Apr 072014

Remarkable news from Australia: a U.S. Navy ship* observed an acoustic signal for over two hours that appears to be from two separate “ping” transmitters. This would be consistent with a lost aircraft’s flight data and cockpit voice recorders, both with still operating acoustic transmitters.

This is amazing.

Speaking of pingers, yesterday the ridiculousness on CNN reached new limits. The pingers have batteries that are supposed to last approximately 30 days. The actual duration depends on the age of the battery, its maintenance and storage. And when the battery dies, the process may be a gradual process (i.e., the ping signal weakens but does not necessarily stop immediately.)

None of this prevented CNN from showing a countdown clock, accurate to the second, showing the remaining life of the pinger batteries.

*Actually, a U.S. Navy device towed by an Australian ship.

 Posted by at 12:20 am
Mar 262014

Some details have been released (leaked?) by Inmarsat and the AAIB about their analysis of the flight path of the missing Malaysian airliner. Some details remain frustratingly absent.

Relying on the measured frequency of the signal received from the missing jet, they plotted possible courses of the aircraft and they concluded that only the route that took MH370 to the southern Indian Ocean is consistent with the data. Here are the two critical slides from the annex of their released material:

They are clearly quite confident about the validity of their analysis, and they may be right. Still, there are a few potential issues with which I am not comfortable.

The analysis obviously relies on two key assumptions: first, that the aircraft traveled at a constant speed and second, that its transmitter had good frequency stability. I am not familiar with Inmarsat equipment used on board aircraft, but I do know that a frequency drift of a couple of hundred Hz, over a period of time of several hours and under changing environmental conditions, is not at all unusual [Update (2014/03/28): I now know (thanks, Craig!) that Inmarsat equipment uses an oven-controlled oscillator, with a frequency stability of a few 10 Hz or better over the course of a year, so this is a non-issue] for an oscillator that is running at around 1.6 GHz (which, I believe, is the frequency range used by Inmarsat.)

The analysis also relies on the estimated range at the time of final transmission, which is what was used to generate the infamous “arcs” along which the airplane is expected to be found. Presumably, similar estimated ranges are available for all the intermediate data points. However, this range information was not published in the currently released document. [Update (2014/03/28): Intermediate range arcs were, however, published by the Washington Post on March 21 (thanks again, Craig!).]

It is also unclear to me why the northern route can be excluded, as the top slide shows. If the satellite was stationary with respect to the ground, the northern and southern routes would have identical Doppler signatures. Presumably the difference is due to the fact that the satellite, though geostationary, still moves with respect to the Earth’s surface, e.g., because its orbit is inclined. [Update (2014/03/28): The orbital inclination of the satellite in question is 1.6° (once again, thanks, Craig!)] But this is not explained.

Finally, I am also concerned about the large deviations in the early stages of flight between the predicted and observed values and what it says about the validity of the analysis.

Just to be clear, I do not subscribe to conspiracy theories. I do believe that it may have been premature to exclude the possibility that the aircraft made an emergency landing and remained intact in a remote area not far from the location of its last transponder signal, but I may very well be wrong about this. However, I do think that a little more transparency would be useful.

 Posted by at 8:48 am
Mar 252014

These are the dreaded words no pilot wants to see engraved on his or her tombstone: “Controlled flight into terrain”.

Yet this is precisely what happened when a 737 was flying into Resolute Bay, Nunavut in August 2011, only to miss the runway on approach and collide with terrain instead, killing 12 of the 15 souls on board.

The reasons are aptly summarized in this brief video from the Transportation Safety Board of Canada.

The sad story of this flight reminds me of something I first learned when I was 17 or so, working on my first ever paying software development contract, for Hungary’s equivalent of TSB Canada. I was taught that it is rare, almost unheard of, for an air accident to have a single cause. Most of the time, accidents happen as a result of a chain of mistakes, and if only one link in the chain is missing, the accident would not occur. In this case, the links of the chain included an inadvertent autopilot setting; a compass alignment issue; bad visibility; and breakdown in communications between the two pilots on board. At any time before the final few seconds, the situation was still salvageable, if only the pilots became aware of what was happening. But by the time the ground proximity warning alarm sounded, it was too late.

 Posted by at 8:21 pm
Mar 232014

For the past week or so, CNN has been blabbering about the presumed fact that the pilots of the vanished flight, MH370, programmed a new route into the flight computer at some time between 1:07 and 1:19 AM.

This was, even according to one of their own experts, blatant nonsense. Wherever this information came from, it did not jive with the known facts. Namely that the ACARS system in board would not transmit a yet-to-be-executed flight plan to the ground even if they subscribed to the transmission of navigational data (which they didn’t.) And that the ACARS system on board was not scheduled to make another transmission until 1:37 AM, at which time it was no longer functional.

It became kind of obvious from sporadic comments that this “fact” was nothing but speculation, based on the presumed smooth turn the aircraft executed shortly after the last voice transmission; someone must have concluded that such a smooth turn was done by the flight computer, and thus it had to be entered into the flight computer, presumably after the last (1:07 AM) ACARS transmission.

None of this made any sense to me, and today, CNN confirmed my suspicions: Malaysian authorities assert that no air-to-ground transmission indicated a route change.

In response to this, CNN quickly presented the straight facts. Or they tried, anyway:

But… exactly where did they get the idea from that the last transmission showed normal routing all the way to Beijing? According to their own words, what Malaysian authorities said was that the last transmission did not show a preprogrammed turn. From this, you cannot conclude anything as to what it did show, especially given the fact, reported earlier, that the airline’s ACARS subscription did not cover navigational data in the first place.

Exactly what would it take for CNN to present the facts correctly, just once, without adding their own bits of creative fiction?

Update (2014/03/23): It appears that CNN is blameless at this point. The piece of creative fiction (if that’s what it is) apparently comes directly from Malaysia’s transportation ministry. That does not make it more believable, though, in my opinion.

 Posted by at 3:35 pm
Mar 162014

So many talking heads are speculating so much about the missing Malaysian jetliner… and most of them will be proven wrong, of course.

So let me add my (likely wrong) speculation. It occurred to me this morning, as I was looking at a New York Times article with a wonderfully informative map:

Look at the wonderful double arc that represents the possible locations of the aircraft at the time of its final contact with an Inmarsat satellite. Note how the center part of the arc is omitted, on the presumption that these areas are well covered by military radar.

But wait a minute… is this the same military radar that failed to notice a stray jetliner with no transponder code in real time?

Of course, we know that 6-7 hours after its last confirmed transponder response, the aircraft was still (at least partially) intact, its satellite phone system still functioning and powered. But not necessarily in the air.

The only actual facts that became available from the media are that the airplane was in regular communication with Malaysian ATC until it was handed over to the Vietnamese; that it never made contact with Vietnam ATC; that its transponder failed shortly before last contact, and its ACARS, some time before that; that there was a possible radar contact but which was ignored by the Malaysian military at the time; and that several hours later, its Inmarsat phone was still communicating.

So what if, after all the wild speculation and insinuations about rogue pilots or hijackers on board, taking the plane to Pakistan or ditching it in the southern Indian Ocean, what actually happened was, in fact, an accident? What if there was a progressive failure of the aircraft (e.g., due to an on-board fire or some other emergency) that may explain why systems did not shut down simultaneously? What if the pilots were nonetheless able to make an emergency landing somewhere, and the landing was smooth enough so as to not activate the plane’s emergency locator transmitter?

So I am betting a dollar that the plane will soon be found… in a remote part of southern Vietnam or northwest Malaysia or maybe Thailand. And if I am right, I hope it happens soon enough to rescue passengers who may still be alive.

Of course in all likelihood, I am just as wrong as all the talking heads on TV.

 Posted by at 4:05 pm
Mar 112014

Boeing 777 Ram Air Turbine

So here is the latest speculation from CNN, now that the missing Malaysian jetliner is presumed to have turned around: it may have suffered a massive electrical failure.

Except that the 777 is a fly-by-wire aircraft. That means that if there is no electricity, the airplane just cannot fly.

And precisely because it is a fly-by-wire aircraft, it also has a beefed-up Ram Air Turbine (RAT). It is capable of generating 7.5 kW of electricity, sufficient to power the most essential systems of the aircraft like, well, its flight control systems and, I presume, its transponder and a radio.

But then, how can I expect informed discussion on CNN? Just as I am writing this, they were discussing the next topic: why did passengers not phone anyone using their cellphones.

Because there are no cellular towers over the open sea, stupid. And even over land, when you are flying 10-12 kilometers above the cellular towers at a velocity of nearly 1000 kph… good luck linking up with a tower long enough to get a call through.


 Posted by at 3:03 pm
Jan 042014

This is what my car told me this morning:

Yes, it needed a new battery. It just wouldn’t start.

The irony is that my car is a hybrid. Which means that when you turn the key, it usually just comes to life, like any decent electric motor would. And behind the back seat, there is a 144 V NiMH battery with enough juice to light up my house. But when the outside temperature is low, the engine computer decides on its own that the engine should be cranked like a low-tech gasoline engine… from the 12 V battery, using an ordinary starter motor. And when that happens in the dead of a Canadian winter, with a battery that was last replaced about six years ago…

Thank goodness for Canadian Tire.

The video, by the way, is a scene from Return to Zork, the first multimedia sequel to the classic Zork series of text adventure games from the early 1980s. The graphics may be a tad dated, but the game is still quite good and entertaining… and plays well in DOSBox.

 Posted by at 6:15 pm
Oct 302013

My wife took the #7 bus yesterday on her way home from the Byward Market.

The bus had to take a detour, due to the ongoing construction on Rideau street.

Then it had to take a further detour, perhaps due to the construction, maybe some other reason (an accident?)

When I spoke to her, the bus was standing still on Chapel street, heading in the wrong direction.

Some 20 minutes later, when the bus was already on Laurier, I turned on continuous GPS tracking of her phone. Tracking information was collected roughly every minute.

All in all, it took her approximately 45 minutes to get home from the intersection of Chapel and Wilbrod streets.

According to Google Maps, the distance is 950 meters on foot, and it would have take 12 minutes to get home walking. Unfortunately, she had some heavy bags with her so walking was not really an option. Although, had she known what was about to happen, she could have gotten off the bus at Besserer and Chapel, only a 700 meter walk from home.

Construction season is so much fun.

 Posted by at 11:20 am
Oct 112013

Hungary once had a proud national airline, MALÉV. I once worked for MALÉV, at least indirectly, when I built software simulators to calculate take-off distances and later, CO2 emissions for MALÉV’s fleet of Tu-154 aircraft. Sadly, MALÉV is no more: in early 2012, after the European Union declared that MALÉV received illegal subsidies from the Hungarian government, the airline went bankrupt and was liquidated.

Earlier this year, we saw some encouraging news: a private group of investors were trying to create a new national airline, designed to compete at the high end of the market. Their initial announcements were received with hope by some, with skepticism by others. The airline hit some bureaucratic hurdles as it was trying to get its newly leased small fleet of used 737s off the ground; their inaugural flights were repeatedly postponed.

But now, we learn that a prospective investor from the Middle East withdraw from the project, and as a result, the airline is unable to pay the salaries of its 70-odd employees for the month of September. In other words, for all practical intents and purposes, it is bankrupt. And this is probably a world first: a national airline that goes bankrupt without ever getting a single scheduled flight off the tarmac.

 Posted by at 11:37 am
Sep 172013

Lest we forget, this is a really big deal not just for Bombardier but also for Canada: the successful first test flight of Bombardier’s new C-series jet.

This new jet puts Bombardier in direct competition with the two giants, Boeing and Airbus.

Not bad from a country of less than 34 million people.

 Posted by at 3:54 pm
Jul 272013

I was watching RDI’s coverage of the memorial ceremony that was taking place last hour in Lac-Mégantic, the location of the horrific derailment a few weeks ago that claimed so many lives.

I was impressed by the size and beauty of Sainte-Agnés church where the mass was taking place, so I went to Google to find out more.

It was, of course, unsurprisingly difficult to find background material, as search results were dominated by recent articles about the disaster. But, after wading through some directory entries and such, I came across a true gem: the story of the “Electrical Priest”, Father Joseph-Eugene Choquette.

When he was not attending to his priestly duties, Father Choquette spent a fair bit of his time as an amateur scientist. And what an amateur he was!

Bringing a player piano to his church (and drawing the ire of his parishioners when they found out that it was not their vicar who was in secret a talented musician) was just one of his many pranks (perhaps an unintended one in this case). Apparently, he also liked to play with electricity, to the extent that visitors to his house were often shocked by a jolt of current when they touched a doorknob or sat down in a booby-trapped chair.

But Father Choquette was interested in more than mere pranks. He also experimented with telephony and electric lighting. Having installed a personal lighting system (powered by a dynamo hooked up to a windmill) that proved to be a success, he proceeded with a more ambitious plan: a generating plant to light the whole town. He remained directly involved with this project until his death; parishioners often found their vicar strapped to a pole 25 feet in the air, working on a faulty transformer.

When Father Choquette died, he left much of his equipment and collections to the Sherbrook and Saint-Hyacinthe Seminaries and to the Convent and College of Megantic. That was nearly a century ago. I wonder if any of his belongings still survive somewhere.

 Posted by at 1:10 pm
Feb 212013

The news is that Dennis Tito, the first ever space tourist to go to the International Space Station, is planning a privately financed manned flyby mission to Mars in 2018.

I don’t know how feasible it is. I actually have doubts that they will succeed. And the scientific value of such a mission would likely be negligible.

Even so… I dearly hope that they succeed. And if they asked me to go, I’d sign up without hesitation, despite the prospect of spending 500 days with another human being locked up in a tiny capsule, despite the significant probability that we won’t make it back alive.

It is okay to think about the economics, technical feasibility, and scientific value of a space mission, but all too often these days, we forget that other thing: inspiration. Sometimes, that’s worth a great deal. A generation of Soviet scientists and engineers inspired by Sputnik or the flight of Gagarin, and a generation of American scientists and engineers inspired by Apollo and Armstrong’s “one small step” can bear witness of this.

 Posted by at 7:01 pm
Feb 092013

Kafka was a Jew. No, I am not trying to engage in anti-Semitic racial stereotypes. It’s just that this is the only way I can make sense of the Kafkaesque event that happened to an Israeli student in Tel Aviv the other day.

Namely that city workers appeared next to her legally parked vehicle, painted disabled parking signage under her car, and then had the car towed.

And when she complained, they called her a liar. Fortunately, the building across the street had security cameras that recorded everything. If only such cameras had been commonplace in Kafka’s time.

 Posted by at 7:44 pm
Jan 312013

I arrived back from Dallas late last night, after an uneventful flight.

While in Dallas, I decided to re-visit the site of Kennedy’s assassination. I had a very good reason to do so: I wanted to photograph the actual school book depository this time.

You know, when you stand on that corner, there is a very prominent red building that looks just like the place: it’s on the corner, it’s red brick, it even has a museum store at its ground floor. Nonetheless, it’s not the building you are looking for. 501 Elm Street is not the former school book depository; it is called the Dal-Tex Building, and except for some conspiracy theories, it has nothing to do with Kennedy’s murder.

No, the right building looks a lot more inconspicuous from street level, hidden by some large trees.

The place where I was standing was in fact the very spot where Kennedy was hit. Or rather, the sidewalk nearest to the spot; I didn’t think it would be a good idea to try to stand in the middle of a traffic lane. In any case, while a small white X does mark the spot on the asphalt, there is an actual plaque next to the sidewalk that is a tad more informative.


While I was walking towards the Kennedy site, I saw some strange buildings. In fact, I noticed them the previous day already, but as I was trying to hide from the occasional squalls of rain, I took no pictures then. Amidst well maintained office towers, sparkling clean streets and whatnot, I was confronted by the sight of several entire office towers that were empty and abandoned.

Weird. Is this a sign of a bad economy hitting Dallas, or just the normal fate of office buildings past their prime, waiting for orderly demolition?

And on my way back to my hotel, I saw something that made me laugh real hard. Wednesday was a cold day by Dallas standards, only about +10 degrees Centigrade, and a strong wind on top of that. The few people who braved the sidewalks looked like they were dressed for an arctic expedition. (I was just wearing an ordinary man’s jacket. I wonder what they thought of my attire.) So I was walking down this street and suddenly, I came across this bunch of flying rats, I mean city pigeons, huddling on a grating embedded in the sidewalk, which was presumably venting warm air.

A pity that there were no stray cats nearby.

Anyhow, my talks delivered, my meetings done, I was ready to fly back to Ottawa, which I did in due order, arriving home at the not altogether ungodly hour of 11 PM, allowing me to enjoy a good night’s sleep in my own bed for a change.

 Posted by at 9:56 pm
Jan 292013

Travel demons were out to get me yesterday. First, my flight from Ottawa to Chicago was canceled and I was rebooked on a later flight. (At least I did get to Dallas eventually.) Next, the Dallas Sheraton was overbooked for whatever reason (maintenance, they say) and instead of being able to go to bed (finally) at 2 AM, I was shuffled over to the Hyatt. (At least it was something nearby, not all the way across town in Fort Worth.) Third, the room the Hyatt first assigned to me turned out to have been already occupied by a very morose person who quite understandably did not take it kindly that someone was trying to barge in on him in the middle of the night. (At least his door was securely locked, so I did not actually manage to barge in.) Fourth, the room I finally ended up in was rather noisy, in part because of a neighbor listening to a very loud television at 4 AM, in part because of the trains right under my window. (At least I was on a high floor.)

Yet if things didn’t turn out this way, I would not have woken up to a very unexpected, deeply historic sight through my window.

Yes, the infamous Book Depository building. The very place from which Lee Harvey Oswald supposedly fired his fatal bullet, when I was just a few months old.


 Posted by at 5:59 pm
Jan 292013

I may be sitting on board a decidedly 20th century airplane but I suddenly feel like I arrived in the 21st at last… being able to check my email and post to my blog from 30,000 feet.


 Posted by at 12:18 am
Dec 212012

My other extracurricular activity today involved a shovel.

That is because we ended up with quite a few inches of wet, heavy snow, courtesy of this year’s first major winter storm. And I like to shovel the snow off my balcony, rather than let it rot the deck and leak in through our balcony door.

At least I didn’t have to go anywhere. Those who did had a hard time on the roads. A poor double-decker actually ended up in the ditch this morning.

But hey, we’re all still alive! Contrary to certain Mayan prophecies, the world did not come to an end. The daily struggle of our existence continues.

 Posted by at 10:31 pm
Dec 112012

ios6mapsI admit I, too, joined the happy chorus of Android phone owners ridiculing Apple’s decision to drop Google Maps in favor of a half-baked homegrown Apple solution in iOS6.

However, those bad maps are no joke. Apparently in Australia, several people found themselves in life-threatening situations when Apple’s mapping program guided them to a snake-infested desert instead of a tourist destination.

 Posted by at 9:14 pm