Thai Airways Emergency!

[WaiWai]

QUOTE (Mobi @ 2007-11-06 13:31:19)

Just as well there was no emergency.

....

Flying Biman is an emergency.

At least they managed to stay awake, unlike the Merkin pilots in the news .

Two commercial pilots allegedly fell asleep on a flight between Baltimore and Denver, with one pilot waking up to "frantic" calls from air traffic controllers warning them they were approaching the airport at twice the speed allowed.

[think_too_mut]

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.

You remember that Helios Airways flight between Cyprus and Athens where all passengers and crew went for a long sleep...not to wake up when the plane run out of fuel and crashed? Aircon failures upthere are not naive things, you can't just open a window.

http://en.wikipedia.org/wiki/Helios_Airways_Flight_522

[lopburi3]

If I recall correctly the plane that overflew Greece for several hours had an air conditioning problem (which is tied to pressurization?) so perhaps the term is correct - that the problem was the air conditioning system and no mention will be made of what this caused?

[sibeymai]

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

<a href="http://www.computerworld.com/action/article.do?articleId=9015839&command=viewArticleBasic" target="_blank">http://www.computerworld.com/action/articl...iewArticleBasic://http://www.privateline.com/Cellbasi...iewArticleBasic

://http://www.privateline.com/Cellbasi...ticleBasic</a>

</a>

Please check your facts first

"line of sight", or more usually, "direct line of sight" is a simple term describing a situation where a transmitter has an unobstructed straight line path to a receiver, or visa-versa. Microwave is an example of a transmission method which requires such a direct line of sight path.

Mobile phone signals require no such "line of sight" path. Their connectivity is limited only by the signal strength sent and received between the phone and the transmitter. The signal strength depends on the transmission power of the phone, the transmitter, the distance between each, the physical obstacles between each and the prevailing terrestrial and solar weather conditions at the time of transmission.

Cell network engineers may indeed not design their networks to provide service delivery for the aircraft scenario. If today, when such instances occur or in the case of the hiker on the mountain, it causes a cell network problems then the network software is the component at fault.

I hardly think airlines would have agreed to ban the use of mobiles in flight just to make the telcos happy although I'm sure the telcos are happy to provide airlines with a slightly modified dedicated service for inflight calls at a premium price.

But conspiracy theories between airlines and telcos is so way off topic this is the last I'll post on this thread.

[thai_narak]

If I recall correctly the plane that overflew Greece for several hours had an air conditioning problem (which is tied to pressurization?) so perhaps the term is correct - that the problem was the air conditioning system and no mention will be made of what this caused?

i agree. no airconditioning means no air fresh to breath at and no pressurization in the cabin. if the oxygen mask aren't working then this is very dangerous as the cardon dioxide concentration may rise and may become toxic.

[onethailand]

I thought cabin pressurization was independent of air-conditioning... shows how much I know about that

BTW a similar problem happened in the US - a private jet carrying golfer Payne Stewart lost pressurization and the occupants of the aircraft died of hypoxia.

[Cobalt60]

Suprised how this has turned into a mobile phone debate and not a 'why the heck didnt the oxygen work' question.

[thai_narak]

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

<a href="http://www.computerworld.com/action/article.do?articleId=9015839&command=viewArticleBasic" target="_blank">http://www.computerworld.com/action/articl...iewArticleBasic://http://www.privateline.com/Cellbasi...iewArticleBasic://http://www.privateline.com/Cellbasi...iewArticleBasic

://http://www.privateline.com/Cellbasi...ticleBasic</a>

</a>

Please check your facts first

"line of sight", or more usually, "direct line of sight" is a simple term describing a situation where a transmitter has an unobstructed straight line path to a receiver, or visa-versa. Microwave is an example of a transmission method which requires such a direct line of sight path.

Mobile phone signals require no such "line of sight" path. Their connectivity is limited only by the signal strength sent and received between the phone and the transmitter. The signal strength depends on the transmission power of the phone, the transmitter, the distance between each, the physical obstacles between each and the prevailing terrestrial and solar weather conditions at the time of transmission.

Cell network engineers may indeed not design their networks to provide service delivery for the aircraft scenario. If today, when such instances occur or in the case of the hiker on the mountain, it causes a cell network problems then the network software is the component at fault.

I hardly think airlines would have agreed to ban the use of mobiles in flight just to make the telcos happy although I'm sure the telcos are happy to provide airlines with a slightly modified dedicated service for inflight calls at a premium price.

But conspiracy theories between airlines and telcos is so way off topic this is the last I'll post on this thread.

two of you, yes YOU! stop fighting here.

put it like this. cellular network are not designed to served flying subscribers, simply because of mobility reason. all the systems we have now TDMA, GSM, CDMA, UMTS are not designed for the skies. in TDMA and GSM, fast handovers and roaming criteria for flying subscribers is not supported. roaming criteria means your registration to the network whether local or not, do you that we have divided the network in the several hundreds of location areas where your mobile has to re-register? of course you don't... also, antennas are not designed to propagate to the skies this is why we are tilting them downwards to avoid interfering each other, this is critical cellular networks. in UMTS and CDMA, the network will not necessarily crash but imagine 200 subscribers on-board trying to set up RRC to the cell site and all mobiles powering up because they are too far to the site, and then after 1-2 minutes move to another cel the do the same, this will cause overload to system and will screw up RRC drop statistic in the network although this is not necessarily a real problem but still the system is not designed to support this.

so, turn your phone off when you fly.

[thai_narak]

I thought cabin pressurization was independent of air-conditioning... shows how much I know about that

BTW a similar problem happened in the US - a private jet carrying golfer Payne Stewart lost pressurization and the occupants of the aircraft died of hypoxia.

wild guess, i never knew. but i really do not want to breath from your breathe.

[percy2]

put it like this. cellular network are not designed to served flying subscribers, simply because of mobility reason. all the systems we have now TDMA, GSM, CDMA, UMTS are not designed for the skies. in TDMA and GSM, fast handovers and roaming criteria for flying subscribers is not supported. roaming criteria means your registration to the network whether local or not, do you that we have divided the network in the several hundreds of location areas where your mobile has to re-register? of course you don't... also, antennas are not designed to propagate to the skies this is why we are tilting them downwards to avoid interfering each other, this is critical cellular networks. in UMTS and CDMA, the network will not necessarily crash but imagine 200 subscribers on-board trying to set up RRC to the cell site and all mobiles powering up because they are too far to the site, and then after 1-2 minutes move to another cel the do the same, this will cause overload to system and will screw up RRC drop statistic in the network although this is not necessarily a real problem but still the system is not designed to support this.

so, turn your phone off when you fly.

Thats not a reason to switch your phone off, but it is a reason for the network providers to get their act together.

Cheers

[thai_narak]

put it like this. cellular network are not designed to served flying subscribers, simply because of mobility reason. all the systems we have now TDMA, GSM, CDMA, UMTS are not designed for the skies. in TDMA and GSM, fast handovers and roaming criteria for flying subscribers is not supported. roaming criteria means your registration to the network whether local or not, do you that we have divided the network in the several hundreds of location areas where your mobile has to re-register? of course you don't... also, antennas are not designed to propagate to the skies this is why we are tilting them downwards to avoid interfering each other, this is critical cellular networks. in UMTS and CDMA, the network will not necessarily crash but imagine 200 subscribers on-board trying to set up RRC to the cell site and all mobiles powering up because they are too far to the site, and then after 1-2 minutes move to another cel the do the same, this will cause overload to system and will screw up RRC drop statistic in the network although this is not necessarily a real problem but still the system is not designed to support this.

so, turn your phone off when you fly.

Thats not a reason to switch your phone off, but it is a reason for the network providers to get their act together.

Cheers

of course you can turn it on as you like. the reason i wrote is in the network point of view and to stop these fighting guys writing about line of sigh, microwave, etc. that they don't even know about. read my last post about the reason to turn your phone off on board.

edit: by the way, i'm a radio engineer so i know what i'm talking about.

Edited November 6, 2007 by thai_narak

[sibeymai]

two of you, yes YOU! stop fighting here.

OK, OK. Not another word from me about the poor quality of software on mobile networks......

As another poster said.....

Suprised how this has turned into a mobile phone debate and not a 'why the heck didnt the oxygen work' question.

Did the oxygen masks not deploy or did they dploy and not provide oxygen ?

Oxygen masks wouldn't deploy automatically unless there was depressurisation. If it was an air conditioning failure, as Thai Airways says, and not a depressurisation then the oxygen masks not deploying would appear to be correct function. There would be plenty of oxygen in the cabin already assuming pressurisation is maintained for the time taken to make an emergency landing.

If there was depressurisation then one assumes that cabin crew can also trigger the deployment manually if necessary. If after having been deployed no oxygen was available then that is a very serious matter.

Based on the information given so far the former scenario seems to have occurred.

[Mosha]

The Helios incident was on a Discovery Channel Äircrash I"nvestigations" episode. On the previous flight a fault had been reported. The aircraft was tested during which procedure a vital component was switched off. After the work was caried out the maintenance guy forgot to switch the equipment back on.

The oxygen masks in the passenger areas are only supposed to provide oxygen to allow the aircraft to decend to a safe altitude, not for sustained flight.

[Losangels]

BTW a similar problem happened in the US - a private jet carrying golfer Payne Stewart lost pressurization and the occupants of the aircraft died of hypoxia.

Yeah I remember that incident, it was on auto pilot and flew until the fuel ran out and then crashed . Heard that the it was tailed closely by one of the jets from USAF. Very sad thing for the accident to happen which I believed happened within a few days after his US Open victory

[think_too_mut]

I tried to find out what plane it was. From the TG web site it is a B-777. The same type that plies between Japan and Thailand.

I am a bit worried.

[Mosha]

The page I looked at says equipment varies. Fed Travel gives the info as equipment 777-300 except on tuesday when it's a A330-300.

[jstumbo]

I saw a mythbusters episode where they dealt with this very question,

How do mobile phones affect avionics?

They tried many different ways of disrupting the avionics, using mobile phones with varying frequencies among other methods, and none of the tests showed the slighest amount of interference with the avionics systems.

It is indeed a misnomer.

The government in the US looked into lifting the ban on in flight calls, but did not lift it mostly because people do not want to be stuck next to someone talking on their phone the whole flight.

[TheEmperorOfTheNorth]

Maybe it WAS an air conditioning problem, so Captain Somchai decided to open a window. :-) That would have depressurized the lot pretty quick.

[thai_narak]

I saw a mythbusters episode where they dealt with this very question,

How do mobile phones affect avionics?

They tried many different ways of disrupting the avionics, using mobile phones with varying frequencies among other methods, and none of the tests showed the slighest amount of interference with the avionics systems.

It is indeed a misnomer.

The government in the US looked into lifting the ban on in flight calls, but did not lift it mostly because people do not want to be stuck next to someone talking on their phone the whole flight.

if they lift the ban then it's good for us radio engineers as we can have more jobs optimizing the network to serve the skies. it will be a major upgrade for the radio base stations and antenna and new features for fast handover should be develop to cope with the airliner's speed. separate cell sites have to be designed just to serve the skies. unfortunately, 3G (UMTS) is not capable of this service due to its coverage limitation (500m to 1km only) as it is based on 2Ghz band and in this range of frequencies path loss so great. cell loading is also a possible problem due to the bundled subscribers on board the plane (200 people) that will cause the cell to shrink due to sudden increase of interference while they are passing the cell on softhandovers. so only GSM can evolved to provide such service. but i think it's still a bad idea...

[Mosha]

Maybe they could arrange it so that people who want to use their mobile phones, could sit on the wings with the smokers.

[sibeymai]

Next it will become an offence to use a mobile phone in the toilet of an aircraft.

[thai_narak]

just watched the news, one indian passenger was interviewed and he said that the plane was vibrating in the air and all passengers were very scared. looks like it's more than an air-conditioning problem to me.

i hope Jai Dee can give an update soon.

Edited November 6, 2007 by thai_narak

[Bates]

Thai Airways flight TG 415 made an emergency landing in Hat Yai on Tuesday morning after the pilot discovered a problem with the air pressure system

http://world-airliner.com/smf/index.php?topic=255.0

[Mosha]

I saw the news report, still no word if it was a Boeing or Airbus.

[mrbojangles]

Glad to hear all is OK Jai Dee. Must have been a bit nervey

could sit on the wings with the smokers.

Sometimes on a long haul, i wish we had that choice but they don't even give us that. Mind you if they did let us, they'd put us out there and laugh their heads off at us trying to light the ciggies

[phuketrex]

Glad to hear all is OK Jai Dee. Must have been a bit nervey

could sit on the wings with the smokers.

Sometimes on a long haul, i wish we had that choice but they don't even give us that. Mind you if they did let us, they'd put us out there and laugh their heads off at us trying to light the ciggies

You may well laugh about sitting on the wings so read this!!!!!!!!>>>>>>>>>

MOSCOW, September 24 (RIA Novosti) - A 15-year-old boy from the Urals suffered acute frostbite after riding the wing of a Boeing-737 plane on a two-hour flight from Perm to Moscow, Russian radio station Mayak reported on Monday.

After clinging on for the entire 1300-kilometer (808-mile) flight to Vnukovo Airport, the boy, named Andrei, collapsed onto the tarmac. His arms and legs were so severely frozen that rescuers were at first unable to remove his coat and shoes, the radio station said.

The airport did not confirm the report. "We have no information on this," the Vnukovo press service told RIA Novosti.

However, Moscow's air and water transport control department said the radio's claim was true. A department spokesman said the incident occurred on Friday, and that the boy's parents were immediately informed, and flew to the capital the same day.

Doctors said it was nothing short of a miracle that Andrei survived the flight, with temperatures hitting minus 50 degrees Celsius (-58 Fahrenheit), the radio station said. The Boeing-737 has a cruising speed of 900 kmh (560 mph).

The boy reportedly made the journey after a commonplace domestic dispute. Angry with his father, who reportedly has a drinking problem, and with his mother for siding with her husband in family rows, Andrei ran away to the neighboring village, where his grandmother lives. On reaching the village, he decided to go on, and hitched a 220-km (137-mile) ride to the regional center, Perm, where he was dropped off at the airport.

It remains unclear how Andrei was able to climb on a plane wing un-noticed, and the Perm Airport security service is being asked some serious questions, the radio station said.

Andrei is now being treated in a Moscow hospital, Radio Mayak said.

[thai_narak]

just several weeks ago a stow away man was discovered hiding in the front wheel of the KL-singapore flight.

http://www.cnn.com/2007/WORLD/asiapcf/10/1...y.ap/index.html

[Mosha]

When booking in and asked for a seating preference, I would reply as long as it's not next to a smoker I don't care.

"Sir it's a non smoking flight""

"Yes I know, I also know people that are ready to kill after 15 minutes without a cigarette"

[thai_narak]

I saw the news report, still no word if it was a Boeing or Airbus.

i don't know if this is accurate but it looks like an Airbus 330/300 according to the list.

cargo_time_table.pdf

Edited November 6, 2007 by thai_narak

[Mosha]

Could be my Fed Travel info is correct.