The Airbus A380 cockpit

This is a cut-down still of part of the Airbus A380 cockpit, taken from airbus.com. It's from a panoramic viewer, on a page that uses Flash to let you pan and tilt and zoom in and out of a view in any direction, so that you can really explore the cabin in detail, in high-res. If you want to look out of the window, look backwards, or look up at the ceiling while it spins, you can do that. The mouse scrollwheel zooms you in and out. It's nice. The 360-360 photography is by gillesvidal.com.

The A380 is a very nice plane, with a famously-great cockpit control surface layout. It has a comfortable, relaxing, reassuring look to it (as opposed to some of the more traditional layouts with lumpy panels and dials everywhere all screaming "Look at MEEE!"). It doesn't look scary – as a newbie, you can look at this user-interface and half-kid yourself that you might actually be able to fly it.
My concern when I first heard about the Airbus' screen-based system was: what happens if a screen develops a fault, and you lose a whole bank of virtual instrumentation? Well, the A380 panels tackle that problem brilliantly – you notice how the eight main portrait-format screens all seem to be the same size? Well, they're completely interchangeable. You're supposed to be able to pop out any of the main screens and swap them round, live. There's a couple of little grey rectangles below the bottom two corners of each screen panel, presumably those are the finger-latches. And apparently you can completely change the layout, so if one panel's connection points are messed up, you can watch its data somewhere else. I like this plane.

So let's explore ...
Twin side-joysticks and QWERTY keyboards. I don't know what those two rounded plastic bulges are ... perhaps they're calming devices, for the pilots to put their hands on in moments of stress. Or maybe they're there so that if you get thrown towards the panel, you have something to grab onto that doesn't accidentally result in you pressing an Important Switch by accident.

Three spare seats at the back (for parties), and an overhead camera (so that you can remember what you did the next morning). Fun Wagon!

Note the video camera views, on the centre screen. Useful for parking, and also for reminding yourself which airport you're at. Also for checking that you still have the right number of engines, that none of them are on fire, that all your control surfaces are present and correct, and that your wheels haven't fallen off. Without cameras (or a periscope), it's not always easy to know if your wheels are really down, because planes tend not to have glass bottoms. The central panel showing the video views is the obvious "spare" section of control surface to use in flight for additional functions if further equipment is retrofitted that needs its own display space (like customised additional avionics – rocket launchers, anyone?). There's a pull-out shelf thing in front of each seat that gives the pilots additional keyboards and pop-up screens for general flight admin and map-browsing.

Very Importantly: what looks like three cup-holders per side, left and right, away from the important controls, plus another five at the back left. It's deeply important to have enough cup-holders (one for fresh coffee, one for water, and one for soup, or perhaps noodles?). That's assuming that the holes aren't for something more boring. There's a clunky laptop-py thing at the back, for system-level stuff.

I like the documentation holder on the back of the door, made out of two types of sticky tape. But what's that panel in the door, with the nasty scratch gouged in it? Is it a “people” version of a cat-flap? I also like the design of the door-hinges, with the hinge protruding inside the cabin, and the screws accessible. That means that the cabin crew can remove the door from its hinges from the inside, if it jams (say, after a crash). Someone's put a lot of thought into this.

Twin microphones (for karaoke duets? Pilot-copilot comedy banter?). Between the "emergency power" and "oxygen" switches overhead (up above the left windscreen variable-speed wiper knob), there's also an intriguing switch marked “Entertainment”. Hmm.

Rear right, there's what looks like a locked cabinet marked CDROM. Well, if the Batmobile has one, I suppose the 380 ought to have one, too.

"Escape rope" compartments on both sides. Down to the rear left, by the fire extinguisher (whose sign I initially misread as “portable fire eating”), there's a hatch set into the floor. I've seen this hatch drawn on a schematic with a ladder poking through that exits through the front wheel port. I guess this means that if you're a pilot and you have a panic attack before takeoff, you can pop down through the floor and run away across the airfield without the passengers realising that you've gone.

The seat covers have large tags facing each other saying "Pilot" and "Copilot", which might be useful for resolving cabin arguments. Point at the tag. 'Nuff said. Also handy for avoiding those embarrassing "But I thought YOU were supposed to be flying the plane!" moments.

So, a very nice vehicle.

The only design decision here that I'd query is the upholstery. Pinstripe? Hmmm. But perhaps there's a reason for that, too ... perhaps striped material doesn't show sweat stains so easily. You don't want to be settling down into your seat for a long-haul flight, and be too conscious of the big sweaty patch left by the previous pilot. Eurgh. I wonder how often they change the covers?

With the addition of deep-pile furry tiger-pattern seat covers, vibro-back-massagers built into the seats, a proper entertainment system with giant speakers, and a couple of foot spas, I'd give this cabin 10/10.

Putting Periscopes on Airplanes

One the subject of airplanes, a wacky idea I had about twenty years ago was designing aircraft cockpits to include periscopes.

A dumb idea? Not necessarily.

See, one of the problems with large aircraft is taxi-ing. Aircraft are designed to fly. They aren't really designed to be driven. So if you're in the cockpit of a 747, and you want to park it somewhere, you can't really see what you're doing. You're high up, your visibility sucks, and you have this nose-cone thing sticking out in front of you, guaranteeing that you have no chance of seeing what's just in front of your wheels. Consequently, expensive aircraft get trashed from time to time while they're still on the ground, while somebody is simply trying to find somewhere to park them.

What you need in this situation is a periscope – not to look up, but to see how things look from beneath the aircraft. You want to be able to pull a lever, and have a chunk of optics pop out of the bottom of the aircraft giving you a 180-degree or 270-degree view, relayed up to the cabin and perhaps projected onto a curved mirrored trim just below the windscreen. Worried about debris on the runway? Check the periscope. Trying to park? Check the periscope. Coming in to land, and not sure if your landing gear is deployed? Check the periscope. Unsure if one of your engines has just flamed out? ... you get the idea.

Consider the case of Concorde. One of the most difficult engineering tasks in designing Concorde was supposedly the design of the nose. Concorde has a looong nose, and it needs to be pointy and smoothly tapered for efficient supersonic flight. But when Concorde comes in to land, it glides in at an angle with its nose in the air, and the pilots can't see where they're landing. To get around this the engineers developed a "droop snoot" for the plane – an entire nose section that could swivel to point downwards when the plane landed, to give the pilots a fighting chance of seeing what they were doing. This was a difficult bit of engineering, with double windshields and so on.

Wouldn't a pop-down periscope system have been simpler?

Okay, so nowadays the idea's probably becoming a bit redundant. With recent aircraft, with their instrumentation displayed on LCD panels, it's probably easier to embed reliable cameras into key positions in the airframe and allow the copilot to switch one of their screens to camera view. The data networks are probably already in place, and the instrumentation panels are now flexible and modular. We're probably approaching the point where a pilot will trust a set of cameras more than a set of odd additional direct optics.

But for the last few decades, large planes probably really should have all had periscopes.

Fear of Doors

If you ask most people what the single most dicey bit of equipment is on an airplane, you'll get a range of answers.
The obvious answer is the wings. But actually, wings are pretty stable things. They don't flap or do anything fancy, and the airframe is fitted to them pretty solidly. Wings tend not to fall off. Okay, so the control surfaces sometimes do fall off (some years back, a large flap landed in Richmond golf course that no airline wanted to claim), but this isn't as big a deal as you might think. The tailfin is important for stability, and you certainly don't want to lose that, but they're usually overengineered, too. Wheels are handy if you're planning on landing, but as long as you know that your undercarriage has failed, you can take appropriate steps. So maybe the little undercarriage warning light is one of the most important pieces of kit on the plane.

Engines are another matter. Jet engines are beautiful pieces of kit, but they're somewhat exposed. You have delicately-engineered compressor blades whose outer tips shear a helical scream through the air at more than the speed of sound, and they operate without safety covers. They're damned strong, but they're only designed to cut and chop air at supersonic speeds. Not water. Or ice. Or large items of poultry.

Try to convince a cruising jet engine that it ought to suddenly try being a food processor and attempt to make some albatross pate, and it gets unhappy. Blades can break and fly off. Control lines can get severed, and fuel tanks punctured. If you're lucky, when the engine tries to inhale a flock of geese, it'll just stop.

So bird strikes are dangerous. But they happen far more often than most people think, often to freight aircraft, where the incidental loss of an engine or an altered flightplan doesn't result in any scared passengers or a news story. Airliners have multiple engines, and unless you lose all of them, the pilot can usually try to do something with what's left.

If you're an airliner passenger, perhaps you should be rather more worried about geese than about the idea that the wings might fall off the plane.

So-o ... back to engineering. What's the most dangerous bit of equipment that the passenger is allowed to see? Perhaps it might actually be the aircraft's doors.
People don't think of doors as being dangerous. Doors are not supposed to be difficult pieces of engineering. But airliner doors are slightly different. See, there's no “safe failure mode” for an airliner door. If you need it to open in an emergency, it HAS to open, but while airborne, the door mustn't fly open when someone trips over and accidentally falls against it. It has to be really easy to open (or everyone dies), but not too easy (or everyone dies).

The door and its housing also have to operate under extremes of temperature, when the plane is parked in baking Saudi desert heat, or on a frozen Moscow runway with maybe a quarter-inch of ice on the seals. It has to cope elegantly with thermal expansion and contraction. If the door sticks, you do NOT want to damage the mechanism by forcing it too hard. If it's damaged, you can't fly.

Added to this was the problem that in older aircraft designs, the doors were liable to be one of the last things to be designed. And in the older “tapered” planes, you couldn't necessarily design a door in advance and place it anywhere you wanted ... oooooh no, the fuselage curvature was different all over the plane, sometimes a door designed for one part of the plane simply wouldn't fit anywhere else. And what happened to this mission-critical component whose failure could bring down a plane? It got slammed. It got shoved. People banged their luggage against it.

On recent airliners these things are better. Passenger doors now tend to be inward-opening, with a “bath-plug” taper to their cross-section that means that even if the locks fail, the internal air-pressure pushes the door tightly against it's frame. The doors are relatively small, rigid, and thick, and the higher you fly, the harder the doors are pushed into their mounts by the pressure-differential. The Airbus range (and the later Boeings) also have noticeably cylindrical fuselages, and while this may sometimes look like an ugly design cop-out, it helps with some aspects of the engineering. A “cylindrical” plane can be produced more easily in a range of “stretched” or “squashed” versions by adjusting the number of standard prefabricated sections. And it means that ... magically ... the doors work better. A door can start to be be designed and extensively tested as soon as the aircraft dimensions are decided, and then the resulting design can be deployed and duplicated at any point along the cylindrical section of the fuselage.

But for cargo-bay doors, things aren't so great. Cargo doors have to be big for loading, and while passenger doors can be designed with a “plug” taper so that they can't be forced open by air pressure when unlocked, cargo doors often open outwards. They also have a larger surface-area-to-edge ratio, so they're less rigid. They flex more. And the guys who load are using motorised equipment to move multi-ton pallets about, so you might expect the occasional accidental prang. And they aren't necessarily experts in aircraft safety.

As a result, serious cargo door failures in airliners do happen from time to time, sometimes leading to some of the passengers experiencing an unscheduled exit from the plane. In the worst-case scenario, in a pressurised aircraft at high altitude, the resulting explosive decompression can rip apart the plane's innards, destroying the control systems and bringing down the aircraft.

http://www.absoluteastronomy.com/topics/Turkish_Airlines_Flight_981
http://www.absoluteastronomy.com/topics/United_Airlines_Flight_811

See, people just don't RESPECT doors.

Happy flying!