Friday, June 26, 2009

My British Tour Diary

To be there, first you gotta get there.

In my line of work, seniority is everything. Or, more pertinent to my point of view, juniority is nothing. I'm not quite at the bottom of the barrel, but I can see it pretty clearly. Accordingly, I should consider myself lucky that what I got for June was not completely horrible.

Still, it was a bit dodgy. The best I could do to accommodate our Grand Tour was a reserve line (i.e., on call), the end of which was two days after I wanted to be in England. Because I was a hostage to fortune, I couldn't buy an airline ticket to travel with my wife and son, since I wasn't sure I could be there.

On this occasion, though, fortune smiled broadly upon us. Skeds tossed me a trip that left only a few reserve days at the end, two of which were off limits for crew rest. Since there was no way I could get used, I was able to travel on the same day as the other SWIPIAW and the man-child.

I got home at 1 am on the 8th. Sleep as fast as I can. Get up. Unpack. Repack. Next day, head for England.

One of the benefits of being a pilot is the ability to jumpseat just about anywhere for free. However, this particular excursion, being international, was going to be a bit dodgy. I could have waited and tried to leave in the afternoon with Sue and Eric, but if I couldn't get on with them, the day would be shot. So I headed to O'Hare the first thing in the morning, figuring that there would be enough flights to Heathrow that I would be bound to get on something, and get there before they did.

That last bit was kind of important. Vague travel plans combined with no comm capability -- think of life before cell phones -- made contingency planning tough. The fallback option was for them to press on regardless, and for me to do planes-trains-buses as required to intercept the lodging itinerary. Obviously, getting there before they did would make a lot of problems go away.

I got to O'Hare on schedule, then headed directly for the international terminal to catch a ride on British Airways. Memo for future reference: BA does not accept offline (i.e., non BA pilots) jumpseaters. BAstards.

Okay, Plan B. Back to the American Airlines gates. List for jumpseat. Learn that recession memo may not have gotten to everyone. Terminal is packed, and flight oversold. Memo for future reference: one of the knock-on effects of militant Islam, combined with, umm, obscure, government reasoning is that I can't get on a flight deck jumpseat for an international flight.

Plan C. Trudge to United gates. Recession not readily apparent there, either, as they are trying to buy off 20 people as I walk up to the gate.

Verging on 9 pm, twelve hours after leaving home, Plan D. Trudge back to American gates for the last flight that evening. Fortunately, it would arrive at Heathrow an hour before Sue and Eric. Note as I plod past commuter gates that the last flight to Memphis leaves in 10 minutes. Quick call to my company's jumpseat schedulers. There is a four am flight to Stansted (nearish to Cambridge), and a seat is available.

This presents a conundrum. American, IF I can get on, avoids all the contingency problems. Going on Company leaves those problems completely intact, but does offer the certainty of getting in country, albeit to a different airport five hours later than Sue & Eric. I pretty quickly concluded that this was a real life bird-in-the-hand problem, so I headed to Memphis.

Once there, with a couple hours to kill in flight ops, I worked the contact angle. National Rental Car was no help. However, I was able to send an email to the first nights lodging, a B&B in York, with my arrival info, and noting I planned on trains and a cab getting me to York

(It is worth noting at this point that by that point I would have crossed 17 time zones in four days, and gone three nights out of five with essentially no sleep.)

Cue the sequence denoting passage of time: plane taking off, cruising, landing, parking.

Fine, I'm in England. However, I have no idea how to get from Stansted to York. So, contradicting the conventional wisdom that men won't ask for directions, virtually the moment the airplane door cracks open, I ask the ramp agent how to get to the first night's destination.

"What is the best way to get to York?"

"Oh, no need to worry about that. Your wife is here."

As my jaw was plummeting to the floor, just before the loud, anvil-like clang, I wondered if my fatigue was so extreme as to render me delusional.

As it happened, Sue and Eric stuck to our comm-out plan. If not at arrivals, proceed to car rental agency. If not at agency, stick to itinerary until I showed up at wherever they were to be staying on the day I could get there. Since they hit the road just as the afternoon rush hours were, getting out of London was an M25 traffic nightmare. Glaciers routinely move faster, some of your more athletic trees can keep up. Cold remedy companies should consider using the visuals as a metaphor for painfully clogged sinuses. After a couple agonizing hours, it was intuitively clear to Sue -- and the rental GPS (aka Betty) confirmed -- that their arrival at the York B&B was going to be late. Sue decided it would be a Real Good Idea to get in touch with them, so she decided to just buy a cheap pay-as-you-go cellphone at a fortuitously placed roadside services area.

The B&B told her how to work the after-hours arrival, and mentioned that ohbytheway I had sent an email.

Sue told Eric to find out from Betty how far they were from Stansted.

They had 45 minutes to drive the 5.8 miles to the cargo ramp. That is just lottery winning kind of lucky.


You have a friend in England

Still bafflegarbed at this turn of events, we continued the march to York in a continuous driving rain. Even more bafflegarbing, we were cut loose to drive on the left side of the road. It's amazing no one died.

Our rental barge was a Skoda something or other, most notable (to me, anyway) by its motor: a turbo-charged diesel. If you care about cost-per-mile, probably nothing beats a diesel, including anything of the Prius ilk. Great torque, especially after the turbo kicks in. Have to re-calibrate my thinking a bit, though: shifting needs doing about 2000 rpm lower than a regular motor. That, and getting it off the line.

Despite having driven almost nothing other than manual transmissions my whole life, I stalled the thing every third try. I am only guessing here, but because of the high compression ratio diesels require, they have very little torque at tick over, despite being able to pull stumps once under way.

We finally got to York just before 11pm. Sue was practically quivering in anticipation of going to a pub, so we did that immediately after checking in at the B&B. On the way back, we relied on old-fashioned memory to re-find the B&B. I don't know whether to blame cognitive deficits, or darkness and heavy rain. In any event, we turned a street too soon.

Pulling away from the subsequent signal, I stalled the car. Instantly, the car behind me started flashing his brights and leaning on the horn with both hands and a foot.

Oh, for Pete's bloody sake.

After chewing up every bit of four seconds to get restarted, I turned left, stayed in the left lane, and proceeded at no great speed. Despite having another lane, the car behind me stayed right on my tail, still with the lights and the horn. Now we are wondering aloud whether he is trying to tell us something: flat tire? wrong side of the road? lights off? Not apparently. Moment of panic, but no. No. Still puzzled.

A couple hundred yards on, and another stop signal. The other car, now far quieter, pulls to a stop in the adjacent lane. Seconds later, my door is yanked open by this guy who looks like every imaginable justification for "three strikes and your out" sentencing legislation. "Get out of the car you [insert loud graphic obscenities here]".

It didn't take long to suss that getting out to defend my honor was probably not going to be a winning strategy. Nor was waiting for the light to turn green. Nor would stalling. Thankfully, I had a credible Grand Prix standing start available just when I needed it. Twenty feet of rubber closed my door firmly, and I chose enough side streets to frustrate whatever desire he might have had to continue our conversation.

All three of us more or less simultaneously said "What the heck was that about?"

My second thought was that he probably should investigate other cultures before he travels abroad. If he was to try that in, say, Texas, Arizona, or Alaska, like as not he'd get his head blown off.

Welcome to England.

Well, no, not actually. That bizarre incident aside -- I promise my hands never left the steering wheel -- during our whole stay we never had a chance to look even mildly confused for more than a few seconds before someone stepped up to offer assistance; everyone was always friendly and courteous, almost as if the entire country was trying to make up for the the York incident.

Driving in England is a challenge. Having to overcome ingrained habit to drive on the left is hard enough. Doing simple things like pulling out of a car park onto a lightly traveled road is the worst: looking the wrong way to pull into the wrong lane. If I sound like an expert here, I am.

Besides driving on the wrong* side, roads are narrow, twisty and dark. Roundabouts come in infinite variety, occasionally including traffic signals. For those who haven't driven there, this is applied mixed metaphor: think Yield sign and stop lights at the same time.

The Brits really do need to create some insignia for rental cars indicating the driver is a foreigner. They already have one for drivers on provisional (learner) licenses: A big white circle affixed to the aft end of the car, with a very prominent red "L" in it. Not only would it have encouraged other drivers to self-defensively give me a great deal more breathing room, it would also attenuate their irritation at my more than semi-occasional benign buffoonery.

The nagging non-trivial worry about having nevertheless declined the rental car insurance coverage aside, the trip went perfectly. Britain must be the prettiest country on the planet, and the Tourist Board apparently obsessively dedicated themselves to ensuring perfect weather when it mattered, while leaving the rainy and windy bits for when we were driving, sleeping, or in need of a rainbow.

Cut to the Chase already

Of all the forms of writing, travelogues are the hardest to get right. So, rather than a blow-by-blow, here are some observations in absolutely no particular order.
  • Betty the GPS was more than just convenient. No, Betty doesn't really do anything that can't be done with a map. However, her voice directions allowed us to keep both heads up, and not looking away from the road to find street signs which were noteworthy primarily in their absence, and secondarily in their promiscuous changability. Huge safety bonus. Also, gave the man-child something to mess with.

  • The critters could not get enough castles.

  • In a beautiful country, Bath could well be the prettiest city. Most of the buildings are made from a nearly buttery yellow sandstone. The entire place glows at sunset.

  • As I have said elsewhere, the Internet Cloaking Device reveals clearly the person underneath. Thanks to my peripatetic job, I have been able to meet a good half dozen of Post Judd Alliance. Not once have I been disappointed. Meeting Brit and Anna was a great addition to our trip. We just missed Ali Choudhury, but it looks like there will be a do-over near the end of July.

  • Whoever said the intertubes would lead to the complete atomization of human relationships was operating in a complete clue vacuum.

  • Managed to see Shakespeare's "As You Like It" at the Globe. Taking the time to read the play first was a great help. The no longer so little man knew he was going to hate it. I told him he was wrong. I couldn't have been more right.

  • We had a couple hours to kill before the play. Well, not "kill" exactly, London has no end of stuff to see. But we wanted to keep it close -- no point in buying tickets, only to show up two minutes late. So we went to the Tate Museum a few hundred yards along the Thames: modern art from top to bottom. With frighteningly few exceptions, modern art is pretentious, ugly, embodied faux-intellectual onanism. Resuming above ground nuclear testing within the building could scarcely create a worse mess.

  • Why can't American drivers be even half as good as British drivers?

  • If I was a car manufacturer -- Toyota, Porsche, BMW, Skoda, name it, I would subcontract Apple to design the software. Everything else aside, no one does look and feel like Apple does. The Skoda had an amazing amount of electronic wizardry on board. Unfortunately, it all gave the impression of being hurled through the passenger's side door in a wicker basket.

  • During time in London, we stayed in Hounslow. As Brit or gaw could quickly tell you, that is not the posh part of town. Our arrival the first night was a bit late, so I went to a takeaway around the corner from the decidedly threadbare hotel. On ordering, I couldn't help but notice all the references to halal this and halal that. Clearly, I was in a Muslim establishment. While waiting for my order, the proprietor insisted I have some (presumably halal) chicken wings on the house. I retaliated by shamelessly overtipping.

  • The more perceptive among you might have been able to hazard a guess that I am not particularly religious. That said, I cannot imagine how a hypothetical absence of all the Christian edifices from Britain's landscape would improve things in the least.

  • If you want reasonably priced lodging in London, it will take you an hour on the tube to get to London from your lodging.
Since I am getting tired of typing, and you have long since wished this pathetic imitation of Lileks would come to an end, I'll let pictures do the rest of the work.

York

Edinburgh Castle. It was the woman-child's idea for the More Guinns in More Places lineup.

More More Guinns in More Places, this time along the Scottish border.

We stopped at the ex-RAF Upper Heyford, near Oxford, to show the critters without where they would never have begun otherwise. The RAF Commander's building is still open to the public, and they have a pretty good history video they show on demand.

We could also get to the Officers' Club, where Sue & I met. It has been slowly crumbling since the base closure in 1994. I wouldn't be surprised if it is still standing in 2394. (One place I lived in back in the day had "1462" engraved in the arch over the doorway.)

The man-child learning to pilot a canal boat. He is a very quick study.
*Wrong as in non-standard, but not as in without reason. WayBackWhen, England was plagued with highwaymen. Most people are right handed, so the English drove their carriages on the left in order to leave the right arm free to handle a weapon. Or, so I was told with a very convincing delivery, anyway.

Tuesday, June 09, 2009

Interregnum

My daughter plays in a High School age flute ensemble. I thought the whole point of the exercise was musicianship.

It is not.

Rather, it is a thinly veiled pretext to hoover Dad's wallet. What I did not know when she joined, but do now, is that they go on an exhibition tour every year. Not to Wasilla, nay, not even Juneau. Lordy, no.

England and Scotland for two and a half weeks.

As if that isn't hoovering enough, my SWIPIAW decided that if the woman-child is on the mud peanut*, then the rest of us need to be on the mud peanut.

Ordinarily, SWIPIAW is a model of prudent household budget management. But, not when it comes to traveling. Lordy, no. Making Congress look like a well disciplined team intent on squeezing every penny until you can hear the Lincolns scream, she has set the botgun* to full auto, and taped down the trigger.

So, for the next week and a half, the absence of writing will perfectly join with the habitual absence of content, while join our daughter in Edinburgh, to see the sights.

Given a little luck, we should meet the Brits in Bath along the way.

Over, and for a little while, out.



* It rains a lot on the ol' Blighty. If you look at a map of the British isles and scrunch up your eyes, it looks like a peanut. Hence, Mud Peanut.

** The Thai currency is the bot, which is as good a generic name for persuaders as one can find. That makes your wallet a botgun. Setting to full rapid automatic, as only Team Estrogen can do, sends those bots spewing everywhere.

Friday, June 05, 2009

Air France 447

The loss of AF 447 is a real puzzler. In the modern aviation era -- which I take to be roughly since the advent of the 707 -- and particularly the last twenty years, the sudden destruction of an airliner while in cruise flight is vanishingly rare.

What is worse in this case is that almost all the clues lie under a couple miles of water, and might never be found. However, that does not mean there is absolutely nothing to go on.

Watts up with that? posted an excellent detailed meteorological analysis of the conditions along 447's route of flight. It paints a pretty compelling picture that violent weather was the ultimate cause of 447's demise.

However, while it goes some way towards what, since the author is a meteorologist, not a pilot, there isn't a whole lot of discussion about the other "w" word: why did the four year old A330, one of the most modern airliners in the world, get in that position? After all, thunderstorms are not rare phenomena. For professional pilots, thunderstorm avoidance comes with the territory, particularly during the summer.

Obviously, one must detect to avoid. To that end, there are essentially two systems available to a pilot: the Mark One Mod Zero eyeball, and radar.

In many cases, visual acquisition works fine. During the day, cumulonimbus clouds are distinct, and at night the lightning can be seen for a hundred miles. Unless, that is, the thunderstorms are embedded in more widespread cloud. In that event, our eyes need help.

Enter radar. On modern airplanes, the radar is an amazing piece of kit. Among other things, it will overlay a color display (colors correlated to precipitation intensity) on the navigation display, and can, in the takeoff and landing phases, predict windshear.

Which, on the face of it, makes AFR 447's run-in with severe weather even harder to understand.

Time to dig a little deeper.

To visualize what the radar can see, imagine looking at an airplane from the side. The radar beam emanates in the shape of an isosceles triangle, with the apex at the airplane's nose, and the base at the range setting of the navigation display. The apex's included angle is roughly 10 degrees, centered around the pilot-set tilt angle, which is pitch stabilized (i.e., within platform limits, the angle is with respect to the horizon, not the airplane's horizontal axis; that means pitch changes do not affect the display). The triangle sweeps 90 degrees either side of the nose, providing a panoramic view of the weather ahead.

What about that tilt angle? That depends upon altitude. The closer to the ground, the greater the tilt angle, up to about 5 degrees, to reduce ground clutter. At cruise altitude, on a typical day, the tilt angle is roughly zero to -0.5 degrees. That means the lower edge of the beam hits the ground about 80 miles from the airplane's nose. Beyond that there may be some ground returns, but it is easy to distinguish them from weather returns, because only weather will appear within 80 miles.

You might begin to notice a limitation here. Just inside eighty miles, low altitude precipitation will not show, because it is just below the beam. The closer to the airplane, the higher weather can be, and still remain below that sweeping triangle, until a thunderstorm directly under the airplane will be outside the radar's field of view.

However, since an airplane will cover that 80 miles in about ten minutes, that means a thunderstorm would have to climb nearly explosively from low altitude in that time in order for its effects to reach a plane at 35,000 feet.

Which they can do. A self respecting thunderstorm probably has as much energy as a middling nuclear weapon, and can, once it starts developing, climb at 6,000 feet per minute. Put in more ordinary terms, that is a vertical velocity of about 70 miles per hour. The airplane I fly climbs better than just about anything that isn't an F-whatever. Lightly loaded, it can manage about 8,000 feet per minute at lower altitudes.

So it is entirely possible, although not common, for a burgeoning thunderstorm to climb fast enough to smack an airplane from below, all the while remaining just out of view.

That is why, if in an area with convective activity*, we will shorten the display range to get a more detailed picture, as well as essentially eliminating the possibility of getting schwacked from below.

There is also a less obvious radar limitation. What we see on the display is, in effect, colors that are correlated with the ratio of returned to transmitted energy. The more precipitation, the greater the ratio, and the color will change from light green through yellow to red. However, if there is enough precipitation, then no radar energy gets through that to anything behind it: sufficiently intense storms act like an impenetrable wall.

The other aspect to consider is aircraft performance. At cruise, we operate inside a fairly small envelope, sometimes referred to as the "coffin corner". Ten to twenty knots faster, and we hit maximum mach; twenty or so knots slower, and we run out of buffet margin. Additionally, typical cruise at about Mach 0.8 translates into a turn diameter of as much as 25 miles.

So, if an airplane runs quickly rising air, akin to suddenly going downhill, airspeed can suddenly increase beyond max mach. Conversely, passing through sinking air means the airplane must "climb" just to stay level, and may not have sufficient thrust to maintain altitude and airspeed.

Turn radius just complicates matters. When it comes to thunderstorms, pilots always have to have a "bolt hole", which has to be pretty big at altitude.

Finally, there is the A330 itself.** It is a full fly-by-wire airplane which, among other things, incorporates flight envelope protection. It won't let the pilot go to slow, or too fast, or bank too steeply, or let the pitch get out of hand. If things go wrong, it will also go into manual reversion which, if my memory of that simulator session serves, is very unpleasant.

None of this comes as any surprise. Weather avoidance is so common as to be essentially a routine part of the job, made far easier with color radars, and easier still on modern airplanes that overlay radar returns over the God's-eye-view navigation display.

Yet AFR 447 is gone, nonetheless.

Time to start speculating.

Despite all the technology, AFR 447 hit violent weather through one or more of:

    Sheer bad luck. Directly overflying an extremely quickly building thunderstorm that just managed to stay out of view.
    Bad luck of a different kind, mixed with bad planning. They got into a widespread area of rapidly building storms, and, thanks to that large turn circle, ran out of bolt holes.
    Failure to note that severe foreground weather was hiding stuff behind it, and thereby running out of boltholes. This problem is rare, and relatively insidious. However, all flight manuals address it in detail.
    Complacency led them to not be continuously working with the radar.

I think the most likely explanation for the encounter is running out of boltholes.

Having hit the weather, what caused the airplane to come apart? In and of itself, turbulence, no matter how extreme, probably isn't the cause. Aircraft structures are both very strong and resilient. However, at altitude, the narrow speed envelope can come into play. Strong up and down drafts can cause airspeed excursions outside the coffin corner***. That happens, and the coffin corner has built in margins. However, a sufficiently strong updraft could cause an irreconcilable problem: can't fight the updraft, because of greatly increased airspeed, yet going with the updraft could, due to temperature effects on Mach number, result in exceeding critical Mach.

This is where a little more speculation comes in. The A330's flight control system would have been trying to keep airspeed within the envelope, and if it was physically unable to do so, might have gone into manual reversion. Given the circumstances, that would likely have made the airplane impossible to fly. (IIRC, pitch control becomes an approximate kind of thing).

Alternately, they may have gone enough beyond maximum mach to reach critical mach, which would have put enough of the horizontal stabilizer into shock stall so that the airplane would have lost the stabilizer's balancing effect, and pitched sharply nose down, making the overspeed problem even worse.****

Either way, or for that matter, any other way, still leaves the fundamental problem largely unfazed: why did AFR447 fly into such severe weather?

Thunderstorms contain as much energy as an atom bomb. As strong as modern airplanes are, going through one can cause excursions beyond controlled flight, leaving pieces scattered over miles of ocean floor, and thousands to grieve.



* Satellite based weather observation is so good that I can't remember running into convective activity about which we had not been previously warned.

** I have flown the A320, which has an essentially identical flight control system. However, that was seven years ago, so my memory may let me down.

*** On descent into Narita yesterday, we ran into substantial turbulence that briefly caused airspeed to increase beyond max Mach, and which the flight control system could not handle without intervention -- briefly leveling until airspeed came back down. Not a big deal, though; just another day at the office.

**** Airplanes designed for supersonic flight move the entire horizontal stabilizer to control pitch for this reason.