Kenya Airways plane crash in Cameroon

Pinguin · Post by **Pinguin** » 07 May 2007, 18:07

Wasn't there a problem with the oxigen on the Helios 737?

JAFflyer · Post by **JAFflyer** » 07 May 2007, 19:58

Helios wasn't a defect at all. The pilots put the pressurization in manual DC instead of auto. Then were confused to hear the take-off warning horn in the air (is the same aural warning system for pressurization in the 737, should be known if you have trained a decompression in the sim). And as they were in cruise, they were very quickly unconscious. Totally human error, aircraft was perfectly fine.

It's not in relation to this crash so excuse me to go off-topic, but just wanted to clarify the helios case.

FLY4HOURS.BE · Post by **FLY4HOURS.BE** » 07 May 2007, 21:17

I would call that incident rather a crashlanding then a crash

A crashlanding is when an aircraft crashes while the pilots attempt to land. Helios 737 was not attempting to land at all.
As you say it ran out of fuel after all people were knocked down due to lack of cabin air pressure.
Studies told that some of the passengers died after the crash due to the fire that resulted from the crash.

I agree that the tanks were empty, but you don't need more than two tanks full of petrol fumes to create an explosion. There's something called unusable fuel quantity that still remains in the tanks.

I'm gonna need to quote www.b737.org.uk :

To date, two 737's, 737-400 HS-TDC of Thai Airways on 3 Mar 2001 and 737-300 EI-BZG operated by Philippine Airlines on 5 Nov 1990 have been destroyed on the ground due to explosions in the empty centre fuel tank. In 1996, the very high profile TWA 800, a 747-100 mid-air explosion was also determined to have originated in an empty centre fuel tank.
The common factor in all three accidents was that the aircraft had empty center fuel tanks. However even an empty tank has some unusable fuel which in the heat will evaporate and create an explosive mixture with the oxygen in the air. These incidents, have sparked (sic) debate about fuel tank inerting.

LX-LGX · Post by **LX-LGX** » 07 May 2007, 22:08

FLY4HOURS.BE wrote:
I would call that incident rather a crashlanding then a crash
A crashlanding is when an aircraft crashes while the pilots attempt to land. Helios 737 was not attempting to land at all. As you say it ran out of fuel after all people were knocked down due to lack of cabin air pressure.
Studies told that some of the passengers died after the crash due to the fire that resulted from the crash. I agree that the tanks were empty, but you don't need more than two tanks full of petrol fumes to create an explosion. There's something called unusable fuel quantity that still remains in the tanks. I'm gonna need to quote www.b737.org.uk : To date, two 737's, 737-400 HS-TDC of Thai Airways on 3 Mar 2001 and 737-300 EI-BZG operated by Philippine Airlines on 5 Nov 1990 have been destroyed on the ground due to explosions in the empty centre fuel tank. In 1996, the very high profile TWA 800, a 747-100 mid-air explosion was also determined to have originated in an empty centre fuel tank.
The common factor in all three accidents was that the aircraft had empty center fuel tanks. However even an empty tank has some unusable fuel which in the heat will evaporate and create an explosive mixture with the oxygen in the air. These incidents, have sparked (sic) debate about fuel tank inerting.

I didn't say that Helios was a crashlanding and I didn't say that a plane with empty fuel tanks cannot explode: I've said I would call the Helios crash rather a crashlanding then a crash. Meaning of crash: a plane with technical failure in mid air (repeat: it's not a definition, it's my difference between crash and crashlanding).

But a discussion between a crash and a crashlanding is not the issue here. Cockpit crew was out and the plane was on autopilot, thus not in a vertical dive (like in most crashes). It didn't felt out of the air: it flew against a hill. But yet no survivors. There were some post mortems showing passengers with smoke in their lungs, and that was explained by some as "so their lungs must still have been working just after touch down and before local fires". But is it a medical certitude? No.

Back to the Kenyan plane: seems no fire broke out. But yet no survivors. I indeed disagree with your conclusion on G-forces. Sitting in a chair with just one safety belt and without your head, neck, arms and legs firmly fixed, you have no chance at all when you hit the ground at 700 km/h. With all respect to the victims: the G-force at impact shakes you to dead.

FLY4HOURS.BE · Post by **FLY4HOURS.BE** » 07 May 2007, 22:56

Flying against a hill is not a crash but a crashlanding. Interesting, but WRONG!!

Crashes are almost always vertical? WRONG!!
Vertical means parallel to the Z-axis.

Sitting in a chair with just one safety belt and without your head, neck, arms and legs firmly fixed, you have no chance at all when you hit the ground at 700 km/h. WRONG!!

Mr. NTSB know it all, Your arguments are highly unprecise.

I'm giving you the G-theory written on most of the ATPL books. There are always exceptions to everything. The G's won t kill you, but if the plane hits the ground and your plane isn t solid enough to keep its shape, you will be compressed against the ground and killed that way.

Who said there was no fire on this Kenyan flight?

LX-LGX · Post by **LX-LGX** » 08 May 2007, 00:31

FLY4HOURS.BE wrote:Flying against a hill is not a crash but a crashlanding. Interesting, but WRONG!!

Crashes are almost always vertical? WRONG!!
Vertical means parallel to the Z-axis.

Sitting in a chair with just one safety belt and without your head, neck, arms and legs firmly fixed, you have no chance at all when you hit the ground at 700 km/h. WRONG!!

Mr. NTSB know it all, Your arguments are highly unprecise.

I'm giving you the G-theory written on most of the ATPL books. There are always exceptions to everything. The G's won t kill you, but if the plane hits the ground and your plane isn t solid enough to keep its shape, you will be compressed against the ground and killed that way.

Who said there was no fire on this Kenyan flight?

It's not nice that you keep on misquoting me. Example: I didn't say that flying against a hill isn't a crash. I've said that the Helios plane was not a crash like Lockerbie, where the plane went down almost vertically after the explosion.

One will indeed survive the G-force during a fall out of the sky at 700 km/h, but one cannot survive the actual impact after such. Have you then survived the G-force? No, you're dead. It's like saying that an egg can fall 100 metres without breaking. Yes, it can. But then, there is no way to save it when it hits the ground.

Back to the topic: I've said "it seems no fire broke out". If you have knowledge of a fire, off course I will accept it. But on the images I saw on TV, rescue workers were removing bodies from metal debri, plane interior and mud, and there was no sign of damage by fire.

FLY4HOURS.BE · Post by **FLY4HOURS.BE** » 08 May 2007, 08:27

Thanks, we finally tend to agree.
My post about the G's was just a theoretical explanation. Of course the impact will kill.

We'll have to wait until further investigation to know the actual reason of this crash.

And pardon my being arrogant.

earthman · Post by **earthman** » 08 May 2007, 11:43

Lockerbie was not a crash either, since the plane already disintegrated while in the air. The resulting bits and pieces crashed though.

Crash: to undergo sudden damage or destruction on impact. The Helios plane ran out of fuel and crashed into a hill.

Crash landing: an emergency landing under circumstances where a normal landing is impossible (usually damaging the aircraft). For example, United 232 at Sioux City. (This is categorized as a precautionary landing, see below.)

Emergency landing: a non-planned landing made by an aircraft in response to a crisis.

Forced landing: a landing forced by a complete loss of power to all engines.

Precautionary landing: an unplanned landing made with power still available, usually in response to a crisis inside or outside the aircraft.

teddybAIR · Post by **teddybAIR** » 08 May 2007, 12:21

I saw a documentary on national geographic channel where someone from the NTSB clearly explained the three vital conditions to survive a crash:

1. The impact has to be survivable
Research conducted as from the early '50's indicates that the maximum amount of G-forces that can be survived by a human being if he is exposed to them for about half a second is 40G's. Anything above 40 G's is very likely to kill all human life inside as your body can not cope with this kind of forces. An experiment in the late sixties where some fellow tied himself to 'a rocket on rails' showed that at 40 G's, this persons' vains in his eyeballs were ripped, and he broke a lot of bones off course. This suggests that manufacturers need to do everything to keep an airframe intact as long as the impact is equal or below 40G's, because in that case the airframe can potentially kill passengers who essentially survived the impact as such

2. Airframe should remain structurally intact
This has to be understood in the broadest possible sense. After the impact of the airframe and anything in its environment, the next danger for surviving passengers generally is its direct environment. This refers to the fuselage itself and any flying object within the cabin, whether it originates from inside or outside the aircraft. Any object flying around with sufficient speed, can potentially kill or severelly hurt people if it hits them on vital locations.

3. The direct environment should remain survivable
When the aircraft has come to a rest and all direct effects from the impact are gone, another danger appears: that the environment that is created in and directly around the cabin is not suitable to sustain life. This means that conditions are that extreme (fire, heat, toxic gases, water filled cabin,...) that it cannot sustain human life for any longer that a handfull of seconds. Measures that are taken in this direction are the use of tissues that do not easily catch fire and research on flexible fuel tanks, that do not burst as easily as classic ones.

I do not want to speculate on the cause of death of the people in the Kenyan airplane, but each of those three elements was probably fatal to a number of passengers.

I sincerely hope that all involved stakeholders take the opportunity to learn maximally from this tragic experience in order to minimize the likelyhood of this to happen again.

My thoughts are with their family and friends,
bAIR

Post by **Bruspotter** » 08 May 2007, 20:42

Hello

If a rocket attack is not the cause I think a possible reason for the so early crash of this plane might be bad maintenance or just the fact that the plane's structure is not really designed for the extreme conditions that the Kenya Airways planes have to deal with every day. I'll explain what I mean:

The intense heat on some hours of the day and the big amount of sand flying around in the deserts around the whole country of Kenya cause a lot of chafing with the structure so it erodes a lot faster and besides of that corrosion will occur much faster because of the sand and the heat. Corrosion will also be much more agressive there. No wonder that often (old) planes crash because of the combination of age (not in this case) and extreme factors in which the plane is continuous operating. Think about the 'Aloha Airlines' B737 crash in the years' '80 (end) or '90s I think (don't know anymore exactly). The plane had to deal alot with salt coming from the salt air above and around the sea, and Hawaii is an Island so... . In this case this is also the case for Kenya, but then the sand is the enemy. I think if you would know how many other (much older) planes crash in Africa every year (ex. still flying DC-3's there) without making news, you would be astomished. I can believe that some people up there have never before heard of the word 'Corrosion control'.

Anyway, I await the crash investigation and I'm very curious. But my guess goes out to this, it has a big chance seen the extreme factors there.

Best regards: Yannick

SilverJET · Post by **SilverJET** » 08 May 2007, 22:05

Bruspotter wrote:Hello

If a rocket attack is not the cause I think a possible reason for the so early crash of this plane might be bad maintenance or just the fact that the plane's structure is not really designed for the extreme conditions that the Kenya Airways planes have to deal with every day. I'll explain what I mean:

The intense heat on some hours of the day and the big amount of sand flying around in the deserts around the whole country of Kenya cause a lot of chafing with the structure so it erodes a lot faster and besides of that corrosion will occur much faster because of the sand and the heat. Corrosion will also be much more agressive there. No wonder that often (old) planes crash because of the combination of age (not in this case) and extreme factors in which the plane is continuous operating. Think about the 'Aloha Airlines' B737 crash in the years' '80 (end) or '90s I think (don't know anymore exactly). The plane had to deal alot with salt coming from the salt air above and around the sea, and Hawaii is an Island so... . In this case this is also the case for Kenya, but then the sand is the enemy. I think if you would know how many other (much older) planes crash in Africa every year (ex. still flying DC-3's there) without making news, you would be astomished. I can believe that some people up there have never before heard of the word 'Corrosion control'.

Anyway, I await the crash investigation and I'm very curious. But my guess goes out to this, it has a big chance seen the extreme factors there.

Best regards: Yannick

Please come on, an aircraft of six months with environmental corrosion? If you believe this you also believe pigs can fly! And the bad maintenance, I don't believe this is an issue too. Kenya Airways is a very good company, they did tremendous efforts to renew their fleet within the passed years. And they are for about 26 % in control of KLM. Kenya Airways Engineering does all the maintenance, some maintenance is done outcontracted to KLM Maintenance or other mostly European maintenance facilities. So please think twice before posting something like this.

Robertcarion · Post by **Robertcarion** » 08 May 2007, 22:39

And may I add that Nairobi is not surrounded by desert but by savannah, there is a slight difference. Also humidity in Nairobi is not that great. I have been there, you can trust me. The thing is apparently from what witness have said, there is a big hole where the plane crashed, filled with water with the plane covered up, so this looks more like the aircraft nose-dived in the ground, doesn't look much like the plane suffered structural failure. Anyways its very sad when something like this happens.

achace · Post by **achace** » 09 May 2007, 03:24

Just read in Flight of an emergency AD on the 737-800 regarding spoiler deployment and loss of control possibilities after take-off.

Lets all hope it is just a coincidence.

Cheers
Achace

Flying-Belgian · Post by **Flying-Belgian** » 09 May 2007, 09:10

KQ's chief pilot has stated that the 737's wreckages were found at a distance of 5,42 km of DLA airport.
So according to him, the aircraft hasn't been airborne for more than 30 seconds.

Though he did not want to enter polemics with Cameroon authorities, this is really puzzling, when one remembers that they were looking for the plane at distance of more than 150 km !!!

I would not like to investigate over there...

F.B

David747 · Post by **David747** » 09 May 2007, 09:12

Unfortunately, I haven't been following this story as closely as I should, but is there any initial cause to the accident?

teddybAIR · Post by **teddybAIR** » 09 May 2007, 11:15

Bruspotter wrote:
Think about the 'Aloha Airlines' B737 crash in the years' '80 (end) or '90s I think (don't know anymore exactly). The plane had to deal alot with salt coming from the salt air above and around the sea, and Hawaii is an Island so... .

Another reason why the fuselage of the aloha 732 corrupted was the amount of cycles the the airframe had already performed. At the time of the incident the plane was already 19 years old and had made 89.090 cycles, whyle the 737-200 is only designed for about 75.000 cycles. This high amount of cycles in such a short period of time was caused by the fact that the airplane was mainly operated on short inter-island flights and that the rate of compression and decompression was far higher than for other aircraft.

Ofcourse, the salty environment only added to the effect, but the main cause is probably that the airframe had performed an excess of 14.000 cycles!

Source: NTSB

Robertcarion · Post by **Robertcarion** » 09 May 2007, 13:40

achace wrote:Just read in Flight of an emergency AD on the 737-800 regarding spoiler deployment and loss of control possibilities after take-off.

Lets all hope it is just a coincidence.

Cheers
Achace

Can someone confirm if the boeing 737-800 of KQ is a short-field performance, because that is the type the AD is aimed at.

regi · Post by **regi** » 09 May 2007, 15:59

so my rocket attack idea comes into spotlight.

SilverJET · Post by **SilverJET** » 09 May 2007, 16:57

I don't know what caused this crash, I hope the investigators will reveal what caused it in the future.

Knowing the fact that there where thunderstorms and heavy rain. Could it be possible something like windshear could have coused the plane to stall and finally crash? I know it happend with a Mandarin Airlines MD11 and a Delta Tristar in the past, but twice on approach. I don't know if this could happen on take off? When windshear occurs it pushes the plane vertical down due to a great amount of airflow from above to the grond.
(Correct explanation of windshear in Dutch >http://nl.wikipedia.org/wiki/Windshear English > http://en.wikipedia.org/wiki/Wind_shear)

FLY4HOURS.BE · Post by **FLY4HOURS.BE** » 09 May 2007, 17:42

Windshear on take-off is only a factor when it becomes a tailwind as crews are trained for take-offs within the limits of the plane which are predefined in the 737 handbook.
But then again take-off in tailwind is not recommended in the 737 handbook in excess of a certain number of KTS.
The question will be whether the crew have respected these limitations.

Moreover, 737's take-off with 80% of the available thrust, and still have alot of power in reserve. The plane wasn t filled up to the maximum.
So you gotta be strong to make it stall in a normal take-off.

Corrosion is out of question, as dry and hot climates are actually the best ways of protecting the structure. Why do they otherwise all park their airliners in the deserts in the USA?
There is not that much maintenance to do on a new bird.

A terrorist attack is to be considered.

A production problem can also be considered.

Hope they recover the black-boxes.