dailynewsnblog
One of the key features of the Airbus A330neo over the older A330ceo airliner is its new and improved wings. These are considerably longer and more aerodynamic than the older A330s, but still smaller than the larger A350’s wings, although not by much. Airliner wings are marvels of engineering, although limited by regulations that engineers are forced to work within.
It is possible that the A330neo (launched 2018) and Airbus A350 (launched 2015) could be the last of commercial aircraft designed with conventional non-folding wings. The industry is continuing to explore new ways to improve fuel efficiency by increasing the wing’s aerodynamic performance, while also complying with regulations. Here is what to know about the A330neo and A350 wings.
A New Wing For The A330neo
The primary improvement for the A330neo (new engine option) was the new engines, exclusively the Rolls-Royce Trent 7000. But Airbus included a range of other upgrades to the popular aircraft, including an increased maximum takeoff weight, increased range, updated avionics, an updated cockpit, more advanced lightweight materials, and more. But perhaps the biggest change to the A330, aside from the new engines, was the new wings.
The improvements allowed the Airbus A330neo to fly an extra 1,500 nautical miles further than the A330ceo while providing a 14% better fuel per seat. Airbus claims the A330-900 has a 25% lower operating cost compared with previous-generation aircraft. To improve the aircraft’s aerodynamic performance, Airbus stretched the wings, giving the A330neo a wingspan of 210 feet (64 meters), up from 197.8 feet (60.3 meters) with the A330ceo.
These new wings come with an aspect ratio of 11, the highest of any commercial aircraft in production. The wings are better optimized for engine/nacelle/pylon integration. They reduce drag while generating more lift at all speeds and flight phases. In all, the new wings are estimated to have improved the A330’s fuel efficiency by 4%. One issue with the older A330ceo wings was that they were designed in common with the quad-engined A340, resulting in a suboptimal wing for both jets.
Cleansheet Wing For The Cleansheet A350
While the A330neo is an update of the A330ceo with new engines and wings, the A350 is a cleansheet aircraft. Over 70% of its airframe is made out of advanced materials like composites. It was built with advanced aerodynamics and achieves a significant reduction in fuel burn per seat compared with previous-generation aircraft.
The entire wing uses advanced carbon fiber reinforced polymers (CFRP) to minimize weight and maximize strength. This is in contrast with the A330neo’s wings, which extensively use CFRPs, but the underlying structure remains metallic. The A350’s wings come with a high aspect ratio that is optimized for Mach 0.85 and has a 31.9° sweep. The A350’s blended winglets are integrated into the wing planform, allowing for drag reduction.
|
Wing sizes (per Airbus) |
Airbus A350 |
Airbus A330ceo |
Airbus A330neo |
|---|---|---|---|
|
Wingspan |
212.4 feet (64.75 meters) |
197.8 feet (60.3 meters) |
210 feet (64 meters) |
|
Aspect ratio |
9.5 |
10 |
11 |
|
Wing area |
4,769 ft² (443.0 m²) |
3,893 ft² (361.6 m²) |
3,907 ft² (363.0 m²) |
Comparing the A350 wingtips with the A330neo’s wingtips, they are more vertical and sweeping. The A330neo’s wingtips are inspired by the A350’s wingtips, although they are less aggressive. The A350 was built in response to Boeing’s cleansheet Boeing 787 Dreamliner. Compared with the wings on the 787, the A350’s are typically stiffer and straighter, while the 787’s noticeably flex more in flight.
7 Ways Airbus Made The A330neo Different From The Original A330
The A330neo represents progress in seven key areas compared to the older A330ceo.
How Much Longer Is The A350 Wing?
How much longer is the A350 wing compared with the A330neo? Not much at all, although this is due to ICAO regulations, not Airbus engineers. The A330neo currently has a wingspan of 210 feet (64 meters), while the A350 has a wingspan of 212.4 feet (64.75 meters). The A350’s wing is “clipped” to fit within Code E regulations.
If the A330neo were to be free of Code E regulations, the optimal wingspan would likely be somewhere around 220 feet (67 feet), given the aircraft’s existing aspect ratio of 11 (the optimal aspect ratio would be around 12 to 13.5). The A350 comes with an aspect ratio of 9.5, and its optimal aspect ratio would be around 12 for this type of aircraft. The optimal hypothetical wingspan would be around 239 feet (73 meters) or similar to that of the 777X.
Put another way, the A350’s wingspan is only 2.4 feet (0.75 meters) longer than the A330neo because of restraints from Code E regulations. Without that design constraint, the wingspans and aspect ratios of both wings would likely grow, but they would grow the most for the A350, as it is the most constrained. Theoretically, if engineers had been free to design the most efficient wing, the A350’s wings would have been around 20 feet (6 meters) wider than the A330neo’s, plus or minus a few feet.
Staying Within Code E Regulations
One of the banes of the lives of engineers designing aerodynamically efficient wings for modern widebody airliners is the ICAO Code E regulations. The regulation allows aircraft to have wingspans of up to 213.3 feet (65 meters) to use Code E airport gates and taxiways. Modern wings are generally optimized to make as much use of this allowable wingspan as possible, although it forces design compromises.
This forces a compromise between span and induced drag. If Airbus were to ignore gate limits and design the most aerodynamically efficient wing possible for the A350, the wingspan would likely grow to around that of the 777X (around 70 to 72 meters) while also increasing aspect ratio somewhat. It would likely also change its wingtip devices. Overall, it would likely be able to reduce induced drag by around 7% and decrease fuel burn by around 1.5% to 3%. But this is just a thought experiment.
That said, Boeing has found a way around Code E regulations with its folding wingtips. This has allowed the 777X to achieve around a 10% greater wing efficiency gain over the older 777-300ER. Boeing claims “Unconstrained wing: Longer wingspan than the A350-1000 results in better aerodynamic efficiency.” Still, this too has compromises like increased complexity, increased weight, and increased scrutiny from the FAA that could be contributing to delaying its type certification.
Boeing 777X Vs. Airbus A350-1000: Who Will Win The Battle For Tomorrow’s Flagship?
The 777X is nearly ready for service, how will it fare against Airbus’ A350?
The Future: Truss-Braced Wings
In the future, the shape of wings could change significantly. If Boom Supersonic is right, then delta wings might become popular again. If JetZero is right, then blended wing bodies are the future. If Boeing and NASA are right, then truss-braced wings could be the future. Note that these possibilities are not mutually exclusive. Boeing is currently working with NASA to produce the X-66A truss-brace wing experimental aircraft.
The demonstrator is expected to conduct its first flight tests in 2028 and 2029. NASA says, “In the future, aircraft with long, thin wings supported by aerodynamic braces could help airlines save on fuel costs.” Truss-braced wings allow for a much longer wingspan and a much thinner wing. These could allow for aspect ratios of 14-18, and reduce induced drag by 20-30%. This could result in fuel burn reduction of 8-15% for larger aircraft. This offers far greater benefits when exceeding Code E regulations, compared with an optimized conventional wing.
It is unclear what the optimal truss-braced wingspan for an aircraft the size of the A350 would be, but it could be somewhere in the 295-foot ballpark (90 meters). It is unclear how these aircraft could overcome airport gating issues. They may be designed to fold like the 777X. Alternatively, these aircraft might have to accept Code F regulations and the gates built for the A380. Narrowbody truss-braced wings may be built to fit within Code E regulations.
Conventional Wings Best Optimized Within Limits
The A330neo and A350 wings are a product of underlying aircraft (updated or cleansheet), ICAO airport code regulations, and the relative size of the aircraft. The A330neo’s wings are able to be closer to their optimal wingspan and aspect ratio within Code E, thanks to the A330 being a smaller aircraft. At the same time, the A330’s wings do not benefit from a cleansheet design, meaning their underlying structure remains aluminum.
The A350’s wings benefit from the whole aircraft being a cleansheet aircraft, and so they make greater use of lightweight composite materials. But Code E regulations mean there are more compromises to its wing design, including its aspect ratio and the wingtip devices used. Airbus chose to remain conservative and on the safer side by designing conventional wings, unlike Boeing, which took a risk by introducing folding wingtips for its Boeing 777X. For now, aircraft manufacturers are continuing to stick with conventional wings, although it’s possible blended wing bodies and/or truss-braced wings could become the next generation of wings in the 2030s or 2040s.
It appears Airbus is following Boeing’s lead. Airbus is now working on developing the successor to its popular A320 narrowbody aircraft, and its Airbus UpNext subsidiary is experimenting with eXtra Performance Wing (X-Wing) on its heavily modified Cessna Citation VII. These feature folding wingtips, suggesting the Airbus A320 will have longer than 171-foot (52-meter) wingspans, which Code D regulations limit narrowbody aircraft to. The A320 replacement may come with folding wingtips.
