Spacesaver for an A330 ?

[45 before POL]

As a fellow aviation industry employee travelling back from sunnier climes aboard a charter(name not mentioned) nearly 24 hours late due to a nose wheel change... It was obvious to the eye that the replacement tyre was not a match to the the other. This was in height and also Girth(excuse the pun). After a long discussion around it by the co- and a ground engineer the flight departed. The question I have to raise is . Are tyres of different sizes used and what safety issues does this entail??

[Golden Rivet]

From my dim and distant memory of the smaller buses, it was permissible to mix different size/types of tyres. The aircraft maintenance manual gives you the permissible intermix.

Although visually different in size, when loaded, because of the different tyre characteristics they both take up the same size.

Got me when I first came across it - probably the same for the big buses.

GR

[HiSpeedTape]

Hey Rivet, Your memory serves you right almost. Differing wheel sizes ie 46 and 49 diameter are permissible in accordance with the MM on the main landing gear of the smaller busses but remember to reprogram the BSCU. Also intermixing of tyre types is allowed between bias and radial tyres but once again consult mm. Intermixing of nosewheels with differing tread patterns usually leads to complaints from the jockeys of shimmy. I dont think that there is any allowance for different wheel diameters on nose landing gear though.

Cheers
HST

[45 before POL]

Thanks for the info, much help from a non-techie view.