ISO-3324-1-1997.pdf

A Reference number ISO 3324-1:1997(E) INTERNATIONAL STANDARD ISO 3324-1 Fourth edition 1997-12-15 Corrected and reprinted 1998-09-15 Aircraft tyres and rims Part 1: Specifications Pneumatiques et jantes pour aéronefs Part 1: Spécifications Copyright International Organization for Standardization Provided by IHS under license with ISO Licensee=Aramco HQ/9980755100 Not for Resale, 04/16/2007 10:37:50 MDTNo reproduction or networking permitted without license from IHS -,-,- ISO 3324-1:1997(E) © ISO 1997 All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying and microfilm, without permission in writing from the publisher. International Organization for Standardization Case postale 56 CH-1211 Genève 20 Switzerland Internet isoiso.ch Printed in Switzerland ii ContentsPage 1Scope 1 2Normative reference 1 3Definitions.1 4New tyres 2 4.1Tyre size designation .2 4.2Tyre markings .2 4.3Bias tyre dimensions and growth allowances 3 4.3.1Tyre dimensions 3 4.3.2Determination of growth allowances.3 4.3.3Method of dimensioning and inspection tolerances for rim diameters, dimension D, for rims with single heel radius . 3 4.4Radial tyre dimensions and dimensional tolerances 5 4.5Determination of clearance allowances .6 4.5.1Clearance around individual tyres 6 4.5.2Spacing between twin tyres7 4.5.3Spacing between tyre and tandem .7 5Retread tyres 10 5.1Tyre size designation .10 5.2Tyre markings .10 5.3Retread tyre dimensions 11 6Rims11 6.1Fundamental rim standards .11 6.1.1Symbols11 6.1.2Rim dimensions 12 6.1.3Alternate asymetric rim flange contours .15 6.2Inspection tolerances of rims .17 6.2.1Inspection tolerances for dimensions in millimetres .17 6.2.2Inspection tolerances for dimensions in inch17 Copyright International Organization for Standardization Provided by IHS under license with ISO Licensee=Aramco HQ/9980755100 Not for Resale, 04/16/2007 10:37:50 MDTNo reproduction or networking permitted without license from IHS -,-,- © ISOISO 3324-1:1997(E) iii 6.2.3Method of dimensioning and inspection tolerances for rim diameters, dimension D, for rims with single heel radius . 17 6.3Valve, fuse plug and over pressure hole locations for connections to valve or plug hole location, (Vmin)19 6.3.1For tubeless tyres 19 6.3.2For tube-type tyres.19 6.4Rim flange height .19 6.5Width between rim flanges.19 Annex A (informative) Aircraft tyre size designations 22 Copyright International Organization for Standardization Provided by IHS under license with ISO Licensee=Aramco HQ/9980755100 Not for Resale, 04/16/2007 10:37:50 MDTNo reproduction or networking permitted without license from IHS -,-,- ISO 3324-1:1997(E) © ISO iv Foreword ISO (the International Organization for Standardization) is a worldwide federation of national standards bodies (ISO member bodies). The work of preparing International Standards is normally carried out through ISO technical committees. Each member body interested in a subject for which a technical committee has been established has the right to be represented on that committee. International organizations, governmental and non- governmental, in liaison with ISO, also take part in the work. ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization. Draft International Standards adopted by the technical committees are circulated to the member bodies for voting. Publication as an International Standard requires approval by at least 75 % of the member bodies casting a vote. International Standard ISO 3324-1 was prepared by Technical Committee ISO/TC 31, Tyres, rims and valves, Subcommittee SC 8, Aircraft tyres and rims. This fourth edition cancels and replaces the third edition (ISO 3324-1: 1993), of which it constitutes a technical revision. ISO 3324 consists of the following parts, under the general title Aircraft tyres and rims: Part 1: Specifications Part 2: Test methods for tyres Annex A of this part of ISO 3324 is for information only. Copyright International Organization for Standardization Provided by IHS under license with ISO Licensee=Aramco HQ/9980755100 Not for Resale, 04/16/2007 10:37:50 MDTNo reproduction or networking permitted without license from IHS -,-,- INTERNATIONAL STANDARD © ISOISO 3324-1:1997(E) 1 Aircraft tyres and rims Part 1: Specifications 1 Scope This part of ISO 3324 gives specifications for new and retread aircraft tyres and for aircraft rims. 2 Normative reference The following standard contains provisions which, through reference in this text, constitute provisions of this part of ISO 3324. At the time of publication, the edition indicated was valid. All standards are subject to revision, and parties to agreements based on this part of ISO 3324 are encouraged to investigate the possibility of applying the most recent edition of the standard indicated below. Members of IEC and ISO maintain registers of currently valid International Standards. ISO 4223-1:1989, Definitions of some terms used in the tyre industry Part 1: Pneumatic tyres. 3 Definitions For the purposes of this part of ISO 3324, the definitions in ISO 4223-1 and the following definitions apply. 3.1 aspect ratio (AR): Ratio of section height to section width. 3.2 balance mark: Identifying red dot, located on the sidewall at the light spot of the tyre. 3.3 chine: Annular protuberance located around the shoulder area of the tyre, designed to deflect water. 3.4 ply rating: Term used to identify a given tyre with its maximum load when used in a specific type of service. It is an index of relative tyre strength. 3.5 skid depth (mould): Depth of the deepest tread grooves in the mould. 3.6 venting mark: Identification dot, other than red, located at the vents of tyres. 3.7 retread tyre: Tyre which has been subjected to a retreading operation. Copyright International Organization for Standardization Provided by IHS under license with ISO Licensee=Aramco HQ/9980755100 Not for Resale, 04/16/2007 10:37:50 MDTNo reproduction or networking permitted without license from IHS -,-,- ISO 3324-1:1997(E) © ISO 2 4 New tyres 4.1 Tyre size designation The tyre size designation for new design tyres in accordance with this part of ISO 3324 shall include a three-part size marking as follows: Overall diameter × Overall section width - Nominal rim diameter tyre overall diameter and overall section width, both expressed in millimetres (mm) or both expressed in inches (in); nominal rim diameter, expressed as a code (see table 1). For radial-ply tyres, the letter “R” shall be inserted between the overall section width and nominal rim diameter in the tyre size designation replacing the hyphen (“-”). The size designation may also include one of the following letter prefixes: Bindicates tyres for 15° bead seat rims with 60 % to 70 % rim width to tyre section width ratio; Hindicates tyres for 5° bead seat rims with 60 % to 70 % rim width to tyre section width ratio. 4.2 Tyre markings The marking of new tyres shall include the following: a)tyre size designation; b)ply rating (optional); c)maximum speed rating expressed in knots (kn) or miles per hour (mile/h); NOTE 1 Mile/h is also sometimes written mph. d)skid depth (mould) expressed in millimetres or inches; e)original serial number and date of manufacture: the date of manufacture shall be expressed numerically and may use a system of marking based on the Gregorian calendar (for example 12 March 1989 becomes 9071, the 9 representing 1989 and 071 representing 12 March which is the 71st day of the year) or specify month and year of manufacture with a dash (“”) separating them (for example March 1989 becomes 0389); NOTE 2 The numerical date of manufacture may form the first four digits of the manufacturer's unique serial number. f)the word “tubeless” if applicable; g)manufacturer's (brand) name, and country of manufacture; h)balance mark; i)venting mark if applicable; j)rated load (kg or lb); k)part number. Copyright International Organization for Standardization Provided by IHS under license with ISO Licensee=Aramco HQ/9980755100 Not for Resale, 04/16/2007 10:37:50 MDTNo reproduction or networking permitted without license from IHS -,-,- © ISO ISO 3324-1:1997(E) 3 4.3 Bias tyre dimensions and growth allowances 4.3.1 Tyre dimensions New inflated tyre dimensional tolerances shall be calculated using the factors shown in figure 3 or 4. When used, the size designation as defined in 4.1 determines the maximum overall diameter and maximum section width of the new inflated tyre. Therefore tolerances shall be specified as a minus from the permitted maximum dimensions. Tyre dimensions shall be measured after the new tyre has been mounted on the specified rim, inflated to its rated inflation pressure, and allowed to stand for a minimum of 12 h at normal room temperature and the inflation pressure readjusted to the original value. The maximum section width includes elevations due to labelling (marking, decorations, and all protective bands or ribs except chines). 4.3.2 Determination of growth allowances 4.3.2.1 General Growth allowances provide for the increase in tyre dimensions over the maximum new inflated tyre dimensions to allow for growth or stretch of the tyre during service. 4.3.2.2 Dimensions and symbols The following dimensions and symbols are used (also see figure 2): Inflated new tyreInflated growth tyre Maximum section width1)WWG Maximum shoulder width2)WSWSG Maximum overall diameterDoDG Maximum shoulder diameterDSDSG Maximum section heightH Maximum shoulder heightHS Aspect ratioAR Ply ratingPR Specified rim diameterD Nominal rim diameter codeDr Section height growth factorGH Section width growth factorGW Minimum lateral distance required from wheel centreline to adjacent structureWX Minimum radial distance required from axle centreline to adjacent structureRX Minimum lateral clearance3)CW Minimum radial clearance3)CR Minimum shoulder clearance3)SX 1) Maximum section width includes protective side ribs, lettering bars and decorations, but does not include chines (water deflectors) present on certain types of nose wheel (or auxiliary gear) tyres. 2) Maximum shoulder width does not include chines (water deflectors) present on certain types of nose wheel (or auxiliary gear) tyres. 3) These are minimum clearance allowances between the maximum grown tyre and the adjacent structure. Copyright International Organization for Standardization Provided by IHS under license with ISO Licensee=Aramco HQ/9980755100 Not for Resale, 04/16/2007 10:37:50 MDTNo reproduction or networking permitted without license from IHS -,-,- ISO 3324-1:1997(E) © ISO 4 4.3.2.3 Calculations 4.3.2.3.1 Determine grown dimensions as follows, using the appropriate growth factor given in 4.3.2.3.2: WG = GWW WSG = GWWS DG = Dr + 2GHH DSG = Dr + 2GHHS H DD = or _ 2 H DD s sr = _ 2 4.3.2.3.2 Growth factors are expressed in figure 1. Section width growth factor, GW = 1,04 Section height growth factor, GH = 1,115 (0,075 × AR) Figure 1 Growth factors 4.3.2.3.3 Obtain the new tyre dimensions Do, DS, W and WS, as shown in the tyre tables (see annex A); such dimensions should be considered maxima. 4.3.2.3.4 The maximum shoulder width, WS, and the maximum shoulder height, HS, are determined by the formulae: WS = 0,9 W HS = 0,9 H Copyright International Organization for Standardization Provided by IHS under license with ISO Licensee=Aramco HQ/9980755100 Not for Resale, 04/16/2007 10:37:50 MDTNo reproduction or networking permitted without license from IHS -,-,- © ISO ISO 3324-1:1997(E) 5 4.3.2.3.5 Nominal rim diameters are shown in table 1. Table 1 Nominal rim diameter code Nominal rim diameter, Dr inchmm 44102 55127 66152 77178 88203 99229 1010254 1111279 1212305 1313330 1414356 1515381 1616406 1717432 1818457 1919483 2020508 2121533 2222559 2323584 2424610 4.4 Radial tyre dimensions and dimensional tolerances The dimensions to be specified for radial tyres are the grown tyre dimensions. They include: a)the maximum overall diameter, DG; b)the maximum section width, WG; c)the maximum shoulder diameter, DSG; d)the maximum shoulder width, WSG1); 1) For some tyre sizes, the maximum shoulder width should be calculated using the formula: WSG = 0,88 WG Consult the tyre manufacturer for application recommendation. Code Copyright International Organization for Standardization Provided by IHS under license with ISO Licensee=Aramco HQ/9980755100 Not for Resale, 04/16/2007 10:37:50 MDTNo reproduction or networking permitted without license from IHS -,-,- ISO 3324-1:1997(E) © ISO 6 e)the minimum static loaded radius, SLRG,min; f)the maximum static loaded radius, SLRG,max. DG, WG, DSG, WSG are the maximum permitted grown inflated tyre dimensions. SLRG is the loaded radius when the grown tyre is inflated to its rated inflation pressure, and loaded to its rated load against a flat surface. Grown dimensions shall be measured on tyres that have completed a sufficient number of take-off cycles. Tyres shall be allowed to cool to room temperature and shall be measured at the rated inflation pressure. The size designation defined in 4.1 determines the maximum dimensions of an equivalent new inflated bias tyre that would have the same grown dimensions as calculated in 4.3.2. 4.5 Determination of clearance allowances 4.5.1 Clearance around individual tyres Clearance allowances between the tyre and the adjacent parts of the aircraft shall be provided by the aircraft manufacturer. These allowances are to be based on the maximum overall tyre dimensions plus growth allowances due to service, plus the increase in diameter due to centrifugal force. Minimum distances to adjacent parts of the aircraft are determined as specified in 4.5.1.1 to 4.5.1.3. 4.5.1.1 Determine the maximum grown tyre envelope as specified in 4.3.2. for bias tyres and 4.4 for radial tyres. (This is the dotted line labelled “grown (used) inflated tyre” in figure 2.) 4.5.1.2 Obtain the radial (CR) and lateral (CW) clearances from the formulae in a) or b) as appropriate. For speeds which do not fall into the stated categories, clearance dimensions are to be interpolated. a) For dimensions in millimetres: CR = 0,084 WG + 10 for 230 kn (265 mile/h) = 0,07 WG + 10for 213 kn (245 mile/h) = 0,063 WG + 10 for 204 kn (235 mile/h) = 0,06 WG + 10for 195 kn (225 mile/h) = 0,047 WG + 10 for 182 kn (210 mile/h) = 0,037 WG + 10 for 165 kn (190 mile/h) = 0,029 WG + 10 for 139 k