March 13, 2024 - No. 11 In This Issue : FAA Issues New Warning Of Wiring Issue On 737 MAX Wing Spoilers : Is Boeing About To Buy Back Spirit AeroSystems? UPDATED : GPS Jamming On The Increase Near Russia : Aircraft Cabin Air International Conference - 17 & 18 September - London : MGL COLOR AIRSPEED / VSI INDICATOR - BLAZE SERIES : Bjorn’ s Corner: New aircraft technologies. Part 49. Engine Maintenance : NTSB Investigating Another Boeing 737 MAX Aircraft : Investigators say they confirmed pilots' account of a rudder-control failure on a Boeing Max jet : Ospreys Cleared to Fly Again After Deadly Crash Despite Mechanical Failure with Unknown Cause : PIPER RUDDER AD 'TARNISHES' PROCESS, AOPA CONTENDS February 27, 2024 By Jim Moore : What’s the problem with my #4 cylinder? FAA Issues New Warning Of Wiring Issue On 737 MAX Wing Spoilers Marisa Garcia Senior Contributor Mar 11, 2024,07:05am EDT The Federal Aviation Administration has published a new proposed airworthiness directive for BoeingBA -4.3% 737 MAX planes following reports of improperly installed spoiler wire bundles. This fault has caused unintended rolls in flight and could lead to pilots losing control of the aircraft. The FAA was prompted to issue the AD following a report of “a non-conforming installation of spoiler wire bundles that led to unintended spoiler motion, including one instance of spoiler hardover.” Spoilers are panels mounted on wings that, when extended, disrupt airflow over the wings, resulting in increased drag and less lift. If a spoiler ‘hardovers,’ it has reached its maximum limit and is effectively jammed. FAA Reports ‘Multiple Unusual Spoiler Deployments’ On 737 MAX Planes The FAA has received reports of “multiple unusual spoiler deployments, which resulted in an un-commanded roll to the right” during the cruise phase of flight. The FAA investigation “identified the potential for a hardover of more than one flight spoiler on the same wing, which can exceed full lateral control capability leading to loss of control of the airplane.” In the cases reported, the “spoilers” warning light on the aircraft affected switched on, and the spoiler control electronics issued a spoiler fault code. The FAA says the fault was “intermittent and was seen on multiple flights.” The root cause was determined to be “wire chafing damage due to spoiler control wire bundles riding on the landing gear beam rib in the right wing trailing edge due to non-conforming installation of spoiler wire bundles that occurred during production.” The FAA issued a notice of proposed rule-making after determining that the “unsafe condition..is likely to exist or develop on other products of the same type design.” Boeing issued an alert bulletin for this issue on July 14, 2023. The bulletin notifies operators and maintenance organizations of necessary inspections and repairs. It specifies procedures for measuring spoiler control wire bundle clearance and details how to ensure adequate clearance when the fault is found. The FAA’s proposed AD would make completing the tasks specified by Boeing’s alert bulletin mandatory to address this “unsafe condition” on Boeing’s 737–8, 737–9, and 737–8200 MAX planes. “The agency has no way of determining the number of aircraft that might need these repairs,” the FAA notes in the advisory bulletin. It estimates costs for inspection at $85, and repairs at $425. Boeing Has More Issues To Address The FAA has also asked Boeing to address a 737 MAX design problem that could disable the jet’s anti-ice system, potentially leading to “loss of thrust on both engines.” Boeing must also address a separate de-icing fault that affects Boeing Model 787–8, 787–9, and 787–10 Dreamliner airplanes in service. Following an unfavorable report by an Organization Designation Authorization Expert Review Panel examining Boeing’s Safety Management System, the FAA has given the aircraft manufacturer a 90-day deadline to present a turnaround plan. Boeing must detail corrective actions that would address the expert panel’s findings and multiple non-conformances identified during a six-week FAA audit. The Department of Justice is conducting a criminal investigation into the Alaska AirlinesALK +3.3% Boeing 737-9 MAX mid-exit door plug blowout. Boeing has admitted it could not find documents to explain why the door plug was removed and replaced during Spirit AeroSystemsSPR -7.8% repair work conducted at Boeing’s Renton facility to fix rivets on the edge frame on the Alaska Airlines 737 MAX 9. According to reports, the DOJ will look into whether Boeing complied with the terms of its 2021 settlement after two deadly crashes attributed to faults in Boeing’s 737 MAX Maneuvering Characteristics Augmentation System. Is Boeing About To Buy Back Spirit AeroSystems? UPDATED By Spyros Georgilidakis | March 1, 2024 Boeing is in discussions that could see it buy aerostructures supplier Spirit AeroSystems, in a possible bid to limit its quality problems, among other things. The company that is now called Spirit AeroSystems in Wichita, Kansas, used to operate as Boeing Wichita. This was until 2005 when Boeing “off-loaded” the operations to a group of investors. At its creation, the new company continued producing the same parts for Boeing as it always had. The reason Boeing sold the operation was because its management wanted to focus on Boeing’s “core” activities. And somewhat oddly, this didn’t include the Wichita aerostructures facility. Boeing identified its focus to be aircraft design and final integration and assembly. The Wichita site wasn’t the only such Boeing asset to go, but it was arguably the biggest. Initially, the split seemed to work. Spirit made and continues to make large structures for all Boeing aircraft, including the entire fuselage of the 737. After the split, Spirit expanded by buying more aerostructures operations worldwide. It also got new customers, including Airbus. Spirit bought a number of facilities on the east side of the Atlantic Ocean. One of these was the former Short Brothers aircraft manufacturing plant in Belfast, Northern Ireland, which makes wings for the Airbus A220. Spirit makes components for many more Airbus aircraft at other sites, including composite fuselage sections and other key parts for the A350. Boeing Buying Spirit – Righting a Wrong? Fast forward to 2023 and 2024, and the situation between Boeing and Spirit looks decidedly less rosy. Last year, Jon Ostrower in The Air Current made an extensive dive into the problematic relationship between the two companies. Not only did the arrangement have a lot of inefficiencies, but it also limited Boeing’s ability to control quality in the Wichita plant. Boeing repeatedly had to send employees over, to investigate high numbers of faulty Spirit parts. Photo: NTSB This didn’t just impact Boeing’s quality, it also slowed down production. But even though many Boeing executives agreed that spinning off “Boeing Wichita” was a bad idea, a reversal seemed very unlikely. Boeing’s management has repeatedly dismissed the possibility of a Spirit tie-up. Among other reasons, this was because buying back Spirit wouldn’t come cheap. Boeing’s finances have taken a series of hits since 2019. And of course, re-integrating Spirit into Boeing would mean off-loading some assets. Like those involving Airbus parts manufacturing, for example. Well, now the news is that Spirit is in discussions with Boeing for a possible merger. And at the same time, Airbus is talking with Spirit about purchasing its Belfast A220 wing facility. Some European Help? Some would ask, why Airbus would effectively spend money to help Boeing acquire Spirit. That’s assuming that Airbus’ investment is necessary for such a deal, which isn’t a given. However, the A220 is the only aircraft for which Airbus currently doesn’t produce the wing in-house. And streamlining the A220 supply chain is an ongoing goal for the European manufacturer. On the west side of the Atlantic, Boeing must show regulators, lawmakers, and the public that it is serious about tackling its quality issues. And bringing Spirit back in-house could be a way for Boeing to send a strong message. The NTSB’s preliminary report on the Alaska 737 MAX-9 blowout, along with whistleblower accounts of the sequence of events that led to the omission of fitting four bolts and nuts to the door plug, describe a problematic back-and-forth between workers of the two companies. It likely wouldn’t have happened, if everyone worked for the same employer. Opened plug (left) and closed later (right) with bolts missing, during interior work. But can Boeing actually afford to buy Spirit today? Spirit’s stock value has dropped substantially following the events of the past few months. Even before the Alaska accident, two quality issues with 737 production that became public last year, hurt the supplier’s value. That said, the news of such a merger caused Spirit’s shares to gain 13% in value. It will be interesting to see if Boeing can muster regulatory support for such a move. Even after taking on Airbus work, over 60% of Spirit’s revenue involves parts for Boeing aircraft. Update: Boeing Releases Statement on Talks With Spirit Late on Friday the 1st of March, Boeing released a statement, confirming that talks with Spirit are ongoing: We have been working closely with Spirit AeroSystems and its leadership to strengthen the quality of the commercial airplanes that we build together. We confirm that our collaboration has resulted in preliminary discussions about making Spirit AeroSystems a part of Boeing again. We believe that the reintegration of Boeing and Spirit AeroSystems’ manufacturing operations would further strengthen aviation safety, improve quality and serve the interests of our customers, employees, and shareholders. Although there can be no assurance that we will be able to reach an agreement, we are committed to finding ways to continue to improve the safety and quality of the airplanes on which millions of people depend each and every day. Source GPS Jamming On The Increase Near Russia By Spyros Georgilidakis | February 29, 2024 Three European countries are reporting an increase in GPS jamming in parts of their airspace, and they believe it is originating from Russia. It has now been two years since Russia’s renewed attack on Ukraine. And soon after those events, there were reports of GPS jamming and even spoofing attempts, in various areas close to Russia. These GPS disturbances haven’t stopped. On the contrary, countries like Finland, Norway, and Poland are reporting that GPS signal interference may be getting broader. Finland was one of the first countries to report such interference, early in 2022, as Finnair crews flew near Kaliningrad. Finland then identified GPS disturbances coming from the east of the country. Weeks later, Poland and other countries identified other areas with likely GPS jamming activity. These areas included the Black Sea, and even affected areas with Russian presence but away from Russia itself, like the Eastern Mediterranean. Photo: Tomas Piachewski GPS Jamming – A Problem For More Users Aviation authorities have been maintaining and updating a list of areas with such disturbances. Close to Russia’s border, GPS jamming is now a regularity and affects both military and civil aircraft, including air ambulances and police helicopters. Helicopters, in particular, often depend on GPS. Unlike other aircraft, air ambulances and police helicopters need to use GPS for navigation in more ways than simply to fly between airports and/or helipads. Locating missing people or people in distress often relies on GPS coordinates, with few if any alternatives in case of jamming. Russia reportedly interferes with GPS signals in order to defend against drones and other devices near its borders. It is worth remembering that, despite its dominant, daily presence in civil hands, GPS remains a military tool. The reason it came to be was to guide military assets and weapons to their targets. Other Global Navigation Satellite Systems (GNSS) were conceived for broader purposes. But GPS remains the most popular GNSS in use. Plus, other such systems are subject to jamming or spoofing, just like GPS. MGL COLOR AIRSPEED / VSI INDICATOR - BLAZE SERIES By Larry Anglisano February 21, 2024 Overview The ASV-2 is a 3 1/8” sunlight readable encoding altimeter, airspeed and wide range vertical speed indicator. The altimeter contains an internal high accuracy 24 bit digital altitude sensor which calculates altitude from -1000 ft up to a maximum of 35000 ft. The ASV-2 outputs various formatted RS232 serial data protocols compatible with serial input transponders such as that from Garmin, Magellan, Northstar, Trimble, Microair etc. The altimeter can display altitude in feet or meters and local pressure can be set in millibars or inches of mercury. The VSI indicator can be displayed in either feet/minute (ft/min) or meters/second (m/s). The VSI can be calibrated by the user once the instrument has been installed in the aircraft. Airspeed is based on the pressure generated by a pitot tube system and a static port is provided as well for use in high speed aircraft. The ASV-2 instrument measures airspeed from 16mph to 250mph and is well suited to slower aircraft due to very good sensitivity and linearity at low air speeds. Airspeed can be indicated in statute miles per hour (mph), kilometers per hour (km/h) or knots (kts). The ASV-2 also provides a programmable Vs and Vne airspeed alarm output. ASI sensitivity can be calibrated by the user to cater for errors caused by pitot tube placement. In addition, the ASV-2 provides an encoder test function, flight timer since takeoff and records the maximum airspeed reached. The ASV-2 provides a parallel Gillham code interface when used in conjunction with the MGL Avionics CNV-ALT. Features • An internal high accuracy 24 bit digital altitude sensor calculates altitude from –1000 ft up to a maximum of 35000 ft (-304m to 10668m) • The ASV-1 outputs various formatted RS232 serial data protocols compatible with serial input transponders such as that from Garmin, Magellan, Northstar, Trimble, Microair etc. • Provides a parallel Gillham code interface for transponders when used in combination with the MGL Avionics CNV-ALT • Built in encoder test function • The altimeter can display altitude in feet or meters • Local pressure can be set in millibars or inches of mercury • Contains a wide range VSI indicator from +/-20 ft/min to as high as +/-10000 ft/min • VSI units can be in feet/minute (ft/min) or in meters/second (m/s) • Measures airspeed from 16mph to 250mph and is well suited to slow aircraft due to very good sensitivity and linearity at low air speeds • Includes a flight timer since takeoff • Airspeed units can be set to miles per hour (mph), kilometer per hour (km/h) or knots (kts) • Contains a programmable Vs and Vne airspeed alarm output • Records maximum airspeed reached in permanent memory Bjorn’ s Corner: New aircraft technologies. Part 49. Engine Maintenance March 8, 2024 By Bjorn Fehrm March 8, 2024, ©. Leeham News: We are discussing the different phases of a new airliner program. After covering the Design and Production, we now look at the Operational phase of a new airliner family. For the operational phase, the airplane must pass scrutiny for Continued Airworthiness. The biggest item in a regulator’s Instructions for Continued Airworthiness is the required Maintenance program to keep an airliner airworthy. We discussed airframe maintenance in the last article. Now, we look at engine maintenance. Figure 1. The CFM56-7 engine for the Boeing 737NG. Source: CFM. Engine Maintenance requirements The engines on an airliner are the most important system for its safe flight. They are also the most expensive part of the aircraft’s maintenance, with engine maintenance costs normally exceeding the airframe maintenance costs over an aircraft’s lifetime. Engines undergo strict certification programs, where rules for overseeing the engine and its maintenance are established. The maintenance concept combines On-Condition maintenance with Hard-limit maintenance. On Condition Maintenance On-condition maintenance constantly oversees critical engine parameters, such as engine use, temperatures, vibrations, oil deposits, and wear, as seen during optical inspections of the engine’s internals through borescopes. The most important parameter is the temperature of the engine’s turbine section. The turbine section has an Exhaust Gas Temperature, EGT, sensor placed in the low-pressure turbine area (Brown module in Figure 1). The EGT is only allowed a certain highest value; otherwise, parts of the hot section of the engine can be damaged. As an engine wears, the engine’s control computer (FADEC) injects more fuel into the combustor to keep the rated thrust level at takeoff and climb. This gradually raises the EGT as the engine gets worn by use. Figure 2 shows the typical EGT profile during the engine’s highest stress point, takeoff. During the rest of the flight, temperatures are lower, and engine wear is less. The diagram shows a new engine with the largest margin between the maximum allowed EGT (red line) and the peak value during takeoff (Blue curve). Figure 1. EGT values during takeoff for an engine during different phases in its life. Source: Leeham Co. A worn engine gradually narrows the margin between the EGT and the maximum allowed EGT. At a certain point, the engine is removed from the wing and sent for a hot parts performance restoration shop visit (Orange curve). An engine that has passed its first engine performance restoration shop visit does not regain the full EGT margin of a new engine. Thus, the number of takeoffs until the next shop visit due to EGT margin loss will be lower than for a new engine (Cyan curve). The time of shop visits due to EGT margin is determined by flight safety concerns (engine damage) and economic factors, as the restoration cost increases nonlinearly beyond a certain engine deterioration. Hard timed limits During the design and certification of the engine, the OEM and regulator agree on the life limits of critical parts of the engine. Most of the limits are fatigue limits for shafts, discs, and blades in engine compressors and turbines. An engine is designed to handle the loss of a fan blade due to a bird strike or similar event (it has a fan case that can contain a lost fan blade), but it’s not designed to contain a compressor, turbine blade, or parts of a burst disc. Thus, such an event must not happen. Therefore, the regulators and industry have developed methods to calculate the fatigue limits of engine parts. The OEM proposes such limits to the regulator as part of the engine certification, which the regulator accepts as the start limits for the engine. Gradually these limits are increased as in-service experience is gained with the engine. These parts are called Life-Limited Parts, LLPs. At a certain Flight Cycle limit, these parts must be replaced with new ones. The cost of a complete LLP stack can be up to a third of the new engine price. Thus, an engine’s LLP limits are an important safety and cost parameter. Short Haul versus Long Haul engine limits Short-haul engines are predominantly worn by takeoffs, thus the Flight Cycles (FC). They are takeoff stressed up to 10 times a day, with flight times of an hour or two. Typical for a mature engine like the CFM56 is that the engine has a performance shop visit at half the LLP Flight Ccyle limit, and then a full engine overhaul is done when the LLPs are due for replacement. These limits vary between engines and how mature the engine designs are, but typical short-haul values for mature engines are 10,000 to 15,000 flight cycles for the Performance Restoration shop visit, and then the full overhaul with LLP stack changes at 20,000 to 25,000 Flight Cycles. New engine types have early lives with limits as low as half these values. Long-haul engines live a different life. They take off one or two times a day and then spend an average of six to eight hours at lower-temperature cruise conditions. Here, engine erosion and corrosion, especially from salty or dusty air, dictate engine wear. These engines stay on the wing for 5,000 to 8,000 Flight cycles when they have reached a mature state, representing 30,000 to 50,000 Flight Hours. Such engines often only have one LLP change cycle. The influence of the environment When discussing how long an engine will stay on the wing, the environment where the aircraft flies has a large influence. An inland climate without hot temperatures is a benign environment, while a hot and dusty Gulf Area is a Harsh environment. A seaside environment like an island or coast area is also a Harsh environment. The time on the wing can change by a factor of two between these environments. Shop visit costs About two-thirds of the shop visit costs are for replacement parts like turbine/compressor blades, stator, or combustor parts. The parts costs are even higher for the visits where LLPs are changed. Restoration visits are in the single-digit million dollars for engines like the CFM 56, whereas the full visits, including the LLPs, cost close to $10m. Long-haul engine shop visits exceed the $10m mark, with the largest engines costing double that. Add the LLP stack, and we talk even higher values. NTSB Investigating Another Boeing 737 MAX Aircraft Zachary Folk Forbes Staff Mar 7, 2024,01:39pm EST Updated Mar 7, 2024, 03:12pm EST TOPLINE The National Transportation Safety Board announced on Thursday it was investigating the Boeing 737 MAX 8 after a pedal that controls the rudder became “stuck” while an aircraft attempted to land in February, two months after beginning an investigation into the 737 MAX 9. The investigation was opened after a 737 MAX 8 experienced steering issues while trying to land. KEY FACTS The investigation began after a United Airlines flight experienced a close call while trying to land at Newark Liberty International Airport on Feb. 6, according to the NTSB’s preliminary report on the incident. While trying to maintain a centerline on the runway to land in Newark, the United flight’s captain reported his rudder pedal remained in “neutral” position while they applied a “normal” amount of foot pressure. The captain was able to safely land the plane with no injuries by using the aircraft’s nosewheel steering tiller, the report noted, and the pedal began functioning normally about 30 seconds after touchdown. The plane’s first officer also confirmed their rudder pedal stopped working during the landing, and data from the aircraft’s flight data recorder corroborated the pilots’ accounts. The NTSB could not initially reproduce the error, but further testing of the plane’s rudder control system revealed that “cold soaking” certain parts could have caused the pedals to not respond (the NTSB said they would continue to investigate this potential issue). Both Boeing and United told Forbes in statements the aircraft returned to service last month, and United said the part causing the issues was only present on nine aircraft in its fleet, which have all since replaced the part. KEY BACKGROUND The 737 MAX planes, which have only been flying since 2017, are Boeing’s best selling aircraft. However, they have been controversial for years after two 737 MAX 8 aircraft crashed less than a year apart. In October 2018, a Lion Air flight from Indonesia crashed into the Java Sea, killing 189 passengers and crew members. Five months later, an Ethiopia Airlines flight crashed in the East African nation, killing all 157 occupants. The FAA grounded all 737 MAX aircraft after the two crashes, but later cleared them to resume operations in 2020. NEWS PEG Boeing is under increasing scrutiny from federal regulators after a door plug on a 737 MAX 9 detached mid-flight on an Alaska Airlines flight. The incident caused the FAA to ground 171 MAX 9 jets, which have since largely resumed flying. After an investigation, the NTSB found the Alaska Airlines jet was missing bolts attaching the door plug to the aircraft. The agency also warned that Boeing has a “quality control problem.” The NTSB has continued to criticize the aircraft manufacturer, telling a Senate committee on Wednesday that the company has still not provided all the information investigators have requested since the close call in January. Investigators say they confirmed pilots' account of a rudder-control failure on a Boeing Max jet Story by DAVID KOENIG, AP Airlines Writer © Provided by The Associated Press Federal investigators said Thursday they confirmed pilots' account of a brief failure of rudder controls on a Boeing 737 Max after it landed at Newark Liberty International Airport in New Jersey last month. United Airlines pilots said pedals that control rudder movement on the plane were stuck as they tried to keep the plane in the center of the runway during the Feb. 6 landing. The pilots were able to use a small nose-gear steering wheel to veer from the runway to a high-speed turnoff. The rudder pedals began working again as the pilots taxied to the gate with 155 passengers and six crew members on the flight from Nassau, Bahamas, according to a preliminary report by the National Transportation Safety Board. Boeing said this is the only rudder-response issue reported on a Max, although two similar incidents happened in 2019 with an earlier model of the 737 called NG or next generation, which has the same rudder-pedal system. The manufacturer said the issue was fixed by replacing three parts. The plane has made dozens of passenger-carrying flights since then, according to data from FlightAware. United said the parts were related to a landing feature that was designed for other airlines, and United has only nine planes with those parts. The airline said it will work with Boeing, the NTSB and the Federal Aviation Administration “on next steps for these aircraft.” Related video: NTSB investigates Boeing 737 Max after 'stuck' rudder pedals incident at Newark Airport (News 12 (Video)) NTSB investigates Boeing 737 Max after 'stuck' rudder pedals incident at Newark Airport Play Video The NTSB said preliminary information from the plane's flight data recorder, one of the so-called black boxes, confirmed the captain's description of the event. United was able to recreate the same problem on the 2-year-old plane during a test flight at the Newark airport three days later, and reported the problem to the NTSB. Mechanics couldn't find an obvious cause for the malfunction during an inspection, but they replaced parts of the rudder control system, and the plane operated normally during a second test flight, the NTSB said. The NTSB said that when it subjected one of the removed parts to cold for one hour in a laboratory, it failed to produce the torque needed for the rudder pedals to work. The NTSB said it plans further testing of the part. Pedals in the cockpit control the rudder, which is attached to the vertical part of the tail and can be used to point the nose of the plane left or right. United, Boeing, parts supplier Collins Aerospace and the Federal Aviation Administration are taking part in the ongoing investigation. Collins did not immediately comment. Ospreys Cleared to Fly Again After Deadly Crash Despite Mechanical Failure with Unknown Cause A CV-22B Osprey tiltrotor aircraft assigned to the 27th Special Operations Group, Cannon Air Force Base (AFB), New Mexico, takes off for a Weapons School Integration mission at Nellis AFB, Nevada, May 30, 2023. (Wyatt Stabler/U.S. Air Force) Military.com | By Konstantin Toropin and Thomas Novelly Published March 08, 2024 at 8:59am ET Military officials have announced that the V-22 Osprey -- an aircraft that already has one known parts issue -- is returning to flight despite an investigation into a deadly Air Force crash in November revealing another new mechanical failure that is not fully understood. The V-22 Joint Program Office -- part of Naval Air Systems Command -- grounded the aircraft nearly three months ago after a deadly crash of an Air Force Special Operations Command Osprey on Nov. 29 off the coast of Japan that killed eight airmen. That same office now says data analysis has led to lifting the grounding, even as many aspects surrounding this latest chapter in the Osprey saga remain shrouded in secrecy. The move to push the crucial aircraft back into service despite lingering questions, and the investigations into the Japan crash and an earlier deadly Marine Corps Osprey crash in Australia not being fully completed, sparked concern among families connected to the aircraft -- and drew a rebuke from a House chairman who leads a key oversight committee looking into the safety issues. "We have high confidence that we understand what component failed, and how it failed," Marine Corps Col. Brian Taylor, the program manager for the V-22 program, told reporters in a hours-long briefing Wednesday. The briefing was provided to reporters on the condition that it could not be immediately published. "I think what we are still working on is the 'why,'" Taylor said, noting that "this is the first time that we've seen this particular component fail in this way." The Osprey is valued among the Marine Corps, Navy and Air Force for its ability to fly long distances, at higher speeds than helicopters, and land in relatively tight locations. The airframe has become crucial for its flexibility and ability to conduct a wide variety of missions like moving large numbers of troops or cargo while being able to be refueled mid-flight. Neither Taylor nor any other official who spoke with reporters Wednesday would identify the part that failed or offer any major details on procedural changes that are being made as part of the aircraft's return to flight. Instead, Taylor explained that the decision to return the aircraft to the air was based on "data gathered from this particular mishap investigation but, then, also a deep evaluation of the close to 750,000 flight hours that we have on V-22s over the last ... 20 or so years." The fix, Taylor said, is not any sort of hardware change to the aircraft. "We're changing some inspection intervals. We're changing some other kind of maintenance and procedural limits that we have on the aircraft that address this particular issue," he explained. The Air Force special operations Osprey that went down Nov. 29, call sign Gundam 22, was on a training mission off Japan's Yakushima Island. The deadly crash triggered a grounding of all Air Force, Marine Corps and Navy V-22s. Additionally, three Marines were killed in an MV-22 Osprey crash during training in Australia last year. Both incidents are still under investigation. The new part failure is now the second known, persistent mechanical issue that is plaguing the Osprey. The aircraft also has a yearslong problem with its complex system of clutch assemblies that have caused at least 15 mishaps -- some of which could have become fatal -- since the Osprey entered operations. That problem was revealed only because it prompted the Air Force to briefly ground its fleet of Ospreys in the summer of 2022. Despite assurances from the Marine Corps that the problem was under control, the clutch issue became deadly in June 2022 when one of its Ospreys crashed in the California desert, killing five Marines. An investigation into that crash was made public last summer, and Taylor made a strikingly similar defense of the aircraft to Military.com at that time. The Osprey program manager argued last July that data analysis of some of the more recent incidents involving the clutch led officials to believe that replacing a critical component -- the input quill assembly -- more frequently was 99% effective despite skepticism from a Marine Corps widow of one of the pilots. Just like now, Taylor conceded to Military.com then that "we have a good understanding of what happens and where it happens, and it happens inside of the input quill" but that "the piece that we're missing, really, is just the initiating events ... that's the part that we're continuing to look for." Military officials at first argued that the exact hours it takes for the input quill to degrade was an operational secret and refused to provide it to reporters. The release of a Marine Corps investigation a few months later, however, revealed that figure to be 800 flight hours. Crawl, walk, run ... fly While the Joint Program Office has lifted the grounding for flights, Air Force, Marine Corps and Navy officials said they all plan to proceed judiciously -- meaning it could be weeks or even months before they put their Ospreys in the air. Investigations are ongoing into the Air Force's crash, but all three services -- the Air Force, Marine Corps and Navy -- said part of their response has been to put their V-22 crews through extensive simulator training following the incident. "Our crews have been in the simulator since the stand-down to hold a modicum of their capabilities as it moves forward," Lt. Gen. Tony Bauernfeind, the head of Air Force Special Operations Command, told reporters. "Aviation is inherently risky, and that's why we train so hard and focus so hard on risk management so that we're never taking unnecessary risks. And when risks are identified, we are finding ways to mitigate that risk to the maximum potential," he said. Other services, such as the Marines, are following similar guidance. Brig. Gen. Richard Joyce, the Marine Corps assistant deputy commandant for aviation, told reporters that pilots with Aviation Combat Element-Crisis Response-Africa in Djibouti and MV-22 crews with the 26th Marine Expeditionary Unit were pulled out of their areas to go back for simulated training. "We pulled them out of country, flew them to Japan to get in the simulator to try to minimize degradation and proficiency by continuing to exercise the systems in a virtual environment," Joyce told reporters. Vice Adm. Daniel Cheever, the commander of Naval Air Forces, told reporters that, similar to the other services, his aircrews will slowly work their way back into the cockpit and then aboard ships. "What I need to do is get them up to a certain amount of flight hours for currency and proficiency before I put them on a ship," he said. "So, as we build that capability and capacity, you have weeks, maybe over a month time frame that will build that currency and proficiency and crawl, walk, run into this thing ... then we'll get back to mission." Meanwhile, Bauernfeind said Air Force Special Operations Command has convened a safety investigation board and an accident investigation board in addition to conducting a comprehensive review of the Air Force CV-22 force as a whole. That final review is analyzing whether the CV-22 force is appropriately organized, trained and equipped for safe and efficient special operations. Despite not disclosing the cause of the crash and stating that investigations are still ongoing, the service officials all seemed to be inherently OK with the risk their pilots may be taking on. Cheever specifically cited "transparency" -- "just sharing information and data and that kind of stuff" -- as a chief reason for why he was confident the Navy could operate the aircraft safely. When asked for more details, he said: "I don't want to get in front of our investigation, so I can't divulge any of that." Families fear lack of transparency Adding to the mystery surrounding the Osprey's return to flight is a lack of detail about how the families of the aircraft's most recent fatal crash feel about the situation. As part of the agreement laid out by Naval Air Systems Command to receive the information about the lifting of the grounding order, Military.com had to agree not to contact any of the family members of airmen killed in the Nov. 29 crash. Officials said that the reason was families were still receiving official notification about the lifting of the flight ban. The Associated Press reported last week that the ban was being lifted. Meanwhile, officials who briefed reporters Wednesday offered competing narratives on the process of notifying families. Taylor, the Osprey's program manager and a key figure in getting the aircraft back in the air, told reporters that he needed "to wait for the investigation to come out in order to be ... more transparent" with the public and noted that "the families of those eight fallen airmen ... deserve to hear first exactly what happened and exactly what transpired." However, Bauernfeind said that the families have been getting "updates on the status of the safety investigation board" and his "intent is to make sure that our families are aware of the process." But Bauernfeind also told reporters that only the Air Force's internal investigation into the crash -- the Safety Investigation Board -- was complete, while the broader Accident Investigation Board, the results of which the general said would be shared with the families, was "less than double-digit weeks" away from being finished. Military.com did speak with a member of the Osprey community who said they have been in contact with many other families in the community and that there is a strong sense of concern and fear for service members who operate the platform. The member, who spoke on the condition of anonymity, noted that many of the families within the tight knit community have "so much loyalty to the Osprey. ... They want to see it continue flying; I want to see it flying" before clarifying that "I want to see it flying, but safely." "It's not like these people want this to be grounded forever -- they want the dark era to be over, but there's a lack of transparency that needs to be addressed," they said. Taylor told reporters that he believes "without hesitation" that the Osprey should return to flight. "I firmly believe in the V-22, and I would fly one anytime," he added. However, the member who spoke with Military.com noted that "the people that are making these decisions, obviously, aren't in these aircraft" on a regular basis. They said that the crews operating the Osprey don't balk at the idea of combat situations. "You could be in danger, you could be shot at, but you have a mission to do and it's an acceptable risk," they said. "But that's a very different mindset versus, say, a training mission. You need these quals, it's an ordinary day, ordinary operations. Your aircraft might suffer a catastrophic failure and could fall out of the sky, but we're doing what we can." The families aren't the only critics. Congressional leaders have also spoken out about the move to get the Osprey flying again. House Oversight Committee Chairman James Comer, R-Ky., railed against the move in a press release ahead of the official announcement. "Serious concerns remain such as accountability measures put in place to prevent crashes, a general lack of transparency, how maintenance and operational upkeep is prioritized, and how DoD assesses risks," he said. Comer launched an investigation into the aircraft shortly after the Air Force's deadly crash. At the time, he gave Defense Secretary Lloyd Austin until Jan. 4 -- two weeks -- to provide him documents. Now, two months later, Comer says that his committee "has yet to receive adequate information requested from DoD" and noted that lawmakers "will continue to rigorously investigate the DoD's Osprey program to attain answers to our questions on behalf of American taxpayers and protect U.S. service members defending our nation." 1980s first-generation tiltrotor technology Military.com reported last year that the Air Force, Marines and Navy have stopped new purchases of the aircraft and said only that they "will complete the MV-22 and CMV-22 programs of record, with deliveries through 2025." Despite seemingly frequent deadly crashes and incidents with the V-22 over the last few years, experts say it's highly unlikely that any of the services would stop flying them altogether. Jeremiah Gertler, a senior associate with the Center for Strategic and International Studies think tank in Washington, D.C., who specializes in aviation, told Military.com that, until a suitable replacement for the V-22 is ready to be immediately adopted by the services, officials will find the best ways to keep flying the Osprey. "Do they keep flying these until they're replaced by something else?" Gertler said. "And history suggests that the answer to that is 'yes.' They're not going to make the capability go away and rely on older technology until they have something to move to." The grounding put operational challenges on all the services and some, like the Navy, had to rely on older aircraft such as the C-2 Greyhound to complete their mission requirements. Gertler said the services could revert to older technologies, but as global tensions increase and as many of the service branches turn their eyes toward competition in the Pacific, that's not a likely long-term solution. "They can step back and do things the way they were doing it before V-22 existed, but that requires them to change their operations in ways that they don't want to," Gertler said. "That's why they bought the V-22 in the first place, was to improve the way they were doing things. So, the idea of stepping back 20 years in time is not appealing to the services." Bauernfeind signaled to reporters that the V-22 has provided a unique capability for the Air Force but also criticized it as "1980s first-generation tiltrotor technology." He also noted that the Defense Advanced Research Projects Agency, or DARPA, has a program looking into an experimental vertical takeoff and landing plane. Notably, in 2022, the Army announced Bell's tilt-rotor V-280 Valor as a replacement for the service's fleet of Black Hawk helicopters. Gertler said that if it proves successful for the Army, there's a chance the other services may want that aircraft in the future, too. While a replacement for the Osprey is not near, the services said they remain, mostly, confident in the procedures, training and increased maintenance they've put in place. "I have high confidence the protocols we're putting in place will avoid a catastrophic event like this happening again in the future," Bauernfeind told reporters. "I never say things with a finality because there is an inherent risk of what we do in military operations." Related: Air Force Confirms Parts Failure Occurred in Deadly Japan Osprey Crash that Left 8 Airmen Dead PIPER RUDDER AD 'TARNISHES' PROCESS, AOPA CONTENDS February 27, 2024 By Jim Moore A chorus of aviators, aviation mechanics, and groups including AOPA called for the FAA to rescind a proposed airworthiness directive that would affect nearly 31,000 vintage Piper aircraft, citing a lack of evidence of risk, unjustifiably broad scope, and a broken process. The FAA included more than 30,000 vintage Piper models, including this PA-11, in an airworthiness directive that AOPA and others deemed far too inclusive for the available facts to justify. Photo by Chris Rose. The proposed AD, published October 6, was drafted in response to two separate "accidents," according to the proposal—a classification that was among many points disputed by the Short Wing Piper Club in comments filed February 8 that AOPA supported (in addition to providing its own comments). The events in question both took place in Alaska, in 2020 and 2021, involving rudder component failures in flight that ended with both aircraft landing successfully with dog-eared rudders and a broken rudder post. "There is no evidence or reports of broken rudders," the Short Wing Piper Club wrote. "The results between a broken post and a failure of the rudder assembly are significantly different. The rudder assembly’s operation was significantly reduced, but it did not fail. The broken posts did not result in an accident; rather, the reports were of incidents."The group, which consulted with AOPA Vice President of Regulatory Affairs Murray Huling, who, in turn, cited the group's technical analysis in AOPA's comments, found fault with many aspects of the proposal, including estimated cost, and the lack of provision for acceptable repairs. Huling, in AOPA's comments, noted the proposed AD's applicability is "severely out of scope." "AOPA understands the necessity to issue an AD when a valid safety concern is identified and verified; however, when a blanket applicability statement is utilized, as in this case ... over 30,000 aircraft, of which the majority should not be affected by the AD, it tarnishes the FAA AD process," Huling wrote. "AOPA requests that the FAA accomplish a thorough review based on the evidence provided by numerous commenters." Huling noted that AOPA and the FAA have since identified a breakdown in the airworthiness concern sheet process that "failed to achieve its intended goal" in this case. "AOPA reached out to the FAA office responsible for the ACS process and discovered that the system put in place years ago had dwindled to being almost non-existent. AOPA is stepping up and is working with the FAA to reinstitute the ACS notification process to help ensure this type of situation does not arise again. The FAA can then reach out to the industry for expertise before issuing a proposed AD. The revamped ACS process is in development now, and we hope to have it fully operational in the next few months. AOPA appreciates the FAA's help in bringing this important tool back. " What’s the problem with my #4 cylinder? By Paul McBride February 5, 2024 Question for Paul McBride, the General Aviation News engines expert: I just installed an older Insight GEM 2 in my 1971 Piper PA-28-140D that I pulled out of my other Cherokee, which just got a JPI 900 upgrade. When I removed it, the GEM 2 worked great. On the first flight with the GEM 2 installed I noticed #4 CHT rose to 500 on climb out (OAT -3 up here in Canada) and the other three cylinders were 400 or just under. I pulled power and got #4 back to 400 (was still reading hotter than the other three) and headed back to the airport. On my way back I tried full power again while being leveled off and #4 rose quickly to 500. I landed, shut it down, pulled the plugs (which looked good), I borescoped and looked at the valves, cylinder walls, etc., and nothing looked obviously wrong. Baffling looks normal with no obstructions. I did notice on mag drop #4 took the longest by about 10 seconds to see an EGT rise. I also noticed where the exhaust exits the cylinder, it looks white and like it was running hotter than the others. I haven’t hit it with a temperature gauge externally after it was running, but the cylinder was hotter than the others by touch. I am thinking an air leak on the intake tube is causing a lean cylinder? Or maybe a crack in the cylinder wall? Or oil compression ring blocked? Maybe I should try ring flush? Someone suggested the cam may be worn, so I could try and measure the valve movement. The cam was changed more than 20 years ago, with only 300 hours on it. The plane lived in Northern Alberta during this time so corrosion shouldn’t be that much of a factor. Engine is a Lycoming O-320-E3D Factory with 1,900 hours, but was pulled apart at 1,600 hours (20 years ago) and rebuilt (300 hours on engine since rebuild). The problem cylinder is chrome and has 400 hours. All cylinders are P10 oversized. Magnetos are Slick and have 75 hours since rebuild. Plugs have been tested and cleaned. The engine runs great and appears to make full power. Any help would be greatly appreciated. Thanks, Tyler Paul’s Answer: Tyler, I’d say that you have an interesting situation here, so let’s see if we can offer a few suggestions. It’s too bad your aircraft doesn’t have a manifold pressure gauge because that may offer some hints as to what’s going on in the #4 cylinder. If you had a manifold pressure gauge and we suspect there is an intake leak somewhere, the manifold pressure at idle would be somewhat higher than if there were no leaks. I did observe the one picture showing the exhaust stack gasket with some kind of sealant on it, which is not a good thing. I’d suggest this sealant was put on at some time in the past because there was blow-by at the exhaust flange, and someone thought they could correct this issue by applying a sealant. No sealant of any type should be applied in this area. There is a possibility that this leak could be causing an erroneous reading of the CHT on the #4 cylinder also. There is another way to look for an induction leak and that is by using soapy water with a paint brush around the intake pipe where it attaches to the cylinder and also where it goes into the sump. There also maybe a loose clamp on the intake hose where it attaches to the oil sump. Or the sleeve that is swaged into the sump where the hose attaches may also be loose. When it comes to older aircraft, anything is possible so, as you can imagine, it also makes troubleshooting more difficult. Looking at the photos you provided, I didn’t see anything alarming other than what I would expect for an engine with this many hours on it. I was looking for any signs of a clean piston dome, which would indicate a very lean mixture, but they all show deposits, which is normal. So where do you begin to troubleshoot from here? My suggestion is that you correct the exhaust stack gasket first, because we know that isn’t good. Next, I’d check for induction leaks at both ends of the intake pipe on the #4 cylinder, making sure the hose at the sump is in good condition and the metal tube is not loose where it goes into the sump. Finally, make certain that the hose clamps are tight. I’d hope the probe wiring is long enough to allow you to move the #2 cylinder probe to the #4 cylinder just to check it to see if it still reads high on the gauge using the known good #2 probe. Tyler, I don’t think there are any really serious issues here, but just some simple troubleshooting to check things out. This type of situation is not uncommon when dealing with aging aircraft. For now, I’d forget all of the other suggestions you mentioned because I don’t think we need to dive that deep into troubleshooting the problem at hand. ABOUT PAUL MCBRIDE Paul McBride, an expert on engines, retired after almost 40 years with Lycoming. Send your questions to askpaul@generalaviationnews.com. Curt Lewis