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/ARP5257B AEROSPACE RECOMMENDED PRACTICE ARP5257 REV. B Issued 1997-11 Revised 201
5、0-07 Reaffirmed 2015-08 Superseding ARP5257A Tire Overspeed Landing Test RATIONALE ARP5257B has been reaffirmed to comply with the SAE five-year review policy. SCOPE This document covers the basis of, and test procedure for, an overspeed landing test on aircraft tires with rated speeds of 190 mph (3
6、06 km/h) and above. The conditions requiring an overspeed test, alternatives, test requirements and pass/fail criteria are addressed. 1.1 Purpose The purpose of this ARP is to define a test procedure for the qualification of aircraft tires to an overspeed landing requirement. 2. REFERENCES There are
7、 no referenced publications specified herein. 3. OVERSPEED LANDING TEST JUSTIFICATION 3.1 Definition An overspeed landing is a landing which is made at a speed above the rated speed of the tire. This landing is typically the result of a failure condition on the aircraft, but may also occur if landin
8、g over the aircraft maximim landing weight at a high altitude airport on a hot day with a significant tailwind. 3.2 Applicability The overspeed landing requirements arise from failure conditions on the airplane, specifically failures which preclude getting the aircraft into a normal landing configur
9、ation. This failure may result in an overspeed landing if the failure occurred when the airplane was near takeoff weight and the means or time were not available to dump fuel. Each aircraft should be evaluated as to the applicability of this test. 3.3 Alternatives Demonstrating overspeed landing cap
10、ability of a tire is an alternative to the selection of a tire with a speed rating sufficient to meet this failure condition. Since the overspeed landing is a rare occurrence and is related to a failure, use of a higher speed rated tire is not recommended. The intent of this test is to insure that i
11、f such a failure occurs, the tires will have sufficient capability to make a successful landing. Continued serviceability of the tire is not required. 4. TEST DEFINITION 4.1 Test Specimen The test tire may be either a new tire or a tire used in other testing. The tire should be at its full molded tr
12、ead depth. The tire should be inflated at room temperature to the rated pressure (corrected for flywheel curvature). 4.2 Test Parameters The temperature of the tire carcass or contained gas should be at least 105 F (40.5 C) at the start of the test. No adjustment in tire pressure may be made during
13、the test. Tire load should be as specified by the airframer or rated load. The initial speed should not exceed rated speed plus 25 mph (40 km/h). The 25 mph (40 km/h) represents a reasonable margin over rated speed, capable of covering most failure conditions. If the overspeed landing requirement fo
14、r the airplane is higher than 25 mph (40 km/h) over the rated speed of the tire, consideration should be given to a tire with a higher speed rating. 4.3 Test Conduction If the Universal Load-Speed-Time Curve of Figure 1 is being used, the tire should be subjected to one cycle as shown in Table 1: TA
15、BLE 1 TEST CONDITION UNIVERSAL LOAD-SPEED-TIME CURVE Symbol Time (s) Speed (mph) Load T00 Up to rated + 25 0 T12 Up to rated + 25 As specified or rated T2End 0 As specified or rated For 190 mph (306 km/h) and 210 mph (338 km/h) rated tires, the end time should be determined using a deceleration of 5
16、.0 ft/s2(1.52 m/s2) from the initial velocity at T1to a complete stop. For speed ratings over 210 mph (338 km/h), the deceleration rate should be set such that the total roll distance from T0 to T2is 13 500 ft (4115 m). The 13 500 ft roll distance represents the maximum expected runway length availa
17、ble for stopping. If the Rational Load-Speed-Time Curve of Figure 2 is being used, the tire should be subjected to one cycle as shown in Table 2. The ramp up of load and ramp down of speed will be specific to the airframe under test and will be supplied by the airframer. TABLE 2 TEST CONDITION FOR R
18、ATIONAL LOAD-SPEED-TIME CURVE Symbol Time (s) Speed (mph) Load T00 Up to rated + 25 0 T1End 0 As specified or rated SAE INTERNATIONAL ARP5257B 2 OF 5TEST LOADTIME(s) TEST SPEED + 25 MPH (40 KM/HOUR)Slope equivalentto5fps2(1.52m/s2), withrolldistance nottoexceed 13,500 ft.(4115 m)T1T0T2S0L0L1S1LOAD (
19、LB) FLYWHEEL S P EED (M P H ) L0= UnloadedconditionL1= Test loadS0= Stopspeed (MPH) S1= Initialspeedequal totest speedplusmarginT0= Time at initial application oftire loadT1= Time at whichtest load is reachedandflywheel decelerationbeginsT2= Time at whichspeedreaches S0FIGURE 1 GRAPHIC REPRESENTATIO
20、N OF A TYPICAL UNIVERSAL OVERSPEED LANDING LOAD-SPEED-TIME TEST CYCLE Slope to be defined by deceleration rate as noted in Section 4.3. SAE INTERNATIONAL ARP5257B 3 OF 5FIGURE 2 GRAPHIC REPRESENTATION OF A TYPICAL RATIONAL OVERSPEED LANDING LOAD-SPEED-TIME TEST CYCLE TEST LOADTIME(s) TEST SPEED + 25
21、 MPH (40 KM/HOUR)T0T1S0L0L1S1LOAD (LB) F L YWHEEL S P EED (M P H ) L0= UnloadedconditionL1= Test loadS0= Stopspeed (MPH) S1= Initialspeedequal totest speedplusmarginT0= Time at initial application oftire loadT1= Time at whichspeedreaches S0SAE INTERNATIONAL ARP5257B 4 OF 54.4 Success Criteria for th
22、e Overspeed Landing Test The tire should be capable of completing one overspeed load-speed-time cycle as defined in 4.3. Upon completion of the test, the tire should be capable of retaining inflation pressure with a loss of pressure not exceeding 10% in 24 hours from the initial inflation pressure.
23、Ambient temperature should be measured at the start and finish of the test to assure that pressure change was not caused by an ambient temperature change. The tire should not lose any chunks or pieces larger than 1 inch x 1 inch (25.4 mm x 25.4 mm) during the test. 4.5 Data Submittal The following d
24、ata should be submitted to the airframe manufacturer: a. A plot of actual tire load and speed versus time. b. Test tire weight, serial number and loaded radius and skid depth. c. Actual tire casing or contained gas temperature at the start of the test. d. A description of the tire and tread conditio
25、n after test completion. e. Inflation pressure loss during a 24-hour diffusion test after overspeed landing test completion. 5. NOTES 5.1 A change bar (|) located in the left margin is for the convenience of the user in locating areas where technical revisions, not editorial changes, have been made
26、to the previous issue of this document. An (R) symbol to the left of the document title indicates a complete revision of the document, including technical revisions. Change bars and (R) are not used in original publications, nor in documents that contain editorial changes only. PREPARED BY SAE COMMITTEE A-5C, AEROSPACE LANDING GEAR SYSTEMS SAE INTERNATIONAL ARP5257B 5 OF 5
