Thai Airways Emergency!

[percy2]

Really glad to hear he's ok.

If cell phones were a danger to aircraft they wouldn't allow them in the cabin.

It will come to that, if only for anti-terrorist reasons.

im surprised there not banned already .

It will never happen. Because if you ban them from carry on you would also have to ban them from checked luggage.

That would be pushing the general populace too far.

Cheers

[pampal]

The problem with using mobile in an airplane is that

A mobile used on the ground connects to one cell in the network, but at altitude it can connect to many different cells, thereby possibly causing confusion and problems in the cellular system.

If you are flying near a border, you could connect to cells in two different countries, the system cannot tell where you are because you are simultaneously connected to two different cells in two different countries.

In the USA they use mainly CDMA/TDMA cellular systems and to a lesser extent GSM systems, whereas in Thailand they are mainly on the GSM network, very different systems with different charecteristics.

What system do Hutch use?

Cheers

Hutch has unveiled their CDMA system in Thailand this year and it is expected to be fully operational by the end of 2007.

Thanks for pointing that out.

Cheers

Edited November 6, 2007 by pampal

[cclub75]

He said the pilot sought an emergency lading after there was a problem of air conditioning system in the passenger cabin.

Air conditioning... or depressurization ?

I mean, it's totally different !

JaiDee said "depressurized".

[sibeymai]

The problem with using mobile in an airplane is that

A mobile used on the ground connects to one cell in the network, but at altitude it can connect to many different cells, thereby possibly causing confusion and problems in the cellular system.

If you are flying near a border, you could connect to cells in two different countries, the system cannot tell where you are because you are simultaneously connected to two different cells in two different countries.

In the USA they use mainly CDMA/TDMA cellular systems and to a lesser extent GSM systems, whereas in Thailand they are solely on the GSM network, very different systems with different charecteristics.

A mobile phone at ground level can be within range of multiple cells at the same time just the same as a mobile phone at 11,000m. The altitude of the phone is irrelevant to the cell network's software which passes the phone to whichever cell has the strongest signal regardless of the phone's altitude.

Different networks in border areas, or different networks within the same country also pose no problems as the network acccessed is controlled by the phone settings, not by the network software.

Please try to post accurate information in future.

[xyborg]

<br />

Unfortunately mobiles dont interfere with avionics - big misnomer.

<br /><br />As a computer engineer of 20 years experience I tend to agree, even more so since no convincing evidence specific to mobile phones has been established beyong the fact that radio waves can interfere with electronics.<br /><br />I can recall from experience one computer system which would crash every time a navy ship turned on its weapons system within 1,000 metres so the link between radio interferance and it's effect on computers is real enough in my mind.<br /><br />But the radio energy of a naval weapons system is many more times that of a planeload of passengers, probably even on an A380. Even the plane's own systems would probably generate more radio energy than all the passengers could combined.<br /><br />So why airlines persist with this dogma is a mystery.<br /><br />Glad to hear the plane landed safely. Three cheers for the pilots.<br /><br />Edit: after re-reading the original post I apologise for assuming Jai Dee sent the sms in-flight as it appears it may have been sent after landing.<br />

<br /><br /><br />

Lets hope they keep the myth going , last thing I want on a 13 hour flight to Thailand is some wa****er telling his council house buddies, "yeah I'm on a plane geting sh**faced"

[qualtrough]

Unfortunately mobiles dont interfere with avionics - big misnomer.

OK, perhaps I am being pedantic, but a 'misnomer' is when something is inappropriately or incorrectly named.

[xyborg]

<br />

Wicha Noenlop, director of the airport, said none of 287 passengers onboard THAI Flight TG415 were injured when the plane made an emergency landing at 10 am. The plane left the Suvarnabhumi International airport at 9 am.<br /><br />He said the pilot sought an emergency lading after there was a problem of air conditioning system in the passenger cabin.<br /><br />He said the temperature in the passenger cabin was too high because of the problem.

<br /><br /><a href="http://nationmultimedia.com/breakingnews/read.php?newsid=30055061" target="_blank">http://nationmultimedia.com/breakingnews/r...newsid=30055061</a><br /><br />Will be interesting to see Jai Dee's take on this.<br /><br />Close to ground does not mean 30,000 feet up. It also doesn't mean just before you land. If you don't believe it, try turning your cell phone on as you start to descend, and see how long it takes for you to pick up any signal at all. Just make sure any phone booting sounds are muted <img src="style_emoticons/default/wink.gif" style="vertical-align:middle" emoid="" border="0" alt="wink.gif" /><br /><br />In any case, the point has been made.<br />

<br /><br /><br />

So one of the air crew opened the door to let some air in ??? hence depressurisation!!

[cdnvic]

Different networks in border areas, or different networks within the same country also pose no problems as the network acccessed is controlled by the phone settings, not by the network software.

Please try to post accurate information in future.

Unless you have your phone set not to roam, you can get switched to a tower over a border. Used to happen to me quite often. I had my phone set to roam as I moved around my local area and bounced between two providers depending on the mountains. Unfortunately that also allowed it to connect to American towers across the water, and that was rather unexpected (and expensive).

[thai_narak]

The problem with using mobile in an airplane is that

A mobile used on the ground connects to one cell in the network, but at altitude it can connect to many different cells, thereby possibly causing confusion and problems in the cellular system.

If you are flying near a border, you could connect to cells in two different countries, the system cannot tell where you are because you are simultaneously connected to two different cells in two different countries.

In the USA they use mainly CDMA/TDMA cellular systems and to a lesser extent GSM systems, whereas in Thailand they are solely on the GSM network, very different systems with different charecteristics.

just some comments...

in GSM and TDMA you connect to one cell at a time and handover to another cell as you move but in CDMA/UMTS/3G you always connects to 3-4 cells, they call this softhandover. as you move, the serving cells changes depending on your signal strenght and C/I ratio. all this assuming you're on the ground not flying.

if you are flying and are 35,000ft or 10.66km above the ground you may not have any cellular coverage at all. the maximum distance of a cell in GSM operating in 900Mhz is 35km (for extended cells only and this is a feature activated only in rural areas). this is the farthest distance and shrinks as frequency goes up in the higher band; 3G is in 2Ghz band and may have a coverage of approx. 500m depending on the load. the antennas are also not facing up in the sky to cover the passing airliners but are tilted downwards to the cities, road, and people's houses. cellphones may work in the airport while you are taxiing (obviously) or just above the ground for maybe a few kilometers above the ground from the signals reflected from buildings, water (or sea), mountains, etc. but not for more than 10km. also, the aircraft is sheilded and the signal looses more than 3db when inside the airline.

the main reason i think that the mobiles are not allowed (to turn-on) is that when they are powered "on" the mobiles are constantly trying to establish connection to the network (we call this location update in telecom) when they are out of coverage. when the mobiles are searching for the network they are using power step alogorithm to the point that they are on "full power" when they are trying to do "location update" to the network that is picked-up (in a very weak signal of about >-110 dbm in GSM) and this procedure may cause interference to any electronic devices. the "location update" procedure will continue until it's successful.

Edited November 6, 2007 by thai_narak

[onethailand]

if you are flying and are 35,000ft or 10.66km above the ground you may not have any cellular coverage at all. the maximum distance of a cell in GSM operating in 900Mhz in 35km (for extended cells only and this is a feature activated only in rural areas).

Found exactly what I was looking for - thanks. In the case of 9/11, they were above rural Pennsylvania - where the signal coming from a tower would likely be at its strongest.

A signal isn't likely, though, if you are near a city, unless you get close to ground.

[thai_narak]

if you are flying and are 35,000ft or 10.66km above the ground you may not have any cellular coverage at all. the maximum distance of a cell in GSM operating in 900Mhz in 35km (for extended cells only and this is a feature activated only in rural areas).

Found exactly what I was looking for - thanks. In the case of 9/11, they were above rural Pennsylvania - where the signal coming from a tower would likely be at its strongest.

A signal isn't likely, though, if you are near a city, unless you get close to ground.

exactly, that's why it was possible for them to make calls and send SMS. the system in Penn is TDMA (much more like GSM).

Edited November 6, 2007 by thai_narak

[onethailand]

back on topic... hopefully by now Jai Dee has made it safely to KL. I"m sure an update is forthcoming when he reaches the hotel (unless of course he's only going down for the day).

[george]

back on topic... hopefully by now Jai Dee has made it safely to KL. I"m sure an update is forthcoming when he reaches the hotel (unless of course he's only going down for the day).

He has promised us an update when he is arriving KL. The plane is delayed for another 3 hours though, on a new aircraft.

[kmart]

I'm glad everyone is okay.

[Scott]

I absolutely don't care why they don't let you use cell phones on a plane, I am just very, very glad they don't. Talk about a nightmare flight--a hundred or so people yakking away!

[Mobi]

Oxygen supply failure is the most serious aspect of this mishap. I assume the Aircrew have an independent or even a redundant oxygen system. Anyway 'all's well that ends well' for Jai Dee and his fellow passengers.

On a slightly lighter note - although it wasn't very light at the time - I was once on a Biman, Bangla Desh Airline flight and when we hit a bit of turbulence a number of oxygen masks dropped down. There was no emergency, just loose overhead flaps containing the masks. The stewardess came round and pushed them all back up in their places, except for 2 or 3 which kept falling down again. She finally gave up trying, and a few minutes later the first officer appeared with some gaffer tape and taped them up!

Just as well there was no emergency.

[pampal]

A mobile phone at ground level can be within range of multiple cells at the same time just the same as a mobile phone at 11,000m. The altitude of the phone is irrelevant to the cell network's software which passes the phone to whichever cell has the strongest signal regardless of the phone's altitude.

the altitude indeed makes all the  difference, it's called line of sight and that means that on the ground you can never be connected to as many cells as you are in the air.

It's simple physics.

check out these links

http://www.privateline.com/Cellbasics/cell...esairlines.html

http://www.computerworld.com/action/articl...iewArticleBasic

://http://www.privateline.com/Cellbasi...ticleBasic

Please check your facts first

Edited November 6, 2007 by pampal

[kmart]

I absolutely don't care why they don't let you use cell phones on a plane, I am just very, very glad they don't. Talk about a nightmare flight--a hundred or so people yakking away!

Roger that. I'm not sure if the cell frequencies mess with the on-board avionics, but they would certainly &lt;deleted&gt; with my ambience.

[tijnebijn]

Oxygen supply failure is the most serious aspect of this mishap. I assume the Aircrew have an independent or even a redundant oxygen system. Anyway 'all's well that ends well' for Jai Dee and his fellow passengers.

On a slightly lighter note - although it wasn't very light at the time - I was once on a Biman, Bangla Desh Airline flight and when we hit a bit of turbulence a number of oxygen masks dropped down. There was no emergency, just loose overhead flaps containing the masks. The stewardess came round and pushed them all back up in their places, except for 2 or 3 which kept falling down again. She finally gave up trying, and a few minutes later the first officer appeared with some gaffer tape and taped them up!

Just as well there was no emergency.

That plane was very clearly in a very exellent condition

I have been on such a plane before , and tell you I will never fly with such

aircraft again , just gave me the creeps .

[Dakhar]

Some time ago the show "Myth Busters" did an episode on this topic (cell phone use screwing up avionics) and it was found that it was HIGHLY UNLIKELY.... but they still advised you to leave your cell phone off during flights.

[cdnvic]

Just as well there was no emergency.

Flying Biman is an emergency.

[Darknight]

Unfortunately mobiles dont interfere with avionics - big misnomer.

As a computer engineer of 20 years experience I tend to agree, even more so since no convincing evidence specific to mobile phones has been established beyong the fact that radio waves can interfere with electronics.

I can recall from experience one computer system which would crash every time a navy ship turned on its weapons system within 1,000 metres so the link between radio interferance and it's effect on computers is real enough in my mind.

But the radio energy of a naval weapons system is many more times that of a planeload of passengers, probably even on an A380. Even the plane's own systems would probably generate more radio energy than all the passengers could combined.

So why airlines persist with this dogma is a mystery.

Glad to hear the plane landed safely. Three cheers for the pilots.

Edit: after re-reading the original post I apologise for assuming Jai Dee sent the sms in-flight as it appears it may have been sent after landing.

The reason why they ask you to switch a phone of is pretty straightforward.

When cell phone go out of reach of the transmitters (who's beams are positioned horizontally over the earth not vertically.) They tend to start ringing but when you pickup you get no connection. this is probably because the phone receies mixed signals.

Basically a lot of phone start ringing at the same time and this is really annoying for other passengers , as they have no connection, try to ring back etc....

I always switch my phone off as well when i go gliding , and my glider has no worthy electronic avionics to speak off :-). otherwie the dam_n thing just starts bugging me and i can't reach it.

DK

[asiaworld]

Good to know Jai Dee is ok.

Main reason airlines dont want mobile usage...

1. Use airphone, makes more dosh

2. 200-300 people yapping on a mobile would be well disturbing to other passengers.

BTW received mobile call mid flight from one of my pilot mates.

PRECISELY

[pampal]

Flying Biman is an emergency.

[pampal]

Further explanation

Why can't I use my cellular phone on an airliner?

Cell phones on airliners interfere with the terrestrial cellular telephone network. Interference with a plane's avionics or navigation system is poorly documented and a secondary problem. Except to the Federal Aviation Administration, which usually favors no risks and consequently prohibits cell phone use on-board. Why allow the possibility of a cell phone interfering if you can simply ban them? But let's get back to the problem we can demonstrate.

Cell phones transmit in nearly straight lines. From an airplane a cell phone can connect to nearly any cell site in view below, causing much turmoil, especially with a jet moving 500 miles an hour, passing by one cell after another far more quickly than the systems were designed for. Here's something from the cellular basics article to clear this up:

Mark van der Hoek describes two people, a businessman using his cell phone in the city, and a hiker on top of a mountain overlooking the city. The businessman's call is going well. But now the hiker decides to use his phone to tell his friends he has climbed the summit.

From the climber's position he can see all of the city and consequently the entire area under cellular coverage. Since radio waves travel in nearly a straight line at high frequencies, it's possible his call could be taken by nearly any cell. Like the one the businessman is now using. This is not what radio engineers plan on, since the nearest cell site usually handles a call, in fact, Mark points out they don't want people using cell phones on an airplane "Knock it off, turkey! Can't you see you're confusing the poor cell sites?"

It may be true that airlines profit so greatly from their own in-plane phone services (like the GTE Airfone) that they do not want people using their own mobiles. It may also be true that cell phones do cause interference with an airplane's electronics. Read the _Wired_ article below. But remember, proving either is difficult compared to showing the real problem they present to the terrestrial cellular telephone network. At the least, though, it seems reasonable that cell phones should be allowed to work while a plane is on the ground.

[george]

The wait will be longer at Hat Yai Airport. TG415 is now delayed with new ETD from Hat Yai at 16.00.

[Thanyaburi Mac]

TG 415 from Bkk to KL emergency landing at Hat Yai. Plane de pressurised at cruising altitude, oxygen did not work, forcing emergency landing.

Jai Dee.

11.20 am

I hope he's All right.

Anyone have any news?

Nation and Bangkok Post both reporting aircon problems.

http://www.nationmultimedia.com/breakingne...newsid=30055061

THAI plane makes emergency landing at Hat Yai airport

Hat Yai, Songkhla - A Thai International Airlines plane heading to Kuala Lumpur makes an emergency landing at the Hat Yai International Airport Tuesday.

Wicha Noenlop, director of the airport, said none of 287 passengers onboard THAI Flight TG415 were injured when the plane made an emergency landing at 10 am. The plane left the Suvarnabhumi International airport at 9 am.

He said the pilot sought an emergency lading after there was a problem of air conditioning system in the passenger cabin.

He said the temperature in the passenger cabin was too high because of the problem.

If the air condition system could not be fixed soon enough, passengers would be transferred to another flight to Kuala Lumpur, he said.

The Nation

xxxxxxxxxxxxxxx

http://www.bangkokpost.com/breaking_news/b...s.php?id=123324

Thai Airways makes emergency landing at Hat Yai

(BangkokPost.com) - Thai Airways flight TG 415 heading from Bangkok's Suvarnabhumi airport to Kuala Lumpur made an emergency landing in Hat Yai on Tuesday morning, after captains found that air conditioning system in passenger cabin did not work properly.

All of the 287 passengers were reportedly safe.

The aircraft asked for emergency landing at the Hat Yai International Airport at 10 am, which was about an hour after it took off.

According to the airport director Wing Commander Wicha Nernlop, a captain reported that temperature in passenger cabinet was high, which was resulted from a problem of the air conditioning system.

It is expected that the plane will resume its flight in the afternoon. But if the problem cannot be fixed, Thai Airways will send in another plan to take passengers from the airport to their destination.

xxxxxxxxxxxxxxxxxxxx

[onethailand]

Something doesn't add up. Why would the airline feel the need to report that no passengers were injured, and that an emergency landing had taken place, because the air-conditioning failed?

Normally, this would be called an unscheduled landing, not an emergency one.

[Mobi]

I smell a rat.

Thai Airways has a history of denial - its a cultural thing

[thai_narak]

I smell a rat.

Thai Airways has a history of denial - its a cultural thing

might be your socks Mobi...

kidding...