Air stories

Air stories moved to www.plasticpilot.net

2007-08-28T22:51:00.001+02:00

Dear reader,

given its succes, and to make things easier to manage, but also easier to read for you, this blog has been moved to www.plasticpilot.net

I'm sorry if this cause any inconvenience to you, but hope to see you there soon !

PlasticPilot

High-end aviation - Privatair flying luxury

2007-08-27T21:00:00.001+02:00

One particular branch of aviation has always attracted lots of interest and fantasies, because it's both discreet, and reserved to a happy few: private jets and business jets. Anyone heard some stories about golden lavatories in these flying palaces... Well, this is partly true.

To illustrate this, I chose to talk about a particular company: Privatair (please note that I'm in no way affiliated to Privatair, and pictures in this post come from their website). This company is amongst the ones offering private taxi, together with JetAviation and a few others.

Such companies offer taxi services for businesses or wealthy individuals. If you can afford it, this kind of services has lots of advantages, including:

1) You define the schedule
2) You go through quick customs / security / immigration checks in the airport's VIP zones
3) A personal limo will take you to your plane, avoiding all check-in and boarding burdens
4) Aircraft performance permitting, they fly you to any small airport close to your destination
5) Personnal service on board is, let's say, above standard

Now, let's have a look and unveil some of the luxurious interiors that made the reputation of such way of travel... As mentioned before, Privatair operates quite a wide fleet, so I selected some pictures from their website for different size of aircraft.

Start with a LearJet 60, for a handful of passengers.

As you can see, the interior is tiny, but quite cosy... I hope you noticed the flower and the bottle of champagne on the table.

If your clan is a bit bigger, you can then opt for a Global 5000, which offers more room.

I personally slept in some hotel room that were not so well equipped !

Last but not least, if you're travelling far away with all your (extended) family, why not renting a 767 ? Yes, you read correctly, a 767, even one with extended range...

At this point the question are: who uses that, and does it really make sense ? The first answer is quite obvious: there is a market for such companies. They flew for years, and in some busy airports, they can represent up to 30% of the traffic !

Apart from a few very wealthy and inactive people, most of the customers are businessmen moving from one part of the world to the other. In an economy where salaries of top managers can be expressed in thousands of dollars a day, the shareholders probably don't want them to be waiting inactively, or spending hours in transfers and connecting flight, don't they ?

And video conferencing or e-mail can't solve all problems, there are still cases where a good old handshake is needed. And in such cases, planes just become time saving machines...

To finish with an little story, you should know that even working at the airport, and having good friends working there, it's just IMPOSSIBLE to get on board of such planes for a short visit... secrecy's one of the first values of such companies...

About air disasters and investigation reports

2007-08-26T12:14:00.000+02:00

One of the lessons I learned from the creation of this blog is that a large interest for crashes and air disasters exist amongst readership. As I already mentioned, the work of the investigators is not easy, very time consuming, and base on many sources of information (testimonies when available, black-boxes, wreckage analysis, expert works, ...).

These reports are the only valid pieces of information when discussing air disasters. Any other published information is based only on speculation, stolen and / or distorted information. Reports are quite complex to read and understand, but they are nevertheless available to public.

So as to familiarize you with such reports, here are some links to the reports published after accidents that attracted lot of media attention. Please feel free to comment if you have any question or remark.

Concorde crash in Gonesse, 25th of July 2000 - French BEA
Ueberlingen mid-air collision, 1st of July 2002 - German DFS
TWA800 in-flight breaku p, 17th of July 1996 - US NTSB

I did not select these accidents because they all occurred in July, but because they represent different type of accidents, and have been produced by different investigation agencies. Thus they give an overview of what an investigation report is.

A tribute to Commander Caroline Aigle

2007-08-26T12:02:00.001+02:00

I've never been a fan of military aviation, but today I want to express all my sympathy and compassion to the family, friends, and colleagues of French Pilot, Commander Caroline Aigle, who died on Tuesday, the 21st of August 2007, from a rapidly evolving form of cancer, at age 32.

Commander Caroline Aigle was one of the people who helped modern aviation to progress, as she was the first female fighter pilot in the French Air Force. She got her chase pilot license in 1999.

One of the reasons for which I admire them is that she also combined her very demanding military career with being mother of two children. This certainly deserves high respect from all of us.

China Airlines Boeing 737 catches fire in Japan - About certification standards

2007-08-20T20:02:00.000+02:00

Today, a Boein 737 from China Airlines caught fire on japanese airport in Okinawa, after landing. All passengers were able to leave the plane, only three of them have been lightly hurt. The following YouTube video shows some images from this fire

As always, the media said it was a miracle that no one have been killed... What they forgot to mention is that the certification standards include evacuation rules. The rule says that the plane must be evacuated by a full load of passengers using only half of the exits within 90 seconds.

This has to be demonstrated by the manufacturers. Obviously the demonstration takes place with calm people, but it's in the dark, with their seat belts fastened at the beginning. The following video has been taken during the official demonstration for the Airbus 380. They evacuated through 8 of the 16 emergeny slides.

You also might object that there are no obese people amongst the "passengers" this day...

Nevertheless, this requirement demonstrated its usefuleness with this chinese Boeing, and it is not the first time... In 2003, an Airbus 340 with 309 passengers did crash-land in Toronto. All of the passengers have been evacuated within 90 seconds, and beleive me they were all but trained ! On top of that, the aircraft was also under fire, so half of the exits were useable, exactly as by the rule !

So, friends journalits, it is certainly a good thing that all those people could evacuate the plane safely, but this is because of WORK, not because of a miracle !

Flying through hurricane (post with speedlinks)

2007-08-20T19:07:00.000+02:00

As hurricane Dean is starting the season, let's talk a bit about hurricanes, their impact on traffic, and planes flying through them. Yes, you read correctly, some planes do fly through hurricanes. In fact, the US National Oceanic and Atmospheric Organisation (NOAA) has planes flying through each of them !

To remain simple, a hurricane is a zone of very low pressure, arround which strong winds are setting up. Wind speeds can be far above the maximum values admitted by airlines for their operations. However, the wind is not a big problem compared to the windhsears, or changes of wind, which cause severe turbulence. Shortly said, commercial traffic does not fly through them, nor close to them.

So who does, and why ? There are two reasons for flying through a hurricane: research, and forecasting. In fact, getting data from the site directly helps forecasters to do a much better job than with sattelite observation only, and for this purpose, crews are flying through each and every hurricane, as I mentionned before.

Now, some speedlinks for those of you how are more interested in this topic:
Geoff Fox report on his "passenger flight" through a hurricane
An excellent video from "science daily" from crews actually flying throug hurricanes
Paper about hurricanes from NOAA

And obvioisly, if any of you has more details to share, any comment is welcome.

Greenpeace protesters arround Heathrow - UPDATE

2007-08-19T22:13:00.000+02:00

According to the latest BBC report on the Greenpeace protesters around Heathrow, some minor issues occured between some protesters and the police. This apparently occured when the protesters invaded the BAA offices.

Given the kind of charges against some of the arrested ones, I doubt they came because of the climate (BBC report extract):

"Six people have been arrested during the day - two for assault on a police officer, one for carrying Class A drugs, one for criminal damage, one for going equipped to cause criminal damage, and one for failing to give a name and address after anti-social behaviour."

Again, I just hope that this situation will not evolve to something worse, which would be a loss for anyone. Anything possible must be done to avoid any further degradation in this very complex and tense context.

The black-box is orange

2007-08-17T18:18:00.001+02:00

Each time an aviation accident occurs, the media talk about the black box. This is always presented as kind of a magic tool to solve all issues with the investigation. As I already mentionned in previous posts about the TAM crash in Sao Paolo and others, life is not so easy, and I'd like to unveil some of the black-box mistery with this post.

First of all, there are two black-boxes, not one. The first one is the "Cockpit Voide Recorder", and its name is quite self explanatory. It just records all voice communication, as well as cockpit noises. It can help to explain the human factor part of an accident.

The second one is the "Flight Data Recorder", or more recently, "Digital Flight Data Recorder", or DFDR. This one records several parameters, including but not limited to:
1) Air parameters (speed, altitude, ...)
2) Aircraft configuration (flaps position, gear position, control column inputs, control surfaces position)
3) Engine parameters (power, pressures, temperatures, ...)

Depending the type of operation and the number of seats of the aircraft, it can be mandatory or not to have CVR, FDR, or both. On modern airliners, there are also technical recorders, called "Quick Access Recorder", or QAR, which are used by maintenance teams to monitor the technical status of the aircraft.

If you want to know more about FDRs, the french incident investigation burea produced a very good report about them, including details of their functionning, regulations, and some pictures.

Oh, and by the way, the black-boxes are orange, so as to be easier to locate for rescue / investigation teams. They are in protected cases, supposed to resist a crash, but it frequently happens that they get damaged. This was particularly true with the magnetic tape ones, where the tape tended to melt, or to be damaged by sea water.

It is also quite frequent to not have the very last seconds of recordings, because of communication failures between the aircraft and the recorder, in case the aircraft is broken up, or if electrical cables are damaged by overloads.

The analysis and transcription of black-box contents can be done only be certified and assermented officers.

To close this post, here is a link to the French air incident investigation bureau website, listing some other equivalent organisations. From here you can find many investigation reports. And please remind that these reports are the only one holding established facts. All the rest is journalist work as its best.

Greenpeace protesters arround Heathrow

2007-08-14T22:38:00.000+02:00

The media are quite active these days about the so-called "Climate camp" that Greenpeace set-up close to Heathrow. The purpose of this demonstration is to make people aware of the impact of aviation on the environment, as well as to fight against airport extension.

As I'm part of this industry, I guess I'm probably not exactly objective. The BBC made an excellent paper online, interviewing both Greenpeace and the BAA (British Airport Authority). I don't want to enter in the ecological debate here. As I mentionned, I'm not exactly objective, and I don't know the subject well enough to discuss it as seriously as needed.

My only wish regarding this demonstration is that it won't impact the Heathrow operation, especially not for security reasons. Greenpeace made clear that it is not their objective, and I beleive they are sincere.

Nevertheless, each time few hundreds of people do gather, some unlawful interference can occur. If some ultra-activists infiltrate the pacifist demonstration, the whole thing could turn into a riot, which would be bad for both Heathrow, Greenpeace, and the police, which is also persent in force.

I personally saw this kind of changes in a demonstration because of a few people joining it only to create some trouble. It was during the G8 gathering in Evian, close to Geneva. During the whole day, the demonstration in Geneva were quiet and peaceful, but in the evening some black-block activists mixed with the pacifists. The center of the city has been literally destroyed. Not any single shop window was intact after that.

It was hard for the police to identify the activists as they were mixed with pacific demonstrators. The result was a destroyed city, the pacific demonstration and its message were forgotten because of the riots. No winners in this.

So yes, I hope the Heathrow demonstration will remain pacific and safe to the airport operations, and that a healthy dialogue will start between ecologists and the industry.

Philipe Vignon to leave EasyJet Switzerland by october

2007-08-12T20:35:00.000+02:00

The commercial director of EasyJet Switzerland, Philippe Vignon, announced today on the swiss tv show "mise au point" that he will leave EasyJet by october 2007. The interview is in french only, and was about the enviromental impact of airlines, and potential new european taxes. M. Vignon gave clear and smart answers, and in the end, when the journalist asked him if he would still say the same things in ten years, his answer was something like "In principle yes, but I won't work for EasyJet anymore."

Even the journalist was surprised ! Philippe Vignon then explained that he will leave the company by mid-october.

Philippe Vignon has been part of EasyJet Switzerland from its very beginning, approximately ten years ago. He became publicly known, and became quite a reference for swiss-french media about aviation and EasyJet.

He appeared periodically on TV in the news, and even in a pseudo-trial, where he defended the company in a case of problems with mass reservation.

Security breach in Nice airport - Safety and security illustrated

2007-08-11T20:44:00.001+02:00

On a very recent flight out of Nice airport, on the french riviera, I could observe a security breach. I report this story here to illustrate the way security and safety are dealt with in air-transport industry, and that even the stronger system is only as strong as its weakest element.

I don't know anything about how security is handled in Nice, but I've quite an idea how important access control is, particularly regarding access of passengers to planes. The security system is supposed to prevent any unauthorized access to planes or airside areas. As any system, it is made of equipments (doors, locks, badge readers, ...), procedures (who is allowed to open, what to monitor, close behind yourself, ...) and humans (staff, crews, ...).

This is often depicted as a triangle, and each possible risk relates to one of the angles, and is mitigated by one or both of the others. Typically, there are special procedures to cover an equipment failure, humans are monitoring the automatics in the equipment, and so on...

Now that we described the basic approach, let me tell you what I saw today while waiting for boarding. An airline crew was going to its plane via the waiting hall. For an unclear reason, they were not accompanied by any groud staff (procedure ?). Apparently the captain knew how to unlock the gate.

One of the flight attendant opened the second gate as the rest of the crew were going thourgh the first one. The captain probably did not saw that the second gate has been opened, but when the whole crew continued on its way to the airplane, this second gate remained open.

The abnormal thing here is that the flight attendant who opened the second gate did not closed it (human), and no-one crosschecked it (procedure / human). This gate remained open for approximately 45 minutes. There is an equipment question here, as there could be an alarm or a limit to the time a non-staffed gate can be open.

As a matter of fact, this gate was open without being staffed nor monitored for about 45 minutes, until I mentionned it to the boarding agent of my own flight when I did get on.

The question is then "how to make the system better, without preventing any business activity, and at affordable price ?". This is a very important question in the security and safety domains. Not leaving crews getting to their planes unaccompanied ? Not sure the airport can afford the necessary staff... Ring an alarm if a gate is opened without being staffed ? This could lead to tons of wrong alarms, and the equipment cost could be quite high. Insist on security in crews / staff recurent training ? Probably a good solution...

Cockpit recording from TAM Airbus crashed in Sao Paulo Congonhas

2007-08-03T22:18:00.001+02:00

The media have been buzzish over the last days, as a transcript from the Cockpit Voice Recorder (CVR) from the TAM airbus 320 that did crash in Sao-Paulo Congonhas has been made public. Apparently it has been read to a congressional commision in Brasil, which from my point of view does not mean public...

Personally, I deeply regret it, for various reasons. At first, the source of this document is unclear. Is it officially released from the investigation team ? I don't think so, such teams tend to work very privately until the report is finalised.

Is it from "a source close to the investigators", as journalists often say when they get stolen information ? The source is not know yet, but the transcript is already published on several websites, with various comments, interpretations, and even some conclusions !

This is exactly the other bad thing I see in having such things published at this stage. This recording is only one piece of the huge set of information that will contribute to the investigations. One can not draw conclusions only on that.

Secondly, even experts will probably argue for months on the exact meaning and content of the recordings. Getting a proper understanding and conclusions on base of a simple transcript is certainly well beyond the capabilities of amateur bloggers (me included) and journalists.

So please, once again, leave the investigation team doing their job in peace. We will discuss later on, when the official report will become public. Anything in between is only speculations.

One important button...

2007-08-02T19:34:00.000+02:00

Any modern airliner cockpit is full of buttons, even if the recent tendendy is to simplify them as possible. Each of this button has a special purpose, and some are more important than others, depending of the flight...

There is one however which I find particularly interesting, if not fun. As you know, pets travelling by air are flying in a special compartment, known as the "Animal Bay". This is a special cargo compartment, pressurized, with other particular equipment...

On the British Aerospace AvroLiner, also known as Jumbolino, the heating system of the animal bay is directly controlled from the cockpit, by a push button hidden behind the co-pilot's control colums (look at the inset on this picture).

Hopefully, the checklists are are making its use standard, otherwise airlines would regularly hand puppies back totally frozen, as the outsite air temperature at jet cruise altitude is typically in the -50°C range !

I will certainly later on publish a post on all the gadgets and gizmos found in a cockpit, but this one is so particular that it deserved its own post, don't you think so ?

How safe are low-cost airlines ?

2007-07-23T15:54:00.000+02:00

The new model
When easyJet started operating years ago, it raised tons of questions amongst the potential customers. How can they be so cheap ? Will they survive the market ? Will the other survive the market ? Are they on time ?... but the main one certainly was "Are they as safe as a classical company ?"

The answer to this one is definetly yes. They certainly had some incidents, but no crash for the time being. Ryanair also has a virginal crash record for the time being.

The low cost airline is sustained by three pillars:

1) Modern fleet and single type of aircraft
2) Reduced services to passengers
3) High added value at minimal cost

Let's go through them all...

Fleet management
At initial startup, easyJet was operating with boeing 737's only, and now they operate a fleet made of Airbus 319's only. There are multiple advantages to a single type fleet. First, you need less pilots. In a classical company operating many type of aircrafts, you need reserve pilots for each and every types. In a single type fleet, you need reserve pilots only for one type, so you can operate the same number of aircrafts with less pilots, and then you can offer them very attractive salaries.

It is not unusual to have slightly higher salaries by low-costs companies than in classical ones for flight crew (pilots). Ground handling crew is another story...

The same applies to maintenance spare parts and mechanics. Airplane mechanics are licensed for a certain number of aicraft types, but not all. So operating a single type of aircraft makes the maintenance less complex to manage, and you need spare parts for this single type only.

The drawback of the single type fleet is the reduction of possible operations. Classical companies have various types for various operations (short flight, trans-oceanic, ...). So the low-costs as we know them from the last years will not operate trans-oceanic flight.

Reduced service to passengers
The most widely known reduction in services offered to passengers on low-cost airlines is the fact that you have to pay for your sandwich / croissant / coffee if you want some. But this is by far not the sole reduction.

On low-cost airlines, you have no customers desk. Some of them are even no longer accepting ticket-ordering by phone, but only over the internet.

Bookings can usually not be modified, or at very high prices. And one of the most important thing making a low cost easier and cheaper to operate is the absence of alliances with other companies. When you travel with a classical company and that the flight is cancelled, the company will try to put you on a flight from a different company, or a later flight. Can you imagine the kind of commercial agreement and operational issues raised by such a possiblity ? A low-cost company will never offer that. Your flight is cancelled ? Take the next one, or buy a new ticket by a concurent.

Welcome to Paris Beauvais airport
An other way of reducing passenger service is to land in less expensive airports, which means a bit farther away, but also sometimes quicker to go through. The transfer to terminal / customs / immigration process in Luton is much shorter than in Heathrow, especially if you land just after a 747 of Chinese people.

The risk with this strategy of smaller airports it to fall in extreme cases. From my point of view, it's ok to say that Gatwick is an airport in London. Saying the same about Luton is already ... different. The one hour bus trip is quite long, especially if the previous flight did last for 1h15 !

The extreme example of this is a company selling tickets to Paris Beauvais airport. For those of you not knowing where Beauvais is, 66 kilometers north of Paris. The bus transfer lasts for 90 minutes when traffic is ok. As a comparison, Luton is "only" 45 kilometers north of London.

easyMoney

Every added value is importan for a low-cost company, especially if it is for free. This is why easyJet recently introduced the "Speedy Boarder" offer. For an additional 2.5 english pounds, you obtain the possibility to board before any other passenger. So the cost for the company is a slight change in the website, and an adapted boarding procedure. Virtually no cost.

Knowing that the average benefit per passenger and per leg is 2 english pounds, any person paying for speedy boarding will bring the company double benefit ! How easy is that ?

No crash allowed
Losing a plane in a crash is always a human tragedy at first. No one discusses that. But it also has financial and economical impact on the airline. Many classical airlines, including the most prestigious ones (AirFrance, Swissair, United, Lufthansa...) lost planes. They all survived this tragedy, with more or less consequences.

No low-cost company could survive a crash. This is because media and most potential customers will react to such an event by thinking "Huh. They're low-cost, so they're unsafe, that's why they had this crash".

Despite being totally wrong, this would be the natural way of thinking of most people. Because of this, a low-cost airline can not "afford" an accident, and thus they invest a lot in flight safety.

No evolution
Some older airlines tried to go low-cost, or to have a low-cost subsidiary, but this is probably not possible. First the airline company will suffer from it, and customers would become unclear if the company is low-cost or not.

Secondly, such a mixed company would need the classical infrastructure, so no cost reduction can be expected here.

A tribute to Captain Hans Georg Schmid

2007-07-23T14:47:00.000+02:00

The swiss pilot Hans Georg Schmid got killed today, in the crash of its experimental aircraft after take-off from Basel (LFSB), on a flight to Oshkosh (KOSH). This was an attempt to re-create part of the original Atlantic Ocean crossing by Charles Lindbergh in 1927.

Hans Georg Schmid used to work as an airline captain for swissair, but he also held several aviation speed records, including speed around the world. More information about him on his website.

He was a major supporter and actor of all flying activities, and his death is an enormous loss for all the community.

All my thougts go to his familly and relatives on this sad day.

PS: once again, only investigation report will contain reliable facts, all what media will report in betwee will be speculation only, disregard it.

Airbus 320 crash in Sao Paulo Congonhas

2007-07-18T14:30:00.000+02:00

When I heard about the crash of the TAM Airbus 320 this morning in Sao Paulo, my first thoughts were for the victims, their families, and then to the rescue and support staff.

Then, I wanted to issue kind of a warning via this blog. After each air disaster, the media get frenzy with information they get from anyone and by any way. Given the emotional and mediatic impact of such a crash, but also due to its possible economical impacts, a nasty game could (pessimistic people would say will) start.

On one hand, the airline, on the other hand, the aircraft manufacturer. Most of time they co-operate in good state of mind, but in case of an accident, they can suddenly become the worst ennemies, to avoid being designated as responsible. Under some circumstances, airport authority and air taffic control authorities could be involved, but it seems it is not the case here.

On top of that come the media, wanting to make the best possible coverage of the event, in terms of attracting audience. Not to report things as close as possible to the truth. So please be careful when reading or seeing reports in the media. Keep the following things in mind:

1) The exact circumstances will be determined by the investigation team, and this process will last for months, if not years.

2) All actors will try to minimize their potential responsibilities, especially in terms what the general audience thinks of this accident. A bad public reputation can kill an airline, even quicker than legal action. Thus airline representatives will do all what they can to protect their image.

3) Media will report opinion of anyone with even the slightiest connection to this business, from the tower controller to the man getting the trolleys back from the parking lot to the terminal.

4) Some insiders will say things like "With that weather / in those conditions, I would have ... / They should have done this or that". Two remarks regarding this kind of comments. First, the persons talking this way were not present (only the crew was), so they don't know the conditions to the detail. Secondly, we are always smarter after the incident, aren't we ?

So once again, our thoughts at this stage must go to the victims and their families. Let the investigation team do its jobs. I will certainly re-post about this incident when the report will be published. Anything in between would be speculation only.

Pilot - Co-pilot

2007-07-14T20:53:00.000+02:00

The presence of two pilots in a crew is one of the key points to airline safety. Technically speaking, any modern airliner could be flown by a 6 years old, given all the automatics work good.

A common joke says that three things are needed to fly a plane: a computer, a pilot and a dog. The computer to fly the plane, the pilot to feed the dog, and the dog to bite the pilot if he tries to touch the controls.

The crew operates according to the airline standards, and includes a captain and a co-pilot. This distinction only defines who is holding the final autority. There is a second distinction which defines the operational roles of each: pilot flying and pilot non-flying. This is normally defned before each leg, and they normally change for each leg.

The principle is simple: the pilot flying manages to keep the plane in a correct attitude, and to fly it, or manage the auto-pilot. The pilot non flying manages navigation, communication, and monitors the pilot flying.

This split of tasks is something like tactics (pilot flying) and strategy (pilot non flying). One is managing short term, while the other is working on a longer term. This has proven to be a very efficient way to have a crew of two reaching very good safety.

A crash years ago involved a crew having problems with the flight computer, who did not behaved as expected. The normal way to work it out would have been to have the pilot flying to manually fly the aircraft while the pilot non flying would manage the computer problem.

In that case, both pilot and copilot started working on the computer, so no one was flying the plane. This was shortly after take-off, and the plane crashed after flying a barrel.

One other critical issue with the non flying pilot monitoring the flying pilot is that they must have a quite similar experience. In an unbalanced crew, there is a risk that the flying pilot would not listen to remarks from the non flying pilot.

So there are crew of two not because the task can not be managed by one, but to introduce redundancy, and because co-operation, when well defined, makes 1 + 1 greater than 2.

Fuel dumping

2007-07-09T22:17:00.000+02:00

I promise I don't start a series, but as my previous post was already about dumping things, this post was quite natural as the next step. It is also motivated by a very recent case.

Each plane has some limitations in terms of weight for various phases of flight, and in this case what is of interest is the maximum take-off weight, and the maximum landing weight.

The maximum take-off weight is obviously limited by some structural constraints and by the power available. The maximum landing weight is also limited by strength of the aicraft fuselage, and of the dampers, and for long-range aicrafts, the maximum take-off weight can be higher than the maximum landing weight. Keep cool, I did not say that a plane landing with a weight higher than its maximum landing weight would explode or be destroyed, but it would need a serious inspection before going back in operation.

Under normal circumstances, a plane taking-off with a weight over its maximal landing weight will land within limits, as most of the fuel will be burnt in flight, making the plane weight below the maximum landing weight.

Nevertheless, if such a plane has to land earlier than expected for any reason, one option to make it light enough is to dump part of the fuel within the atmosphere before landing. All planes facing such possibility have to be equipped with proper jettisoning devices.

Now, what about our ecological friends ? Given the speed and altitude at which fuel will be "sprayed", all of it will remain in the atmosphere, as the droplets are so small that they are maintained in the air by local airflows.

But let's do some calculations, based on the particular case I mentionned in the introduction. This particular plane dumped 60 tons of fuel between Geneva and Dijon. This looks to be a lot. To make the computation easier, let's assume that fuel has a density of 0.7, which is not that wrong. This means that this plane did dump about 86 cubic meters of fuel. Still seems a lot ?

This dumping took place between Geneva and Dijon, so over a distance of 75 nautical miles, equivalent to 139 kilometers, so 0.6 cubic meter per kilometer. This is roughly a bathtub every kilometer.

Given the altitude of the plane, one can imagine that when reaching ground (but remind this is not the case !), the fuel would spread over a 1km area, so the 0.6 cubic meter would be "spread" in a square of 1km x 1km, which is 1'000'000 square meters. Assuming it is spread evenly, this would result in a fuel layer of 0.0006 millimeters, or 0.6 microns !

Compare that to what is emitted daily by cars, trucks, and also envisage how bad an problematic landing could be with 60 tons more on board, and you will realise that this fuel dumpings are not so critical things.

All details of the case I used as example, and links to additional resources can be found here.

Airplane toilets are chemical

2007-07-07T20:22:00.000+02:00

I will fight a new myth with this post. When you go to lavatories during flight, what you leave there is not ejected in the sky !

Many people beleive it is the case, but not. Doing so would lead to various problems. First, given the temperature oustide planes is approximately -50°C, anything would freeze, and any of your solid "production" would then fall as frozen piece. This could be unpleasant, if not dangerous for other planes.

The second issue would be to deal with a temporary and uncontrolled openning in the airplane pressurized envelope. This is the part of the fuselage that helps to maintain a constant air pressure to allow passenger breathing normally despite altitude. Any hole in that would leave air go out, making pressure and temperature falling.

So, no, the airplane toilets do not send anything outside. Instead, they are chemical. All what you leave is compressed and goes in a tank with a special product that helps containing odours and to stop the development of bacteriae.

During groud stops, the handling staff checks amongst other things the level of the tanks, and if they're full, or close to full, they have to drain it. As you can imagine, they double check all the tubes before doing... any leak would not be so friendly to clean.

Speaking about toilets, you should observe something during your next flight. It can be a 30 miuntes or 12 hours flights, this principle is always verified. As soon as the captain turns off the "Fasten seat belts" sign, there is systematically someone standing up within 30 seconds to go to the lavatories. Have a check.

One final word about plane toilets and common fantasies. In some movies, people are having sex in flight in the lavatories. I don't know how this would be possible, for at least two reasons: first is that the room there is hardly enough for a single people, so what about two ? and did you notice that there is always a queue to go in ? So how to go in two at a time, if possible ?

Tips for people who fear to fly

2007-07-03T19:16:00.000+02:00

I know lot of people getting nervous when boarding time comes, and get even more stressed at take-off. For some times, I have been one of those, when I started to know some more about that way of travelling, so I know how deep and animal such a fear can be. I did recover since, and here are some tips for those people, to help them make their trips enjoyable. Those tips are in the form of a series of thoughts that should help, so just reharsh these before and even during flight.

1) Planes do operate daily in all sorts of conditions, with an excellent safety record. No plane will suddenly fall in pieces and bits to the ground.

2) The pilots went through a long training process, and are re-checked each and every six months. It is not their first flight.

3) The crew also wants to reach destination safely. They don't want to die in a plane accident.

4) You don't have any information about what's going on. As a passenger you're not in a position to assume anything about it. Even if you hear noises you don't understand, don't make any conclusion on that, it is impossible to you.

5) If weather makes you worry, remind that planes can go through any weather except thunderstorms, which can be detected and avoided using on-board weather radar.

6) Don't look outside all the time, trying to find something scary. By doing so, you will feel that time passes by slowly, and any thing you won't understand will make you even more affraid.

7) Keep your mind busy with anything else. Read, do crosswords, sudoku, eat, talk to someone else, but stop thinking someting goes or will go wrong. Stop looking at your watch obsessively.

On a longer term basis, many airlines do offer courses to help their passengers to overcome their fears. These courses used to be free, but this happy time is over. Nevertheless, the results are quite good, so if you get stressed each time you have to fly, and you fly frequently, thing of such a course.

To conclude, the basic thing that makes most people stressed in flight is that they don't accept not to be in control, nor informed about the flight. In some aspects, flying is like an act of faith, you place your life in the hands of the crew.

Said so, it sounds scary, but have a second thought. When you take a taxi, or bus, or even when you drive, you also put your life within other hands. Not speaking about eating food from an unknown cook, being opened and put in pieces by a surgeon you saw only twice before, or using a lift installed and maintained by staff you don't know.

May be the flight experience is more intense because you're seated to your seat, in a confined volume, but in fact the process of having your life depending of someone else is really common. What about walking through a zebra crossing, for example ? Are you not at risk, at the mercy of any driver coming ?

Airport population - Faune control

2007-06-27T20:55:00.000+02:00

This post is inspired by a recent event that lead to temporary closure of Milano Linate, which is Milano second airport, so may be not a major one, but not exactly the municipal airport.

Linate had to be closed, in a planned way, for several hours, for the purpose of chasing hares that were living here. This operation involved many kilometers of nets, and hundred of people to hunt the furry ones. You can find a complete coverage of this event by CBS.

Hare control is really an issue, but most of time the "Faune control units" at the airports deal with birds. The big issue is that large birds can not be easily ingested by engines, and could cause some damages to windshields, wings, and any part of an aircraft.

There is a whole business in chasing birds from airports, with various equipment, including, but not limited to:

-) Remote guns (producing sounds only)
-) Mini fireworks, silent and screaming
-) Loudspeakers prodcasting other birds noises (predator noises)

Part of the problem is also that many airports have open fields where they leave some grass for decoration or ease of maintenance purposes, and this attracts small animals (mice, rats, ...), and when the grass gets its periodical cutting, it does in turn attarcts more birds looking for easy food.

I know a place where they recently tried to leave the grass get longer, but then larger animals started to live here... and to eat the lighting system cables !

To fight against these problems all airports have some "Faune control", patrolling all day long, looking for birds, and trying to chase them.

May we have your attention for the following presentation about safety on board

2007-06-26T20:34:00.000+02:00

You all have heard at least one these standard safety briefings. They contain however at least two important points that can save your life once.

The first is about not inflating your life jacket before leaving the aircraft. You probably noticed how bloddy long the boarding can be, so imagine what a de-boarding of scared passengenrs can be. Add to that a thick and impractical inflated jacket, and you understand why. The only possible exception to this rule is when the plane is already filled up with water.

To be certified, any airliner must fulfill an evacuation test, consisting in evacuating the total number of passengers via half of the emergency exits within 90 seconds. Sounds crazy ? Recently, an AirFrance Airbus 340 did crash in Toronto, in a survivable way, but caught fire on one side, so they were exactly in the 50% of exits available. And they made it in time. I was quite surprised, because certification always takes place with trained pseudo-passengers, in a relaxed mood.

The other important point in the safety briefing is to put your own oxygen mask first in case of depressurization. This is really a life saver. In case of sudden depressurization at cruise altitude, your lungs won't have enough air pressure to continue transferring oxygen in your blood, hence the masks. The issue is that you have approximately 18 seconds before being so dizzy that you become helpless to anybody or yourself.

Given the noise, sudden drop in temperature and potential fog within the cabin, 18 seconds is not so long to find and put your mask in place. You can then help anyone else, but if you start by helping someone, there are strong chances than you will be incapacited before achieving anything.

One more remark, which is really common sense. Keep your seatbelt fastend after landing until the engines are off and the sign is switched off. First, you won't save any time buckling off early, or may be half a second. But if the pilot has to brake sudenly, you could have a close and unpleasant encounter with the seat in front of you. Beleive me or not, but dozen of people have broken arms, or strong neck injuries yearly because of that... How silly is that ?

To close this post, a sample of safety announcement. The text is the original united one, but the picture...

Captain on the bridge - Handcuffs and tigers

2007-06-25T21:19:00.002+02:00

Ok, this old naval idiom is no longer used when a flight captain enters or leaves a cockpit, but some captain prerogatives survived the time when they change from boats to planes.

Let me first be a bit disapointing for all romantic readers... a flight captain can not get passenger married. This stopped when the move from ship to boat took place... sorry.

Amongst his trendemous responsibilities, the captain is sole responsible for the safety of all passengers and crew on board. This means that he can take any action he think is needed to protect aircraft and passenger safety, even if this violates each and every other rules ! Be sure he would have to report to ATC, aviation authorities, and his airline, but this will be later on. In the action, the captain is really the one deciding things.

Now, something else we heard a lot in the media recently as a french TV producer created an incident on board a flight from South Africa to Paris. The captain of a flight can decide to put a passenger under arrest, and if deemed necessary, to have the crew restraining the passenger freedom of movement, by using handcuffs.

A final word to close this post, about policemen flying on airliners. In the industry wording, they are called "tigers". Even the crew does not know them, and they interveine only if the safety of the flight is endangered by unlawful interference. They won't move if something only looks suspicious, or if a passenger is misbehaving under influence of alcohol or so.

This restriction in their actions is to protect their identity. There are not so many of them, and if they had to act for any small incident, it would be easy for terrorists to identify them, even by creating incidents with the sole purpose of then neutralize the tigers.

Be sure that many airliner seats daily are occupied by tigers, and this helps passenger safety.

Planes and cell-phones

2007-06-24T17:33:00.000+02:00

You certainly all know that it is forbidden to use cell phones on board planes. Let's talk about that, as this is something some people find frustrating, let's have a look at that. This is a particularly hot topic as some airlines (including Air France) are now allowing this, via their own antenna on board.

As a cell-phone owner, you probably already noticed that when you put it beside a radio or a tv, when someone's calling you, the tv / radio speakers are disturbed and emitt loud cracks. But as soon as you get your cell-phone away, the cracks diminish quickly.

These cracks come from the interference between your sound system and the microwave-like waves used by the cell phone technology. In a plane, the same could occur. And as the plane antenna are dispatched under the fuselage at various places, a cell-phone could potentially generate the same cracks in the radio used by pilots to communicate with air-traffic control, or for with the radio-navigation system.

From a technical point of view, the probability is extremely remote, but hey, would you like to take a chance ? Imagine for a second that your phone creates an interference with the instrument landing receiver while the plane is following its signal, 30 meters above groud, and give then an incorrect indication to the autopilot. This phone call could have been delayed... no ?

So the easiest is to switch off your phone while boarding the plane. You will then avoid dancing while seated to find it in your pockets, and have a longer "phone off relaxation" time.

What planes can and can't do - Wind

2007-06-23T20:11:00.000+02:00

One important thing when talking about aerodynamics is that the speed which is relevant in lift generation is the relative speed between air and wing. Speed relatively to ground has no influence, except for take-off and landing.

If wind is blowing, planes will take-off and land in opposite direction, so for the same air speed (needed to generate lift) the ground speed will be less, so the ground roll will be shorter, and more controllable.

The problem with wind start when they are fluctuating. If there is a sudden change in wind speed during an approach (what is called a "windshear"), the relative airspeed could be significantly changed, leading to potentailly strong changes in lift, then in vertical speed.

By chance, modern airliners have computers that know the airspeed from airspeed sensors, and groundspeed from GPS, so they can detect any windshear and notify them to pilots. The only "cure" is just to apply full power, and go arround for a second approach.

The other major issue with wind is when it is not blowing parallel to the runway. As the plane is moving relatively to air, the only way to maintain a straight ground track (needed for landing, isn'it ?) is to fly with the nose in the wind direction, flying in a "crabby" fashion.

This is perfectly ok to maintain a trajectory relatively to ground, but raises an issue, as the landing gear are not orientable, so immediately before (in some case after...) landing, the plane must be put in line with the runway.

Some examples of this technique are shows in the following video. Please understand that clearly, what you will see is indeed very good pilot skills, not bloody pilots missing their landings.

The next video is from a simulator (no airline will ever allow its pilots to even try such an approach), but it is very good for demonstration, as it shows the same approach from outsite and inside the planes, with angles that would be impossible to shoot from in reality.

The next time you will have a firm landing in crosswind conditions, or a go arround, please remind that this is how to do. And a go arround is never a bad option.