A380 MLG bogies ?

[rb1957]

I've watched several A380s land. It looks like the MLG bogies are pitched nose down for landing, contacting with the front tire first. As opposed to other jets which contact with the aft wheel first.

I wonder why ?

another day in paradise, or is paradise one day closer ?

 

[ERAU82]

Landing on the forward or aft tires on a bogie configuration is to alleviate loading to the strut and to lessen the pitch moment of the aircraft. Most aircraft land aft tires first but there are several besides the A380 that lands forward tires first - the 767-400 for example.

 

[WKTaylor]

A bit off subject... RE A380 "[aft/outboard] square tyre[tire]' after it taxis in [hope this is not a repeat].

Aviation experts baffled after British Airways A380 lands at Heathrow with a SQUARE tyre
Captain of the A380-800 received a tyre pressure warning on take-off Aeroplane flew from Hong Kong to London Heathrow on a 13-hour journey One pilot said that the tyre probably detached from the wheel on landing An aviation expert said the shape was a quirk of A380 weight distribution. See more news from British Airways as a flight lands with a square tyre

By Georgia Diebelius and Ted Thornhill for MailOnline

http://www.dailymail.co.uk/travel/t...-Airways-A380-lands-Heathrow-SQUARE-tyre.html

Published: 09:26 EST, 9 May 2016 | Updated: 04:28 EST, 10 May 2016

An astonishing picture has emerged of a square-shaped tyre on a British Airways A380 that touched down at London's Heathrow Airport.

Aviation experts have been left baffled by the misshapen deflated wheel, which was part of the landing gear on a flight that arrived from Hong Kong on Friday.

The Civil Aviation Authority described the incident as 'curious', a serving pilot admitted he wasn't sure how it could have occurred and even an aviation safety expert from the Royal Aeronautical Society said the square tyre was 'a bit mysterious'.

Engineers were left puzzled when upon inspection of the damaged aft right outboard body tyre, it appeared to be shaped like a square (pictured)

The captain of the Airbus A380-800 received a loss of tyre pressure warning on take-off.

Following the indication, the crew made the decision to continue the flight and reportedly called ahead to London to request a tow tug as a precaution in case the aircraft could not taxi to the gate under its own power.

After the 13-hour flight the double-deck, wide-body Airbus landed safely on runway 09L and made its way to the gate without assistance.

According to the Aviation Herald, crew were left puzzled when an inspection revealed that the right outboard body tyre had deflated not just at the bottom, but in such a way that it appeared squarish.

Patrick Smith, author of best-selling book Cockpit Confidential, told MailOnline Travel that he was not certain how the tyre had become square.

He said: 'The photo appears genuine, but I'm unsure how such a thing would happen, exactly.

'The tyre deflated and the subsequent rotation caused it to fold in on itself in four symmetrical segments.'

A Civil Aviation Authority spokesman said: 'It is a curious one. Not seen anything like it before.'

“ It is a bit mysterious. It's a safe aircraft, but it's an interesting phenomenon”

Aviation safety expert Kumar Mysore

Even aviation safety expert Kumar Mysore, from the Royal Aeronautical Society, said that the event was a 'bit of a mystery'.

He told Mailonline Travel that the reason for the square shape was very probably a quirk of the way the weight is distributed onto the wheels in an A380.

He said: 'It is a bit mysterious, an interesting phenomenon.

'The deflated tyre would have been round when the aircraft touched down, it would not have rotated on four square edges as the picture would have us believe. The round wheel would have rotated on the flat ground, with the deflated tyre wobbling around the wheel.

'The tyre has taken this shape after the aircraft came to a halt.

'The aircraft weight is on the wheel - made from a well-designed light but strong aluminium alloy. You can see that the wheel is not damaged at all, as it is designed to take this weight.

'The effect of the weight on the deflated tyre is the same as when you squeeze a rubber ring toy with different intensity, it can turn into a different shape.

'In an A380, for this particular situation, it happens to be squarish. In a 747, for instance, the load of the aircraft does not give rise to this particular shape.'

He added: 'The reason for the deflation could have been overheating brakes over-pressurising the tyre and making it burst - though that's unlikely as the pilots receive a warning if the brakes are too hot - or a foreign object on the runway at Hong Kong cutting into the tyre. In all these cases pilots are well trained to handle the situation safely.'

A serving airline captain, meanwhile, stressed that the aircraft was never in danger.

He said: 'To lose one [wheel] is no big deal.'

A spokesperson for British Airways said: 'Our flight landed normally last Friday with one of its 22 tyres deflated.

'The A380, in common with other large commercial aircraft, is designed to be perfectly safe when landing with a deflated tyre.

'Our engineers quickly changed the tyre and the aircraft went back into service.'

Read more:

http://www.dailymail.co.uk/travel/t...lands-Heathrow-SQUARE-tyre.html#ixzz48GBOR2DE

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Regards, Wil Taylor

o Trust - But Verify!
o We believe to be true what we prefer to be true. [Unknown]
o For those who believe, no proof is required; for those who cannot believe, no proof is possible. [variation,Stuart Chase]
o Unfortunately, in science what You 'believe' is irrelevant. ["Orion", Homebuiltairplanes.com forum]

 

[FreddySvan]

About that A380 tyre. I guess the pressure was lost at takeoff because of a leak between the tyre and rim, then it somehow sealed itself at cruising altitude. When descending the increasing external air pressure made the tyre implode. I have seen a oil barrel implode and it gets that square shape as well.

Just my 5 cents.