PPL-H!

Well, almost exactly one year after my "discovery flight", I passed my PPL-H checkride and became a qualified helicopter pilot. To my pleasure and surprise, my wife - who has never been at all keen on helis and until now has never flown in one - agreed to be my first passenger. So last weekend I did my first helicopter "Bay Tour", departing from Palo Alto towards the coast, with a slight detour to fly over the Montebello Ridge vineyards so she could see them from the air. Then out to San Gregorio, up the coast over Half Moon Bay, over the Golden Gate and back over the city. I've done this numerous times in airplanes, but the view from the heli is much better and of course you're lower too. The flight was a success from all points of view, with a very happy passenger who agreed - despite her attachment to our plane - that this was even better.

One of the hardest parts of flying helis, for me anyway, was to get a really smooth pickup. Hovering seems impossible at first, but after about five hours it's under control and getting better. Autorotations are fun, and if you're used to landing the Pitts then they don't seem too dramatic. Getting them right is tricky and takes some fairly aggressive manouvering, and (in my opinion) you can never practice them enough. But in the end, pickups were the hardest.

Here's the problem. While you're sitting firmly on the ground, the position of the controls isn't affecting anything. Hence, you have no feedback about whether they're in the right position or not. As soon as the skids completely leave the ground, you're flying, even though you're only an inch off the ground, and everything depends on the position of the cyclic and the pedals. A touch too much left cyclic and right pedal, and you're whizzing off to the left while spinning round to the right - not good, especially if you're in a confined area or on soft ground.

Instructors and textbooks say the same thing - lift the collective slowly until you're "light on the skids", correct the control position, then lift further. Easy to say, harder to get a feel for. It's just like learning coordinated turns in a plane - the instructor says, "but surely you can feel it, without even looking at the ball?" And you say (or at least I did), "errr, no, I can't". Now I can feel it, after over 1000 hours and 100+ hours of aerobatics, but it took a while.

So my experience was, you so-so-gently pull up on the collective, waiting to feel the heli come alive as the weight comes off the skids. And then it starts to turn or to move, and in an instant of panic you yank up the collective and you're three feet off the ground and you've zoomed off several feet from your starting point, before you brought things back under control. This is not the way to pass a checkride, something my instructor made very clear to me.

The fix, for me, was an exercise where I deliberately set the cyclic and the pedals way off where they should be, then, as the collective came up, gradually corrected them as I felt things starting to move. After a few times doing that, I'd overcome the panic instinct to yank on the collective, and after that it was just practice. It's very satisfying - now that I can feel what "light on the skids" means - to make small corrections just before the thing leaves the ground, and have it move smoothly and vertically through those first few inches.

The other hard thing, getting close to the checkride, was slope work, where you delberately have the weight partly supported by one skid and partly by the rotor. The amazing videos you see of helicopters touching a steep hillside, yet still flying, are all about this. Again it's all about feel for the controls during the critical moments, and tiny movements of the collective. It's a real feeling of victory when you can hold the heli, half on the ground and half off, then sooo gently let it down onto the other skid. And even better when you can smoothly lift it off again. It takes a lot of practice.

Finally, a couple more pictures from our Bay Tour. There are more on Flickr.

The Blue Cogwheel of Death

Last week I had the great good fortune to be invited to the Computer History Museum's Annual Fellow Awards event. I first visited the Museum when it was in Boston, shortly after it opened there, and I again find myself living close by. The collection is truly amazing - if you haven't been and you find yourself nearby, you should definitely go.

And of all the amazing items, the most outstanding is the Babbage Difference Engine, courtesy of Nathan Myhrvold, who paid the London Science Museum to build him one and then lent it to the Museum. It weighs four tons, and is eight feet high by about twelve feet long (I didn't have a tape measure with me so this may not be accurate). In principle it's extremely simple - repeated addition can be used to calculate any polynomial whose degree does not exceed the number of stages in the machine, and hence to approximate a great many interesting functions. However given that it is built with 18th century technology, the reality is anything but simple. To anyone who admires mechanics and machinery, it is truly a thing of beauty - four tons of gleaming brass and steel and cast iron, thousands of cams, levers, wires and pulleys. To sit down and design it from scratch now would be an achievement; that Babbage did so over two centuries ago is almost beyond belief.

The machine is operated by a large crank handle, which is turned slowly and evenly by a trained operator. Sadly though, when I was there to see it, a short way round the first turn the handle jammed solid. No amount of gentle persuasion would shift it. The docents (guides, for any British readers I may have) told us that this happens occasionally, and when it does, the machine needs to be reset. As you may imagine, this involves a lot more than pressing a button and waiting a couple of minutes. Screws have to be loosened, cams carefully reset to their starting position, and goodness only knows what. In any case it takes way too long to do in front of an audience.

I feel quite honored to have seen the first computer ever built, crash.

Millennium

Wow! I just finished the third volume of Stieg Larsson's Millennium trilogy. What an amazing piece of writing! I really think it's the most absorbing, entrancing fiction I've ever read (and I've read an awful lot of it). Unusually for me, I read it very slowly, savoring every sentence - normally I race through fiction, but with Millennium I wanted to make the most of it, especially since I know there will never, ever be another one.

It was hard to find all the volumes. The first one I found quite by chance, through an Amazon recommendation. Then when I wanted to read the second volume, I found that it isn't available in paperback in the US. I managed to get a "grey import" of the UK edition (which apparently is a different translation). But the third volume isn't available in the UK or the US, and won't be for some time. Luckily, though, it has been available in French (and Spanish) for quite a while, so I bought the French imprint from amazon.fr. I was concerned that it would "feel" different in French, but I needn't have worried - the author's style comes through in exactly the same way in either language. The French translation has a few oddities in it, but it's nicely done and enjoyable to read from a literary point of view. (Although there's a huge blog full of nit-picking criticisms by people with no life, who say they couldn't possibly read a translation where the subjunctive future pluperfect is used incorrectly, and so on - which of course is entirely their loss).

The pivotal character is of course the extraordinary Lisbeth Salander. Obsessive, brilliant, almost pathologically introverted, hacker extraordinaire, gifted with a photographic memory, and completely fascinating. She is pivotal - but not always central. In the first book she is an important, but not central character - everything revolves around Mikael Blomqvist. The second book is really hers, with Blomqvist often absent for a long time. Then in the third book, her circumstances (I won't say more, read it for yourself) keep her out of the main action for nearly the whole book, and Blomqvist is back on center stage. Until the climax of the whole series, the courtroom scene at the end, where she destroys one of her principal enemies (she has plenty) in a single blow.

Sadly, Larsson died shortly after finishing the third volume. It is rumored that the fourth volume was well advanced, but his heirs have said it will never be published. There are quite a few places where you can see loose ends left to be picked up later, and we'll never know, now, what Larsson had in mind - did the awful you-know-who really put the pictures on his computer, or were they planted by one of Salander's hacker friends? I'm sure he was going to tell us. Maybe it's better to have three extraordinary books, and be left panting for more, than to have ten (his original goal) that gradually deteriorate into repitition and mediocrity, which so often happens with long series. (Think how keen Conan Doyle was to be rid of Holmes).

In any case, a front-runner for "best read of a lifetime". Now I just have to wait for the English-subtitled movie versions to appear, and maybe re-read the third volume when it finally appears in English.

Ergonomics and Supermarkets

This morning I stopped in the Safeway next to the hotel I'm staying at, to get a couple of things. The staffed checkouts were quite busy, so against my better judgment I decided to use the self-service checkout for my three items.

I should really know better. With the honorable exception of ATMs - which somehow they got right early on and and which have stayed right ever since - just about ALL of these self-service booths seem to have been expressly designed to be impossible to use successfully without help. Which is why, for example, you will always find airline staff hanging round the self-service machines at airports. (Although they do mostly seem OK now, but for a long time they would always have some trick to catch you out just when you thought you were getting there. For example, the British Airways machines wanted to check the card used to buy the ticket - impossible if you had a company ticket issued through a travel agent. And I NEVER got a Lufthansa machine to work in the days when I flew with them just about every week).

Anyway back to Safeway. To my amazement, it let me scan all three items. As long as I ignored the irritating voiceover telling me about all the other things I could do, it seemed to be going well. Then came time to pay. I slid my card through the debit card reader, keyed my PIN, tapped "confirm", and all seemed well.

Except that the actual checkout screen said "amount paid $0.00". I pressed the help button and the store manager came along. Turns out you FIRST have to tell one screen how you want to pay, and THEN use the separate payment machine. It took several minutes to straighten it all out, made more complicated by the fact that I refused to scan my card again since I'm sure that I would then have ended up paying twice.

Now, how hard would it have been either:

a) to figure out that when you slide your card, you probably want to pay by card, so accept the payment

b) or if that is really too hard, then disable the card reader until you have made a payment choice?

In the end it all ended OK, in that I left the store with the items I wanted and didn't get arrested for shoplifting. But why does it have to be so painful?

Mount Diablo and the Morgan Territory

After nearly ten years in the Bay Area (is it really that long?), there are still spectacular things that we have still to do. This has been a frustrating weekend for flying - my plane is in the shop having a new gadget installed, and my favorite Pitts wasn't flying either for its own reasons. I've flown over Mount Diablo numerous times, so it seemed like a good idea to go and see it close up.

A look at the map showed an interesting road passing east of the mountain, under the flight path that I've taken so many times between Livermore and the practice area. This is very rough terrain, and most of us have decided that in the Pitts, with its brick-like gliding ability (glide ratio about 3.5:1), it's best avoided since there are really no good options if the engine stops. The road is called Morgan Territory Road, and it is truly spectacular.

Livermore stops abruptly crossing I-580, and from there northwards is country as empty and seemingly isolated as the back country east of Paso Robles - which really is isolated! This is under my usual return path into Livermore, and as it often happens, it looks very different when seen from the ground. Soon an easily-missed right turn takes you into Morgan Terrtory Road itself, and shortly afterwards it becomes a single-track road, rare indeed around here. It twists and turns under a canopy of trees, giving occasional glimpses of the main Diablo peak, soon reaching a parking lot and trailhead. We didn't have time for a long walk, but it was a beautiful place.
After a picnic, we continued round the mountain. Eventually we came back into some dull suburbs, though constantly dominated my Mt Diablo. It's a long, slow, twisty road up, climbing 3500feet, with magnificient views south to Livermore and west to the bay. Then, suddenly, you're at the top, and the views are in all directions. Of course I've had the same view many times, but it's different when you have your feet on the ground.

This is definitely one to add to the "favorite roads" list, along with the Nacimiento-Fergusson Road, and the long drive down the San Andreas fault from Hollister to Ojai.

chirari-to (ちらりと)

One of the many things that makes learning languages fascinating is the completely different way that other languages view and express the same thing. Even between similar languages like English and French, this can sometimes result in words that are absolutely impossible to translate without a lot of context, moche for example (probably most simply glossed as "not very nice", but it can be "ugly" and a whole range of "not nice"-like meanings).

With completely unrelated languages like English and Japanese, this happens all the time. Thanks to my teacher, I just came across an especially nice one, chirari-to, written only in hiragana (ちらりと). It's so hard to translate that most Japanese-English dictionaries don't even have it as an entry. If they do, they just give it in one or two fixed phrases like chirarito miru, to glance at.

But in fact, it can be used in made-up phrases and has a stand alone meaning all of its own, which is something like "glancingly". Combined with "to hear", chirarito mimi ni iru, it means "to overhear by chance". My teacher agreed that chirarito nioi o kagu (i.e. with "to smell") could mean "to catch a whiff". She didn't think that chirarito yomu (with "to read") is something people would say, but then I found it on someone's blog (chirari to yonda manga - a manga that I happened to read).

Which makes me wonder how far you can take this. I wonder whether in the right context you could use chirarito korosu, "to kill by chance and without it being really important", as some samurai might say about a peasant he'd beheaded for being in the way on his journey home? Best yet would be chirarito haru, since haru (broadly, "to stretch") is another of those impossible-to-translate words with dozens of meanings depending on the exact context. It's enough to give a translator nightmares.

(Apologies for the romaji, when I tried to type hiragana I got very unexpected results and it was just too hard to do).

Off Airport

The two main reasons for using a helicopter, rather than an airplane, are (a) to land where there is no runway and (b) to hover in place. So, naturally enough, these form part of helicopter training. Tonight we did a bit of both. Both are harder than they look. We went out to a remote area and landed on hilltops and on gravel tracks. After circling round to look for animals, power lines, fences, people, houses and so on, you try to land on a hilltop. Compared to an airport (a) you don't know the altitude, so you have to judge everything by eye (b) it's surrounded by hills and other inconvenient obstacles (c) typically there are trees whose distance from the target you have to judge from afar (d) surfaces look deceptively smooth until you get up close. So when we finally got to a landing hover above our first chosen location, we realised that the grass was eighteen inches high. Probably you COULD land there if someone's life was at stake, but it's too risky for a training exercise - you have no idea what is under the grass until you get the skids on the ground, and there's always the risk of tail-rotor damage.

Off to the next place. We find a gravel track winding around the contours of some hills, and make a couple of approaches to it. But the chosen landing spot looks awful small until you get very close in. It's hard to believe you can get this big helicopter (relatively speaking) into that tiny postage stamp of gravel, surrounded by trees. I confess that as my instructor flew the short final I had visions of our rotor blades thwacking into the adjacent bank (forgot to mention that part). In fact there was plenty of room, or adequate anyway. But then you have to get off again, with said bank directly in front and trees on either side. No problem (if, like my instructor, you have 10,000 hours of heli time) - lift off into a 5 foot hover, 180 degree pedal turn, and swoop back off the way you come. But it takes nerve and experience - which of course is what the training is all about.

We survived all that, and went off to practice high-altitude hovering - OGE is the technical term, short for "out of ground effect", i.e. far enough away from the ground that it doesn't interfere with the down-draft from the rotor, which provides extra lift when close to the ground. It's surprisingly hard to enter a hover smoothly. For a fixed-wing pilot the idea of stopping just doesn't come naturally, so as the airspeed gets down to 40 knots or so it already feels like you're standing still. It takes very careful control of the cyclic and collective to get to zero airspeed without losing control of altitude - either climbing or descending. We were doing this just under a Class B shelf, which made it more important not to gain altitude - as my instructor pointed out rather forcefully when I got to within 100 feet of it.

Then you have to stand still. The ground is a long way away when it comes to judging position to within a few yards, and a 25 knot headwind didn't make it easier. The GPS helps a lot, although you have to remember that a ground speed of 10 knots can be in any direction - the GPS doesn't know which way the heli is pointing.

So after a bit of practice at that, we took advantage of our hover to practice "settling with power" also called "vortex ring state". This is one of the peculiarities of helicopters. If you descend too fast with very low airspeed, the rotor falls into the downward-rushing column of air that it is creating itself - and stops providing any lift. Recovery, as long as you have enough altitude, is similar to stall recovery in an airplane - push the nose down and accelerate out of it. If you don't have enough altitude, you will hit the ground very hard - which is why it's best to practice at altitude (also like stalls).

Then back home. If all goes well, my next flight will be another solo.