Airliners.net

At the company I work for we maintain following Tire Pressures on the A32X Family Aircrafts.

A320 - NLG 178 to 187 & MLG 200 to 210.

A321 - NLG 168 to 177 & MLG 212 to 222.

While I do understand the increase in MLG Tire pressure on A321 due to the obvious load increase, I could not find any particular reason for the reduction of NLG pressure on the A321.

Kindly advise Tire pressure trend in your company for the Nose wheels on longer Aircrafts of the family like A321/A333/B773.

Not sure why, but the 737s here are similar. -400 and -500 they run the same wheels and tires, with the main tire pressure the same all around but the nose tire pressure slightly less on the -400 than on the -500s.

Maybe the 321 has less weight on the NLG than the 320 does? You'll really see those differences when you carry out a re-weigh on the airplanes. Some are nose heavy and some are nose light. For example, when jacking an Embraer 175, there is no nose jack, we use one on the tail instead.

Thanks CanadianNorth & m1m2.

Looks like Nose wheel on A321 carries a bit less load than the A320.
But what difference would it make if we keep the same pressure for Nose wheel on longer jets. Won't it ensure fleet commonality?

Any idea the trend on widebody families like A332/333 and B772/773?

StereoTechque wrote:

But what difference would it make if we keep the same pressure for Nose wheel on longer jets. Won't it ensure fleet commonality?

Under- or overinflated tires wear unevenly. While an underinflated tire is much worse than an overinflated tire you don't want either. An overinflated tire has less contact area with the ground.

StereoTechque wrote:

Any idea the trend on widebody families like A332/333 and B772/773?

B777 tire pressures for maximum airplane gross weight in psig (sorted by MTOW):

NLG:
B777-200/200ER: 202
B777-300: 200-202
B777-200LR/B777F: 214-218
B777-300ER: 187-215

MLG:
B777-200/200ER: 205-215
B777-300: 215
B777-200LR/B777F: 218
B777-300ER: 221

The trend is the same. Especially when you look at the 200LR and 300ER with a comparable MTOW (less than 1.2% difference)

Horstroad wrote:

B777 tire pressures for maximum airplane gross weight in psig (sorted by MTOW):

So Boeing also pretty much has the same trend for the family aircraft.
Longer the jet, slightly lesser the pressure of the Nose wheel.

StereoTechque wrote:

Horstroad wrote:

B777 tire pressures for maximum airplane gross weight in psig (sorted by MTOW):

So Boeing also pretty much has the same trend for the family aircraft.
Longer the jet, slightly lesser the pressure of the Nose wheel.

As a first thought, it may be about lever arm and resulting momentum. Longer arm for longer plane.

kalvado wrote:

StereoTechque wrote:

Horstroad wrote:

B777 tire pressures for maximum airplane gross weight in psig (sorted by MTOW):

So Boeing also pretty much has the same trend for the family aircraft.
Longer the jet, slightly lesser the pressure of the Nose wheel.

As a first thought, it may be about lever arm and resulting momentum. Longer arm for longer plane.

A lot of aircraft mass is just in front of the main gear (engines, a good portion of the wing, fuel). This stays the same when the aircraft is stretched and so, although overall heavier, there is less weight on the nosewheel due to noted lever arm.

kalvado wrote:

StereoTechque wrote:

Horstroad wrote:

B777 tire pressures for maximum airplane gross weight in psig (sorted by MTOW):

So Boeing also pretty much has the same trend for the family aircraft.
Longer the jet, slightly lesser the pressure of the Nose wheel.

As a first thought, it may be about lever arm and resulting momentum. Longer arm for longer plane.

^This. The longer fuselage and location of CG puts less weight on the nose of a longer aircraft.

Wacker1000 wrote:

^This. The longer fuselage and location of CG puts less weight on the nose of a longer aircraft.

Yes that is exactly I think the reason is.
In fact if we continue to fill up same pressures as the shorter siblings, it will result in Nose tyre a bit lightly loaded causing Crown wear of the tyre