The German firm on Monday said it has begun installing a serial production line for the Jet’s electric propulsion units at its manufacturing facility in Wessling, Germany. The company expects the first prototype propulsion systems—which will support for-credit type certification testing with the European Union Aviation Safety Agency (EASA)—to roll off its production line in the second quarter of 2024.

The production of electric propulsion systems for Lilium’s flagship Jet marks another key milestone in the commercialization of the aircraft, which the company began building in December. It hopes to achieve type certification in 2025 ahead of a global launch in 2026.

Lilium’s propulsion assembly line was designed in partnership with automation and robotics supplier Schnaithmann Maschinenbau GmbH, with which the manufacturer has worked for years to develop production plans. Schnaithmann will also provide workflow design, jogs, and tools for Lilium’s aerostructures assembly and final assembly line.

“The electric jet engine is a unique, core Lilium technology, critical for aircraft performance and for which we have secured not only a team of highly qualified system suppliers but also important intellectual property,” said Jan Nowacki, senior vice president of manufacturing for Lilium. “With the support of Schnaithmann, we look forward to implementing state-of-the-art manufacturing solutions capable of being scaled up and replicated for high-volume production.”

Lilium and Schnaithmann developed initial production plans several years ago in anticipation of this week’s announcement. The manufacturer’s aerostructures assembly line—located in the same building as the newly announced propulsion system assembly line—already uses Schnaithmann equipment to handle the Jet’s wings and canards.

The Wessling site also comprises a testing and manufacturing center, propulsion and aerostructures facility, final assembly building, and battery assembly building and logistics hub.

“With nearly 40 years of experience in supplying automation technology to global industries, we are proud to participate in the industrialization of the Lilium Jet,” said Gerd Maier, member of the Schnaithmann management board. “The eVTOL industry has the potential to change aviation in a positive, sustainable way, and we are delighted to be able to play a key role in helping Lilium scale up towards high-volume production.”

Lilium delivered the first of seven Jet fuselages to Wessling in December. The company will manufacture seven aircraft to use for EASA type certification validation, which it expects will begin late this year.

The manufacturer’s all-electric seven-seater is expected to fly passengers between towns and inner cities, cruising at 162 knots on trips spanning 25 to 125 sm (22 to 109 nm). The firm said the aircraft’s propulsion unit will be key in providing performance, unit economics, and comfort for regional air mobility (RAM) services.

RAM is a subset of advanced air mobility (AAM) that involves connecting cities across a broader region, as Lilium plans to do. It contrasts with the urban air mobility (UAM) approach adopted by many competitors, which intend to concentrate flights within a single city or metropolitan area, such as New York or Los Angeles.

The Lilium Jet propulsion unit consists of electric jet engines (or e-motors) integrated into a propulsion mounting system, which forms the rear part of the aircraft’s wings and front aerofoils. The company said the system will improve payload and aerodynamic efficiency, reduce noise, and provide thrust vector control to maneuver the Jet through all phases of flight.

Several components for the propulsion unit are provided by suppliers such as Honeywell, which is working with partners Denso, Aeronamic, and SKF to deliver e-motors, fans, and electric motor bearings, respectively.

The system powers 36 electric ducted fans embedded in the Jet’s wings. The unique architecture differs from competitors such as Joby Aviation or Archer Aviation, which are using tilt rotors that reorient themselves during the transition between vertical and forward flight.

In 2023, Lilium assembled the first complete electric engine for the Jet on a pre-series line. The engine is designed to deliver what the manufacturer claims is an industry-leading power density of over 100 kilowatts, despite the system weighing just less than 9 pounds.

Crewed flights of the Lilium Jet are expected to begin later this year as the company eyes for-credit testing with EASA. But Lilium is also the only eVTOL manufacturer with certification bases from both EASA and the FAA.

Earlier this month, the company designated Orlando International Airport (KMCO) as a key hub for its RAM service in Florida, which it announced in 2020. Fractional aircraft ownership company NetJets agreed tentatively to purchase 150 Lilium Jets and operate them across the Florida network, which will be supported with maintenance services from Bristow Group. FlightSafety International has agreed to train an initial cohort of Florida eVTOL pilots.

Lilium further announced support for Florida Legislature House Bill 981, which would designate Orlando International Airport as Florida’s official AAM test site. The legislation would also create a pathway for safe, efficient vertiport permitting in the state.

Last week, Lilium placed an order for 120 Star Charge electric aircraft charging systems, intended to juice up its ground and flight test aircraft. The manufacturer will also deliver chargers to customers investing in vertiports, further supporting its RAM ecosystem.

In addition, Lilium last week partnered with private and commercial operator PhilJets—which agreed to purchase 10 aircraft—to explore RAM networks in the Philippines, Cambodia, and across Southeast Asia.

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The post Lilium Prepares to Ramp Up Production of Electric Jet Propulsion Units appeared first on FLYING Magazine.

These were the words of Richard McSpadden Jr., who was aboard the Cessna 177RG Cardinal belonging to former NFL tight end turned FBO owner Russ Francis. The pair launched from the airport in Lake Placid, New York, on October 1 for a photo flight for the Aircraft Owners and Pilots Association. McSpadden, the senior vice president of the AOPA Air Safety Institute, was a commercially rated pilot who had flown with the Air Force Thunderbirds.

Per protocol on these flights, Francis, as the owner of the airplane, would do the takeoff and landing, and Spad would take the controls for the air-to-air portion of the flight.

According to witnesses, the engine of the Cardinal surged during the takeoff and did not sound like it was making full power, yet the takeoff continued. The aircraft was in the air and out of usable runway when it turned and headed back to the airport. The runway is on top of a berm—the airplane came down in the ravine below its edge. Both men were alive and talking to rescuers, then moments later, they had passed away. The National Transportation Safety Board is still investigating the accident.

This hit me hard because I often talked with McSpadden about aircraft accidents and the importance of teaching and practicing the loss of thrust on takeoff. Although we still don’t know what caused the problem aboard the aircraft, there is a strong takeaway from this accident: if it could happen to Spad—Thunderbird Number One with all his training and experience—it could happen to any of us.

Briefing for LOTOTO

I have written far too many stories about fatal accidents that were attributed to an uncommanded loss of engine power. Often the accident happens because the pilot fails to maintain the appropriate speed as indicated on the aircraft’s emergency checklist—or worse yet, pulls back on the stick or yoke trying to stretch the glide, resulting in a stall-spin-die scenario.

A variation of this is when the pilot, trying to return to the runway, puts the aircraft into a steep bank resulting in a loss of vertical lift and a knife-edge impact in the ground.

While the procedure for engine loss at altitude is taught as an emergency usually before first solo, many pilots are not taught to brief the takeoff. That means a review of rotation speed, calling airspeed alive, and procedures if there is a loss of power on takeoff, until they begin their multi-engine training. This is a disservice to the aviation community.

Granted, in a twin, the loss of engine power on one side is dramatic in a different way, as it results in asymmetrical thrust, and the nose yaws and toward the dead engine. If the aircraft has lifted off, the asymmetrical thrust results in an uncommanded and often unrecoverable roll toward the sick engine resulting in a crash. Unless you bring the power on both engines back immediately and pitch for the appropriate V speed, you probably won’t live to tell the story.

In a single engine aircraft, a loss of engine power isn’t necessarily going to be fatal—as long as the pilot takes prompt and corrective action to maintain airspeed and has someplace to put it down.

Know the Speed You Need

There have been fledgling pilots who ask with some trepidation if a loss of engine power during takeoff is common. The answer is no, but knowing what to do if it does happen is like knowing how to put out a grease fire in your kitchen—you do not have time to experiment and an improper procedure like using water on the fire—or pulling back on the yoke or stick—can make a bad situation worse.

In the aircraft, you need to know what airspeed to pitch for. This is critical.

This speed will vary by make, model, and configuration. This information comes from the pilot’s operating handbook or aircraft flight manual and may even be placarded in the aircraft.

The pilot should also note rotation speed, and do the takeoff calculation before getting into the airplane, noting runway condition, temperature, and pressure.

Knowing what performance to expect helps you determine when a takeoff is going poorly and should be aborted. Identify an abort point. For example, if you calculate based on given conditions that you will need 1,130 feet to lift off from that 3,600-foot runway and you’re approaching 2,000 feet and you’re not up yet and the tachometer shows less than full power, abort.

Quick Reference Cards

If you fly multiple aircraft you may find it handy to make notes for each one and keep them with you for review before a flight in a particular airplane.

The first flight school I worked at had more than 10 Cessna 172s of varying models. The older models had airspeed indicators in miles per hour, the rest of the fleet was in knots. This could and did result in confusion that came back to bite a few pilots. I didn’t want to be one of them, so I wrote out the emergency speeds and V speeds for each aircraft on 3 x 5 notecards and carried them in a pouch worn around my neck that also held my airport ID. I did a quick review of the speeds for the aircraft I was assigned before each flight. 

The speed to maintain during a loss of engine power on takeoff was the big one—a knot or two could make a difference in the outcome of a situation, and I had no desire to be Junior Test Pilot in the event of an uncommanded loss of engine power, especially when I had someone sitting next to me counting on me to keep them safe.

Verbalize the Procedures

The loss of thrust or control on takeoff is part of my pre-takeoff briefing. It is concise and to the point:

If during the takeoff roll there is anything abnormal, be it an issue with controllability or engine power, we will bring the power to idle and come to a stop on the runway, then assess.

If the aircraft has lifted off and there is usable runway ahead, we will pitch for (insert speed here after verifying with checklist), land on the runway, and assess.

If the aircraft has lifted off and is out of usable runway, we will pitch for (insert speed here) and aim straight ahead or a gentle turn of no more than 30 degrees off the runway centerline aiming for someplace unpopulated, soft, and inexpensive.

Should You Turn Back?

Turning back to the runway can be a dicey situation. It is one of those scenarios I frequently practice in the ATD. If the aircraft is at least 1,000 feet agl, and the aircraft is light enough, it may be possible. It might even be doable at 800 to 700 feet. Always have an idea of where you will put it down if getting back to the runway is not an option—is there an open area of the extended centerline you could land in? An empty parking lot? Trees? A swamp? A road or street? To be clear: I am not a big fan of trying to put it down on a road or street because of power poles, cars, and street signs, however, the law of gravity cannot be denied, so do your best not to endanger anyone else.

In a Two-Pilot Situation

When flying with another pilot, the loss of thrust or controllability on takeoff briefing needs to include who will be pilot flying, because two pilots fighting over the controls is not going to help. One pilot should be pilot flying, the other should be making the radio calls if appropriate and time permits. “I will be pilot flying, you will back me up on the radio,” is the phrase to use.

Oddly, there are some CFIs that say this loss of thrust/control briefing is unnecessary and doesn’t do anything but scare the learners. I disagree—and so do the learners, like the one with the Cessna 150 who noted a lack of rpm on takeoff despite the throttle set to full power and aborted before he ran out of runway and options at the same time. Airport Mom was proud.

The post Loss of Thrust on Takeoff appeared first on FLYING Magazine.

The new models are the DHK200 and the DHK235. Both will share the same dimensions and weight of the DHK180, which has a rated takeoff power (RTP) and maximum continuous power (MCP) of 180 horsepower.

The DHK200 will produce RTP and MCP of 200 horsepower, while the DHK235 will produce  RTP and MCP of 235 horsepower.

DeltaHawk anticipates the certification and availability of the DHK200 in the third quarter of 2024, followed by certification and availability of the DHK235 in the first half of 2025.

Company officials are hopeful the momentum created by the introduction and certification of the DHK180 will be mirrored by the DHK200 and DHK235. The DHK180 went into production last summer.

• READ MORE: DeltaHawk DHK180 Engine Heads To Production

“Following FAA certification of the DHK180, customer interest and reservation deposits from aircraft OEMs and individual owners in both certified and experimental markets has been extremely high,” said Christopher Rudd, CEO of DeltaHawk Engines. “Our two new engine models build upon the same innovative, pilot-focused technology as the DHK180, while offering even more capability for higher power applications—as will additional engine models yet to be announced.”

About the Engines

DeltaHawk Engines, founded in 1996 and based in Racine, Wisconsin, designs and builds FAA-certified, jet-fueled piston engines for general aviation aircraft and hybrid-power systems.

All the DeltaHawk engines are based upon a clean-sheet design and feature an inverted-V engine block, turbocharging and supercharging, mechanical fuel injection, liquid cooling, direct drive, and, according to the company, 40 percent fewer moving parts than other engines in their category.

DeltaHawk notes the engines produce more usable torque than traditional aircraft engines in their class, all while burning significantly less fuel.

NASA recently selected the DeltaHawk DHK180 engine for its Subsonic Single Aft Engine project, known as SUSAN. Additionally, Ampaire has selected it for a hybrid proof-of-concept aircraft.

DeltaHawk is also working on a new program to develop additional variants of its engine family that will utilize hydrogen fuel in a wide variety of applications, including aviation, commercial road vehicles, and military mobility.

For more information, please visit the DeltaHawk website.

The post DeltaHawk Adds 2 More Engines appeared first on FLYING Magazine.

ZeroAvia, a developer of hydrogen-electric propulsion systems, on Monday announced it completed a $116 million Series C funding round to support certification of its ZA600 engines and the scaling of its technology for larger aircraft.

The round was co-led by previously announced financiers Airbus, Barclays Sustainable Impact Capital, and NEOM Investment Fund, as well as the U.K. Infrastructure Bank (UKIB), which joined as a “cornerstone-level” investor. Bill Gates’ Breakthrough Energy Ventures, Amazon’s Climate Pledge Fund, Horizons Ventures, Alaska Airlines, and several others were named as participants.

“This is a great example of the bank supporting a first-of-a-kind technology that has real potential to have a telling impact on carbon emissions and help position the U.K. at the forefront of a developing green hydrogen ecosystem,” said Ian Brown, head of banking and investments at UKIB.

According to ZeroAvia, the bank’s financing will promote the company’s growth plans in the U.K., where it has been predicted that one-quarter of carbon emissions will come from aviation by 2050.

“ZeroAvia has grown rapidly in the U.K. as we have worked to deliver two major historic milestones in aerospace engineering, as we look to preserve the benefits of flight through clean propulsion,” said Val Miftakhov, founder and CEO of ZeroAvia. “This backing by such a preeminent investor as [UKIB] will help us deliver the first commercial zero-emission flights and help the U.K. realize substantial export potential.”

UKIB, meanwhile, has the opportunity to become a market leader in the country’s quest to eliminate aviation emissions by the 2050 timeframe. Founded in 2021, the bank’s mandate is to back emerging technologies and crowd in private investment while driving regional growth and taking on climate change. It said a successful rollout of hydrogen engines in aviation could catalyze the development of wider hydrogen infrastructure.

“Aviation and hydrogen are sectors that need significant private investment to get to net zero,” said Brown. “By providing confidence to investors, our equity has helped to crowd in the private investment needed for the continued development of this cutting-edge technology and should help stimulate the development and deployment of hydrogen technology across other hard-to-decarbonise sectors.”

ZeroAvia’s latest funding comes three years after a series A investment led by Breakthrough Energy, the Climate Pledge Fund, and other participants in November’s round netted it $21.4 million. It followed that up last year with a Series B from Barclays, Neom, International Airlines Group, and American Airlines, bringing its total raised to $150 million.

The company is starting small: Its ZA600 engine, a 600-kilowatt, hybrid-electric powertrain, will be retrofitted on regional turboprops with nine to 19 seats and a range of 300 sm (260 nm) by the end of 2025. Two years later, the ZA2000, a 2-5 megawatt model, is expected to support aircraft with 40 to 80 seats and a 700 sm (608 nm) range.

So far, ZeroAvia has secured experimental certificates to test its engines with the FAA and the U.K.’s Civil Aviation Authority (CAA) using three separate testbed aircraft.

The company has already hit several flight test milestones, most notably using a Dornier 228 equipped with one ZA600 engine and one conventional stock engine. Since completing its maiden voyage in January, the aircraft has gone through a range of tests, including flying at 5,000 feet, weathering a 23-minute endurance test, and operating in just-above-freezing temperatures.

ZeroAvia says it has a number of engineering partnerships with key aircraft OEMs, such as Cessna, Beechcraft, and de Havilland Canada. It claims to have nearly 2,000 preorders from major global airlines, including United Airlines, which in 2021 signed on as an investor and agreed to purchase up to 100 engines.

Simultaneously, the manufacturer is working on several projects. The most recent is a collaboration with Airbus to explore certification for hydrogen-powered systems. The partners also intend to examine liquid hydrogen fuel storage, fuel cell propulsion testing, and the development of hydrogen refueling infrastructure.

Another venture involves Textron, with which ZeroAvia will collaborate to install the ZA600 on a Cessna Grand Caravan turboprop. The company is also working with European airport operator AGS Airports to develop hydrogen fuel infrastructure and zero-emission routes, while a partnership with autonomous cargo aircraft developer Natilus will see it add its engines to the company’s Kona model.

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The post ZeroAvia Completes $116 Million Series C to Support Hydrogen-Electric Engine Tech appeared first on FLYING Magazine.

According to the company, the test results indicate the new engine will have applications in  multiple markets in addition to aviation, such as commercial power applications, defense platforms, and zero-emission vehicles.

“Environmental responsibility is a foundational pillar of our company” said Christopher Ruud, CEO of DeltaHawk. “In the general aviation industry, our family of engines are creating a highly reduced net-carbon footprint coupled with airborne lead removal, thanks in large part to their fuel efficiency and capability to burn next-generation sustainable aviation fuels [SAFs]. Now with our planned ability to expand our engine family to include variants that will utilize hydrogen fuel in aviation, commercial, and military applications, we’ve taken another major step toward environmental sustainability, climate neutrality, and a zero-emissions future.”

• READ MORE: DeltaHawk Gains Type Certification on Jet-Fueled Piston Powerplant

About the Company

Since its founding in 1996, DeltaHawk said it has been striving to create a cleaner, more efficient, engine for the GA market. The company holds numerous patents for its clean-sheet engine designs.

According to the company, the use of proven internal combustion engine (ICE) technology with hydrogen fuel replaces more expensive, highly infrastructure-reliant fuel cell systems. That allows for a significantly reduced power degradation curve over time compared to current fuel cell technology, providing better fuel economy than fuel cells after the initial period.

DeltaHawk said its compact, lightweight, and durable design, based on patented two-stroke technology, makes this new engine family an ideal solution for hydrogen fuel. 

More information on the company website is available here.

The post DeltaHawk High on Testing of Hydrogen Engine appeared first on FLYING Magazine.

EAGLE—which stands for Eliminate Aviation Gas Lead Emissions—includes partners from aviation industry associations, the FAA, fuel producers and distributors, airport operators, and local community and environmental experts. With the aim to transition away from leaded avgas—100LL—by 2030, EAGLE has the twin missions of supporting development of replacement fuels and advocating for the continued supply of current fuels until the OEMs, operators, and pilots feel secure in the safety and security of the new fuel source(s).

It’s a tall order. Though four entities reported significant progress with their specific candidate fuel, there are varying degrees of confidence in both the composition and distribution prospects of each one.

The EPA’s Next Step Lies Ahead

And time is of the essence—though it’s not prudent to panic yet, according to leaders like Chris D’Acosta, founder and CEO of Swift Fuels, which is currently working on one candidate fuel. What would trigger that response? The Environmental Protection Agency announced its proposed endangerment finding on leaded avgas last October, and it stands to finalize that this October, on schedule.

What does that mean? It doesn’t mean that leaded avgas will be banned immediately. At the briefing, General Aviation Manufacturers Association (GAMA) president and CEO Pete Bunce outlined the steps that would follow the finding. “The people that have to implement the rules are [at] the FAA,” said Bunce of the next steps following the endangerment finding. “There’s a very structured process.” He estimated that there would be about two or three years to completely field the transition fuel. That’s part of the reasoning behind the 2030 goal EAGLE set, to work through this “very methodical process.”

“We have smart people working in these four companies, and we’re going to have a solution,” said Bunce.

• READ MORE: UND Aerospace Transitions Full Fleet to Unleaded Avgas

Four Fuels

Representatives from each of the companies or partnerships working on those fuels presented their progress, starting with D’Acosta. 

Swift Fuels

Eight years ago, Swift Fuels began delivering the first batches of its UL94 unleaded avgas, and it can now be found in roughly 81 locations across the U.S. The current fuel serves as a drop-in replacement for 130,000 aircraft on the registry—for which FLYING awarded Swift its 2023 Innovation Award. The success of UL94 sets the stage for its higher octane 100R fuel that will serve the remainder of the GA fleet. Swift followed a dual certification program with UL94, acquiring ASTM acceptance as well as supplemental type certificate approval from the FAA. It is pursuing the same path with 100R.

Swift offers a “forever STC” that covers the UL94 as well as future fuels, along with all of the placarding and any changes in documentation. The underlying goal is to establish a sense of security among those who will put the fuel into their tanks—both at the airport and on the airplane. “The emotional uncertainty at this time is really counterproductive to everybody’s interests,” said D’Acosta.

GAMI

George Braly of General Aviation Modifications Inc. presented next, reporting on the nearly 14 years since GAMI began development on its unleaded avgas replacement—and culminating with the issuance of its blanket STC for all aircraft powered by spark-ignition engines in September 2022. “GAMI has fixed the problem,” said Braly, summarizing what had been the general feeling at the time of the STC’s debut. GAMI is working with OEMs like Robinson (for rotorcraft implementation) and Cirrus in its SR22T, considered one of the most complex powerplant installations to accept the new fuel. 

While the STC has been available for nearly a year, GAMI is still struggling to supply the fuel to the market. To this end, Braly announced it had partnered with “an extremely large producer of aviation jet fuel,” VTOL, to produce the G100UL in quantity. That Houston-based company has finished its 4 million-gallon tank toward making that happen.

LyondellBassell and VP Racing

Two of the fuel developers are pursuing approvals through the Piston Aviation Fuels Initiative (PAFI), established by Congress to achieve fleet authorization through a collaborative industry-government process. LyondellBassell/VP Racing is the first of these. VP Racing is a Texas-based developer of fuels and additives for the automotive racing industry, and LyondellBassell produces high-octane lead components for automobiles. In his remarks at the briefing, Dan Perot of LyondellBassell admitted the partnership was “relative latecomers to this race,” as it started in 2018 to develop its answer to the high-octane avgas question.

“We chose to stay with the PAFI program despite delays during the COVID period,” said Perot, “because we felt that it provided the best mechanism for us to learn what the industry needed, communicate with the FAA and OEMs, and secondly, and maybe most importantly, it required ASTM certification for the fuel.” 

According to Mark Walls of VP Racing, the partnership’s fuel meets all D910 specs, is of the same density as 100LL, and is poised to be cost-competitive. The company is about to enter “full-scale” testing after preliminary work in Lycoming and other engines. Like other fuels in development, Walls said its avgas is fully compatible with 100LL in case of mixing in aircraft tanks.

Afton Chemical and Phillips 66

The second partnership pursuing PAFI-based authorization is between Afton Chemical, headquartered in Richmond, Virginia, and Phillips 66. The pair are also working on new lubricants to accompany the high-octane unleaded fuels. Enrico Lodrigueza with Phillips 66 updated on its progress, detailing the candidate fuel, which uses manganese—a coenzyme used in the human body to break down carbohydrates and proteins, a transition metal—to replace the tetraethyl lead in 100LL. The fuel has an ASTM specification in place, ASTM 28434, according to Lodrigueza, which is “substantially similar” to the D910 spec for 100LL.

Lodrigueza characterized the manganese-based octane booster in use. “Manganese is not a heavy metal. That’s one major difference…it’s an essential nutrient.” As far as testing, the partnership has had “a lot of vetting” by subject matter experts and is ready to proceed with detonation testing at the Tech Center on a Lycoming engine. As with all of the potential replacement additives, close scrutiny is being placed on what issues may occur with the new element in the fuel, such as spark plug fouling. The lubricants testing will also ensure compatibility with whatever oil is in use, for example.

What’s Next?

Clearly, the four candidate fuels are in different states of availability for testing—some more broadly than others—and both the engine and airframe OEMs are eager to keep going. Bunce summarized the position of the manufacturers. “We have the money, our manufacturers have the money to purchase it, to be able to go and look at that fuel and understand what chemical components are in relation to the spec to be able to run it and to do the type of testing that we feel comfortable that we can put our families into that aircraft employing that fuel. And if we see good or bad, we will share it, as manufacturers, to the FAA., That’s our obligation—but that’s the right thing to do.”

The post EAGLE Initiative Shows Measured Progress, Fuel Contenders Say at Oshkosh appeared first on FLYING Magazine.

The announcement was made on Tuesday at the Paris Air Show, along with several updates on the airframe and engine development as well as manufacturing and testing plans. The final product—the Overture—is projected to fly at Mach 1.75 in overwater cruise powered by bespoke Symphony engines running on 100 percent sustainable aviation fuel.

Mainline Suppliers

Leonardo, based in Rome, will provide its expertise in composite structure development and manufacturing as engineering lead for the Overture’s fuselage structural components integration, and serve as a design and build partner for fuselage sections—including the wingbox. The cross section of the Overture has a larger diameter at its fore section growing smaller towards the rear of the airplane. The design is intended to “minimize wave-drag and maximize fuel efficiency at supersonic speeds,” according to a statement from the company.

Aernnova, in Madrid, a large tier-one aerospace supplier, has been chosen to design and develop the Overture’s gull-shaped wings, which are structurally thinner than typical subsonic wings. Their nature is intended to reduce drag and increase efficiency at high speeds.

Aciturri, based in Miranda de Ebro, Spain, and another major tier 1 supplier, has been selected to provide the empennage to the Overture. A horizontal stabilizer that allows for greater control at subsonic speeds, including takeoff landing, is a key element to the tail design.

Symphony Engine Milestones

Florida Turbine Technologies (FTT) of Doral is the main partner on Boom’s proprietary engine, named the Symphony, and it continues to move forward in the two-spool, medium-bypass turbofan’s development. Scholl gave details on the powerplant’s specs along with teasing photos of the cross section that include the aforementioned optimization to run on 100 percent SAF. “Symphony features a high-specific-flow fan,” said Scholl, “which allows us to reduce the frontal area of the engine, which reduces supersonic drag.” Other details include:

• 35,000-pound thrust
• single-stage 72-inch fan
• air-cooled, multi-stage turbine
• FAA Part 33 and EASA CS 33 compliant
• adherence to ICAO Chapter 14 noise levels

Use of additive manufacturing will enable lightweight composition, low parts count, and reduced assembly costs. The engine features three low-pressure compressor stages, six high-pressure compressor stages, three low-pressure turbine stages, and a single high-pressure turbine stage. Former Rolls-Royce CTO and Singapore Aerospace programme chair Ric Parker serves as lead on the engine program, which has been under the magnifying glass when it moved away from former engine partner Rolls-Royce and went with a trio of new collaborators: FTT, GE Additive, and Standard Aero. Scholl spoke to this tangentially, stating that the need for a bespoke engine “specifically optimized for sustained supersonic flight and sustainable supersonic portions of that.” The vertical integration strategy is key to achieving this.

• READ MORE: Boom to Lead New Powerplant Design for Supersonic Jet

Manufacturing of the engines at scale will take place at FTT’s facility in Jupiter, Florida, Scholl revealed at the press conference. He also updated on progress of the company’s “iron bird” testing facility at its headquarters on the Centennial Airport (KAPA) on the south side of the Denver metro area in Colorado. 

“This is the integrated test facility, where we will be able to put all of the systems hardware through exhaustive testing, with software and hardware in the loop, with thousands of simulated first flights before Overture makes its maiden voyage,” said Scholl. Flight controls, electrical power, and landing gear will all be operable in the iron bird facility.

Fuel System as CG Control

One of the unique aspects of the Overture includes systems architecture updated upon during the press conference by Scholl. While avionics, flight controls, hydraulics, and gear systems were touched upon—and will meet FAA and EASA Part 25 regs—he offered a bit of insight on the fuel system, which will be used to provide center of gravity (CG) control during both sub- and supersonic operations.

The all-composite makeup of Overture enables the use of complex aerostructures to create the contoured fuselage and gull-wing planform. Overall, the use of already certified technologies have been chosen thus far to reduce the risk on the program, as it breaks ground in significant ways in commercial passenger service.

The program remains on track in its 10-year development cycle—where it stands 3.5 years in—for a planned type certification in 2029.

The post Boom Aerospace Delivers Update on Supersonic Model appeared first on FLYING Magazine.

The liquid-cooled,180 hp, 4-cylinder diesel engine uses an inverted “V” configuration and mechanical fuel injection, along with a slimmer design expected to fit more efficiently into modern aircraft cowling. It’s turbocharged and supercharged, direct drive, and has been assembled with 40 percent fewer parts than other engines in its class.

“We began by completely reimagining what a general aviation engine should be,” said Christopher Ruud, DeltaHawk’s CEO. “And the result is that we now have a certified engine that is a game-changer. It’s been a long time coming but, in engineering, simple is hard. However, this engine’s performance, simplicity, and reliability have made it worth the time and the investment, as it is truly ‘power reimagined.’”

A Long Road to TC

It’s not easy or cheap to bring a new powerplant into the GA market, and the DeltaHawk story proves this to be true once again. Few new designs have surfaced in the past 60 years.

The DHK180 stems from the DH180 originally on display at EAA AirVenture 2014 on a Cirrus SR20. After the Ruud family took controlling ownership in 2016, the path toward certification became clearer: The 180 hp variant showed up at Oshkosh in 2019, also on the SR20, and at that time DeltaHawk expected certification by the end of that year. With a little delay—and pandemic induced slowdowns—the engine has now acquired the TC it needs to move into the production phase.

Good things come to those who persevere, however. According to the company, it has had interest from potential suitors from kit builders to the military—even from NASA to power its Subsonic Single Aft Engine Aircraft (SUSAN) scale flight test vehicle.

DeltaHawk expects to deliver the first of its production DHK180s in 2024.

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Since I purchased my airplane in 2021, I’ve been carefully choosing upgrades to address its most glaring shortcomings. Throughout this process, I freely acknowledge the indisputable fact that the weakest point of the entire system is the shortcoming found in the left seat. Indeed, for me to suggest that anything else is more in need of improvement is akin to Steven Seagal suggesting that the casts of The Shawshank Redemption or Citizen Kane should take some acting classes.

Nevertheless, it’s fun to calibrate one’s airplane to their liking through modifications. For the more technically-minded, even a certified airplane is a blank canvas to tweak and improve. It becomes a question of what sort of flying experience you’re after and then what modifications will help you to achieve that experience in the most cost-effective manner.

For me, one of the most concerning parts of many flights has always been the takeoff. Particularly on shorter strips and on hot days, departure-end obstacles have always loomed large. Equipped with a relatively anemic 145 hp engine and a propeller that has flown for around 4,000 hours without an overhaul, one of my biggest goals was to make takeoffs from shorter strips more fun than concerning.

The first step was to evaluate all my available options. The most obvious was also the most expensive—an engine upgrade. Continental and Lycoming both offer fire-breathing alternatives to my 170’s stock engine, ranging from 180 to 210 hp. When combined with a constant-speed propeller, they produce enough thrust to throw your head back upon brake release and transform those departure-end obstacles from objects of doom to laughable runway decorations.

This intoxicating power comes at quite a cost, however. After including the engine, the mounting kit, the STC, the propeller, and labor to install it all, the total bill for the modification can exceed $80,000. And while it completely transforms the airplane, a price tag like that is enough to make you consider dealing with those departure-end obstacles in a more cost-effective manner, perhaps with a chainsaw under cover of darkness. So a new engine was off the table from the get-go.

Depending on the aircraft, bolt-on options might be available to increase horsepower. Power Flow Systems sells exhaust systems that increase horsepower for a minimal investment. A company called Airworx out of Alabama is currently testing a set of high-compression pistons for the Continental O-300 that they predict will increase horsepower from 145 to 180. Unfortunately, neither of these options is available for my engine at this time.

Finally, it occurred to me that there was another option—a larger-diameter, flatter-pitch McCauley propeller known as a “seaplane prop” owing to its popularity with floatplane operators who demand additional thrust for takeoff. With my aircraft/engine combination, I could simply order one of these and trade cruise speed for takeoff and climb thrust. And installation was as easy as unbolting the old prop and bolting the new one on.

The term “seaplane prop” generally refers to the fixed-pitch 1A175/DM 80/42 propeller, and those last two numbers are the most noteworthy. In this case, the 80 refers to the propeller’s diameter in inches, and the 42 refers to the number of inches the propeller would move forward in one revolution if it were in a solid medium like wood, with no aerodynamic slip. Compared with my stock 76/53 prop, the seaplane prop would move a greater volume of air, and the flatter pitch would enable the engine to achieve higher static rpm and thus, more power on takeoff and climb.

As I tend to prefer bopping around from one airport to another while staying close to home over long-distance traveling, the resulting loss of cruise speed seemed inconsequential to me. And the list price of around $5,700 was a fraction of an engine conversion. If my existing prop was long enough in the tooth for me to consider replacement, why not switch to a prop more suited to the flying I was doing?

In my case, I had built a good working relationship via social media with the people at McCauley and Textron Aviation, and they agreed to provide me with a prop in exchange for regular feedback and features on a platform separate from FLYING. My writing here was not included in the agreement, so I’m able to freely discuss its pros and cons here in greater depth and detail.

Upon receiving the prop, I called my mechanic and arranged a time for him to drive to my hangar for the installation. The installation took him less than one hour. Just like that, I’d unlocked additional thrust from my engine.

My first takeoff was absurd. While I wasn’t able to produce exact measurements, I estimate the tail came up in half the distance as usual—perhaps 50 or 60 feet—and I lifted off in perhaps two-thirds my typical distance. Partial fuel and frigid temperatures produced a climb rate of roughly 1,500 to 1,700 feet per minute on the upwind and crosswind legs, which was nearly twice what I was used to seeing.

This performance took me by surprise. I reached 500 feet agl about a third of a mile sooner than usual, and I reached pattern altitude as I was turning from crosswind to downwind rather than at midfield. When I reduced power abeam the numbers and reached over to add the first notch of flaps, I realized that the climb performance was such an improvement, I had forgotten to raise the flaps after takeoff and had been happily trundling along downwind with two notches extended the entire time.

Subsequent takeoffs were similarly enjoyable, and I felt like I had a new airplane. When I took a 220-pound friend up for a ride a few weeks later, the resulting takeoff and climb performance seemed on par with that of my old prop and no passengers. So it seemed as though the upgrade produced a performance gain roughly equivalent to having a 220-pound dude hop out of the airplane.

Surely, I thought, there must be some serious downsides to the propeller. What might they be?

Some might consider the cost to be a downside. At nearly $6,000, the price isn’t exactly pocket change. But as an upgrade, one could sell their used prop to nicely offset the cost by at least $1,500 to $2,000 if it’s in decent shape. 

Another potential downside is the slightly reduced ground clearance. While three inches isn’t a huge amount, it can be a concern with small tires on a taildragger or when installed on a tricycle-gear airplane and operated on rougher, uneven surfaces. In both cases, a switch to larger tires can reduce or eliminate the concern.

On an entirely superficial level, I do miss the mirror-like finish on my old polished prop. It lent a vintage, retro look to my 1953 airplane that has been lost with the new matte black prop. But I suppose I can always have it stripped and polished in the future.

The most potentially significant downside is the reduction in cruise speed. I haven’t evaluated it for long enough to have produced entirely accurate numbers, but it initially appears as though my cruise speed has dropped from roughly 110 to 115 mph down to 95 to 100 mph. Add a headwind to the equation, and the ensuing 75 or 80 mph groundspeeds will become pretty tedious. But I anticipated and accepted this tradeoff going into it.

Ultimately, I’ve found that the propeller has instantly unlocked fantastic takeoff and climb performance with a significant but acceptable reduction in cruise speed. It doesn’t feel on par with a 180-hp engine upgrade, but it easily feels like I’ve got an additional 10 or 15 horsepower on tap. And most important, it has erased much of the trepidation I’ve had at some of the shorter strips around and has given me more confidence to clear departure-end obstacles with room to spare.

Provided an aircraft owner is willing to sacrifice some top-end cruise speed, I recommend the propeller highly. McCauley manufactures the 80/42 prop for all Cessna 170 models as well as all 172 models up to and including the P. It is also approved for the Aeronca Sedan, Challenger, Citabria, and Scout as well as the Piper PA-18-135 Super Cub and all 56 examples of the Jodel D.140B Mousquetaire II ever built.

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As long and as frustrating as the hunt for the perfect airplane can be, it’s important to remain disciplined. On the one hand, it would be a mistake to remain a perpetual shopper, endlessly waiting for the perfect airplane to appear at the perfect price. But on the other hand, one must exercise patience to ensure their first airplane purchase is smart.

Among all the first-time buying advice I see and hear, many of the same items pop up regularly. Ensure the airplane doesn’t have a corrosion problem. Ensure the engine has been operated somewhat regularly and has not been sitting. Ensure the logs are complete, with no surprises. Obtain a thorough pre-purchase inspection from someone intimately familiar with the type. It’s all great advice that should certainly be followed.

But how can one look beyond the usual pre-purchase checklist and peer into a figurative crystal ball to predict what future maladies may surface? How can one anticipate and prepare for issues that might not reveal themselves for another two years…or five? To gain this level of knowledge, one must become something of an amateur detective. Fortunately, doing so is both simple and fun.

The easiest way is to join an airplane’s type club and engage with current owners. A phone call here or an email there can easily evolve into an enjoyable, hour-long micro-education about an aircraft type, providing a thorough understanding of the concerns and intricacies specific to it. In a matter of hours, one can learn from the expensive and extensive mistakes of others, all for an annual membership fee that’s typically around $50. That’s less than dinner for two at Olive Garden.

Over the years, I’ve only ever met one airplane owner that wasn’t completely enthusiastic about educating me about his airplane. It wasn’t entirely his fault, however, considering I ignored multiple “No Trespassing” signs, proceeded to trespass upon his property, and knocked on his back door on an otherwise peaceful Sunday afternoon. He was a good sport, however, and I received none of the gunshot wounds promised by the aforementioned signs.

Virtually every other airplane owner will happily indulge a prospective owner-to-be in the hopes of bringing them into the fold. While investigating the Beechcraft Musketeer, for example, I learned that many are equipped with the Continental IO-346. This is widely regarded as a great engine, but as it was only ever produced for the Musketeer, it is an orphan engine. Parts are extraordinarily difficult to source, and further investigation revealed that multiple engine shops simply refuse to work on them.

More than one owner with whom I spoke expressed regret that they hadn’t investigated this concern more thoroughly. While they love their engine and airplane, they dread the day when they are forced to find parts and maintenance for major work. In the meantime, they actively scour eBay, Craigslist, and other sources to proactively find and stockpile parts.

Similarly, researching the Mooney M20 series for a recent installment of Air Compare (coming up in FLYING’s April 2023 print edition) taught me things I would never have learned without picking up the phone and engaging with current owners. For this particular article, I was comparing ownership of the M20 with the Grumman AA-5 series. I knew going into it that the retractable-gear Mooney was more expensive to insure than the fixed-gear Grumman, but I vastly underestimated just how much more expensive it is. 

After interviewing several owners of each type and learning how much they pay every year for insurance, I reached out to a broker to conduct a theoretical apples-to-apples comparison. I asked the broker to create quotes for a 40-year-old private pilot with no instrument rating, 250 hours total time, and 5 hours in type. For a Grumman and a Mooney with the same horsepower and hull value, that pilot could expect to pay a premium of $341 per month to insure the Mooney. Adding an instrument rating, total time, and time in type still resulted in an additional premium of more than $200 per month above the cost to own a Grumman AA-5 series.

That’s a significant expense that can easily remain hidden until after the purchase, particularly if the first-time buyer simply accepts that retractable-gear airplanes are generally more expensive to insure without digging deeper for specific numbers. Going into it with a nebulous idea that some increased expense will be there starts to prepare a prospective buyer, but conducting these sorts of investigations fully prepares them.

As more airplanes emerge from their hangars and as more small airports resume hosting their wonderful Saturday pancake breakfast fly-ins, a wise buyer will take just a bit more time to play detective. This way, they will learn the hard lessons as well as the success stories experienced by those whose footsteps they follow.

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