pit, or corrosion on the surface or edge is not found and repaired during preflight inspection or maintenance,” the NTSB said in the alert. “Such damage can concentrate stress from normal airplane operation loads, resulting in fatigue crack initiation and growth followed by propeller blade fracture.” The board wants to remind pilots to carefully inspect the prop during each walkaround and get the prop fixed if nicks or cracks are found. It’s also trying to prompt mechanics to make thorough prop inspections part of every annual. Backcountry and aerial spray aircraft are more susceptible because of the increased risk of damage on unimproved runways. But not all blade failures are on Cubs and Cessna taildraggers. The board recently dealt with a Beech 58 Baron that shed a blade on a recent flight. It had last been overhauled eight years previously when it should have been serviced after five years. “If the recommended overhaul had been performed, the corrosion pits that led to fatigue crack initiation would likely have been detected and removed, preventing the blade separation,” the alert said. Boeing claims no findings of fatigue on older 787 jets ahead of whistleblower testimony By Reuters April 15, 20246:02 PM CDT Updated a day ago A Boeing 787-10 Dreamliner taxis past the Final Assembly Building at Boeing South Carolina in North Charleston, South Carolina, United States, March 31, 2017. April 15 (Reuters) - Boeing (BA.N), said on Monday it has not found fatigue cracks on in-service 787 jets that have gone through heavy maintenance, as the planemaker defended the twin-aisle aircraft program ahead of a U.S. Senate hearing on Wednesday. Last week, a Boeing whistleblower alleged that the company dismissed safety concerns about the assembly of its 787 and 777 jets that fly international routes. The whistleblower, Boeing quality engineer Sam Salehpour, is set to testify in the Senate hearing on the company's safety culture. Salehpour has claimed that Boeing failed to adequately shim, or use a thin piece of material to fill tiny gaps in a manufactured product, an omission that could cause premature fatigue failure over time in some areas of the Boeing 787 Dreamliner. His claims, which are being investigated by the U.S. Federal Aviation Administration (FAA), include remarks that he saw workers "jumping on the pieces of the airplane to get them to align." Boeing has been grappling with a full-blown safety crisis that has undermined its reputation following a Jan. 5 mid-air panel blowout on a 737 MAX single-aisle plane. On a call with reporters on Monday, two senior Boeing officials said there were zero airframe fatigue findings among the near 700 in-service Dreamliner jets that have undertaken heavy maintenance inspections after six years and 12 years. Advertisement · Scroll to continue "All these results have been shared with the FAA," said Steve Chisholm, Boeing's chief engineer, mechanical and structural engineering. Boeing halted deliveries of the 787 widebody jet for more than a year until August 2022 as the FAA investigated quality problems and manufacturing flaws. In 2021, Boeing said some 787 airplanes had shims that were not the proper size and some aircraft had areas that did not meet skin-flatness specifications. The 787, which was launched in 2004, had a specification of five-thousandths of an inch gap allowance within a five-inch area, or "the thickness of a human hair," said Lisa Fahl, vice president of Boeing Commercial Airplanes airplane programs engineering. She said reports of workers jumping on plane parts were "not part of our process." Salehpour's attorney, Debra Katz, said in an emailed statement that her client tried for years to see data that would address his concerns about the safety of gaps in the 787. "Any data provided by Boeing should be validated by independent experts and the FAA before it is taken at face value,” Katz said. Reporting by Allison Lampert in Montreal Editing by Matthew Lewis Air Force’s costliest accidents, maintainer injuries rose in 2023 By Courtney Mabeus-Brown Monday, Apr 8 A crew chief conducts engine inspections on a C-17 Globemaster III at Joint Base McGuire-Dix-Lakehurst, N.J., Jan. 24, 2024. Two people died and 10 aircraft were destroyed in aviation-related mishaps in fiscal year 2023 as the Air Force’s most serious accidents hit a five-year high. The latest milestone was driven by a jump in the deadliest and most expensive accidents, most of which occurred in flight. But an Air Force Times analysis of the service’s safety data found that even as the number of airborne mishaps has plateaued, a spike in maintenance-related incidents has cost the Air Force millions of dollars and — increasingly often — injured airmen on the job as well. Deadly aircraft accidents declined in 2021, Air Force saysSixty-three of the most severe kinds of aviation accidents, known as Class A and Class B mishaps, were reported last year, down from 71 in fiscal 2020. As of April 1, the service had recorded 75 major non-combat mishaps in FY23, which ran from Oct. 1, 2022, to Sept. 30, 2023. That’s up from 67 in the year prior, and from 63 in FY19, according to the Air Force Safety Center. Ground accidents comprised more than 28% of those mishaps in FY23 — up from 19% two years earlier. The increase in Class A and B incidents comes as the Air Force juggles a decades-old inventory with operational demands and a stretched-thin maintainer corps, even as efforts ramp up across the Defense Department to curb the number of accidents involving military vehicles. “Every mishap is different, and each is investigated individually and thoroughly to identify causal factors in efforts to prevent similar mishaps,” Maj. Gen. Sean Choquette, the Air Force’s safety chief, told Air Force Times. “Our goal is to understand the associated hazards, and to eliminate or mitigate them to [the] greatest extent possible in both training and combat operations.” A U.S. Air Force F-15D assigned to the 173rd Fighter Wing sits in a Bureau of Reclamation canal on the south side of the runway after a mishap at Kingsley Field in Klamath Falls, Oregon, May 15, 2023. Absorbent booms surround the aircraft as precaution against the leakage of fuel or other substances. Key findings From nose gear failures to destructive debris, the Air Force saw 52 flight mishaps, 21 ground mishaps — nearly double those in each of the previous two years — and two “flight-related” mishaps among Class A and B incidents in FY23, the Safety Center said April 1. Figures can change as investigations progress after the fiscal year ends. MQ-9 Reaper drones logged 10 mishaps in FY23, more than any other airframe, Air Force data showed. The F-22 Raptor fighter led manned aircraft in mishaps at nine accidents, followed by the CV-22 Osprey tiltrotor transport aircraft and C-17 Globemaster III airlifters at seven incidents each. MQ-9s, C-17s and the F-35 Lightning II fighter saw the highest number of the most severe events, known as Class A mishaps. The Air Force logged 29 Class A mishaps in 2023, up from 24 the previous year; the service averaged almost 27 annually over the last five fiscal years. Class A accidents involve a death or permanent total disability, destruction of a U.S. military aircraft, damages of more than $2.5 million, or a combination of those three criteria. Less-serious Class B mishaps, which can also be life-altering, rose from 43 in 2022 to 46 in 2023. The service has averaged around 41 Class B accidents in the past five years. Those incidents cause between $600,000 and $2.5 million in damages, a permanent partial disability, inpatient hospitalization of three or more personnel, or a combination of those factors. Stephanie Rodriguez-Cosme, 32, of Palmdale, Calif., died Sept. 7, 2023, after she was struck by an MQ-9 Reaper drone's spinning propeller during ground testing. Human toll FY23 fatalities included Stephanie Rodriguez-Cosme, a 32-year-old test engineer and contractor who was struck by an MQ-9′s whirring propeller during ground testing, as well as a civilian employee of the Missile Defense Agency who died after experiencing health problems while flying on a C-17. Neither death was disclosed at the time of the incident; the Air Force allows local commanders to decide whether to publicly announce a fatality. An Air Force investigation, the results of which were released April 5, found that Cosme was incorrectly trained on taking data readings from the drone with its engine running, and wasn’t paying close attention as she approached the aircraft. The investigation report also cited a lack of clear communication between contractors and ground support personnel, and said they were rushed because of previous delays. The service declined to provide more details about the C-17 mishap. The Air Force typically records fewer than six mishap-related deaths each year. But the human toll of aviation accidents isn’t limited to fatalities: • On Feb. 27, a contractor was trapped under a T-38 Talon training jet when its nose gear collapsed during ground maintenance at Holloman Air Force Base, New Mexico. Others freed the maintainer, who was airlifted to a hospital and spent several days in treatment for multiple broken bones and other injuries. • On May 15, a pilot was treated for minor injuries after an F-15D Eagle assigned to the Oregon Air National Guard’s 173rd Fighter Wing experienced an in-flight emergency and skidded off the runway, landing in a canal. • On July 31, a U.S. Air Force Academy cadet landed in the hospital for more than three months after becoming entangled during freefall parachute training. The academy stopped flying for the day and paused parachute training until the next class, which began in October, said Sean Worrell, a spokesperson for the 12th Flying Training Wing. The accident did not spur any changes in policy or procedures, Worrell said. • On Aug. 17, a maintainer was injured by debris when the propeller from one CV-22 Osprey struck another that was parked. Propellers on both aircraft were damaged. • On Aug. 22, an Osprey lost control and hit the ground, damaging its belly and injuring a crew member upon impact. An Air Force Safety Center spokesperson called maintainer injury the top aviation mishap trend that arose in FY23, including a 16% increase in head injuries. The service has tried to curb the number of head injuries through bump caps — lightweight plastic hats or inserts that can lessen the force of impacts — but is reassessing that strategy. While the Safety Center declined to specify what steps it’s taking to keep airmen safe at work, it said it surveys how airmen perceive the amount of risk within their squadrons. Better scores on those surveys can reflect fewer workplace injuries. “Commanders are debriefed on mission areas that are both performing well and those areas needing attention,” the organization said. “This helps command teams to target higher-risk areas, efficiently manage resources and conduct additional training.” Major crashes Meanwhile, manned and unmanned aircraft alike suffered higher rates of the worst accidents. For manned aircraft, the service logged about 1.18 Class A mishaps per 100,000 flying hours — the highest since FY20, when the rate spiked to 1.34 accidents in the same timespan, according to the Air Force. For unmanned aircraft, that rate hit 2.91 incidents per 100,000 flying hours, the most since FY16, when the service saw 3.58 mishaps per 100,000 flight hours. The service did not provide its total number of flight hours in FY23 by press time. The Air Force also saw 10 aircraft totaled, at a rate of 0.58 per 100,000 flying hours. That’s an increase from six destroyed aircraft in FY22, and the most since 2020, when 14 airframes were ruined. Still, Class B mishap rates among manned aircraft fell from 2.14 to 1.95 accidents per 100,000 flight hours between FY22 and FY23. The rate for unmanned aircraft also fell from 0.44 to 0.23 accidents per 100,000 hours in the same time frame. Aircraft destroyed last year included six MQ-9s, which suffered from a variety of problems ranging from engine and electrical system failures to loss of control. Drones are often seen as more dispensible because they are cheaper to replace than manned aircraft and don’t have a human life in the cockpit. Airmen visit an MQ-9 Reaper from the California Air National Guard's 163rd Attack Wing at Springfield-Beckley Air National Guard Base, Ohio, March 18, 2024. (Airman 1st Class Colin Simpson/Air National Guard) The service also lost three manned jets: • In October 2022, an F-35A crashed at Hill Air Force Base, Utah, when turbulence confused its software. • In November 2022, a T-38C Talon training jet crashed in Mississippi after a bird strike shattered its windshield and broke its engines. • In May 2023, an F-16 Fighting Falcon assigned to the 8th Fighter Wing at South Korea’s Kunsan Air Base crashed in an agricultural area about a dozen miles from base during a training sortie. Safety Center data does not indicate what caused that accident. Pilots in each of those mishaps ejected safely. More recently, a UH-1N Huey from the 37th Helicopter Squadron, based at F.E. Warren AFB, Wyoming, crashed and flipped over in a hard landing at Cheyenne Regional Airport during routine training on Aug. 30. Three crew members were treated and released from a local hospital that day, the Air Force said. Engine woes, frequent FOD Engine problems were among the most frequent culprits behind mishaps across multiple fleets. The aging C-17 led the way with five engine-related incidents, four of which occurred while in flight. 1st Lt. Peyton Craven, a spokesperson for Air Mobility Command, didn’t respond to a question about the C-17′s engine issues but blamed the problems on old, overworked aircraft. While the command totaled 12 accidents in FY23, it saw the lowest mishap rate in five years, and a 13% drop from the previous year, Craven said. “The majority of the mishap causes are consistent with what we would expect from aging airframes and flight hour totals,” Craven said. V-22 Osprey fleet will fly again, with no fixes but renewed training. The V-22 is allowed to fly again, and the services will each implement their own training and maintenance protocols to get the fleet back to operations. Raptors and Ospreys tied as the aircraft with the second-highest number of engine problems, with four such mishaps apiece. In two cases, maintainers encountered damage while installing engines in an Osprey, including a winch cable that broke, damaging several components like the input quill. Choquette noted that overall, major engine issues have decreased over the last decade, but did not say by how much. “Our aviation engineering branch directly engages with the Air Force Life Cycle Management Center and the individual aircraft systems safety groups to identify trends at the airframe level,” Choquette said. “These engagements lead directly to policy and procedure updates to enact corrective actions.” Wayward debris was also a factor in at least 10 mishaps. On Aug. 14, an Osprey assigned to the 352nd Special Operations Wing at England’s RAF Mildenhall made a precautionary landing for a potential bird strike. Instead, crews found a plastic bag in its engine, which was replaced. In at least two mishaps, flashlights were sucked into jet engines, including one that caused about $4 million in damages to an F-35 assigned to the 56th Fighter Wing at Luke AFB, Arizona, an investigation revealed. A "Golden Bolt" sits on the flightline at Moody Air Force Base, Georgia, Aug. 29, 2023. The Golden Bolt is an incentive used to encourage airmen to continue thoroughly inspecting their area and looking for debris. Foreign object debris, as such trash is known in military parlance, was one factor that led the number of ground accidents to nearly double from 11 in 2022 to 21 in 2023. Other ground mishaps ran the gamut from engine fire to collisions in transit. In four cases, an aircraft struck another object or was otherwise damaged while being towed. F-22s were damaged in two separate instances: one aircraft struck a hangar door while being towed, while another hit a parked forklift. The Safety Center has taken notice of the rise in problems on the ground, Choquette said. Aviation safety staff have flagged the issue of towing-related mishaps to maintenance leaders across the service, and are considering ways to improve unit-level oversight of ground maintenance. “We analyzed safety board findings from across our major commands and shared recommendations widely to reduce [the recurrence] of these types of mishaps,” Choquette said. “Additionally, we are assessing the ability to assign safety-trained personnel to our maintenance units just as we do in flight units. Our goal is to increase safety expertise and immediate access to risk management data and tools on the maintenance line.” That idea, which could take the form of an official instruction, will be reviewed in the next month, according to a Safety Center spokesperson. The uptick in ground mishaps comes as the Air Force tries to build experience in a young workforce while battling a maintainer shortfall that was expected to grow to nearly 1,800 active duty troops by the end of FY23. Their grueling operational tempo “is leading to unsafe practices and driving experienced aviators and maintainers out of the force,” the National Commission on Military Aviation Safety wrote in its sweeping 2020 report on the topic. “More maintainers would help,” one airlift squadron leader told the commission. “But what would really help is more experienced maintainers. It takes about three years to get good at your job, doing it every day. We’re not even getting to that point with our young airmen.” An MB4 tow tractor pulls an F-22 Raptor to be refueled by a C-17 Globemaster III at Nellis AFB, Nev., Feb. 2, 2024. The fixes Air Force officials offered few specifics about whether last year’s mishaps have prompted changes to policies or procedures. Where Choquette noticed emerging themes among incidents on the ground, Col. Tony Babcock, who oversees policy, procedures and resources for the maintainer corps, argues that FY23 data doesn’t indicate a trend. Training and retaining a highly skilled maintainer corps will help reduce future mishaps, he told Air Force Times. Pay and assignment incentives are being considered to keep airmen in uniform. The service has emphasized the use of augmented- and virtual-reality tools in maintenance classes to help build muscle memory alongside real-world training, he added. “AR/VR does not replace hands-on skill building, but does provide opportunities to engage the students in a different way by enabling familiarity with aircraft,” Babcock said. Air Combat Command and Air Mobility Command, which led the major commands in Class A and B accidents last year at 17 and 12 incidents, respectively, said they look for problematic trends via multiple sources — like accident investigations, safety audits and airmen’s anonymous reports — and adjust policy and tactics as needed. Air Force Special Operations Command logged 12 mishaps in the top two categories as well, followed by Air Education and Training Command at 11, the Air National Guard at seven, Air Force Global Strike Command and Pacific Air Forces at five each, the Air Force Reserve at two and U.S. Air Forces Europe at one. One mishap did not belong to any of the service’s major commands. Since taking command of the Safety Center last August, Choquette says he’s focused on “operationalizing safety and improving data analytics and risk management tools,” to include developing artificial-intelligence tools that help identify risks. The center on April 2 published a new strategic plan pledging to better manage workplace risk, particularly in the nuclear and space enterprises and during deployments. But military aviation is inherently risky, the Safety Center said, and human error almost always plays a role in accidents. “The biggest challenge to reducing mishaps is continued vigilance in ensuring disciplined operations and risk management across all aspects of day-to-day operations,” Choquette said. About Courtney Mabeus-Brown Curt Lewis