noelg
Posts: 2313
Joined: Fri Apr 26, 2002 11:39 pm

Wheel Lock On Landing? (Video)

Sun Jul 02, 2006 7:32 am

I was at MAN filming the arrivals for the A.net meet this morning, and in amongst the A.netters appeared the Onur Air A300.

I took this video of it landing (apologies for the amount of compression Photobucket put on; I have a much higher res version if anyone wants to email me for it):




The aircraft appears to bounce quite a distance (or a very long flare), and engages reversers much later than they usually do.

Notice how when the aircraft is right in front of you when there is suddenly a lot of smoke from the rear wheels. It's definately not liquid on the runway, as no other aircraft caused such a spray, and even if it were water wouldn't the front wheel be smoking/misting too?

Also, right near the end when the engines quieten down a bit I'm sure I can hear the screeching of tyres...

Could this be the brakes locking on and could this not be dangerous?

Cheers
Noel
 
cymro
Posts: 87
Joined: Sun May 08, 2005 10:51 pm

RE: Wheel Lock On Landing? (Video)

Sun Jul 02, 2006 7:36 am

I cant get the video to play is it just me?
 
erjmech
Posts: 4
Joined: Sat Jul 01, 2006 7:14 am

RE: Wheel Lock On Landing? (Video)

Sun Jul 02, 2006 7:51 am

It could be an anti-skid failure or brakes. I have seen a/c with shredded brakes and tires when the anti-skid system does not work properly. Normally and I can not speak for Airbus each main has a wheel speed transducer that sends a signal to the appropriate controller for the brakes. If a wheel is locking up something has failed or......for Mid-Atlantic fans when a pilot lands with the parking break set......
 
noelg
Posts: 2313
Joined: Fri Apr 26, 2002 11:39 pm

RE: Wheel Lock On Landing? (Video)

Sun Jul 02, 2006 7:55 am

Quoting Cymro (Reply 1):
I cant get the video to play is it just me?

Could be you don't have Flash installed - I think it uses Flash to work?

If not, try this:

http://smg.photobucket.com/albums/v6...on=view¤t=OnurAirLanding.flv

Noel
 
cymro
Posts: 87
Joined: Sun May 08, 2005 10:51 pm

RE: Wheel Lock On Landing? (Video)

Sun Jul 02, 2006 8:02 am

Quoting Noelg (Reply 3):

Could be you don't have Flash installed - I think it uses Flash to work?

Thanks I did have it flash installed but was running at version 7 not 8 as required sorted now.
 
worldxplorer
Posts: 360
Joined: Mon Feb 14, 2005 11:12 am

RE: Wheel Lock On Landing? (Video)

Sun Jul 02, 2006 9:43 am

Quoting NoelG (Thread starter):
Also, right near the end when the engines quieten down a bit I'm sure I can hear the screeching of tyres...

I heard that too. Something went wrong. I am no expert so I am just taking an educated guess.

If one tire burst I would suspect that there would just be one burst of smoke rather than several. Several tires could have burst I suppose. The question is why were they breaking so hard? NoelG, how close is the a/c to end of the runway? If the a/c is close to the end then perhaps due to the late engagement of the thrust reversers the a/c needed to break hard. If there was plenty of runway left then I would suspect some sort of a malfunction with auto-brakes.

Like I said, I am just taking educated guesses. Hopefully someone with more technical knowledge will pop in on this thread. I am quite curious myself.

WorldXplorer
 
noelg
Posts: 2313
Joined: Fri Apr 26, 2002 11:39 pm

RE: Wheel Lock On Landing? (Video)

Sun Jul 02, 2006 7:06 pm

Quoting WorldXplorer (Reply 5):
NoelG, how close is the a/c to end of the runway?

He was getting on to the other end of the runway, as you can see from my diagram:

http://www.marshgiddings.com/images/onurairdiagram.jpg

He was between the two exits as you can see - but not dangerously close to the other end as many other aircraft were turning off past where he was - although he was maybe a little faster at that point than the other aircraft.

I don't think it was a blow out as he taxied absolutely fine after that and there was no easily visible damage to the tires. There were also no sparks or anything (although maybe at low speed there wouldn't be anyway).

Cheers
Noel
 
musapapaya
Posts: 990
Joined: Mon Apr 05, 2004 10:02 am

RE: Wheel Lock On Landing? (Video)

Sun Jul 02, 2006 8:34 pm

Will that be some overheating on the brakes? I would suggest outting this to the Tech/Ops department for discussion.

Regards
William
Lufthansa Group of Airlines
 
dl757md
Posts: 1482
Joined: Mon May 24, 2004 9:32 am

RE: Wheel Lock On Landing? (Video)

Mon Jul 03, 2006 3:08 am

Quoting WorldXplorer (Reply 5):
If one tire burst I would suspect that there would just be one burst of smoke rather than several. Several tires could have burst I suppose.

No tires burst. You would have heard it in the video as it is a very loud explosion when one lets go.

DL757Md
757 Most beautiful airliner in the sky!
 
jarheadk5
Posts: 216
Joined: Thu Nov 03, 2005 2:45 pm

RE: Wheel Lock On Landing? (Video)

Tue Jul 04, 2006 3:32 am

The smoke was definitely from braking. I've got no input on anti-skid issues, other than to say something was obviously not working correctly.
If you watch carefully, you can detect the nose dipping a bit, just before the tires lock the first time, as the brakes are applied.

Maybe the crew wanted to make the turnoff at Alpha Echo really badly...
Cleared to Contact
 
bio15
Posts: 1048
Joined: Fri Mar 23, 2001 8:10 am

RE: Wheel Lock On Landing? (Video)

Wed Jul 05, 2006 5:12 am

Quoting WorldXplorer (Reply 5):
If the a/c is close to the end then perhaps due to the late engagement of the thrust reversers the a/c needed to break hard.

The thrust reversers are not part of the equation in calculating the landing distance. Even if the thrust reversers had not deployed at all, the aircraft should have been able to brake safely in the available runway distance.

If you take a closer look the spoilers are only deployed after the second touchdown (since the aircraft bounces off the runway once). The spoilers are usually deployed right after the aircraft touches the runway so it sticks to the ground and braking commences in a timely fashion. The spoiler extension delay apparently leads to the fly-by that takes place during the bounce, and this shortens the available braking distance in a couple hundred feet or so.

My guess is that probably by attempting a smooth landing the pilots ended up overshooting this initial braking point, and probably the need of an early runway exit summed up to generate a landing with heavy braking. Have in mind that everything here are assumptions, only the front seaters in the A300 that day have the facts for this interesting landing.


Alfredo

Who is online

Users browsing this forum: DiamondFlyer and 10 guests