Killer Applications

A Tale of Travel - II

June 14, 2002

A Tale of Travel – part 1


It was the best of times, it was the worst of times.


The quote from Charles Dickens seems appropriate because I was in two minds. I was told I should be happy and elated, embarking on a business trip to Europe. Yet I was apprehensive and reticent because I knew it would be stressful, sleepless, work-laden and I would not have any time to sightsee. The silver lining was that I would not bear any cost.


First stop would be Budapest. Budapest is a tale of two cities, Buda and Pest. Separated by the Danube they have two definitively different characters. Buda the original capital of Hungary is the “City on the Hill” while Pest is a flat industrial and commercial center. Today’s Hungary is rearing on to join the European Union, playing catch up to the time lost during several decades of Soviet domination. Of the countries in Eastern Europe, Hungary was the most progressive and suffered the least, due to an evasive form of pseudo communisms created by its leaders. It appeased the Soviets and yet retained some of the economically rewarding free market traits. This creative concoction has been dubbed “Goulash Communism”, after the famous Hungarian stew (mixture of many ingredients), goulash.


My itinerary took me to Detroit (from Phoenix) where we boarded the transatlantic segment (also called flying across the pond). On long distance air trips the most comfortable aircraft is the Boeing 747, which in its latest incarnation (introduced in 1988) is the 747-400. Sadly, the cash starved airline I was flying, does not posess many of these magnificent beasts, and provided us with a McDonnell Douglass DC-10, an aging creaky aircraft, with less than usual niceties. Manufactured in the 1970’s these planes do not look as well put-together, or as graceful as the 747, but they do have a good flying record.


It was the age of wisdom, it was the age of foolishness.


Like most things technological, aircraft has improved in many ways over the years. Fuel consumption, noise, low-flow toilets, entertainment systems, avionics and range comprise the top improvements. Newer aircraft also require less maintenance and are cheaper to operate. Yet one item to totally neglected by aircraft manufacturers seem to be seats. Regardless of the age of the plane, the seats are abominable, notwithstanding all the lip service paid to passenger comfort in airline advertisements. If only they put car seats in airplanes, life would be so much more comfortable.


Contrary to popular belief, older airplanes are no less safe than the modern ones. Old airplanes have to be completely overhauled, refurbished and upgraded, by law, after a certain number of flying hours. There is no evidence that older aircraft, maintained as per specifications, are more accident-prone.


The major American airlines are saddled with large inventories of older aircraft, making average fleet age 10 to 20 years. High operating costs of these make the airlines less than profitable. Also, the major airlines try to serve all the cities, and have to run the hub and spoke scheduling system, which is inefficient, as airplanes spend more time on the ground, compared to the smaller companies operating on a point-to-point schedule. They lament that small agile companies such as Southwest and JetBlue (US) Ryanair and EasyJet (UK) are eating their lunch with cheaper fares, higher profit margins and intense customer loyalty.


Of course, there is no lunch on the US domestic flights any more. Cost cutting seems to focus on eliminating airline food. Airline food of course, has always had the reputation of tasting like hardly edible cardboard. Yet, in my opinion, edible cardboard is infinitely better than nothing but stale cabin air.


“It was the season of Light, it was the season of Darkness.”


Next hop, over the pond, led us to Amsterdam. It got dark soon after takeoff, and then it got light again, as we touched the Arctic Circle, the land of the midnight sun. The sun shone brighter as we descended into the lower latitudes and soon it was late morning. In seven hours, the clock raced ahead from 9pm to 11am.


Back when travel by jet aircraft was invented, people noticed a phenomenon, unknown till then. Crossing time zones rapidly causes a human body to behave strangely. Jet travel led to the discovery of the “body clock” a mechanism by which the human body tells time. When I was it Amsterdam at 11am, my body clock still believed it was 2am (the time in Phoenix). This phenomenon is known commonly as “jet-lag”.


Jet lag is the bane of foreign travel, especially on business trips. Regardless where you jetted in from, you are expected to be bright and sharp at the 8am power meeting. An impossibility, when the body disagrees.


The list of cures for jet lag, sound like quackery and snake oil. First, light is the mechanism that resets body clock. Spending a day in the sun speeds up the synchronization. Second, food seems to have an effect, high protein breakfasts and high carbohydrate dinners are recommended. Third, the experts advise against any consumption of caffeine or alcohol. That is of course, untenable. A kick of caffeine is what makes the 8am meeting attendable, and some alcohol makes it easier to fall asleep at night (when the body is convinced it is 8am). Finally, there is the magic elixir. There is also some evidence that a drug (or rather hormone) called Melatonin is effective in fixing the problem (I swear by it). It supposedly takes one day to set the body clock ahead or back by an hour. I am never allowed such luxury.


“It was the spring of hope, it was the winter of despair.”


Amsterdam’s Schiphol airport has transformed over the past few years from a pretty dowdy place to a sparkling modern terminal. Shopping, Computing, Internet Access, wireless connections, good food, shopping, and a whole lot of amenities make it a nice place to spend a few hours. Soon my connecting flight was ready and we were off to Budapest. The weather was gloomy so there was nothing much to see.


Arriving in Budapest, I found my hotel, a nice new place with large, modern rooms. The first thing on my mind was to reach out and touch the world through the Internet, so I unpacked the trusty laptop and looked for the phone. Could not find it, looked under the bed, in the cabinets, no luck.


The room had no phone. No phone means no Internet access, no email, no news, no weather. Suddenly life as I am used to seemed to stop. I felt claustrophobic. The only remedy was to step out in search of a cyber café.


That night in Budapest, I lay awake, tired but sleepless. I turned on the television and was greeted with the latest breaking story; a Boeing 757 belonging to DHL (a courier service) had bumped into a Tupolev 154 belonging to Bashkirian Airlines. Of course, two metal containers coming together at 500mph each at an altitude of 35,000 feet is not conducive to human life.


Contrary to popular belief, collisions between aircraft is, well, quite impossible.  Yet it happens.


Even if two aircraft are heading on crossing paths, at about the same altitude, at about the same position, the chances of them meeting is mathematically miniscule. Even if they are headed directly at each other, chances of them being at exactly the same altitude, and exactly headed at each other, is negligibly small. Even if one pilot wanted to crash into the other plane, he (or she) would not be able to they are traveling too fast. Try to crash two paper airplanes together, if you do not believe me. Then multiply the difficulty millions of times.


Mid air collision is the basic concept behind the so-called Star Wars missile defense program. Twenty years, billions of dollars, and plenty of hype not withstanding, it still does not work. It is not possible to crash fast moving objects into each other.


Yet it happens.


The two aircraft in the recent tragedy were equipped with “TCAS” or Traffic and Collision Avoidance Systems. TCAS monitors the transponder responses from neighboring aircraft in response to radar signals from the ground. When it hears responses it sends out queries of its own and from the multiple responses it can compute locations (and elevations) of nearby aircraft. The data is displayed on a screen in the cockpit (since collisions do not happen, pilots sometimes ignore this screen). However if two aircraft get too close, an alarm sounds and a voice tells the pilot to ascend or descend. Two nearby TCAS systems communicate with each other, such that the TCAS warning on one plane advises ascending and the other does the opposite.


As is well known by now, the Russian aircraft was contacted by air traffic control, almost at the last minute and told to descend. The Russian TCAS advised ascent and the DHL TCAS advised descent. The Russian pilot wavered and then took the human advise over the computer’s decision. Even then, with two planes descending and converging, the chances of them actually meeting is totally miniscule.


But they did.


[To be continued]


Partha Dasgupta is on the faculty of the Computer Science and Engineering Department at Arizona State University in Tempe. His specializations are in the areas of Operating Systems, Cryptography and Networking. His homepage is at