Airbus A321XLR – The world of narrowbodies redefined

The Covid-19 pandemic has hit a severe blow to the economy worldwide and none has been hit as bad as the aviation industry. Not one to be put down, aircraft manufacturers have been looking for ways to beat around it and one such aerospace giant, Airbus, is already looking towards a new plane to help drive its recovery and get a leg up on rival Boeing.

What is the A321 XLR?

The newest offering of the A320 family, the A321XLR offers a vast 4700 NM of range, far surpassing any current narrowbodies. The longest range Boeing B737 MAX offers is 3850 NM while the A321LR has a range of 4000 NM. The XLR stands for Extra Long Range and the aircraft can more than handle crossing the North Atlantic, opening up the possibility of airlines using it on routes that have been dominated by the wide-bodied aircraft syndicate up to now.

What sets it apart..

INCREDIBLE RANGE : As the very name suggests, this marvel of technology pushes the range to the highest of any narrow body present today- 8,700 km (4, 700 NM). A typical A321 NEO has a range of just under 6,000Kms while a B737-8 reaches out to about 6,570Kms.

Now unlike the A350 XWB(Extra Wide Body), the A321 XLR isn't exactly fresh-off-the-menu design. Airbus has been constantly upgrading the A320 family and this is a result of one such upgrade only. It has already bagged a staggering 450 orders from over 20 airlines and is scheduled to start deliveries by 2023.

Airbus

This aircraft will provide airlines with a range of up to 4,700nm and a 30% lower fuel burn and CO2 emissions per seat compared with previous-generation aircrafts. The aircraft is positioned at what is known as the "middle of the market" in the aviation industry -- the gap between single-aisle narrow-body aircrafts and twin-aisle wide-body aircrafts.

The Rear Centre Tank- the XLR performance masterpiece

The RCT, which is unique to the new long-range A321XLR, is a permanently installed high-capacity fuel tank that makes maximum volumetric use of the aircraft’s lower fuselage.

Integrated in fuselage sections 15 and 17 and located behind the main landing gear bay ,it holds up to 13,100 litres, which is more fuel than several Additional Centre Tanks (ACTs) combined could previously hold in the A321 aircraft Family.

Airbus

In parallel to this, the structural assembly of section 15 started in mid April with the integration of the shells from the supplier RUAG, the Centre Wing Box coming from Airbus Nantes, and the keel beam and Rear Flange Module supplied by Premium AEROTEC.

A setback

Well Boeing has expressed safety concerns with the European Union Aviation Safety Agency (EASA) over the A321XLR. This is in response to a consultation paper by the regulator about Airbus’s plans to install insulation panels on the floor of the A321XLR. Considering B737 Max's never ending issues, Boeing’s feedback is definitely ironic and not with the purest of intentions, but still fair, since ultimately all safety concerns should be addressed.

In a filing, Boeing’s director of global regulatory strategy stated that: “Fuel tanks integral to the airframe structure inherently provide less redundancy than structurally separate fuel tanks.”

The EASA has accorded the Boeing’s concerns around the “structural crashworthiness” of the tanks, and the risks of fire due to heat transfer from an external threat. Airbus now needs to prove through tests that these fuel tanks are as safe as previous designs.

Airbus

What it could mean for Indian Aviation?

Indigo, the largest Indian carrier broke news last October when it announced the order of 300 A320 neo which also contained the new A321XLR- the longest range widebody ever proposed. The XLR’s range gives airlines the opportunity to start routes that weren’t possible with widebodies. The range of the A321XLR means that long haul routes in Europe, Asia and Africa are suddenly now a possibility from Delhi-Indigo’s base hub. The list goes on to include London, Paris, Tokyo and Addis Ababa as well.

Airbus - a320neo delivery to indigo

So far there are no low-cost alternatives available for long-haul and the addition of the A321XLR could just change that, and possibly capture a whole new market.

The upshot

With the pandemic having decimated air traffic, airlines are likely to have even more need for such aircraft as they rebuild their route networks. An A321 XLR "costs much less to buy and service" as well as fly than a wide-body aircraft.

"Pilot training -- an important element of costs -- can be mutualised between long-haul operations and those for short- and medium-haul flights. With the development of the A321XLR, Boeing faces a very serious mid-market challenge. This aircraft is scheduled to enter service in 2023.

Overview

A hydrogen powered aircraft uses hydrogen rather than fossil fuels such as aviation fuel. Hydrogen can either be burned in a jet engine or can be used to power a fuel cell which generates electricity. Liquid hydrogen has about four times the volume for the same amount of energy of kerosene requiring need of larger fuselage length and diameter for storage. Increased surface area lowers performance significantly due to increased friction and drag. However, hydrogen is about one-third of the weight of kerosene jet-fuel for the same amount of energy. Therefore the performance is a trade-off of the larger wetted area and lower fuel weight.

Artist’s concept

History and Present

You will be surprised to know that as early as in February 1957, a Martin B-57B flew on hydrogen for 20 min for one of its two Wright J65 engines. On 15 April 1988, the Tu-155 first flew as the first hydrogen-powered experimental aircraft. More recent progress have been made by Austria's Diamond Aircraft Industries to successfully test-fly it's flagship 2-seater, DA20 with hydrogen powered fuel cells. Due to present-day impending horror of global warming, mega-manufacturers like Airbus and Boeing have been forced to look into ways to decarbonise aviation industry. In 2020, Airbus announced plans to develop three different hydrogen-fuelled concepts, named ZEROe, with the aim of developing zero-emission aircraft powered using hydrogen gas turbine rather than hydrogen fuel cells.

airbus

Are other stakeholders making aviation industry a scapegoat ?

Before the pandemic grounded most flights, commercial aviation accounted for about 2.5% of global emissions of carbon dioxide. It sounds like a small proportion of the whole, but it is more than those of Germany (2.2%), and this is not the whole story. Carbon dioxide accounts for about half of aviation's contribution to what is known as its effective radiative forcing – that is, its total contribution to the factors that actually drive a rise in global average temperature. Contrails – water vapour trails from aircraft – are aviation's largest other factor.

Are hydrogen powered engines completely emission-free ?

There is the question of whether hydrogen can be produced at scale and at a competitive price without itself having a large carbon footprint. The great majority of hydrogen used in industry today is created using fossil fuel methane, releasing carbon dioxide as a waste product. Hydrogen can be produced from water through a process called electrolysis, driven by renewable power, but this process is currently expensive and requires large amounts of energy. Only about 1% of hydrogen is produced this way at present.

Will there be enough hydrogen for all ?

Investment in electrolysers – the “clean” technology used to separate hydrogen and oxygen atoms in water – is booming worldwide. As a result, green hydrogen production capacity could achieve a 50-fold increase in the next six years, according to some estimates. This means green hydrogen could be on track to supply up to 25% of the world’s energy needs by 2050.

irena

And this rapid and cost-effective scale-up could not be more timely: drastic solutions are now urgently required if the world is to meet the 1.5-degree Celsius target of the Paris Agreement.

Sanctioned projects at a glance

The International Energy Agency (IEA)’s Hydrogen Projects Database counts nearly 320 new green hydrogen production demonstration projects worldwide. This amounts to a total of about 200 MW of added electrolyser capacity. And new projects are being added on almost a weekly basis.

At present, Europe has less than 1 GW/year of electrolyser installed capacity. However, the European Commission recently announced longer-term plans to install at least 40 GW of electrolyser capacity or up to 10 million megatons of green hydrogen by 2030. As part of these plans, larger electrolysers – with up to 100 MW capacity as opposed to the current 20 MW capacity – are expected to be built by 2024 and installed next to demand centres.

irena

Australia has one of the world's highest volumes of green hydrogen production capacity, including about 30 GW of projects in the pipeline. In Asia, the region’s electrolyser capacity could reach +10 GW over the coming decade, driven by demand from Japan, South Korea and China. Across the pond, the USA is also starting to catch up with plans to develop green hydrogen mega-projects in California, Texas and Utah.

According to a report released by the International Renewable Energy Agency (IRENA), green hydrogen production costs have already begun to fall largely due to a decline in renewable energy costs and further cost savings in electrolysis facilities.

Getting green hydrogen to airports: how will it work ?

Green hydrogen is an energy pathway that forms a critical part of strategy to lead the decarbonisation of the aviation industry. This means architecting the future green hydrogen ecosystem for aviation will need to start now in preparation of an entry-into-service of hydrogen aircraft in near future. According to Airbus, it could look something like this.

airbus

Bottom-line

For now, one thing remains almost certain: hydrogen and E fuels are likely to continue to be substantially more expensive than conventional jet fuel for years or decades to come, limiting their role in greening aviation – unless the other costs of aviation come to be weighed differently.

Overview

A prototype is an early sample or model of an aircraft built to test a concept or process. It is generally used to evaluate a new design to enhance precision by system analysts and users and in a variety of contexts, including semantics, design, electronics, and software programming.

Why are prototypes made ?

When an aircraft program is launched, the manufacturer must manufacture several prototypes in order to test various systems and ensure safe and reliable operation for the following models that enter commercial service. These prototypes undergo rigorous testing and are put through all sorts of challenging conditions, including extreme heat and cold.

"The plane has been dragged, dropped, soaked, forced to hover, shudder and flutter"-Said Boeing of its 747-8 testing.

Now that begs the question-''What happens to the prototype once the testing is done ? ''

airbus

The experimentation continues...

The answer to what happens to the aircraft is that it depends on a lot of factors. For instance:

The B787 program did write off the airframes for the first 6 aircraft due to the extensive number of modifications that were required to those airframes. They went to museums of strategic importance to either the manufacturer or the kick-off customer and their country.

Some of these aircraft end up going into lifecycle fatigue testing or are maintained in the ownership of the manufacturer for follow-on testing that would be for upgrades or newer subsequent models.

General Elecric

If the program is a brand new model or significant technological change to an existing model, it has to go through stability and control testing and flutter testing. That literally beats the airframe to hell. It will most likely experience an over-G loading in these tests, and therefore, cannot and should not be used to carry passengers. There would be a potential for cargo in these cases, but then there would be added maintenance costs and hence many wouldn't want such a ''beat'' aircraft.

Musee Aeroscopia

It's a continuous process

While an aircraft program might achieve all the necessary certification, and mass production might commence, the prototype units may just continue as test aircraft. Many early models of well-known commercial aircraft became what are known as ‘testbeds,’ – which is defined as: “A vehicle (such as an airplane) used for testing new equipment (such as engines or weapons systems).”

Thus, the teams at companies like Airbus and Boeing use their prototypes to continue the aircraft development process, looking for ways to improve systems further. The testbed may even be instrumental in developing the next family of aircraft – the first B747 was actually a testbed for developing the Boeing 777 engine program.

Musee Aeroscopia

Post testbed phase

Once the testbed phase is finished, the manufacturer will try and find a new home for the aircraft which could typically be a museum – perhaps one that is aviation-centric. For instance, Seattle's Museum Of Flight would be a great place to see the first Boeing 747 and B737 ever built. Heading over to Musée Aeroscopia in Toulouse, one can witness the gigantic A380 (the 2nd one built) and A320 (first built) in all its glory.

airbus

Bottom-line

Prototype aircraft are generally of less value than the production counterparts, since they are heavier and may not have the normal design configuration. Particularly new aircraft (and its derivatives) tend to go to customers as testing becomes more refined and the cause of less design changes. However, not every aircraft can be sold if the aircraft is too unattractive and end up in a museum and hence many necessitate scrapping.

Unfortunate decompression at 24000 feet

A freezing wind of hurricane force is roaring through the cabin. There's not enough oxygen onboard. The flight declares an emergency yet nobody can hear you. Sounds like a nightmare? Unfortunately, for everyone onboard Aloha Airlines Flight 243, it was a reality.

On April 28, 1988 , Aloha Airlines flight 243, scheduled to fly between Hilu and Honolulu in Hawaii, sustained extensive damage during flight. Though the aircraft was able to divert safely at the nearby Kahului airport in Maui, 65 passengers including the crew were injured, not to mention a flight attendant at the time was also ejected out of the aircraft. This incident consequently, had far-reaching effects on aviation safety policies.

Aloha Airlines Flight 243

So, what exactly caused the emergency that injured many and led to the ejection of a crew member at 24,000 feet ?

What is Aircraft decompression ?

The Aloha Airlines Flight 243 is a classic example of an aircraft depressurisation/decompression. Decompression in simple terms refers to the inability of the aircraft to maintain its designed pressure schedule. Failure to maintain this schedule can be attributed to a malfunction of the system or structural damage to the aircraft itself.

boldmethod - Time of useful consciousness

Why should aircrafts be depressurised, you may ask? As an aircraft gains altitude, the air becomes thinner and it gets difficult to breathe which is why it becomes imperative to mimic conditions similar to that at sea level. Typically modern aircrafts are designed to maintain a pressure of 14.7 PSI -which is generally found at sea level. Now this implies the air pressure inside the cabin is higher than the pressure outside and this pressure differential is maintained to protect the pilots, cabin crew and the passengers from Hypoxia- which is a state of reduced awareness due to insufficient supply of oxygen to the brain.

Types of decompression

Depending on the type of severity and the loss of pressure, it is predominantly divided into 3 categories:

Explosive Decompression : Any decompression which occurs rapidly, say less than 0.5 sec, is graded as explosive decompression-Exactly the one which occurred aboard the fateful Aloha Flight 243. This is one which is potentially fatal as it occurs faster than the lungs can decompress. The extreme noise in such an event can lead to utter confusion and distraction from flight duties, not to mention the danger of flying debris onboard.

Rapid Decompression : Almost similar to explosive decompression yet different in the fact that here the lungs can decompress faster than the cabin and hence the risk of lung damage is significantly less. One can experience  decrease in temperature, as the cabin temperature equalizes with the outside air temperature, Cloud of fog or mist in the cabin that is due to the drop in temperature, and the change of humidity.

Slow Decompression : Warning systems onboard generally notify the crew about depressurisation but it so happens that they do not always indicate the incidence of a slow decompression which can turn fatal only if undetected at early stages. One of the first physiological indications of a slow decompression may be eardiscomfort or ‘popping’, joint pain, or stomach pain due to gas expansion.

Blurred sight

Possible causes

It is to be noted that specific outflow valves maintain cabin altitude at the desired levels. A failure of the system that manages the valves can result in depressurisation. Irregular airflow , unserviceable components in the aircraft air-conditioning system or an engine malfunction can inhibit the free flow of fresh air. Now technically cabin doors are so designed such that the risk of depressurisation is next to nil even if the door is opened while in flight or intentionally. That said, improper maintenance of aircraft parts, fuselage, cracked windows, improper sealing of a door or a window can all lead to structural failure mid-flight , leading to a fatal decompression event.

Hypoxia

The effects of hypoxia (lack of oxygen) cannot be over emphasized. It is important for the cabin crew to realize that even mild hypoxia, though not fatal, can have fatal results. This is because hypoxia can significantly reduce the crew member's ability to perform, and consequently lead to errors that may be fatal. The insidious nature of hypoxia causes a subtle decrease in individual performance, followed by incapacitation, the symptoms may not be identified until it is too late.

Hypoxia can cause a false sense of well-being. It is possible for a person to be hypoxic and not be aware of their condition. Therefore, it is important that the cabin crew recognizes the signs of hypoxia, and provides oxygen as soon as possible, in order to prevent a loss of consciousness.

Oxygen used by Pilots of Fighter aircrafts

Expected steps from the flight crew

The pilots are trained to immediately notify the ATC of the current issue. Normally in the event of depressurisation, pilots descend to a minimum safe altitude of 10,000 feet where the pressure outside and inside becomes more or less similar and it gets easier to breathe. However, the crew may initiate descent with/without obtaining clearance depending on the severity of the situation.

Following a decompression event, the crew is expected to execute the following:

Immediately grab the nearest oxygen mask and stay putSit down on the chair or secure oneself against any tight object.

“The amount of time for which the crew and passengers can perform their duties in an environment devoid of sufficient oxygen” – EFFECTIVE PERFORMANCE TIME

Incapacitated crew would only be a liability in assisting other crew members and passengers. In one such decompression event, a flight attended was heaved out of the cabin head-first but fortunately a passenger clanged onto her ankle that ultimately saved her. Hence personal safety of the cabin crew first cannot be stressed enough.

Cabin oxygen mask

Is this preventable ?

Though such incidents are rare, they do happen and when they do, the aftermath can be catastrophic. Hence to prevent such mishaps from occurring it becomes very important for the pilot and cabin crew to recognize the types of decompression and the immediate course of action that should be followed following such an event and limit the risk of hypoxia and ensure flight safety. The role of operators is equally important as regular recurrent training modes should be implemented emphasising the importance of effective communication (CRM). All it takes is just seconds for an incident to turn into an accident. And that can always be prevented.

At 20,000 Ft, Air India Flight To Frankfurt Suffers Cabin Decompression, returns back safely to Indira Gandhi International  - NDTV (6th March 2019)

IndiGo’s Lucknow-Bengaluru flight on Friday night landed safety at its destination after the aircraft suffered cabin depressurisation when it was about 240 km away from Bengaluru. The Airbus A320 (VT-ITM) has been grounded there for checks and the Directorate General of Civil Aviation is probing the snag. - Times of India (3rd April 2021)

The Directorate General of Civil Aviation (DGCA) on Tuesday, May 24 warned airlines against offering unserviceable seats to passengers on their domestic and international flights.

Earlier this year, the DGCA had conducted an audit of seats and other cabin fittings in aircraft of airlines and found that many had broken or unserviceable seats.

In a communique sent to all Indian carriers, the DGCA said that some of the carriers are offering unserviceable seats to passengers on their scheduled international and domestic operations.

DGCA warns airlines strictly against selling unusable seats to passengers

"This practice is not only causing inconvenience to the travellers but also inviting a serious safety concern as well," the regulator said.

As per Rule 53 of The Aircraft Rule, 1937, all materials including the aircraft seat shall conform to approved design specifications. The installation of any part failing to meet the intended design requirements degrades the requirements of airworthiness, it said.

"Given the above, it is hereby advised to ensure that airlines shall not book passengers beyond the serviceable seats meeting the approved design specification available in the aircraft, released for scheduled services. Any non-compliance in this regard shall be viewed seriously," it noted.

A passenger booked on the flight (AI 161) said that business class passengers were downgraded due to the chaos, and some could not even fly as "their seats were not working."

On May 24th, passengers booked on a London-bound Air India flight from New Delhi were inconvenienced by several hours of delay and chaos over seat allocation on account of some seats not "working."

A passenger booked on the flight (AI 161) said that business class passengers were downgraded due to the chaos, and some could not even fly as "their seats were not working."

ALSO READ - DGCA asks Air India to repair its aircraft’s shabby interiors

Last month, the DGCA had asked Air India to repair its aircraft after a passenger complained of shabby interiors. The passenger had posted on social media a couple of pictures of shabby interiors including a broken armrest of Air India’s Airbus A320 aircraft.

ALSO READ - SpiceJet grounds its B737 aircraft after passenger complains about the cabin’s poor condition

DGCA had conducted an audit of seats and other cabin fittings in aircraft of airlines and found that many had broken or unserviceable seats.

In April, the DGCA had also grounded a SpiceJet aircraft over a passenger’s complaint of dirty seats and malfunctioning cabin panels. The SpiceJet plane took to the skies a day later after all the suggested repairs were effected.

The aviation regulator earlier in May warned aviation companies to follow the rules regarding passenger boarding or face penalties, after receiving multiple complaints of overbooking.

The DGCA in a statement said, "It has come to the notice of this office that various airlines are denying boarding to passengers holding confirmed tickets on a flight, although they have presented themselves for boarding within the time specified by the airline. This practice is extremely unfair to the passengers and brings a bad name to the aviation industry."

The aviation regulator earlier in May warned aviation companies to follow the rules regarding passenger boarding or face penalties

The aviation companies overbook to make sure most of the seats are sold just before the flight takes off. The airline has to face losses due to cancellations and the passengers not turning up, so they started overbooking the flights to make up for the loss.

However, if all the passengers do arrive, some have to be turned down resulting in denying boarding to passengers having a valid ticket and have arrived on time.  

ALSO READ - DGCA finds several deficiencies in 280 aircraft during night inspection

ALSO READ - DGCA to begin conducting night inspections of the cabins of older planes