The A380 is a passenger magnet!
- June 2017 – A380 plus project
- February 2017 – The challenge of Twins for point-to-point operations
A380s, “Sweet Spots” and Storm Petrels
I forecast that the A380 neo will eventually be built and that the A380 will be the largest operating passenger aircraft for decades to come.
The aviation industry continues to evolve. The changing political, economic, cultural, technological and communication landscape is forcing continued consolidation of airlines, routes and aircraft types. It’s a case of “less is more”.
The A380 is a key player in this consolidation, transporting the rapidly increasing number of passengers between congested Asian and European international hubs. (Asia is now the largest (and fastest growing) aviation transport market with 948 million passengers flown in 2012, followed by North America (808 million) and then Europe (781 million) (IATA – 2013))
I am confident that:
- the A380 will fly up until the 2050s, and
- that airline ticket prices will continue to reduce as the seat counts increase on newer aircraft.
Furthermore, I think:
- the A380 will be the last large four (quad) engine commercial passenger aircraft to be built.
The A380 is a passenger magnet. Many passengers tell me “this is the best flight I have ever had” when I meet them in the cabin and farewell them at the door. They comment on the smooth ride that the signature “Dance of the Ailerons” provides. They love the space. They love the entertainment. They love the quietness that calms everyone. A calming white noise pervades the cabin that settles everyone down. Babies don’t cry, so mothers relax, the passengers relax. Meanwhile the pictures outside fly past at 85 percent of the speed of sound.
The A380 has taken the primary role in moving people between the worlds monopoles. The A380 is also aptly called the “RouteMaster”. This is a fitting moniker for the aircraft’s role as the dominant long haul international aircraft of choice for the airlines that have stepped up to meet the challenges for aviations over the next 20 years.
In this blog I’ll share a few of my thoughts about aircraft “sweet spots” and why airlines ultimately invest in one brand of a spread of aircraft to bracket their operational needs. Finally, I’ll discuss why a super sonic car might influence future super aircraft designs.
Every airline’s challenge is to deploy the best aircraft type for its route structure. Indeed the selection of size and weight in aviation follows the same pattern already cast by nature.
The operational environment determines insect’s and bird’s cruising speeds that in turn determines its weight. Small birds are suited for slow cruise sectors whilst international maritime flight is reserved for the fastest cruising (heaviest) birds such as the Pelican and Albatross.
Migrating birds that migrate beyond their “design range” or “sweet spot” range risk perishing at sea. Migrating birds drown if their long range cruising speed is insufficient to make headway into head winds. Reports of mass bird deaths at sea show “natural selection” at work, extinguishing the birds that cannot accurately forecast maritime weather.
The Storm Petrel understands this weight-cruising speed-wind relationship. Its name was derived by early mariners who observed the bird return to take refuge ashore before storms approached, conveniently broadcasting their foul weather forecast.
Using similar logic, we suggest that the Pteranodon, the largest flying reptile (despite its low wing loading) had such high takeoff, cruising and landing speeds that flight was restricted to souring above the cliffs along the shore.
Aircraft manufacturers apply biomimicry into their designs. So the theories for birds also applies to aircraft – that the route length and cruise speed determines the ideal aircraft weight. Everything else is a compromise; passenger count, fuselage size & type, wings and engines.
Aircraft selection also skews towards larger seat-counts for operations into congested airports (in Asia and Europe).
The consequences for Airbus and Boeing are clear. Aircraft manufacturers must understand the demography and travelling habits of travelers and provide aircraft that are tuned to the same “sweet spot” speed and range that suits the market.
The Great Flight Diagram below shows a remarkable relationship between weight and cruising speed. This graph also shows outliers. The Concorde was hopelessly over-winged for cruise flight. Compared with all other flying things, the Boeing 777s and 787s appear to be under-winged (faster) and the Airbus A350s appears to be over-winged (slower). The A380 also appears to be over-winged, but for reasons outside the scope of this review.
The risk of poor aircraft selection is just as critical for the airlines as it is for bird species. Putting the wrong airframe onto a route can have dire consequences. The airline’s challenge is to apply the right aircraft for the required range. For companies that fly long and short haul routes, its imperative to limit the number of aircraft vendors and aircraft types to minimise the costs of manpower, training and maintenance.
A380 Sweet Spot
I calculate that the initial A380 has a sweet spot (maximum efficiency) range of between 5,700 and 6,800 air nautical miles (anm):
- 5,690 anm (London – Singapore, 11.6 hours flight time)
- 6,298 anm (Dubai-Sydney, 13.1 hrs)
- 6,177 anm (Sydney-Los Angeles, 12.8 hrs)
- 6,432 anm (Melbourne-Los Angeles (13.32 hrs)
- 6,521 anm (Singapore-London)
- 6,843 anm (Los Angeles – Sydney, 14.1 hrs)
- 6,661 anm (Sydney – Dubai, 13.2 hrs)
- 7,025 anm (Sydney – Dallas, 14.6 hrs)
- 7,275 anm (Los Angeles – Melbourne, 15.1 hrs)
- 7,907 anm (Dallas-Sydney, 16.4 hrs)
- 7,000* anm (A380s delivered after January 2013 with the re-twisted wings and 6 ton higher maximum takeoff weight)
The Qantas QF7 / QF8 routes Sydney – Dallas (Fort Worth) – Sydney sectors are some of the world’s longest routes and are up to 1,200 nm longer than the original A380’s Sweet Spot range.
- 7,025 anm (12,920 akm) route from Sydney to Dallas. The 7,540 nm ground track is shortened 515 nm by hitching a ride on the 35 knot (average) tail winds on the Pacific for the 14.6 hour flight. A theoretical maximum of about 580 passengers could be planned on this sector.
- 7,907 anm route from Dallas to Sydney. This 7605 nm ground route is biased towards the calmer 18 knot (average) headwinds for the 16.4 hour flight. A maximum of about 385 passengers can be planned on this sector.
I calculate the A330-300’s sweet spot is currently between 3,000 and 3,800 anm (although the heavier weight versions will increase the optimum reach):
- 3,000 anm (Example: 6.1 hours flight time, London – Dubai (2,870 anm))
- 3,800 anm (Example: 9 hours flight time, Sydney – Hong Kong (3900 anm)
B777 vs A380 sweet spots
The A380 and B777 have different sweet spots that suit different regions, markets, economies and demands.
Daniel Tsang’s article, “Is the Airbus A380 Coming of Age?” presents valid comparisons between the B777 and A380 sweet spots for range, direct vs hub, payload, cargo, passenger count. His summary:
- When full, 509-seat A380 has 16.8% lower block fuel burn per seat against 264-seat 777-300ER
- 83% full A380 burns similar fuel per seat against a full 777-300ER
- On payload-tonne basis, 777-300ER is ~25% more fuel efficient than A380
- 1.7% widebody up-gauging mainly done via denser configurations
- 37.5% of total A330 fleet leased, 20.6% 777 & 16.6% A380. Excluding Amedeo, only 11% of total A380 fleet is leased
- Lessors should remove refitting cost penalty to boost A380 appeal
I do not foresee a great future for the A380 in the static USA market that has a penchant for small aircraft operating on many point to point routes. The A380 is still on it’s own for operations (in its sweet spot range) from slot limited hub airports such as Dubai and Heathrow.
B787-10 sweet spot
- The sweet spot for the B787-900 extends out to 8.5 hours (says Emirate’s CEO Tim Clark)
I’ll publish sweet spots for other aircraft in my Big Jets book.
Understanding sweet spots make it easier to understand why Cathay Pacific needs more Boeing 777s, Airbus A330s and A350s than B747s and A380s. Cathay’s Hong Kong home base is located within 5 hours flying range from half the world’s population.
The sweet spot selection involves engine and aircraft manufacturers and airline participation. Click here to view this excellent interview of Airbus and airline CEOs.
Sweet Spot Compromise – A380 for Slot Limited Airports
“I can’t believe the Asian carriers will not buy the A380 in big numbers.” (Tim Clark)
Having introduced the ideal concept of the Sweet Spot, lets now look at compromises and divergences from this rule. For sometimes the the practice is sometimes different to the theory.
Clearly the A380 is currently tuned for the longer haul and efficiency drops if the heavy airframe is flown outside this sweet spot over shorter or longer routes. In these cases the passenger count and freight load must be maximised to protect profits.
- The world’s A380s have flown an average sector length of only 8.3 hours over their first six years of operation.
- Since 2011, A380 average sector length has held at 7,000-7,200 km (CAPA Report Mar 2016)
The A380 is the optimum choice for airlines operating from congested airports or on congested routes. Despite a sweet spot time of 12 to 14 hours flight time, the A380 early adopter airlines have chosen to optimise the A380 for greater seat counts on shorter routes between congested ports. This trend (preferencing higher seat count before the sweet spot range) will continue particularly in markets where more passengers travel into national hubs that have become (politically) land-locked and undersized such as London Heathrow, Hong Kong and Dubai.
- Of the 15 largest airports with A380 operations, all but three – Los Angeles, New York JFK and Hong Kong – are the hub of an A380 operator (CAPA Report 2016)
- 10 longest – Emirates, Etihad and Qantas
- Shortest – Emirates (Dubai to Kuwait) and China Southern
Average A380 Sector Lengths: (CAPA Report 2016)
- Longest – Qantas, Malaysian and Korean
- Shortest – Qatar and China Southern
- Heathrow has operated close to its capacity since the start of the decade. In 2013 it processed 3.4% more passengers, mostly because the airlines squeezed 2.8 percent more seats into (the same number of but) bigger aircraft such as the A380.
- Curfew restrictions further compress the airport’s capabilities.
- Heathrow is one of the A380’s most major airports. Only 30% of its A380 flights are flown by a local airline (British Airways) (CAPA Report 2016)
I think Hong Kong’s airport is saturated. There will be no relief unless larger aircraft substitute the smaller aircraft:
- February 2014: Operations during the two sectors were delayed: (holding), compressed traffic separation on approach, extensive push-back, taxi and takeoff delays – all indicating that the airport was task saturated at these times.
- 26 July 2014, QF128 flight HKG-SYD. Whilst waiting to push back from the terminal at Hong Kong airport last night I heard the crew of another aircraft ask ATC for pushback clearance for their flight from Hong Kong to Shanghai. ATC informed that crew that their flight was number 5 in the queue to fly to Shanghai, but due to congestion on that route, that ATC had negotiated a later takeoff slot time for the flight – that was now delayed by 5 hours!
- Aviation Journalist Ben Sandilands also considers the A380 the inevitable solution to the congestion at the slot limited Hong Kong airport.
Dubai International Airport (OMDB) (DXB)
- Dubai is the world’s No 1 for international passenger traffic (CAPA Report March 2016)
- passenger traffic exceeded 78 million in 2015
- analysts expects 85 million passengers to visit the airport in 2016.
- this number is planned to increase to 100 million by 2019, requiring the city’s second airport Al Maktoum to come on line early.
- the long term ($32b) plan is to increase that number to 200 million.
Air Traffic Control
- Dubai airport is over-saturated. Aircraft in excess of the airport’s capacity are parked by Air Traffic Control in holding patterns above 10,000 feet about 50nm from the airport.
- Probably 95% of all the arrivals that I flew into Dubai in 2015 involved holding periods of between 15 minutes to 45 minutes. The maximum delay has been two hours.
- Most diversions from Dubai during inclement weather are not due to the inability of the aircraft to approach and land in low visibility operations. The diversions occur because aircraft arrive with insufficient fuel reserves to hold long enough to wait for an approach when the airport is using Low Visibility Procedures.
- In the short term, (i.e. before building more runways) Dubai airport should perhaps limit operations to just wide body (A380, B747, B777 and A350) aircraft.
Aircraft manufacturers and some airlines realise that Big Jets are in greater demand for short sectors:
- Insufficient new airports will be constructed to meet the growing demand over the next 20 years.
- Long distance carriers such as Emirates will operate fleets of large jets such as the B777 and A380 to connect the world’s hubs and saturated airports.
- Airbus, realising that the Asian “airpark” is full, is considering a variant of the A330 airframe with a shorter “sweet spot” range. This “trimmed” A330 could have a smaller fuel tank capacity which would lighten the wing structure, wing box and airframe weight. The resulting shorter “sweet spot” range will be better suited to the short intra-asian routes.
Dubai is now so saturated that Emirates is now a B777 and A380 airline. In 2016 Emirates disposed of all their smaller (A330 & A340) aircraft.
Tim Clark, the CEO of Emirates has said;
- “[the next generation] will recognize the value of the A380. I can’t believe the Asian carriers will not buy the A380 in big numbers.”
- “… the A380 has been a big success for Emirates. It’s a boon for our operations to slot constrained airports and we get a lot of positive feedback from our customers.”
Very Large Aircraft (VLA)
Consider the B747 and A380 VLA aircraft deployments. The top five B747 and A380 airports (respectively) for 2013 are: (anna.aero)
- London (B747) \ Dubai (A380)
- Taipei \ Singapore
- Frankfurt \ London
- Hong Kong \ Paris
- Bangkok \ Frankfurt
Note: October 2014, London Heathrow overtakes Singapore to be the world’s second largest port for the A380. Heathrow’s two runways are now operating at 98.1% of flight capacity (increased from 97.8% the prior year).
These lists suggest that the VLA market is primarily used to resolve major hub congestions. Notice that Australian and USA airports fail to appear in the these lists despite the A380 having a “sweet spot” that is ideal for USA-Australia routes. From my own recent observations, the long lines of A380s transiting at the congested Dubai and Heathrow airports reaffirms my conclusion that the seat count currently takes higher priority than the “sweet spot” range. On the five-times daily route from Dubai to London, Sir Tim Clark said that his A380s were running at 95 per cent capacity.
Willie Walsh (CEO of International Airlines Group) stated in this video (47 minute mark) that he is very pleased with the A380. Two A380s (London-Los Angeles) have replaced three former 747s, same passengers, better cost efficiency and freeing up one slot at each airport.
[The A380] It’s a great aircraft. It’s extremely efficient on certain parts of our network (Willie Walsh – CEO – IAG)
Nancy Bird Walton (A380-OQA) (Photo: Richard de Crespigny)
My data analysis shows that that an A380 filled to the brim with 853 passengers (315/538 on the upper/lower decks respectively) provides fuel efficiencies that surpass all other aircraft types, including another darling of the skies, the A330-300.
Airbus is trying to convince airlines to adopt the 525-seat A380 configuration.
Airlines are responding to improve the A380’s efficiency. Approximate seat configurations:
- 407 – Korean
- 409 – Singapore Airlines
- 469 – British Airways
- 484 – Qantas (14 First, 64 Business, 35 Premium Economy & 371 Economy)
- 506 – China Southern
- 507 – Thai Airways
- 517 – Qatar
- 538 – Air France (reducing to 516)
- 526 – Lufthansa (reducing to 509)
- 519 – Emirates
- 615 – Emirates (also considering an 800 seat version for Hajj flights)
- Image Courtesy: CAPA
“When we put the proper seat count on the [A380] plane, the economics are unbeatable and will remain unbeatable” (Doric Chief Executive Officer Marc Lapidus)
“Toulouse – we have a problem!”
Airlines are too conservative and have not put the right interiors into their A380s – Sir Tim Clark
Currently the A380’s limiting freight related weights include: (see QF32 page 345 for more info)
242t – Manufacturers Empty Weight (MEW) (approx)
300t – Dry Operating Weight (DOW) (45 tonne cabin fit-out plus crew plus catering)
369t – Maximum Zero Fuel Weight (MZFW)
Airbus designed the A380 to be as light as possible. Airbus engineers planned (and hoped) that airlines would also fit the lightest cabin layouts, ideally weighing no more than I think about 35 tonnes.
Some airlines have installed cabin designs weighing up to 45 tonnes (heavy seats, furniture, showers, bars and two lane stairs). These “obese” cabins leave just 69 tonnes for passengers and freight (369t MZFW minus the 300t DOW).
Up to 60 more seats can be accommodated by altering the A380’s stairs (says Kiran Rao, Airbus Director of Strategy and Marketing):
- Simplify/remove the rarely used curved steps at the rear of the aircraft
- Simplify the double-width stairs at the front (not required for certification)
Emirates CEO Sir Tim Clark agrees, recently stating “airlines are too conservative and have not put the right interiors into their A380s”.
A380 – Future
If the A380 operation can be improved by another 15%, then its future can be assured for the next 40 years, taking us up to 2050 when demand for world air travel will have tripled. In this case I imagine the A380 being the only heavy lifting aircraft that can provide an equatorial air conveyor between the handful of clusters of the worlds largest mega cities.
Tim Clark, CEO of Emirates recently described the A380 as “A passenger magnet“.
… the A380 is the future. And we don’t like anyone talking about it not being around
… more A380s, not 787-9s, because slots at the major middle east, European, and American and Japan and China airports are at prevailing growth rates, totally wasted on smaller jets (Ben Sandilands)
Evolutionary changes by Airbus, airlines and the engine manufacturers will all contribute to improve the A380’s efficiency by another 8% to 15% over the next 15 years.
- Airbus announced (October 2013) that the A380 program should break even (financially) in 2015 (based upon 30 sales/deliveries per year)
- Airbus is investigating fitting massive winglets for a potential 3% increase in fuel efficiency (curiously based upon the A320). (The wings delivered after January 2013 were re-twisted to provide an improved cruise fuel flow.)
- Rolls Royce has announced plans to improve their engine’s Specific Fuel Consumption (SFC). A 5% Specific Fuel Consumption (SFC) improvement could be achieved by updating the engine’s compressors, high pressure turbine blades and reducing the turbine clearances. Keeping and laminar air flow around the nacelles will also improve the SFC.
- The Rolls-Royce Trent 1000 engine is reported to have a specific fuel consumption (SFC) (efficiency) 10% better than the SFC of the Trent-900 engine on the existing A380s.
- Airlines will be forced to fit better engineered cabins and more condensed seating. Immediate savings can be achieved by removing the unnecessarily wide stairs, unnecessarily heavy seats and obese cabin fitouts.
The A380-800 is 73 metres long.
The A380’s published sales price is US$414.4m (Airbus 2014). This is higher than the “back of the envelope” figure of US$1m per ton of basic weight (without fuel and freight) although deals have been negotiated at bargain prices (Doric purchased A380 (MSN 136) for US$245m)
A total of 318 A380s have been ordered by 19 customers. A380’s now fly to 41 airports.
- Having flown 1.5m flight hours in 180,000 commercial flights, the average flight length is 8.3 hours (Airbus Sep 2014).
- The A380 fleet has carried more than 100 million passengers in more than 2 million flying hours on more than 270,000 revenue flights, representing an average flight length of just 7.4 hours (Airbus Nov 2015)
A380 – 800 Neo
The A380 Neo is the name given to a A380-800 New Engine Option. The A380 Neo’s engine would most likely be the Rolls-Royce Trent XWB-84 engine (84,000 lbs thrust) that currently powers the A350-900. The XWB-84 is sixteen percent more efficient than the first generation Trent engines that entered into service in 1995.
An aircraft’s greatest range is proportional to the engines’ propulsion efficiency multiplied by the airframe’s lift/drag ratio. (Louis Breguet’s Range formulae)
Improved engine efficiency remains the best path to increased range.
Alain Garcia, the former CTO at Airbus, forecast earlier this year that the efficiency of large commercial aircraft will improve by about 45% over the period from 2013 to 2050. Benefits will comprise:
- Acft weight down 8%
- Drag down 12.5%
- Engine Specific Fuel Consumption improve 25%
The A380’s ideal wingspan is about 84 metres.
The A380’s wing design is a compromise that satisfies many limitations
- ICAO Code F aircraft limitations: 80m max wingspan, 80m max length, 80 feet max height, 16m max main gear span
- The wingspan affects the runway and taxiway separations, holding points, aprons, bays, shoulders
- The top of the wing tip must not protrude into the 155 m horizontal obstacle free zone (from 800m prior runway to 1,800m into the missed approach)
- The bottom of the wing tip must have sufficient ground clearance (full fuel) to not limit surface traffic
- Certification requirements:
- Passenger emergency exits must not be more than 60 feet (18·288 m) from any adjacent passenger emergency exit on the same side of the same deck. (This reduces the maximum chord of the A380’s wing root, forcing the designers to reduce the wing taper to get the required wing area)
An aircraft’s Lift/Drag ratio varies with the square root of the Aspect Ratio (wingspan/chord). Whilst the aspect ratios of commercial aircraft have improved by 40% over the past 50 years, the A380’s aspect ratio is now effectively fixed because the wingspan is limited by the 80 metre limit.
- Reduces lift-induced drag (Cdi), by displacing vortices above/below the wing’s plane.
- Improves the Lift/Drag ratio for takeoff performance, permitting increased fuel load, so longer range.
- Increases their wing’s effective span by about 50% of the tips height.
The A350 and B787 wings do not have elevated wing tips. These composite wings can be bent upwards more than conventional metal wings. The A350’s and B787’s high spanwise camber (or dihedral) elevates the wing vortices and removes the need for vertical wing tips.
Scimitar wing tips look good, however they provide no advantage over other types of wing tips.
The A380’s manufacturer’s empty weight cannot be reduced significantly because composites already comprise 25% of the aircraft’s weight. Even worse, range only improves by 25% of the percentage reduction in weight.
Over the past 50 years, engine propulsion efficiency has improved twice as fast as the improvements in aerodynamics (L/D).
So the last frontier for improving the A380-800’s efficiency and range (other than airlines engineering efficient and lighter cabin designs) rests with Rolls-Royce to provides an enhanced engine.
The Airbus A380 neo could be powered by:
- an improved Rolls-Royce Trent 900 engine, incorporating hotter turbine inlet temperatures and reduced turbine clearances for better sealing. Laminar air flow over the engine nacelle will also reduce drag. These changes will improve the engines thermal and propulsive efficiencies and so improve the engine’s specific fuel consumption, and thus improve the aircraft’s range, or
- the existing Rolls-Royce Trent XWB-84 (84,000 lbs thrust) that powers the Airbus A350-900. This engine is larger and more powerful than the 72,000 pound thrust Rolls-Royce Trent 900 engine. Aerodynamicists design the wing and engine as a single structure. This means the A380 wing would need to be redesigned to optimise the air flows with the larger and heavier XWB engine.
The A380-900 will be powered by the Neo designs, so it makes sense for the A380 neo to be the next evolutionary step.
Tim Clark, CEO of Emirates:
- In September 2014 expressed his desire for another 60-70 A380 neo
- In January 2015 offered to increase his order to 100 A380 neo (worth $43b)
- In March 2015 offered to increase his order to 200 A380 neos
- In September 2015 said that new engine and aerodynamic tweaks could make the existing A380 up to 13% more economical.
Such orders would have Emirates owning up to 340 A380s!
Airbus had plans to move to an “A380 neo type” for introduction between 2020 and 2025, Bregier told London’s Sunday Times in July 2015.
- The benefits provided by the A380 neo come at a heavy cost of R&D
- Airbus is reticent to spend R&D resources on an A380 neo that might ideally suit the needs of onc customer (Emirates)
- “an A380neo is at least a decade away” (Fabrice Bregier, June 2105)
Airbus announced the “A380 plus” project at the Paris Airshow June 2017 – a study to improve the A380’s cost per seat by 13%:
- New split “scimitar” winglets measure approximately 4,7 metres in height (an uplet of 3.5m, and a downlet of 1,2m).
- The scimitar wingtip and other wing improvements are forecast to improve the A380’s performance by up to 4%.
- Cabin changes provide for an additional 80 seats (changed stairs, crew-rest, narrower upper deck sidewall and 9/11 abreast seating in premium economy/economy).
- Max Takeoff weight increased by another 3 tonnes to 578 tonnes.
The A380-900 would be the ultimate aircraft of choice for long range intercontinental travel. The space, comfort and performance puts the A380-900 in a category of its own.
I hope Airbus produces the next stretched version of the A380, the A380-900. The A380-900 would be the super conductor in the new globalised and connected world.
The A380-900 is an A380-800 stretched by another six metres to make it fill a “box” 80 metres long by 80 metres wide. The latest “Code F” airports are designed to cater for aircraft having up to an 80 metre wingspan and 16 metre wheel track.
The A380-800 was certified to hold 853 passengers. A friend told me that the A380-900 was planned to inherit this same certification limit.
The A380-900 should enable unit seat costs that will be below what can be achieved by the-1000, 787-10 or the upcoming versions of the
I think the A380 was always designed to be 80 metres long. The cruising speed, large wing area, centre wing tank, fuel tank capacity, and limiting weights all point to this aircraft needing to have a higher wing loading and thus, more passengers and more weight (refer back to the Sweet Spot and Great Flight Diagram).
In 2013, Airbus Chief Executive Fabrice Bregier announced he thought the A380-900 will be available, maybe in in 2023-2028. He asked investors to not be “impatient.” Airbus “will one day launch an A380 neo and we will one day launch an A380 stretch.”
Today however, improvements in efficiency of smaller twin engine aircraft have put the viability of the A380-900 in doubt.
- The new long range composite twin engine aircraft (B878, A350, B77x) are unfortunately providing an intermediate solution at a time when only a couple of hub-hub routes provide seat demand for an A380.
- The risks building an A380 neo and A380-900 are to high for Airbus to shoulder alone. The A380 neo and A380-900 will probably be on hold until airlines place sufficient orders to justify the R&D spend.
And When I Die …
What is the future for A380 aircraft when they come to the end of their operational life?
The A380 was designed with a Fatigue Life 38,000 cycles. Fatigue testing in the static rig has proved the airframe to more than 48,500 cycles (about 25 yrs of airline operations).
It is prohibitively expensive to reconfigure an old A380 to suit a new carrier. Airlines’ customised A380 cabins will probably not suit a new owner. It costs about $US50m to configure an A380 cabin. Replacement Trent 900 engines start at about $10m each.
Emirate’s Tim Clarke is clear: “The A380, its future life, its [residual value] is something everybody is challenging us on. When Emirates is done with it in 12-15 years, we’ll put them in the desert. We’ll cut them up”.
By the 2025 the airspace for big jets will come to resemble the traffic jams on highways choked with cars. Air Traffic in Asia, Europe and the Middle East will be suffering pneumonia, gasping for breath. The busy arterial airways will be choked. Slots at the hub airports will be 100% subscribed.
Journalist Ben Sandilands (now unfortunately deceased) puts it succinctly: “Qantas …. needs more A380s, not 787-9s, because slots at the major middle east, European, and American and Japan and China airports are at prevailing growth rates, totally wasted on smaller jets.”
The only antibiotic and breathing space for these regions will come via the very large jets such as the B777, B747, A350 and A380 all configured for high seat counts. Airlines must deploy these VLAs if their seat costs are to remain competitive.
At the top of this peak, the biggest people carrier will be the A380 neo (hopefully stretched and probably configured with 600++ seats)
A380 voted best passenger aircraft in the world
2015 Readers of ‘Global Traveler’ recently voted the A380 as being the best passenger aircraft in the world. This is a great accolade for an aircraft that has been flying for ten years, completed 8 years in service and that competes with newer aircraft types (B787 and A350). More than 65% of the people who completed the 2015 GT Tested Reader Survey said that they would make an extra effort when buying their airline tickets to ensure that they fly on an A380 in preference to other aircraft types.
The voters acknowledged the A380’s smooth ride, large quiet interior and excellent performance. These markers give credit to Airbus’ decision to add weight to the A380 in sound reduction technologies (high bypass engines, one piece nacelle lining, airframe supersonic airflow management, decentralised air conditioning). It also proves the Dance of the Ailerons and Dance of the Rudders to provide passengers the A380’s hallmarked steady and smooth flight.
Twins for point-to-point (not hub) operations
Twin engined aircraft are encroaching more on what used to be the quad-engined aircraft’s domain.
The increased capabilities afforded by the expanding rules for Extended Diversion Time Operations (EDTO) for twin engine aircraft, means these long range twins can now compete with quads flying over vast oceans, many hours from a suitable airport.
For example, the B787 twin is currently approved for 180 minutes EDTO, with plans to ramp up to 330 mins at a later date.
EDTO’s rules are founded on risk assessments. Even if passengers feel uncomfortable being in a twin engine aircraft over an ocean up to five and a half hours from a suitable airport, the statistics suggest you are safe.
Whilst the A380’s market is being challenged by long rang twins (B777, B787 & A350) the A380 remains the only solution at slot limited hub-hub ports such as London Heathrow, Dubai, Los Angeles and Hong Kong. The A380 is still the best aircraft with a sweet spot to transport 500 passengers over a sector 6500-6800 anm sector.
Last of the Four Engines
I think the A380 marks the last four engine passenger aircraft that will grace the skies.
Four engine (quad) aircraft traditionally provided benefits over the twins:
- better engine optimisation (for the cruise)
- reduced wing bending moments (lighter wing box and wing)
- improved range, payload and high altitude performance
- freedom to work outside the Extended x Operations (ETOPS, EROPS and EDTO) limitations
But these relative advantages of the quad have reduced with time.
Economics now favours the twin over the quad:
- Simpler and lighter structures, Twins gain weight reductions and drag benefits from lightening the structures and optimising the flows over the rest of the wing where the third and fourth engines were removed.
- The integrated aerodynamic flows, wing aero-elastics, manufacturing purchase price, running and maintenance costs
- Cheaper to buy two big engines than four small.
- Extended Time Operations (EROPs) permit twins to fly long distance from suitable airports.
Aerodynamicists prefer to design simpler “semi clean” twins rather than the more complex “dirty” quads:
- An aircraft i s now designed as a compete integrated unit, merging the fuselage, wing and engines into one complex structure. Gone are the days of treating them as many separate entities.
- Quad aero-elastics is more complicated than twin aero-elastics. This is a very complex subject. However for a simple analogy, please view my later blog: “Bio-Mimicry of shaking Dogs”. Whilst viewing the video, imagine the dogs’ ears being aircraft wings. Now consider being the engineer given the responsibility to design the ears, responsible for the shape, structures, aerodynamics and aero-elastics. Now imagine designing how to mount two engines onto the ears. Now imagine mounting four engines onto the ears…
Despite these improvements that now favour twins rather than quads, many limitations remain that prevent engine manufacturers from making engines that could power a twin engine version of the A380.
“The engines canna take anymore, Cap’n!”
( Scotty (Character) – Star Trek)
No engine currently exists that could power a twin engine A380. The A380 “twin” would probably need engines capable of producing up to 150,000 pounds of thrust, well beyond that current generation of engines that top out at about 115,000 pounds of thrust. Many factors currently limit the capability to build super-engines, including:
- physical diameter of the engine (compromising the air frame by raising the fuselage higher off the ground), and
- the capability to build fan and turbine disks that are able to withstand the incredible forces without exploding (going BANG!), and
- the maximum temperature that the High Pressure Turbine blades can withstand.
The good news is that although I think the A380’s tail fin is over-sized for the A380-800, it’s probably the perfect size for the A380-900 or even the A380 twin (I’m a little cheeky).
- Click here to view CAPA’s excellent (Nov 2015) review of the A380‘s market
- Aviation Week recently revealed the Airbus ‘Mega-Twin’ Concept and research into very large twin jets the size of the Boeing 747.
- Emirates discusses the need to provide enhanced engines for the A380
Preventing things going BANG! …
Andy Green and I know a little bit about this.
First, we need to understand that jet engine turbine disks operate very close to their temperature and rpm limits.
Aviation turbine disks are certified to survive rpm over-speeds of just 20% (44% more strain) over the maximum rated rpm. To put the centripetal forces into perspective, each fan blade on the front of the Rolls-Royce XWB jet engine (powering the new Airbus A350) experiences 100 tons of force during takeoff – equivalent to a freight train hanging off each blade.
The high pressure turbine blades (I think the most technically complex components on the entire A380) operate in even more threatening environments. At high power the blades sit within (and are impacted-powered by) exhaust air that is 400 degrees Celsius hotter than the blades melting point!
In the case of QF32, the number 2 engine on my aircraft failed when the intermediate pressure turbine disk exploded under conditions of high temperature and RPM.
Andy Green (and his Super Sonic Cars (SSCs))
Wing Commander Andy Green is the Royal Air Force fighter pilot who in 1997 set the world land speed record of Mach 1.02 (1,228 kph, 763 mph) in the twin Rolls-Royce Spey 202 powered “Thrust SSC” (Super Sonic Car) jet car.
Click here to see the video of the record breaking run. The car’s bodywork was exposed to air pressures of up to 10 tonnes per square metre. Notice the shock waves churning-plowing the hard desert surface into dust. Interestingly, Thrust SSC experienced an unexpected massive increase in drag at Mach 1. The increase was attributed to the shock waves slamming against the desert floor, shattering the hard surface into an air-rock “plasma” – absorbing critical energy in the process.
After setting the land speed record, Andy’s next challenge is to build his Bloodhound SSC car that in 2015 will exceed his previous record by 31%, exceeding 1,000 mph (Mach 1.4, 1600 kmph or 447 metres per second!).
Bloodhound SSC will be powered by a single Rolls-Royce EJ2000 jet engine (from the Typhoon Eurofighter), and a rocket motor (that incorporates an oxidiser “fuel” pump powered by a 750 hp Cosworth Formula 1 engine). The jet engine and rocket will combine to produce about 133,000 thrust horsepower, the equivalent to 180 Formula 1 cars. (click here to view the cockpit). The EJ2000 was first installed into the Bloodhound in October 2014.
You might ask: “Why do we need 130,000 horsepower to travel just 16 times our road speed limit?” The answer comes courtesy of the drag and power equations. Drag is proportional to speed squared. Power is proportional to drag times speed – so power is proportional to speed CUBED! So we need 16 cubed (= 4,096) times as much horsepower to go 1,600 kmph than we do to travel just 100 kmph (although this equation does not account for losses from (shock) wave drag). You will appreciate the Bloodhound’s high finesse (smoothness) when you divide 133,000 by 4,096 to calculate the horsepower the Bloodhound needs to travel at 100 kmph.
What has Andy’s Bloodhound got to do with the Airbus A380 and larger engines? Andy told me that the Rolls-Royce and Bloodhound engineers face similar challenges:
- One of Andy’s limiting challenges for the Bloodhound SSC car is to create the fastest wheels in history that will not explode under radial loads of 50,000 G at high speed. Bloodhound’s 90cm diameter wheels will rotate at 10,200 rpm, faster than most disks in your PC’s hard drive and three percent faster than certified 120% over-speed rpm limit for the the turbine disk that exploded on flight QF32. View the 1,100 mph (10,429 rpm) wheel spin test.
- Rolls Royce also need to create larger and faster turning turbine disks that can power the next generation of commercial jet engines. Their challenge is to continually extend the size and thrust limits whilst protecting reliability.
Although Andy’s wheels will be operating in cool air in the Hakskeen Pan in Northern Cape, South Africa, the research and development for Bloodhounds SSC’s wheels will probably feed back to help Rolls-Royce design bigger more powerful turbine disks that will form the bedrock inside the next generation of larger Rolls-Royce jet engines. Maybe with Andy’s help we will see super-engines capable of powering a future two engine A380!
This blog has covered some theory of flight from the Pteranodon, through the Storm Petrel, Albatross, Concorde and A330 to the A380 quad and A380 twin. It also presents some of the challenges the engine manufacturers will face when building the next generation of turbo fan engines.
The A380 will always sit an outlier on the Great Flight Diagram. It is a remarkable achievement that Airbus managed to build an aircraft that can pushes the limits and sits at the extreme edge of the weight-cruise speed envelope in the Earth’s atmosphere. The A380 is limited by it’s cruise mach number. It should ideally have a smaller wing and cruise at higher indicated airspeeds, however the Mach drag rise makes this impracticable.
I doubt that we will ever see an A380 twin, but history shows that aviators have continually invented and improvised to make the impossible, possible.
Counter to some industry reports, I think the A380 will fill fly for decades, and remain the best of breed for long distance (A380-900) and also for high seat density (A380-800) travel. Tim Clark (Emirates) thinks similarly, stating:
- “[the A380] it’s a really good aircraft.” (November 2013)
- “Our customers love it and it is one of the most efficient aircraft to operate in terms of fuel burn per passenger.” (December 2013)
- “There is nothing out there that resembles what the A380 can do.” (June 2014)
I hope we see the A380neo and the A380-900.
I love the aviation industry! It’s the most thrilling, extraordinary and exciting profession. But never become overconfident and never forget Neil Armstrong’s mantra:
“Expect the unexpected”
I hope you enjoyed this brief tour. The complete analysis will be included in my Big Jets book.
Good luck Andy. Best wishes Airbus, Boeing and Rolls-Royce.
Rolls-Royce is a key sponsor for Andy’s Bloodhound SSC project. Coincidentally, Andy Green is also a Cresta (skeleton bob sled) rider who recently mentored my son Alexander at the Cresta Run in St Moritz.