September 20, 2023 - No. 039


In This Issue 

: Pratt and Whitney Engine Woes Continue

: Rocket Lab suffers anomaly during launch, Earth-observation satellite lost

: United is the latest airline to confirm finding fake parts in plane engines, as supplier scandal grows

: RTX Removal Program To Address GTF Problems

: MTU Targets Quicker Turn-Around Times For PW1100G Inspections

: 600-700 PW1100G engines to be removed between 2023 and 2026: Pratt & Whitney 

: ‘Son of Concorde’ supersonic jet set to make first test flight

: FAA says iron inclusion on B777 GE90 engine could result in uncontained failure

: FAA issues urgent AD to address potential Boeing 777 fuel tank explosions

: Aeralis sets new standard with transonic modular jet

: Watch a rocket engine ignite in ultra-slow motion

 

 


Pratt and Whitney Engine Woes Continue

September 15, 2023 6:00 am ET
By Zach Cooke

Earlier this past week, engine manufacturer Pratt and Whitney announced an extension to the period of time it would take to inspect turboshaft engines on the Airbus A320neo series aircraft. In July, oit was announced initially that a period of approximately 60 days would be needed to inspect engines for contaminants in the engine core. However, the organization announced on September 11th that the new time frame for inspections will be closer to 300 days due to cracking in metal powder found in compressor and turbine disks. 

The latest development involves a quality control issue with powder metal used to make engine components inside the core. The geared turboshaft PW1100G-JM engine was initially certified by the FAA in December 2014. In a combustion engine, air is combusted in the turbine section housed in the core of the engine. The turbine in turn spins the fan, the most visible part of the engine from the front, along with compressor stages, also inside the core.

The fan pushes air around the outside of the core as well as into the compressor section. Air from the fan bypassing the core of the engine is thrust, propelling the aircraft through the atmosphere. The air passing through the core of the engine is compressed through the compressor stages and then combusted, driving the turbine. The gearing of the engine relates to a gearbox allowing the fan and turbine to rotate at different speeds, increasing fuel efficiency. 

In a press release produced by RTX, Pratt and Whitney’s parent company, an estimated 600 to 700 engines will need to be inspected for cracks in high-pressure turbine disks and high-pressure compressor disks. Last month, the company sent a notice to operators of the A320 powered by the engine to make additional inspections, which needed to be completed by September 15 of this year.

The Connecticut-based manufacturer is developing a fleet management plan for airlines to inspect the high-pressure turbine disks and high-pressure compressor disks in engines at additional cycle intervals. While Pratt and Whitney believe that the majority of inspections will be completed throughout the remainder of 2023 and 2024, the thorough process will take until 2026 to be fully completed for all affected engines. 

Industry-Wide Effects
Aircraft utilization rates for airlines operating A320neo series aircraft, equipped with the PW1100G-JM, across the globe will decline significantly throughout the next 3 years. Hawaiian Airlines, for instance, has already incurred significant disruption in schedule due to grounding aircraft from previous issues.

At times in the past year, the carrier has had five out of 16 active aircraft in the fleet parked, initially reported by aviationweek.com. In July, Brent Overbeek, the carrier’s chief revenue officer, hypothesized that it would not be until mid-2024 that Hawaiian would have a full Airbus A321 fleet operating.

However, with the latest development in quality issues, the previous time frame is likely to be pushed back. July’s announcement had Hawaiian pause routes to be operated by A321 aircraft, such as Lihue to Oakland, Calif.  

Delta Air Lines believes their Airbus A321neo aircraft will not see as significant of disruption as other operators, although is waiting for the full estimated impact from Pratt and Whitney at the end of the month. During a recent conference, Dan Janki, Chief Financial Officer for Delta, stated with the delivery of new, low-cycle aircraft, the impact should be less for the carrier. Delta anticipates ending 2023 with 50 A321neo aircraft, awaiting over 100 additional examples to be delivered through 2027.


 

 


Rocket Lab suffers anomaly during launch, Earth-observation satellite lost
By Mike Wall last updated about 12 hours ago
The Sept. 19 launch, Rocket Lab's ninth of the year, did not go well.

Click here for more Space.com videos...

 Rocket Lab suffered an anomaly during the launch of a radar Earth-observation atellite early Tuesday morning 

An Electron rocket carrying a synthetic aperture radar (SAR) spacecraft for the California company Capella Space lifted off from Rocket Lab's New Zealand site Tuesday at 2:55 a.m. EDT (0655 GMT; 6:55 p.m. local New Zealand time).
The Electron's two stages separated as planned about 2.5 minutes after launch. But something went wrong shortly thereafter, ending the flight.

Related: Rocket Lab launches booster with preflown engine for 1st time (video)


A Rocket Lab Electron rocket launches a Capella Space satellite on Sept. 19, 2023. The rocket suffered an anomaly, resulting in the loss of the satellite. 

Rocket Lab's telemetry data, which the company provided during the livestream of Tuesday's launch, showed the velocity of the rocket's upper stage decreasing shortly after its single Rutherford engine was supposed to kick on. 

The upper-stage engine may therefore have suffered an ignition failure or a premature shutdown, though that's just speculation. Rocket Lab did not identify a proximate or ultimate cause, saying in a post on X (formerly Twitter) that it will provide more information as it becomes available.

Tuesday's mission, which the company called "We Will Never Desert You," was its ninth of the year and 41st overall. The anomaly broke a string of 19 consecutive successful launches; the company's most recent failure had been in May 2021.

"We Will Never Desert You" aimed to deliver one of Capella Space's "Acadia" satellites to a circular orbit about 395 miles up (635 kilometers) above Earth. Tuesday's flight was the second in a four-launch contract to send these advanced SAR satellites skyward.

The first mission under that contract, Aug. 23's "We Love the Nightlife," featured an Electron with one used first-stage engine. (Electron's first stage is powered by nine Rutherfords.) That was a big milestone for Rocket Lab, which is working to make the booster reusable.

The company also recovered the Electron first stage on "We Love the Nightlife," after bringing it down softly for a parachute-aided ocean splashdown. "We Will Never Desert You" apparently did not involve a preflown engine, nor was a rocket recovery attempt in the cards; Rocket Lab did not mention such plans ahead of the launch or during the webcast. 


 


United is the latest airline to confirm finding fake parts in plane engines, as supplier scandal grows

BYMARY SCHLANGENSTEIN AND BLOOMBERG
September 18, 2023 at 5:41 PM CDT

United Airlines has found dubious parts in some of its planes.

United Airlines discovered dubious parts in two aircraft engines, adding to the list of carriers worldwide that have found bogus components from supplier AOG Technics.
The parts were discovered in a single engine on each of two aircraft, including one that was already undergoing routine maintenance, a spokesperson for United said Monday. The Chicago-based airline is replacing the engines before the planes are returned to flying, he said.
Related Video

United discovered the parts based on new information from its suppliers, and will continue to investigate as more details become available, the company said. The parts were seals on compressor stator vanes that help direct airflow inside the engine. United didn’t immediately say which type of aircraft the engines had powered.

The company’s disclosure makes it the latest major carrier to confirm that suspect components from AOG were installed in their fleet, including Southwest Airlines Co. and Virgin Australia Airlines Pty. Aviation regulators have said AOG supplied an unknown number of jet engine spare parts backed by falsified airworthiness documentation, kicking off a worldwide effort by the industry to hunt down more components.

CFM International Inc., the joint venture of General Electric Co. and Safran SA that makes the engines for many older-generation Airbus SE A320 and Boeing 737 aircraft, previously said parts with fraudulent documentation had been used in 68 of its power plants.


 


RTX Removal Program To Address GTF Problems
Lee Ann Shay September 15, 2023

Another blow to the Pratt & Whitney geared turbofan (GTF) engine program came on Sept. 11, when parent company RTX (formerly Raytheon Technologies) detailed the extent of its fleet management program, which accelerated engine removals for inspection. Leaders say they completed a “holistic fleet management plan” that should take care of parts riddled with powdered metal problems during manufacturing, which can lead to cracks.

The financial impact to the PW1100 program will be $6-7 billion. The cost breaks down into two buckets, with about 80% being customer support—from the time an engine is taken off wing until it’s back on wing, plus operational disruption costs—and 20% for additional shop visits, mostly for labor and materials, says Neil Mitchill, RTX executive vice president and CFO.

This latest news identifies 600-700 engines needing removal from service by 2026, with most coming off wing between now and early 2024.

This group of engines will require three actions. First, high-pressure turbine (HPT) discs must be inspected between 2,800-3,800 cycles, depending on the engine’s thrust rating. Many engines are reaching this cycle limitation, “which is the driver behind the majority of the incremental removals in 2023 and 2024,” says Chris Calio, RTX president and COO. Second, part lives of compressor and turbine discs in this engine group will be reduced to 5,000-7,000 cycles. Lastly, high-pressure compressor (HPC) discs must be inspected.

These extra 600-700 removals “will obviously put additional pressure on the fleet” because the news comes at a time when about 10% of the fleet is already on the ground “because of high MRO turn times due to material constraints, which also results in longer times between engine removal and induction into our MRO shops,” says Calio.

Obviously, adding shop visits to an MRO network already stretched thin will “create more congestion in our MRO network,” he says, citing the OEM’s estimate of 250-300 days of downtime for each of these engines.

“As a result, we are now forecasting an average of 350 aircraft on the ground for the GTF-powered A320 fleet from 2024 through 2026, with a peak of 600-650 aircraft on the ground in the first half of 2024,” says Calio.

Because the affected parts were made before third-quarter 2021, when Pratt & Whitney improved the powder metal production process, company executives say it will be able to deliver new GTF engines to Airbus as planned, as well as planned spare engines. That puts the onus on the MRO side.

To alleviate this situation and provide engines able to meet their full certificated lives, the company plans to install new HPT and HPC discs when they come in for shop visits.

But to meet the MRO requirement, the key is “driving the industrial ramp needed for MRO output,” says Calio.

In an industry still hindered by parts availability, that isn’t going to be easy. 
RTX’s GTF fleet management overall requires about 3,000 engines to be inspected.
Expect at least one service bulletin to come out in the next 60 days.


 


MTU Targets Quicker Turn-Around Times For PW1100G Inspections
Jens Flottau Matthew Fulco September 13, 2023

MTU Aero Engines is working on a cost-efficiency program and will enter negotiations with partner Pratt & Whitney to reduce the financial impact of RTX’s PW1100G fleet management plan presented Sept. 11. 

The company wants to find ways to reduce the time needed for inspections and potential repairs, according to CEO Lars Wagner.

The Munich-based engine manufacturer updated investors on the fallout for its business Sept. 13. Wagner predicted a reduction in reported revenue and reported operating profit of around €1 billion ($1.07 billion) each. A significant impact on cash-flow is expected for 2024-2026. Nonetheless, CFO Peter Kameritsch expects the company to retain its investment grade rating.

Some 3,000 engines—including PW1000Gs of all types and IAE V2500s, built from mid-2015-mid-2021—may have parts with contaminated powder metal (PM). 

Cracking from PM contamination has been found in high-pressure turbine (HPT) stage 1 and stage 2 disks, or hubs, installed in the motors. Pratt is also inspecting some high-pressure compressor (HPC) disks built at the same time, RTX revealed. Most of the affected engines are PW1100Gs found on A320neo-family aircraft.

Clogged engine overhaul shops and a fast-tracking of necessary inspections on higher-time PW1100G geared turbofans will drive repair turnaround times up to as many as 300 days per engine and could ground 650 Airbus A320neos at one time early next year, RTX disclosed. According to the Aviation Week Network Fleet Discovery database, 1,354 Pratt-powered A320neo family aircraft are currently in service, parked, stored or in parked/reserve status.

Fleet groundings will “average” 350 at any given time through 2026, according to RTX President and COO Chris Calio.

Wagner said talks with Pratt will cover the commercial conditions under which MTU might expand MRO capacity for the GTF work. But Kameritsch made clear that the company will only add GTF maintenance capacity if it is not low margin work that would replace much higher margin independent orders. Another constraint is the consortium’s commitment to deliver new PW1100Gs to Airbus’ final assembly lines supporting the OEM’s production ramp-up.

MTU also wants to find “other ways” to reduce the impact on its business. Wagner indicated that in his view there is still room to negotiate settlement terms within the framework of the partnership’s risk/revenue scheme. He was not prepared to share details of the arrangement.

Should MTU find ways to increase its GTF MRO capacity at favorable terms, the financial impact could be lower. Also, added capacity would reduce aircraft on ground (AOG) time for operators, leading to lower penalties. Wagner also stressed that MTU is exploring ways to reduce the time needed for the shop visits, which RTX defined as up to 300 days per engine. “We want to be significantly below this,” Wagner said. 

Launching a major cost-cutting program is tricky for MTU, Kameritsch said, as the company is in expansion mode with demand for its products high. One way to tackle the situation is for the OEM to delay capital investment where it is not necessary.

Wagner also insisted that he still believes in the long-term future of the GTF and is not concerned that it would lose further market share vis-à-vis CFM International’s Leap program on the A320neo family: “We are confident that we can stabilize or even improve market share.”

The existing durability issues that have been hampering the GTF for years have also led to a cooling of the Airbus-Pratt relationship. Airbus is known to be seriously considering CFM as a second engine provider for the A220 program if, as expected, it launches a stretched A220-500 (or A221).

Eighty percent of the costs that burden the Pratt program partners are to compensate customers, since aircraft will be grounded for an average of 350 days due to the program, while the remaining 20% cover additional labor and materials for the shop visits, Morningstar Investor said in a Sept. 12 research note.

Though Pratt & Whitney is the main supplier of the turbine components, since MTU Aero shares inspection program costs with the Connecticut-based company, “the inspections will result in a headwind for free cash flow over the duration of the program,” Morningstar added.

MTU Aero has lost about $3.6 billion in market capitalization since Pratt parent company RTX Technologies first identified the GTF engine problem in late July.


 


600-700 PW1100G engines to be removed between 2023 and 2026: Pratt & Whitney 
BY RYTIS BERESNEVICIUS
2023-09-13


In a recent update to investors, RTX, the parent company of Pratt & Whitney, said that between 600 and 700 PW1100G engines will have to be removed for inspections between 2023 and 2026. 

“As a result, Pratt & Whitney expects a significant increase in aircraft on ground [AOG] levels for the [PW1100G] powered A320 fleet throughout 2024 – 2026,” the RTX update continued.  

The company disclosed that some engines would need to be removed as soon as possible, with some requiring inspection no later than September 15, 2023. 

In response to the increased number of AOG, the engine maker developed a fleet management plan for the remaining fleet of engines, “requiring a combination of a repetitive inspection protocol, at an interval of between approximately 2,800 and 3,800 [flight] cycles [FC], and part life limits of between approximately 5,000 and 7,000 cycles, for high pressure turbine disks and high-pressure compressor disks”. 

Pratt & Whitney expects to release the fleet plan in a service bulletin (SB) to customers “within the next 60 days” after it discusses the strategy with regulators.  

“The actions set forth in the [special instruction (SI)] and SB are anticipated to result in approximately 600 to 700 incremental shop visits between now and the end of 2026 beyond Pratt & Whitney’s forecast entering 2023,” RTX said. 

Most engines will be removed in 2023 and early 2024, resulting in a significant increase in the AOG of PW1100G-powered jets between 2024 and 2026. 

The Pratt & Whitney PW1100G, also known as the Geared Turbofan (GTF), is one of two choices for Airbus A320neo aircraft family operators, with the other being the CFM International LEAP-1A. 

According to ch-aviation.com data, there are 1,359 Airbus A320neo family aircraft, including the A319neo, A320neo, and A321neo and its variants, powered by the PW1100G. Out of those, 242 are marked as being either in storage or undergoing maintenance. 

Meanwhile, there are 1,576 CFM International LEAP-1A-powered Airbus A320neo family aircraft, with 76 stored or in maintenance. 

$3 billion charge 
While Pratt & Whitney is still unable to provide a final estimate on the operational impact of the accelerated engine inspections, RTX has already booked a $3 billion pre-tax charge in Q3 2023. 

The company also disclosed that for the next several years, the problem will impact its pre-tax operating profit by between $3 billion and $3.5 billion, “inclusive of an approximately $3 billion pre-tax charge in Q3, after partners’ share of charges”. 

Still, RTX highlighted that Pratt & Whitney is trying to increase industrial output and maintenance shop capacity to reduce the operational impact as much as possible. In addition, the engine maker is assessing whether the powder metal problem will impact other engine models, but the current assumption is that “other models will be far less impacted based on existing inspections, lower utilization profiles and/or existing maintenance intervals”. 

Meanwhile, RTX stated that the $3 billion Q3 2023 charge includes “estimates of potential compensation and other consideration for customer fleet disruption and the one-time Estimate-at-Completion (“EAC”) impact of estimated incremental costs to long-term maintenance contracts as a result of this matter”. 

The GTF engine family also exclusively powers the Airbus A220 (PW1500G), Embraer E2 (PW1700G/PW1900G), SpaceJet (PW1200G), and Russia’s MC-21 (PW1400G). 
However, Mitsubishi canceled the SpaceJet program in February 2023, because sanctions imposed on Russia due to its invasion of Ukraine have prevented the further development and/or export of the PW1400G engine into Russia. 

RTX first disclosed the rare condition in powder metal used to manufacture parts of the PW1100G engine during the company’s Q2 2023 results presentation in July 2023. At the time, the aerospace manufacturer said the problem would affect “a significant portion of the PW1100G-JM engine fleet”. 

At the time, RTX did not provide an estimated material impact on its business or its customers. 


 


‘Son of Concorde’ supersonic jet set to make first test flight
All being well, the prototype will pave the way for a new supersonic jet that will travel from the UK to the US in just three and a half hours.

by Adam Gray | Published on 5th Sep 2023


Boom Supersonic
A new supersonic jet could be taking to the skies in the not too distant future.
Boom Supersonic’s XB-1 experimental prototype has undergone extensive ground testing over the past few months.



Fast approaching the final stages of testing, the prototype’s set to take its first test flight before the end of the year.

The testing is helping ready the aviation company’s Overture aircraft, dubbed the “Son of Concorde”, for its first flight in 2029.

Apparently, Overture will be able to fly passengers from the United Kingdom to the United States in just three and a half hours.

The jet, which features four engines and a new fuselage, will be able to fly at supersonic speeds of up to 1,304 miles per hour.

To be precice, the aircraft will cruise at Mach 1.7 over water and just under Mach 1 over land.

The new supersonic jet won’t just fly between the UK and US, though.
More than 600 routes have been planned fro Oveture across the globe.
Last year, American Airlines confirmed its partnership with the company to create aircraft that could travel at “2x the speed of today’s fastest commercial jets”.

“Aviation has not seen a giant leap in decades,” Boom founder and CEO Blaske Scholl previously said in a statement.
“Overture is revolutionary in its design, and it wil fundamentally change how we think about distance,” he added.

It goes without saying, test-flkying the prototype is an important milestone for the company, which has ambitions of developing both sustainable and supersonic flights.
Boom Supersonic

“I believe in a future where more people go more places,” Scholl recently told Yahoo.
“Think about crossing the Atlantic in under four hours, leaving the East Coast in the morning, and making it to a dinner meeting in Europe on the same day,” he added.

“Think about being able to do a rountrip to Asia in 24 hours.”


 


FAA says iron inclusion on B777 GE90 engine could result in uncontained failure
BY RYTIS BERESNEVICIUS
2023-09-05

The Federal Aviation Administration (FAA) has issued a provisional airworthiness directive after General Electric (GE) discovered iron inclusion on the GE90 engine, which is used to power Boeing 777 aircraft.

According to the FAA, GE notified the regulator of the “detection of iron inclusion in a turbine disk manufactured from the same powder metal material used to manufacture certain” high-pressure turbine (HPT) parts. Those include the HPT stage 1 disks, HPT stage 2 disks, forward HPT rotor seals, interstage HPT seals, and stages 7–9 compressor rotor spools for the GE90 engines.

Upon further investigation, the Original Equipment Manufacturer (OEM) determined that the iron inclusion resulted from “deficiencies in the manufacturing process and may cause reduced material properties and a lower fatigue life capability, which may result in premature fracture and subsequent uncontained failure”.

While the FAA issued a notice of proposed rulemaking (NPRM) to address the issue, with stakeholders being invited to comment on the change until October 20, 2023, GE has already been in contact with operators of the GE90 engines.

“As a result, affected operators are already aware of the proposed corrective action and have already performed the actions proposed in this AD,” the FAA said, adding that it has determined that compliance time before further flight would be appropriate.

Still, the FAA warned that, if not addressed, the condition could lead to an “uncontained debris release, damage to the engine, and damage to the airplane”.

Replacing GE90 HPT parts
To comply with the directive, airlines will have to replace certain HPT stage 1 disks, HPT stage 2 disks, forward HPT rotor seals, interstage HPT seals, and stages 7–9 compressor rotor spools that are airworthy.

However, the FAA said that the proposed AD would be “interim”, with further action to follow once GE completes its investigation into the matter. The conclusions from the investigation could result in the FAA issuing another directive.

Overall, the regulator determined that nine engines in the United States (US) have been affected by the NPRM. The FAA also estimated that replacing all of the HPT parts, including the stages 7-9 compressor rotor spools, would cost a total of $2.2 million.

But while the AD requires the replacement of the interstage HPT seal, no GE90 engines installed on US-registered aircraft have any affected seals, which reduces the total cost of compliance for airlines based in the country by $108,936.

The GE90 engines are one of three power plan options for the Boeing 777 aircraft family. Other engines include the Pratt & Whitney PW4000 and Rolls-Royce Trent 800.
According to ch-aviation.com data, out of all the currently active 1,270 Boeing 777s (excluding stored and/or in-maintenance aircraft), 1,084 are powered by the GE90 engines. Meanwhile, the Rolls-Royce Trent 800 powers a total of 101 active Triple Sevens, while the PW4000 is only used on 85 aircraft. United Airlines is the only airline in the US to power its 51 active Boeing 777s with the Pratt & Whitney engine.


 


FAA issues urgent AD to address potential Boeing 777 fuel tank explosions
BY RYTIS BERESNEVICIUS
2023-08-30

The United States Federal Aviation Administration (FAA) urgently issued an airworthiness directive (AD) to address errors made by Boeing in a Requirements Bulletin (RB), which meant that the fuel tanks on some Boeing 777 aircraft were not properly protected against lightning strikes.

Initially, the FAA issued an AD in September 2022 to address “cracking of the left- and right-side ring chords, repair angles, front spar lower chords, and front spar webs (depending on configuration) common to the underwing longeron located at station (STA) 1035”.

The directive was prompted by reports of cracks found on a Boeing 777-300ER’s front spar lower chord that was undergoing underwing longeron replacement, which, combined with cracking in the front spar web, posed a safety hazard in the form of a fuel leak or in more severe cases, could affect the structural integrity of the aircraft.

However, according to the recent AD from the FAA, Boeing has since discovered that its RB from October 2021 “contains errors relating to the application of cap seals to fasteners penetrating the center wing fuel tank which introduce a second, urgent unsafe condition”.
The actions required by the RB from October 2021 and the AD from September 2022, mandate the removal of many cap seals to “accomplish the various modifications and inspections”, the AD continued.

“If these seals are not replaced properly, and the associated fastener has poor electrical bonding to the airplane structure for any reason, the fastener may spark during a lightning strike and cause a fuel tank explosion,” the FAA said in the directive.

As such, the FAA determined that it needed to supersede the September 2022 directive to address the new unsafe condition.

Affecting Boeing 777 fastener cap seals
The regulator noted that the directive, which now requires an inspection and replacement/modification of the center wing fuel tank fastener cap seals, was now being published “without additional service information” due to the public safety risk.

“The manufacturer submitted an initial report of errors in the requirements bulletin affecting cap sealing instructions in late 2022,” the FAA said, adding that due to the length and complexity of the new RB, Boeing handed over the documentation of these errors in July 2023.

While the planemaker said it would revise the bulletin, the FAA noted that the “work will take longer to accomplish than the risk to public safety allows,” which is why the agency superseded the AD from September 2023.

The FAA highlighted three procedural errors relating to the fastener cap seals.
Firstly, operators did not need to apply cap seals to fasteners associated with the underwing longeron of some Boeing 777s. Without the requirement, “a cap seal may fail to be applied following modification of the underwing longeron, compromising the required fault tolerance of the fuel tank lightning protection design”.

Airlines flying these Triple Sevens will have to apply a cap seal of the correct sealant type to the minimum thickness.

Secondly, some Boeing 777s have no thickness requirement and, furthermore, the RB “mistakenly refers to the Boeing Standard Overhaul Practices Manual (SOPM) section 20-50-19 for procedures to apply the cap seal”. The SOPM’s requirements have a cap seal thickness of half the minimum amount.

Even if the aircraft’s aircraft maintenance manual (AMM) procedure included the correct thickness, the FAA noted that “operators may have used an accepted method other than that specified in the SOPM and AMM” since the RB did not specify whether to refer to the SOPM or AMM. As a result, the cap seal could fail to contain a spark from a lightning strike, resulting in a fuel tank explosion. The FAA now requires operators to ensure the minimum required thickness and sealant type, as well as replacing any seal that was already replaced with improper thickness.

Thirdly, the RB required “the removal of certain fastener cap seals; however, the requirements bulletin either does not require that the cap seal be replaced, or does not provide a thickness requirement for the replaced seal”. This means that the fuel tank’s lighting protection is compromised, and the FAA mandates airlines to replace the removed seal with the correct thickness and type.

Boeing making design changes
Since the issue came to light, Boeing has already implemented a design change, meaning that some newly built Boeing 777s will not be affected by the latest directive.
According to the FAA’s estimates, 291 Boeing 777s in the US will be affected by the directive. After the agency published the now-superseded directive in September 2022, it discovered, along with Boeing, that some 777-200s are not susceptible to the unsafe condition because they do not have a fuel tank between the side-of-body ribs.

With the latest AD, Boeing 777s with the unsafe condition will now be identified as those where the Maximum Taxi Weight (MTW), which includes taxi and run-up fuel for the engines and the Auxiliary Power Unit (APU), is more than 547,000 pounds (248,115 kilograms).

Furthermore, since the September 2022 directive, Boeing has already implemented the required design changes for newly built aircraft of the type where the Line Number (LN) is higher than 1,743. According to ch-aviation.com data, there are seven such aircraft, all Boeing 777F aircraft delivered between June and August 2023, including FedEx’s 50th factory-fresh 777, registered as N874FD.

In its latest AD the FAA has retained three actions from the September 2022 directive, namely an inspection, modification, and post-modification inspection, and has added two more. Now, airlines will have to review their Boeing 777 maintenance records and properly seal the caps.

However, the FAA noted that it “has no way of determining the number of aircraft that might need the cap sealing”.

According to the agency’s estimates, the sealing will take airlines up to 109 workhours. With parts ($90) and labor ($9,265), the action will cost $9,355 per aircraft. Some of the costs related to the actions included in the AD could still be covered under warranty.

The AD will be published on August 31, 2023, and will come into effect 15 days after publication.


 

Aeralis sets new standard with transonic modular jet
Aeralis revolutionizes military aviation with its modular light jet, offering versatility, transonic capability, and cost savings.

Can Emir
Created: Sep 18, 2023 10:33 AM EST



UK-based aerospace company Aeralis has unveiled its groundbreaking modular light jet, set to redefine military aviation capabilities. 
The company introduced its innovative aircraft, including the Advanced Jet Trainer, at the Defence and Security Equipment International (DSEI) event. 
Aeralis's vision is to provide maximum flexibility to customers while significantly reducing maintenance costs, and their modular approach is central to achieving this goal.

“I am incredibly proud of the work the Aeralis team has done to develop this cutting-edge design which represents a significant offering in the military light jet market. The modular design provides the Aeralis jet with maximum flexibility whilst including a first-of-a-kind design to enhance aircraft performance. I look forward to quickly progressing the aircraft to its next stage,” said Tristan Crawford, founder and CEO of Aeralis.

Modularity: Redefining military aviation
Aeralis's modular principles have been at the heart of the aircraft's design from the beginning. This approach allows the aircraft to cater to various markets and adapt to different needs seamlessly. The core of this concept is the Common Core Fuselage (CCF), which will serve as the foundation for Aeralis's future aircraft fleet.
Sir Julian Young, who chaired a recent design review, highlighted a key innovation: a unique wing architecture featuring both an inner wing and an outer wing. This innovation enables the aircraft to operate effectively at both low and high speeds, providing it with transonic capability – a game-changer in military aviation.

Flexibility is the hallmark of Aeralis's new aircraft design. It offers multiple configurations, including the Advanced Jet Trainer, Aggressor, Companion, ISTAR, and Tanking options. All these configurations are based on the CCF, which allows customers to acquire additional modules to tailor the platform to their specific requirements.

Aeralis Chief Airframe Engineer Peter Curtis said at the Royal Aeronautical Society's Bedford Branch, "We're not selling an aircraft, we're selling a whole system, we're selling the ability to train pilots – which includes an aircraft, but also all the bits and pieces around it. With the actual flying product, what we're trying to do is maximize the commonality of structures, systems and parts, and add onto that some modularity so that we can have a range of bespoke capabilities, but in a mostly common aircraft."

The aircraft's sleeker design not only enhances its aesthetics but also accommodates additional fuel capacity and electronic capabilities. This ensures increased resilience, maintainability, and overall performance gains. Additionally, significant changes to the fuselage design and the introduction of new wings eliminate the need for bespoke landing gear seen in previous iterations, resulting in readily available commercial off-the-shelf landing gear. This simplifies maintenance and substantially reduces associated costs.
Modular cockpit innovation
Aeralis's modular cockpit is a versatile feature of this innovative aircraft. The single-seat configuration offers extra room for Electromagnetic Warfare (EW) capabilities or additional fuel payload, while the dual-seat option accommodates an additional pilot. Furthermore, the inclusion of a full combat radar in the nose cone enhances combat effectiveness for Intelligence, Surveillance, Target Acquisition, and Reconnaissance (ISTAR) and EW configurations, making the aircraft equally adept at real-world missions and training scenarios.
A milestone in military aviation
The unveiling of Aeralis's modular light jet marks a significant milestone in the development of next-generation military aircraft. Tristan Crawford, founder and CEO of Aeralis, expressed his pride in the team's work, emphasizing the aircraft's modular design's flexibility and groundbreaking performance. With Aeralis's commitment to innovation, this aircraft is set to become operational later in the decade.

Aeralis has been busy forming partnerships with companies like Honeywell, Thales, Rolls-Royce, Siemens, and others. It has acquired approximately $13 million in financing from "a Middle Eastern sovereign wealth fund" and has won several contracts with the UK Ministry of Defence.

In February 2021, the Royal Air Force awarded Aeralis a three-year research and development contract for the modular jet's development and design, highlighting the military's interest in this groundbreaking technology.


 


Watch a rocket engine ignite in ultra-slow motion
Ponder humanity’s spacefaring future from the safety of your computer screen.

BY ANDREW PAUL | PUBLISHED SEP 18, 2023 2:00 PM EDT

Firefly's Reaver rocket engine can generate as much as 45,000 lbs of 
Rocket ignitions are always impressive, but they’re not the easiest to look at with the naked eye for pretty obvious reasons—you can’t be anywhere near their incinerating temperatures, and their brightness is generally blinding. Thanks to popular YouTubers’ high-speed video capabilities, however, curious minds can take a look at a recent test firing to see the complex, beautiful, and perhaps terrifying ignition in action.

The new footage comes courtesy of The Slow Mo Guys, a team of videographers specializing in… well, you can connect the dots. The YouTubers were given a front row seat at a test ignition for one of Firefly Aerospace’s Reaver engines, but unlike previous excursions, this project required quite a bit of preplanning. First off, The Slow Mo Guys only had one chance to nab the shot, since rockets traditionally use up huge amounts of fuel and resources—a single SpaceX Falcon9 rocket, for example, uses tens of thousands of gallons of kerosene and liquid oxygen. 

That single attempt also needed to be positioned, rigged, and timed to begin filming at enough of a distance that wouldn’t injure anything, or anyone. According to Slow Mo Guy Gav Free, a special enclosure capable of withstanding the intense heat and vibrations needed to house their slow-motion camera, while also calibrating the equipment to handle the explosion’s brightness. In the end, Free and his companions settled on exposing their film well over 40 percent darker than usual to account for the luminosity.

All that prep work definitely paid off, judging from the footage. At 2,000 frames-per-second (80 times slower than real time), viewers may be surprised to see an initial, bright green flame. This is produced as a rocket fuel mixture called triethylaluminium-triethylborane (TEA-TEB) combusts upon coming into contact with oxygen and air. After the initial green burst comes the yellow and orange flames—but with such a slow framerate, you can actually see those flames responding to the shockwaves generated by the engine thrust. According to Free, a rocket engine can generate upwards of 45,000 lbs of thrust in a vacuum at temperatures as high as 5,500 F.

 


Curt Lewis