[TusharK]

Michelin will be supplying Indigo Airlines with tyres for its Airbus and ATR aircrafts. These planes will be fitted with Michelin Air radial tyres that are claimed to reduce operation costs.



The Michelin Air X radial tyre uses a radial casing design and is constructed using fewer components, making it more environment friendly. It is claimed to offer better fuel efficiency and reduced operational costs through an increased number of landings. The tyre has improved resistance to foreign object damage.

Indigo Airlines was set up in August 2006. Today, it operates flights to 48 domestic and 11 international destinations and has a fleet of 189 aircrafts. The airline has been adding A320 NEO family planes to its fleet. The planes come equipped with Michelin tyres.

Link to Team-BHP News

[honeybee]

Any idea about pricing etc?

Also what is the rated number of landings these tyres can survive? It would make an interesting study.

[Jeroen]

Originally Posted by honeybee

Also what is the rated number of landings these tyres can survive? .

It really depends on the plane. And of course how that plane is used. Always full, lots of taxing and cross wind landing will lead to more wear.

Hard touch downs versus featherlight touch downs makes a difference too. (the way the tyre spins up when it touches the tarmac is relevant)

But on commercial jets they can do anywhere between 100 - 250 landings.

Tyres get inspected before every flight. Many tyres can be retreaded too!

Jeroen

[honeybee]

A newbie question.

When touching down, are the tyres stationary and start spinning only after touching the ground? Or is there a way to get them spinning beforehand, so they wear less?

[Zappo]

That's actually an interesting thought and I had a couple of reasons popping up in my mind. Still I decided to look this up on the Net. And I found the below excerpt to be really interesting...

It's just not cost-efficient. Any weight-add produces more fuel consumption, any system results in more maintenance costs. It's just easier to change the tires if they're worn out. source: Aerospace engineering

[Jeroen]

Originally Posted by honeybee

When touching down, are the tyres stationary and start spinning only after touching the ground? Or is there a way to get them spinning beforehand, so they wear less?

Although in theory a good idea, nobody has been able to come up with a workable solution. It is all to costly, too complex and too heavy. Everything you add to an aircraft carries a weight penalty. Which means you need to carry and burn more fuel. Replacing tyres or retreading them is still the most economic solution. I think we discussed this on one of the aviation threads on the forum before.

I know of only one fighter jet where they experimented with spinning up the nose wheel. Not so much to do with tyre wear. This particular jet had a very long nose gear and high landing speeds. The nose wheel having to spin up on touch down created extra drag and sometime broke the nose gear upon landing. Not sure how they fixed it in the end. Probably just firmed up the nose gear rather then some spin device

Jeroen

[sharktale]

Originally Posted by honeybee

When touching down, are the tyres stationary and start spinning only after touching the ground? Or is there a way to get them spinning beforehand, so they wear less?

I think they're stationery at the moment of landing, cause otherwise we'd definitely hear a humming noise from below too from the motors.


Your idea seems interesting in theory, but isn't practical IMHO.
Remember, sometimes in those RC vehicles in which as a kid we'd leave the wheel free-running and then manually put the car on the surface, it created a whole lot of stress on the motor and resulted in immediate power-loss. The same principle could be applied here...

[Sutripta]

Look at all the burnt rubber marks on the runway at the point where most airliners touch down. Tyres don't hit the ground running!

Regards
Sutripta

[Jeroen]

Have a look here:

https://www.youtube.com/watch?v=fSodzuCwRYI

A little anorak fact:

When the planes take off and retracts the gear, on most larger aircraft the brakes are applied while retracting. Except for the nose wheel as they rarely, if ever, have brakes.The might have some mechanical devices fitted to stop them spinning too. (Bump stop, or snubbers as they are sometimes called)

The main reason for stopping them is the gyroscopic effect. These are quite big wheels/tyres, heavy and spinnig fast. So when the plane starts turning and pitching whilst the wheels are still spinning, there will be substantial forces on the gear and it’s mounts. So the de-spinning tends to starts as soon as the landing gear starts to retract, sometimes before just to reduces stress on the landing gear due to gyroscopic effects.

Also, preferably you don’t want a spinning wheel in the wheel well. It might still contain some grit and if that is thrown out with force it is likely to hit hydraulic and or electrical lines in the wheel well.

Jeroen

[Ketz]

How would these tyres offer better fuel efficiency? I understand the low operational costs due to reduced tyre changes but don't understand the fuel efficiency part.

[aditya.86]

Originally Posted by Ketz

How would these tyres offer better fuel efficiency? I understand the low operational costs due to reduced tyre changes but don't understand the fuel efficiency part.

I guess its the same as cars. Lower rolling resistance, lesser the fuel consumed.

[Ketz]

Originally Posted by aditya.86

I guess its the same as cars. Lower rolling resistance, lesser the fuel consumed.

what would be the contribution to fuel savings due to the rolling resistance of tyres of the aircraft? The big chunk of fuel consumption anyways happens airborne.

My point was, a tyre company claiming safety and durability aspects are differentiators for aircraft tyres makes sense. Fuel saving does not seem logical unless i am missing something.

[Jeroen]

Originally Posted by Ketz

what would be the contribution to fuel savings due to the rolling resistance of tyres of the aircraft? The big chunk of fuel consumption anyways happens airborne.

My point was, a tyre company claiming safety and durability aspects are differentiators for aircraft tyres makes sense. Fuel saving does not seem logical unless i am missing something.

True, obviously plane use most of their fuel in the air, flying.

But make no mistake, aircrafts, especially on the larger and busies airports do taxi a lot and they use up a lot of fuel.

Here in the Netherlands at Amsterdam airport (certainly not the biggest airport in the world) we have a runway that will take up to 20 minutes of taxi time to get from/to the terminal building! A 747 will easily burn about a tonnes of fuel during the taxi.

Fuel efficiency in aviation is being extremely focussed on any possibilities to save fuel. No matter how small. It still tends to add up because of the sheer size of the industry. Shaving a few kilograms of the onboard trolleys can safe hundreds of thousands of dollars in less fuel on an annualised basis.

So, no it won’t be a huge saving. But it still adds up!

Jeroen

[anandpadhye]

I have been trying to follow the developments in the Indian tyre industry since a few years and I have read the following:

- Aircraft tyres are high tech stuff as they have to withstand high load, high acceleration and high braking. Offroad and truck/bus tyres have to withstand only high load and performance car tyres have to withstand only high acceleration and braking. Aricraft tyres have to face all 3!

- Only the big 3 have the technology (Michelin, Bridgestone and Goodyear) and they won't share it with anyone

- Indian tyre manufacturers haven't been able break through except MRF who started manufacturing Sukhoi main wheel tyres in India in 2014 after what they claim as 6 years of in house research

- Recently they started manufacturing Sukhoi nose wheel tyre:

https://www.thehindubusinessline.com...le20752830.ece

[Sutripta]

Originally Posted by aditya.86

I guess its the same as cars. Lower rolling resistance, lesser the fuel consumed.

Originally Posted by Jeroen

True, obviously plane use most of their fuel in the air, flying.
...
So, no it won’t be a huge saving. But it still adds up!

I thought fuel saving was because these were lighter.
Now if someone could actually dig up the weights.

Originally Posted by anandpadhye

I have been trying to follow the developments in the Indian tyre industry since a few years and I have read the following:
...
https://www.thehindubusinessline.com...le20752830.ece

IIRC, Dunlop used to manufacture aircraft tyres in India.