SAE ARP 4834B-2015 Aircraft Tire Retreading Practice - Bias and Radial.pdf

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1、_ SAE Technical Standards Board Rules provide that: “This report is published by SAE to advance the state of technical and engineering sciences. The use of this report is entirely voluntary, and its applicability and suitability for any particular use, including any patent infringement arising there

2、from, is the sole responsibility of the user.” SAE reviews each technical report at least every five years at which time it may be revised, reaffirmed, stabilized, or cancelled. SAE invites your written comments and suggestions. Copyright 2015 SAE International All rights reserved. No part of this p

3、ublication may be reproduced, stored in a retrieval system or transmitted, in any form or by any means, electronic, mechanical, photocopying, recording, or otherwise, without the prior written permission of SAE. TO PLACE A DOCUMENT ORDER: Tel: 877-606-7323 (inside USA and Canada) Tel: +1 724-776-497

4、0 (outside USA) Fax: 724-776-0790 Email: CustomerServicesae.org SAE WEB ADDRESS: http:/www.sae.org SAE values your input. To provide feedback on this Technical Report, please visit http:/www.sae.org/technical/standards/ARP4834B AEROSPACE RECOMMENDED PRACTICE ARP4834 REV. B Issued 1995-11 Reaffirmed

5、2015-01 Revised 2015-04Superseding ARP4834A Aircraft Tire Retreading Practice - Bias and Radial RATIONALE ARP4834 is the industry document supporting AC145-4A. This industry standard applies to both tubeless and tube type aircraft tires. For tube type tires, the diffusion performance capability of t

6、he assembly is controlled by the inner tube and not the tire. Since this standard defines the minimum performance capabilities of the tire, and not the inner tube, the diffusion performance threshold defined is only applicable to tubeless tires. It is, therefore, necessary to clarify this standard a

7、nd to address diffusion for tube type tires under 7.1.9 and Section 10. 1. SCOPE This SAE Aerospace Recommended Practice (ARP) sets forth criteria for the selection, inspection, retread and repair of worn civil aircraft tires, and the means to verify that the retreaded tire is suitable for continued

8、 service. This document is applicable to both bias ply and radial aircraft tires qualified subsequent to the adoption of this document. 1.1 Purpose This document sets forth the minimum recommended requirements for retreaded tires used on civil aircraft. It also provides criteria for the escalation o

9、f retread level of tires used on civil aircraft. The combined recommendations contained in this document form an acceptable practice, but not the only practice, for retreaded aircraft tires. 2. REFERENCES 2.1 Applicable Documents The following publications form a part of this document to the extent

10、specified herein. The latest issue of SAE publications shall apply. The applicable issue of other publications shall be the issue in effect on the date of the purchase order. In the event of conflict between the text of this document and references cited herein, the text of this document takes prece

11、dence. Nothing in this document, however, supersedes applicable laws and regulations unless a specific exemption has been obtained. 2.1.1 SAE Publications Available from SAE International, 400 Commonwealth Drive, Warrendale, PA 15096-0001, Tel: 877-606-7323 (inside USA and Canada) or +1 724-776-4970

12、 (outside USA), www.sae.org. AS4833 Aircraft New Tire Standard - Bias and Radial SAE INTERNATIONAL ARP4834B Page 2 of 14 2.1.2 ASTM Publications Available from ASTM International, 100 Barr Harbor Drive, P.O. Box C700, West Conshohocken, PA 19428-2959, Tel: 610-832-9585, www.astm.org. ASTM D413 Ameri

13、can Society for Testing and Materials - Rubber Property: Adhesion to Flexible Substrate 2.1.3 FAA Publications Available from Federal Aviation Administration, 800 Independence Avenue, SW, Washington, DC 20591, Tel: 866-835-5322, www.faa.gov. FAA AC145-4A Advisory Circular - Inspection, Retread, Repa

14、ir and Alteration of Aircraft Tires FAA TSO-C62e Technical Standard Order - Tires 14 CFR Part 21 Certification Procedures for Products and Parts. 2.2 Applicable References T&RA Tire and Rim Association - Standards ETRTO European Tire and Rim Technical Organization - Standards 2.3 Definitions RETREAD

15、ING: The term retreading refers to the methods of restoring a worn tire by renewing the tread area, or by renewing the tread area plus one or both sidewalls. Repairs are included in the tire retreading process. PROCESS SPECIFICATION: Documents approved by the cognizant airworthiness authorities cont

16、aining information for performing specialized maintenance, such as retreading tires. RETREAD LEVEL (R-LEVEL) ESCALATION: R-level escalation is the process used to verify that a population of retreaded tires is suitable for an additional service life. LOAD RATING: Load rating is the maximum permissib

17、le load at a specific inflation pressure. Load ratings are established and standardized by the Tire & Rim Association (TRA) or the European Tire & Rim Technical Organization (ETRTO). The rated load combined with the rated inflation pressure will be used when selecting tires for application to an air

18、craft and for testing to the performance requirements of this standard. PLY RATING: This term is used to identify the maximum recommended load rating and inflation pressure for a specified tire. It is an index of tire strength. SPEED RATING: The speed rating is the maximum takeoff speed to which the

19、 tire has been tested. BIAS TIRE: A pneumatic tire in which the ply cords extend to the beads and are laid at alternate angles substantially less than 90 degrees to the centerline of the tread. RADIAL TIRE: A pneumatic tire in which the ply cords extend to the beads and are laid substantially at 90

20、degrees to the centerline of the tread, the casing being stabilized by an essentially inextensible circumferential belt. MAIN TIRES: Main tires support the principal weight of the aircraft. AUXILIARY TIRES: Auxiliary tires support the remaining weight of the aircraft not supported by the main tires.

21、 SAE INTERNATIONAL ARP4834B Page 3 of 14 NOSE TIRE: A nose tire is an auxiliary tire which is mounted forward of the center of gravity of an aircraft. TAIL TIRE: A tail tire is an auxiliary tire which is mounted aft of the center of gravity of an aircraft. CASING: The casing is the structural part o

22、f the tire. COMPATIBLE CASING: A compatible casing for retreading is one capable of passing all retreader acceptance criteria for that size, ply rating, and speed rating. SKID DEPTH: The distance between the tread surface and the deepest groove as measured in the mold. MAXIMUM OUTSIDE DIAMETER (Do):

23、 For the bias tire, it is the maximum new (ungrown) diameter along the centerline of the tire as denoted in TRA and ETRTO. For the radial tire, it is the maximum new (ungrown) diameter of its bias tire equivalent. 3. MARKINGS 3.1 Retread Identification The following minimum information must appear i

24、n permanent markings between the wearing surface and the edge of the newly applied rubber. a. The retreaders name or trademark b. The retread plant identification code c. The month and year the retread was performed d. The letter “R” followed by the number of times the casing has been retreaded. e.

25、Skid Depth - If retread mold skid depth is different than original casing then original skid should be removed from casing and retread skid depth added. 3.2 Casing Identification Retread processing may destroy some or all of the casing identification. The following information must be restored if re

26、moved during retreading: a. Airworthiness compliance markings b. Load rating c. Casing manufacturers name or trademark d. Ply rating or inflation pressure e. Size f. Casing manufacturers plant code g. Date of manufacture h. Serial number SAE INTERNATIONAL ARP4834B Page 4 of 14 i. Speed rating j. Cas

27、ing manufacturers part number k. Tube type, if applicable 3.3 Regrading Procedure a. The ply rating/load rating and/or speed rating on either the casing or the retread may be decreased without approval. All performance and qualification parameters under the new rating must be met. b. If the ply rati

28、ng, load rating and speed rating markings of the casing do not agree with the retread qualification status, they must be buffed off the casing, and the correct markings applied to the casing. c. The casing manufacturers part number must not be altered without original casing manufacturers approval.

29、d. Any upgrading in the speed rating or load rating, or any change in the tire size from the qualified new tire size will be considered a new product. 3.4 Marking Maximum Cut Limit Repairs Casings containing maximum allowable cut limit repairs in the tread area should be identified with a sidewall b

30、rand in line with the repair. The guidelines and conditions under which this brand is applied should be specified in the retreaders specification. 4. CASING SELECTION The new tire casing must be approved by the cognizant airworthiness authority. Unless otherwise restricted by the tire manufacturer o

31、r airworthiness authority, any aircraft tire may be retreaded provided that it meets the inspection and defect limitation criteria, and has met the R-level escalation inspection and test criteria established in the airworthiness authority certified repair station manuals and the retreaders airworthi

32、ness authority-approved process specification. 4.1 Inspection The following nondestructive inspection (NDI) techniques are available in the industry. 4.1.1 Visual All tires shall be visually inspected in the tread, sidewall, bead and liner areas for conditions that need repair or which require the t

33、ire to be scrapped. 4.1.2 Air Injection Tubeless tires may be air injected with a dry filtered gas (e.g., air or nitrogen) to inspect the casing for proper venting, separations, bead and liner condition, etc. Typical air injection pressure range is 100 to 125 psi. 4.1.3 Other NDI Holography, shearog

34、raphy, ultrasonics, X-ray, etc., should be used as necessary. 4.2 Disposition of Tire Casings 4.2.1 Acceptable Casings Tires which meet the acceptable limits for repair listed in the airworthiness authoritys approved retreaders process specification may be repaired/retreaded and returned to service.

35、 SAE INTERNATIONAL ARP4834B Page 5 of 14 4.2.2 Non-acceptable Casings Tires which fail the acceptable limits for repair listed in the retreaders process specification shall be rejected from further aircraft use. Casings not returned to the customer should have the TSO-C62 compliance marking(s) remov

36、ed. 5. REPAIRING Repairs are permitted if the anomaly does not exceed the limitations or the rejection criteria identified in the retreaders process specification, as approved by the cognizant airworthiness authority. Maximum permissible repairs identified in the process specification shall be valid

37、ated by tests and/or analysis for the cognizant airworthiness authority approval before returning to service. The specification shall include each of the repair types for bias and radial tires, as identified in the Appendix A, and additional repairs identified by the retreader. 6. RETREADING PROCESS

38、 The retreading process includes removal of old material, renewing the tread area and curing and bonding of the new material to the casing. A process specification describing each retreaders process must be approved by the cognizant airworthiness authority. 7. QUALIFICATION TESTING General: The test

39、 procedures described herein are intended to ensure compatibility between the original tire casing and newly applied retread. This qualification test is required with the first (R-1) application of a new tread and as otherwise specified in this document. The retread should not fail the applicable dy

40、namometer tests specified herein nor have any signs of structural deterioration other than normal expected treadwear, except when the overload takeoff cycle is run last (see 7.1). Casings selected for retread qualification tests should have at least 80% of their new molded tire skid depth removed by

41、 wear (i.e., worn by aircraft usage). Design and construction differences between radial tires of different manufacture dictate that retread dynamometer testing be conducted on one sample of each manufacturers radial tire casing at the first (R-1) application of a new tread. Qualification of bias ti

42、re retreads on a single manufacturers casing qualifies the retread on other manufacturers compatible casings of the same size, ply rating and speed rating. 7.1 Dynamometer Cycles The retread test tire shall satisfactorily withstand 61 dynamometer cycles as a demonstration of overall performance. The

43、 61 dynamometer cycles shall consist of 50 takeoff cycles, 8 taxi cycles at rated load, 2 taxi cycles at 1.2 times rated load, and 1 overload takeoff cycle starting at 1.5 times rated load. The sequence of the cycles is optional. A single tire specimen must be used to complete these cycles. 7.1.1 Ta

44、keoff Cycles The 50 takeoff cycles shall realistically simulate tire performance during runway operations for the most critical combination of takeoff weight and speed, and aircraft center-of-gravity position. Consideration should be given to increased speeds resulting from elevated airport operatio

45、ns and high ambient temperatures. Starting at zero speed, the tire shall be loaded against the dynamometer wheel. The test cycles shall simulate one of the curves in Figures 1, 2, or 3. a. Figure 1 defines a test cycle that is applicable to any aircraft tire with a speed rating of 120 mph or 160 mph

46、. b. Figure 2 defines a test cycle that is applicable to any aircraft tire with a speed rating above 160 mph. c. Figure 3 defines a test cycle that is applicable for any speed rating and is based on the most critical loads, speeds and distances in accordance with the airframe manufacturers specifica

47、tions. SAE INTERNATIONAL ARP4834B Page 6 of 14 Figure 1 - Graphic representation of a universal load-speed-time test cycle (for 120 mph and 160 mph tires) SAE INTERNATIONAL ARP4834B Page 7 of 14 Figure 2 - Graphic representation of a universal load-speed-time test cycle (for tires rated above 160 mp

48、h) SAE INTERNATIONAL ARP4834B Page 8 of 14 Figure 3 - Graphic representation of a rational load-speed-time test cycle SAE INTERNATIONAL ARP4834B Page 9 of 14 7.1.2 Test Load The load at the start of the test must be no less than the rated load of the tire. The test loads must conform to Figures 1, 2

49、, or 3. Figures 1 and 2 define a test cycle that is generally applicable to any aircraft. If Figure 3 is used to define the test cycle, the loads must be selected based on the most critical takeoff conditions established by the applicant based on the data obtained from the airframe manufacturer. At any speed throughout the test cycle, the ratio of the test load to the operational load shall be the same as at the start of the te