SAE AS 4833A-2014 Aircraft New Tire Standard - Bias and Radial.pdf

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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/AS4833AAEROSPACESTANDARDAS4833 REV. AIssued 1995-06 Reaffirmed 2010-06 Revised 20

5、14-11 Superseding AS4833 Aircraft New Tire Standard - Bias and Radial RATIONALE AS4833 is the industry document supporting TSO C62e. This industry standard applies to both tubeless and tube type aircraft tires. For tube type tires, the diffusion performance capability of the assembly is controlled b

6、y the inner tube and notthe 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 and toaddress diffusion for t

7、ube type tires under 5.2 and 5.3.10. In addition, 8.3.4 is modified to address incorrect references to other sections within the document. 1. SCOPE This SAE Aerospace Standard (AS) sets forth criteria for the selection and verification processes to be followed in providing tires that will be suitabl

8、e for intended use on civil aircraft. This document encompasses new and requalified radial and bias aircraft tires. 1.1 Purpose This document establishes the minimum recommended performance standards for new tires to be used on civil aircraft. All new or requalified tires shall meet these standards.

9、 2. REFERENCES There are no referenced publications specified herein. 2.1 Definitions 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

10、ply cords extend to the beads and are laid substantially at 90 degrees to the centerline of the tread, the casing being stabilized by an essentially inextensible circumferential belt. LOAD RATING: Load rating is the maximum permissible load at a specific inflation pressure. Load ratings are establis

11、hed 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 utilized when selecting tires for application to an aircraft and fortesting to the performance requirements of this do

12、cument. LOADED INFLATION PRESSURE: The recommended pressure determined by multiplying an unloaded calculated tire inflation pressure by the factor 1.04. SAE INTERNATIONAL AS4833A Page 2 of 15 RATED INFLATION PRESSURE: The specified inflation pressure corresponding to the tires static loaded radius a

13、t its rated load. UNLOADED OPERATING INFLATION PRESSURE: The calculated inflation pressure for the tires operating load based upon a tires load rating at rated pressure. MAXIMUM RAMP WEIGHT: The maximum ramp weight of an aircraft is its maximum operational weight. This maximum ramp weight shall be u

14、sed to determine the minimum load ratings and corresponding inflation pressures of the tires used on an aircraft. 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. MAIN TIRES: Main tires support

15、 the principal weight of the aircraft AUXILIARY TIRES: Auxiliary tires support the remaining weight of the aircraft not supported by the main tires. NOSE TIRE: A nose tire is an auxiliary tire which is mounted on the front of the aircraft TAIL TIRE: A tail tire is an auxiliary tire which is mounted

16、on the rear of an aircraft. SINGLE TIRE APPLICATIONS: Single tire applications are those in which one tire/wheel assembly is provided to support the load carried by one landing gear strut. MULTIPLE TIRE APPLICATIONS: Multiple tire applications are those where the load on one landing gear strut is sh

17、ared by two or more tire/wheel assemblies. SPEED RATING: The speed rating is the maximum ground speed to which the tire has been tested in accordance with this document. DYNAMIC BRAKING LOAD: The load applied to a nose tire during deceleration of an aircraft during a landing or rejected takeoff (RTO

18、). STATIC LOADED RADIUS (SLR): The static loaded radius is the perpendicular distance between the axle centerline and the surface against which the tire is loaded, when supporting its rated load, while inflated to its rated inflation pressure. 3. TIRE IDENTIFICATION MARKINGS 3.1 Airworthiness Compli

19、ance The tire shall be marked with the labeling required by the appropriate airworthiness authority standards, for example, Technical Standard Order (TSO-C62). 3.2 Load Rating Tires shall be marked with a load rating as established by the TRA or ETRTO for the specific tire ply rating. 3.3 Manufactur

20、ers Name or Trademark Tires shall be marked with the name or registered trademark of the manufacturer responsible for compliance. 3.4 Ply Rating/Inflation Pressure Tires may be marked with a ply rating as established by the TRA or ETRTO. If ply rating is marked on the tire, the load rating marked on

21、 the tire must be consistent with the ply rating as established by the TRA or ETRTO. If the tire is not marked with ply rating, it must be marked with the inflation pressure which is consistent with the load rating marked on the tire. This load and inflation pressure should be proportioned to the ne

22、xt higher ply rating rated load and inflation pressure for the tire size as established by the TRA or ETRTO. SAE INTERNATIONAL AS4833A Page 3 of 15 3.5 Size Tires shall be marked with the size as established by the TRA or ETRTO. 3.6 Tire Manufacturers Plant Code Each tire shall have a tire manufactu

23、rers plant code, or country code if only one plant exists within a country, on the tire sidewall. This may be encoded in the serial number. 3.7 Date Code Each tire shall have the date of production marked on the sidewall. This may be encoded in the serial number. 3.8 Serial Number Each aircraft tire

24、 must have a unique identification number marked on one sidewall. This is referred to as the serial number and may include the plant code and date code. 3.9 Speed Rating All tires shall be marked with a speed rating in mph. This rating shall be equal to or less than the speed to which the tire hasbe

25、en qualified. The speed marked must be equivalent to those shown in 4.2. 3.10 Tire Manufacturers Part Number Each tire shall have a tire manufacturers part number marked on the tire sidewall. 3.11 Tube Type Tires Tube type tires require that a tube be used with the tire and wheel to maintain the inf

26、lation pressure within the assembly. The words “Tube Type” shall be marked on all tires requiring a tube in their operation. 4. DESIGN REQUIREMENTS 4.1 General Standards Tires selected for use on a specific aircraft must be able to demonstrate their suitability through appropriate laboratory simulat

27、ion of duty cycles of that aircraft. 4.1.1 Material Suitability 4.1.1.1 Temperature It shall be substantiated by applicable tests or shown by analysis that the physical properties of the tire materials are not degraded by exposure to temperature extremes of -40 F and +160 F for a period of not less

28、than 24 hours at each extreme. 4.1.1.2 Wheel Rim Heat For braked tires, it shall be substantiated by the applicable tests or shown by analysis that the physical properties of the tirebead seat materials are not degraded by their exposure to a minimum temperature of 300 F for at least 1 hour. 4.2 Spe

29、ed Rating The speed rating of the tire shall be equal to or greater than the maximum ground speed at takeoff that the aircraft will reach. Applicable dynamometer test speeds for corresponding maximum takeoff speeds are as follows in Table 1. For takeoff speeds over 245 mph, the tire must be tested t

30、o the maximum applicable load-speed-time requirements and appropriately identified with the proper speed rating. SAE INTERNATIONAL AS4833A Page 4 of 15 TABLE 1 - APPLICABLE DYNAMOMETER TEST SPEEDS 4.3 Overpressure The tire shall successfully withstand a hydrostatic pressure of at least four times it

31、s rated inflation pressure for 3 seconds without burst occurring. 4.4 Helicopter Tires Aircraft tires qualified in accordance with provisions of this standard may also be used on helicopters. In such cases, the maximum static load rating may be increased by a factor of 1.5 with a corresponding incre

32、ase in rated inflation pressure without any additional qualification testing. 4.5 Dimensions The tire size with respect to outside diameter, shoulder diameter, section width and shoulder width shall be maintained within the tolerances established by the TRA or ETRTO. 4.5.1 Outside Diameter, Shoulder

33、 Diameter, Section Width and Shoulder Width For the bias ply tire, outside diameter and section width are specified to a maximum and minimum value after a 12 hour growth period at rated inflation pressure. Shoulder diameter and width dimensions are specified to a maximum value after a 12 hour growth

34、 period at rated inflation pressure. Radial tire dimensions are limited by the grown tire envelope in accordance with the static loaded radius (SLR) requirement per 4.5.2. Due to the increased inflation pressures permitted when using an aircraft tire in a helicopter application, tire dimensions arep

35、ermitted to be 4% larger. 4.5.2 Static Loaded Radius (SLR) 4.5.2.1 Bias Tires For bias tire constructions, the design SLR is specified by the TRA or ETRTO. The actual SLR shall be determined on a new tire which has been stretched for a minimum of 12 hours at rated inflation pressure 4.5.2.2 Radial T

36、ires For radial tire constructions, the design SLR limits are specified by the TRA or ETRTO. The actual SLR of a radial tire shall be determined at rated inflation pressure after running 50 takeoffs per 5.3.2 requirements. 5. TIRE TEST REQUIREMENTS 5.1 Balance All tires shall be tested for static un

37、balance. SAE INTERNATIONAL AS4833A Page 5 of 15 5.1.1 Auxiliary Tires The moment of static unbalance (M) for auxiliary tires shall not be greater than the value determined by using Equation 1. (Eq. 1) The values determined must be rounded off to the next lower whole number where M is in inch-ounces

38、and D is the standardized maximum new tire inflated outside diameter of the tire in inches. Tires outside the limits must be corrected by an appropriate means. 5.1.2 Main Tires The moment of static unbalance (M) for main tires shall not be greater than the value determined by using Equation 2: (Eq.

39、2) The values determined must be rounded off to the next lower whole number where M is in inch-ounces and D is the standardized maximum new inflated outside diameter of the tire in inches. Tires outside the limits must be corrected by an appropriate means. 5.2 Inflation Retention After an initial 12

40、 hour minimum stabilization period at rated inflation pressure, the tire must be capable of retaining inflationpressure with a loss of pressure not exceeding 5% in 24 hours. Ambient temperature shall be measured at the start and finish of the test to assure that the pressure change was not caused by

41、 an ambient temperature change. NOTE: For tube type tires, the pressure retention performance of the tube is that defined by AS 50141B. The tube type tire by definition does not have a defined pressure retention performance, and so this test is not applicable to tube type tires. 5.3 Qualification Pr

42、ocedure A single test specimen must be used for a qualification test. The tire must withstand the following cycles without detectable signs of deterioration, other than normal expected tread surface abrasion, except when the overload takeoff condition is run last (see 5.3.9). 5.3.1 Dynamometer Cycle

43、 Requirements All aircraft tires shall satisfactorily withstand 58 dynamometer cycles as a demonstration of overall performance, plus 3 overload dynamometer cycles as a demonstration of the casings capability under overload. The 58 dynamometer cycles shall consist of 50 takeoff cycles and 8 taxi cyc

44、les. The overload cycles shall consist of 2 taxi cycles at 1.2 times rated loadand 1 overload takeoff cycle starting at 1.5 times rated load. The sequence of running the dynamometer cycles is optional. If the overload takeoff is not run last, the tire must not show detectable signs of deterioration,

45、 other than normal expected tread surface abrasion after this test. 5.3.2 Takeoff 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

46、must be given to increased speeds resulting from elevated airport operations and high ambient temperatures. The load-speed-time (LST) data shall be compiled by the airframe manufacturer in compliance with the applicable airworthiness authority requirements. Refer to Figures 1, 2, or 3 for graphic re

47、presentations of the test. M0.025D2=M0.035D2=SAE INTERNATIONAL AS4833A Page 6 of 15 Starting at zero speed, the tire shall be loaded against the dynamometer flywheel. The test cycles shall simulate one of the curves in Figure 1, 2, or 3. a. Figure 1 defines a test cycle that is applicable to any air

48、craft tire with a speed rating of 120 mph or 160 mph. b. Figure 2 defines a test cycle that is applicable to any aircraft tire with a speed rating greater than 160 mph. c. Figure 3 defines a test cycle that is applicable for any speed rating and is based on the most critical takeoff loads, speeds an

49、d distances based on the airframe manufacturers specifications. 5.3.3 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,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 ap