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BMW i8 and Boeing 787: A brave new world

24th Dec 2015 8:00 am

We take a close look at two revolutionary machines that are all set to be templates for the future.

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The values of numbers are changing. 100, for example, is no longer greater than 99. This is because we are living in a changing world where less is more. Let me explain.

Just a few years ago, transport designers across the world were in pursuit of higher numbers. Their efforts focussed on making aircraft and cars go faster with engines that promised bigger performance. The bigger the number, the bigger the appeal. Boeing was toying with the idea of a Sonic Cruiser that would fly as close to the sound barrier as you could dare, and BMW was celebrating with big-bore V8s and oversized V12s. Efficiency was important, but in the overall scheme of things, it came a distant fifth.

And then the bubble burst. Yes, rising demand and the price of oil was already creating havoc but then, 9/11 came along and created a set of new global dynamics. And add to that, climate change; now no longer just a topic of academic discussion. These factors demanded a change in engineering and technological objectives. So, the new challenge became ‘how do we reduce fuel consumption without affecting performance’. How much can we reduce harmful emissions without cutting down on power? How do we reduce the weight of the vehicle rather than how much can we overbuild it. 

BMW i8 vs Boeing 787
Aero and sonic appendages abound on this pair.

Our two stars today, on the face of it, seem as different as chalk and cheese. But under the skin, both are designed to fulfill similar objectives. In the left corner, the BMW i8. A plug-in hybrid sports car with a top speed of 250kph. On the right, Air India’s Boeing 787 with a top speed of 954kph at cruising altitude. One costs around $200 million while the other will put you back by Rs 3 crore. While the car can seat two (though it has four seats), the Boeing can seat close to 250.

Despite their apparent differences, they share more in common than is instantly apparent. Firstly, they represent a new reality; they are markers to the way ahead. Secondly, they are demonstrations of the technology and materials that were once believed to be in the domain of exotics. And thirdly, they represent the long-term vision of two leaders who believed in forging ahead. The i-series cars from BMW, the i3 and the i8, are thought to be part of the personal vision of BMW heiress Joana Quandt, who recently passed and Allan Mulally – who sanctioned the three-cylinder EcoBoost engine later at Ford – is the one who pushed for the Dreamliner.

BMW i8 vs Boeing 787
Both rely heavily on slippery aerodynamics to get the efficiency numbers right.

The sun had just peeked over the horizon when Team Autocar lands up in Gate No.1 at the Santa Cruz Airport in Mumbai. It’s not a gate that you’d know unless Air India pays you your salary and your job is to keep aircrafts flying. Thanks to due diligence in the past week, the red tape is lowered for us as we drive the electric-blue BMW i8 in for its date with the Dreamliner. And then, as if on cue, we see the LED lights of a 787 lining up on the runway behind.

The name Air India isn’t on the tail, so we known it is a Dreamliner. Excitement is high, we’re about to be given a ringside view of the power and the majesty of a full-bore take off from close up. AI 131 carries approximately 55 tonnes of fuel and if the flight is full, there’ll be at least another 140 tonnes to deal with. And when I say ringside, I mean ringside; Air India’s engine maintenance facility is halfway down runway 27, and aircrafts pass so close we can feel the hot gasses as they thunder past.

The new GEnx engines make 72,000 pounds of thrust each, but we can barely hear the whine or the roar from halfway down the runway. We do see the heat haze, however, and we can tell it’s gathering speed too. It looks brilliant, the white nose tucked resolutely between the big turbo fan engines and the menacing stare from the atypically Boeing cockpit windows; and then, as it gets closer, we see the scimitar-shaped wings begin to flex and lift past the top of the cabin like the wings of a bird. Known as a dihedral arrangement, this is done for extra stability, but it also looks great, like the 787 is soaring. The Dreamliner then hurtles past, the whine of the turbine and roar of the exhaust blending as it noses up into the grey sky. Compared to other aircraft, the roar is a bit muted, but it still hits you in the chest and clearly, there’s plenty of thrust here. But the engine note is friendlier, a bit sweeter and it’s less of a burden on the ears.

BMW’s i8 sounds less aggressive too. It looks like a pukka supercar, and with a 0-100kph time 
of 4.4 seconds and a 250kph top speed, it very nearly is. You can feel the g forces for sure, especially when you put your foot down and get that burst of electrical assist. You do need the right road, or an empty apron, but hit the throttle and the i8 slices through the air with a firm push in the back. Yes, truth be told, we do miss having twin-turbo V8s in the back, and a bit more noise on the outside would be great, but the essence of a really fast, fun-to-drive car is all here.

BMW i8 vs Boeing 787
BMW i8 is dwarfed by 150-plus tonne Dreamliner.

Although we’ve primarily come to compare and contrast, let’s look at how each one pushes the boundaries of conventional technology.

Design first. Now this may come as a shock, but the 787 was designed to look modern, and styling played some small part in how it looks today too. The shark fin-like tail on the 7E7, the 787’s conceptual forerunner, was truly radical, but it didn’t make production as Boeing engineers wanted a straighter rudder. The flush mono volume-like nose did make it, however, and so did many other bits.

The BMW i8, on the other hand, is a landmark design; and that’s not just because of its low-slung profile or supercar-like dimensions. No, what sets this car apart is the layered skin that looks brilliant and is like nothing else around. The structure of overlapping and interlocking surfaces, painted in two shades, gives the BMW unmistakable character. And it says a lot about the new-age thinking and engineering too.

BMW i8 vs Boeing 787
Air India’s engine shop is the first one in the region (Note carbonfibre cowling on engines).

The similarities between the two multiply rapidly as we delve under the skin. BMW’s new platform, made especially for this car, is the real gem. Made of resin-injected carbonfibre-reinforced plastic (CFRP), this tub is superlight, literally half the weight of a similar one made of steel. Also, despite it having very heavy batteries, the i8 tips the scales at only 1,500-odd kg, which, all things considered, is quite remarkable. While carbonfibre construction is a bit too expensive for everyday cars today, we are sure to see steady progress in this area. Who knows, somewhere in the distant future, your new Maruti could also be made by using a low-cost method of carbon construction.

On the other hand, Boeing has already democratised the use of carbonfibre. The 787 is the first airliner to have a composite fuselage and part composite wings. The fuselage is made with the help of a giant ‘tape’ that is wound around a structure and cured in a massive autoclave at Kawasaki heavy industries in Japan. This helps eliminate 1500 aluminium sheets and a colossal 50,000 fasteners. The weight saving here alone – around 4.5 tonnes.

There are other areas where the 787 breaks all convention and uses carbonfibre to replace metal. The GEnx engines not only use carbonfibre blades, but the fan’s main cowling is made of carbonfibre as well. This helps reduce the overall mass of the engine and helps make it more silent and less prone to resonance. Next up, the double-brace landing gear; the support arms for which are also made of carbonfibre. And the 787 even uses carbon ceramic brakes, something we find on many sports cars today.

The BMW can’t match the Boeing when it comes to use of carbonfibre in ancillary and support systems, but it makes greater use of electrical energy. While the three-cylinder turbo engine sends 228bhp to the rear wheels, the engine also drives a generator, which sends electricity made during off-load conditions back into the 7.1kWh lithium- ion battery pack. So, in addition to the 228bhp, the front wheels are also powered by a 128bhp, ‘hybrid synchronous’ electric motor that runs off a two-speed automatic gearbox. The electric motor is also different because it creates what’s known as ‘reluctance torque’ as it spins. Unlike a regular electric motor that makes all its torque instantly and then fizzles out, this one delivers more power at higher rotational speeds; which is exactly what you need on a sportscar like this. Trust BMW to be pioneers in this field. So, while the combined output of 357bhp isn’t all that much, the insane 58kgm of torque helps give the powertrain the kick of a mule.

You can’t charge your 787 via a wall socket, as you can the BMW i8, but the Dreamliner pioneers the large scale use of electrical energy as well. In fact, so many systems run on electrical power, many pneumatic and hydraulic system have been replaced on the Dreamliner. And this makes the engines intrinsically more efficient as they are free from parasitic air supply requirements like the air-conditioning. The requirement for electric energy, in fact, is so high that the Dreamliner is a veritable power station, it constantly produces more than one megawatt of power; in excess of 1,00,000 volts. And a lot of that power comes from the GEnx engines that run a pair of generators each.

BMW i8 vs Boeing 787
Heads-up display a ‘little’ different from the i8’s.

But where does all this electrical energy get used? Well, to begin with, there’s the electric engine start, no mistake, then there’s proper brake-by-wire with an electrical braking system used instead of a hydraulic one; yet another first (this technology is yet to find its way to cars) and the wings are now electrically heated as well. Unlike the BMW, though, regenerative braking isn’t used on the 787, but can you imagine the energy you’d be able to sponge up from this 160 tonne aircraft as it brakes from 280kph after touching down?

Both the i8 and the 787 are green vehicles. The i8 produces just 49gm of CO2 per kilometre which is less than a third of what is emitted by something like a 3-series; truly stunning. Not to be left behind, the 787 also pushes the boundaries as far as emissions are concerned. The GEnx engines use what is known as a TAPS pre-combustion chamber that helps pre-mix the fuel with the swirling airstream. This allows the use of a leaner mixture and because combustion takes place at a lower temperature, nitrous oxide emissions are reduced as well.

BMW i8 vs Boeing 787
It’s American, so the pilot gets a cupholder too.

As far as efficient performance goes, the i8 is all but untouchable; it can be as efficient as a hatchback when not driven flat out, and that again, for a sportscar, is unreal. Greater efficiency is also what the 787 is all about. Boeing claims a huge 20 percent reduction in fuel cost-per-passenger; which, of course, is why operators are lining up to buy the plane in the first place.

Carbonfibre construction also makes a huge difference to cabin comfort on the 787.  The windows are larger to begin with, the cabin is pressurised to the equivalent of 1,800 metres instead of the standard 2,400m, because the structure is much stronger, and because the risk of corrosion is less, humidity levels are maintained at a more comfortable 15 percent rather than the normal four percent. So, long-distance journeys like the AI302 flight from Delhi to Sydney are clearly more comfortable.

Both the i8 and the 787 are lighter and considerably more efficient. This is because of  fundamental changes, that are more revolutionary than evolutionary. Revolution, however, generally comes at a price. The Dreamliner, for example, has had its fair share of teething problems, but early ones like lithium-ion battery fires are in the past. The BMW i8 isn’t perfect either, and you can see big sacrifices have been made. Yes, it is seriously clean, massively green and looks better than most supercars. But you often hunger for a bit more performance. Still, even as things stand today, this pair has taken the game considerably forward. This is the remapped DNA of the future of transportation and all the rest of the world can do now is follow.

From the cockpit

Even though the 787 is a fly-by-wire aircraft, Air India pilots say its handling is very robust and similar to other Boeings. This is unlike Airbus’ fly-by-wire aircraft that feel very different. And because the 787 is generally much lighter, momentum and inertia are also much less, so it feels very modern and great to fly. Also, while manoeuvre margin is restricted to 1.3g, as in all commercial aircrafts, the design limits feel much higher. The 787 is also surprisingly nice to fly in bad weather due to new features like the Active Gust Alleviation system (similar to the B2 Spirit stealth bomber) that continuously damps out rough patches, and the big heads-up display that allows you to keep your eyes on the conditions outside.

Air India’s dream team

Air India already has 21 Boeing 787s in its fleet. Six more Dreamliners will join the fleet in future, some of them the higher capacity 787-9s. Currently the airline’s mainstay for medium and long-haul international routes, it flies to approximately 20 international destinations such as Birmingham, Dubai, Frankfurt, Moscow, Hong Kong, London and Milan to name a few, and it’s here that the greater cabin comfort really makes a difference. This is because the stronger carbonfibre cabin allows for a far more natural cabin pressure (similar to 1800m) and humidity (15 percent) levels. The Dreamliner, which has a huge range of 14,000km, also has long-range, non-stop routes such as Melbourne and Sydney. However, to experience the aircraft, you can choose to fly more affordable sectors like Mumbai-Delhi (AI 348), Delhi-Bangalore (AI505), Delhi-Amritsar (AI461).

Akbar Merchant

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