Any Signs Of Heavy Brakeing On The AF A340?

CV990 · Fri Aug 05, 2005 3:13 am

Hi!

I just wanted to comment that if you look to the picture were you can see the burned remains of the AF A340 and also you have a good view of the runway ending you can notice two things:

1 - You clearly see the tracks of the undercarriage on the grass.
2 - You don't see ( at least it's not visible ) any traces of a last minute/second heavy breaking on the runway. There are now signs of blown tyres or pieces of rubber. If the crew was seeing the end of the runway so close they would probably try the enormous effort to make a very heavy breaking, but we don't see that!
Regards

AsstChiefMark · Fri Aug 05, 2005 3:46 am

Breaking? Yup. It broke...into lots of pieces. Wink

Mark

777DadandJr · Fri Aug 05, 2005 4:02 am

You know, amongst all the speculation of what went wrong on AF358, there are two things I find very intriguing.

Based on interviews I've seen with some of the pax, they all seemed to relate that the a/c lost electrical power, just before touchdown. Was the plane struck by lightning as many speculate? Possibly. I know by some pax accounts, they say they saw lightning, but none said they felt it. Wouldn't you be able to feel a lightning strike on the a/c, at least one that was strong enough to knock out the electrical power? If the pax saw lightning, but didn't feel it, could there have possibly been an electrical failure?

The other thing is, in one interview with a Canadian woman who seemed reasonably intelligent, she said she felt that the a/c was going way long on touchdown. Now, at first you might think that most pax probably wouldn't know long from short on landing. But with this woman, she qualified herself by saying that she flys approximately 250,000 miles a year. With that many miles under her wings, I would think that she would know her long from her short.

That leads me to ask, was the a/c indeed way long on the rwy? Could the weather (wind) have caused the a/c to "float" too long before settling down onto the rwy? If the a/c touched down more than 1/2 way down the rwy, it would be reasonably that they could not stop in time.

Just some thought. Feel free to clarify any of my thoughts.

Russ

777DadandJr · Fri Aug 05, 2005 4:03 am

Deleted due to duplicate post.

[Edited 2005-08-04 21:13:34]

lowrider · Fri Aug 05, 2005 4:06 am

You may not see any skid marks if the aircraft was hydroplaning.

FlySSC · Fri Aug 05, 2005 6:40 am

777DadandJr,

You shoud read this :

https://www.airliners.net/discussions...eneral_aviation/read.main/2255266/

No. There was no lost of electrical power.The pre-landing & pre-Take off procedure requires that the F/A turn off all the cabin lights.
THAT'S what some PAX called a "loss of power".

The investigators are now almost sure than no lightning hit the plane before or/and during the landing.
They also said that the plane touched the Rwy at the right place, and not "half Rwy" as some may have said.

You must be very careful with the PAX testimonies...and the personal interpretation they give to some events they often don't understand.

Finkenwerder · Fri Aug 05, 2005 6:44 am

Heavy braking means............The aircraft stops. No significant braking occurred.

A ditch stopped this aircraft not the brakes.

ACDC8 · Fri Aug 05, 2005 6:45 am

I don't want to speculate, because there are always many factors involved in an accident/incident. But the way I see it, this was just an unfortunate case of hydro-planning, thus no brake marks. What caused the A340 to get into that situation, I don't know and that's something none of us will know, at least until the official reports start coming out.

LFutia · Fri Aug 05, 2005 6:53 am

ok then why didnt the spoilers go up then?

ACDC8 · Fri Aug 05, 2005 6:58 am

Quoting LFutia (Reply 8):
ok then why didnt the spoilers go up then?

I'm not sure about the operational procedures on the A340 myself, but it has been suggested that after the aircraft slows down to a certain speed they retract automatically. They may not have been set in the first place for what ever reason (i.e.: the conditions may not have required their use). In my personal opinion, I don't think that the spoilers would have helped much either. Best thing to do, is wait for the reports.

LFutia · Fri Aug 05, 2005 7:04 am

well can't the pilots put them up manually?

ACDC8 · Fri Aug 05, 2005 7:12 am

Quoting LFutia (Reply 10):
well can't the pilots put them up manually?

I'm not sure about the A340 myself, but the basic settings on speed brakes are:

OFF
ARMED
ON

When they are in the ARMED position, they will automatically deploy once the aircraft touches down on the runway. Depending on the aircraft type, they will remain deployed until either they are manually retracted, the throttles are applied (i.e.: go around) or until the aircraft slows down to a certain speed.

In most aircraft the speedbrakes can be manually deployed at various settings for speed control during the descent as well as during landing.

However, if they were not deployed (either manually or automatically) in this situation, I'm sure there may have been a reason, runway conditions or wind conditions perhaps.

gipper913 · Fri Aug 05, 2005 7:25 am

Quoting FlySSC (Reply 5):
No. There was no lost of electrical power.The pre-landing & pre-Take off procedure requires that the F/A turn off all the cabin lights.
THAT'S what some PAX called a "loss of power".

Well...we all know it is SOP to turn off overhead cabin lighting on landing, but certainly not ALL lights like reading lights, etc. So, let's wait and see the final report before dismissing the notion of power failure.

[quote=FlySSC,reply=5]The investigators are now almost sure than no lightning hit the plane before or/and during the landing.
They also said that the plane touched the Rwy at the right place, and not "half Rwy" as some may have said.

Please tell us how and why you have access to the preliminary results of the investigation. Related to an investigator? Or, in all reality, are you guessing like everyone else?

As to overall thread:

CV990, as AsstChiefMark pointed out hilariously, you have run into an English language issue breaking = falling apart while braking = stopping a vehicle in motion.

As with other posters, I would agree that a lack of signs of hard braking indicate the possibility of hydroplaning.

Derik737 · Fri Aug 05, 2005 9:34 am

Quoting Gipper913 (Reply 12):
As with other posters, I would agree that a lack of signs of hard braking indicate the possibility of hydroplaning.

Or that the Antiskid system was doing its job. If I remember correctly, a Jazz airplane landed in front of the Air France. It will be interesting to find out what the runway conditions were when they landed.

skysurfer · Fri Aug 05, 2005 9:39 am

Heavy Braking? Well if it was AQUA/HYDROplaning then you wouldn't be able to tell how hard it was braking, and you wouldn't be able to tell from the brake disks (i assume) due to the fact the rain would have cooled them off before anyone got a significant picture of the brakes/wheels etc.

Cheers

ps, i'm glad everyone got out ok from that accident Smile

MD11Engineer · Fri Aug 05, 2005 10:26 am

I experienced a lightning strike on board of a B747 once. It is not just the flash, but a very loud bang (sounded to me like 5 kgs of dynamite going off without tamping).

The Airbus definitely suffered some damage when it went down into the ravine. The fire at the tail was probably cause by either the trim tank in the horizontal stabliser being punctured or the fuel lines to is being broken. Possibly the APU was running during approach, so that the escaping fuel found an ignition source.

Jan

VC-10 · Fri Aug 05, 2005 10:38 am

Quoting MD11Engineer (Reply 15):
horizontal stabliser being punctured

The trim tank would be empty at that phase of flight, but the trim pipe would be supplying fuel to the APU.

transswede · Fri Aug 05, 2005 10:43 am

I have experienced a lightning strike as well, but in a 777. (MCO-ATL)

There was a flash as the lightning struck or exited the wing I was looking out at, and a loud bang/shake, as if you hit a speed-bump going very fast. We continued to the destination, but the plane was grounded after landing do to minor skin damage.

MD11Engineer · Fri Aug 05, 2005 10:46 am

Quoting VC-10 (Reply 16):
Quoting MD11Engineer (Reply 15):
horizontal stabliser being punctured

The trim tank would be empty at that phase of flight, but the trim pipe would be supplying fuel to the APU.

It should be empty, but you will often still have a few hundred pounds of fuel in there. With the plane ending up in the tail up position, it is highly unlikely that fuel would be running upwards through the APU fuel line without a boost pump running, which shouldn't be if the plane's electric power is off.

Jan

TUNisia · Fri Aug 05, 2005 11:01 am

I know in some of the pictures of the plane after it crashed you could still see the thrust reversers of the A340 engines deployed (in the open position).

VC-10 · Fri Aug 05, 2005 11:07 am

Quoting MD11Engineer (Reply 18):
It should be empty, but you will often still have a few hundred pounds of fuel in there.

In my experience A340's arrive with no more than about 80kgs indicating in the TT.

tribird1011 · Fri Aug 05, 2005 11:27 am

Quoting LFutia (Reply 8):
ok then why didnt the spoilers go up then?

Has it been proven yet that the spoilers didn't deploy?? I don't think so.

As well, in one of the pics on the Air Disaster web site shows that the spoilers on the right wing look like they are up (deployed)

let's wait for the official report to see what happened - perharps it was all a normal approach and landing, followed by a microburst at the threshold of 24L, resulting in an increased tailwind, resulting in the A340 not being able to stop - perhaps it was as simple as this, perhaps not -- let's wait and see...

glad everyone made it out though...

Toulouse · Fri Aug 05, 2005 4:24 pm

Quoting LFutia (Reply 8):
ok then why didnt the spoilers go up then?

The spoolers were deployed from what I've heard of the initial investigation.

FlySSC · Fri Aug 05, 2005 4:36 pm

Gipper913, (Reply#12)

I am not "guessing as everyone else".
The informations I related were given during the last Press conference of Real Levasseur, Chief of Investigators.

BO__einG · Fri Aug 05, 2005 4:48 pm

I heard that the particular runway itself at Pearson airport was not the type and grade of concrete/ashpalt used to effectively control standing water from rainfalls.
I know that many airports have ashpalt grooved runways to help control those standing water better by reducing or eliminating pools and to get the water moving off the runway.

I think that the approach and landing was normal. Once the plane was on the ground as the reversers popped out, something happened.. Maybe hydroplane like what many are speculating and that seems to make lots of sense in this case.

Finkenwerder · Fri Aug 05, 2005 9:18 pm

From memory the spoilers will deploy with Weight on but as soon as power is applied above idle they stow. I'm not sure if applying power above idle in Thrust reverse (TR) will stow the spoilers. The TR doors are in the deployed position TR would normally be cancelled below 60kts. The Aircraft probably left the runway in excess of this speed.

hoya · Fri Aug 05, 2005 10:50 pm

News reports state that the A340 hit the ravine at almost 100mph, indicating that there probably wasn't any heavy braking, or that there was some serious hydroplaning.