1、AEROSPACERECOMMENDED PRACTICEARP6225Issued 2014-11Aircraft Tire Inspection - In-Service Removal CriteriaRATIONALEOn the same aircraft it is possible to find tires from different manufacturers. Since each tire manufacturer may have different removal criteria for a specific condition, this ARP harmoni
2、zes this data and presents common criteria related to the tire sizeand type. This is a compilation of data extracted from tire manufacturers Care and Service Manuals and also from in-service experience.TABLE OF CONTENTS1. SCOPE 32. REFERENCES 33. BACKGROUND 34. PROCEDURE . 35. TIRE REMOVAL CRITERIA
3、. 95.1 Tread Wear Criteria. 105.1.1 Normal Wear . 105.1.2 Uneven Wear (shoulder, center). 105.2 Tread Damage Criteria 135.2.1 Flat spots. 135.2.2 Tread Rubber Reversion. 135.2.3 Skid-Through Burst . 145.2.4 Peeled Rib. 155.2.5 Thrown Tread 155.2.6 Tread Cuts 165.2.7 Chevron Cutting 175.2.8 Groove Cr
4、acking . 185.2.9 Rib Undercutting . 195.2.10 Open Tread Splice 195.2.11 Rib Tearing 205.2.12 Tread Chipping and Chunking 205.3 Sidewall Damage Criteria 215.3.1 Cuts on the Sidewall . 215.3.2 Circumferential Cracks 215.3.3 Weathering and Cracking 225.3.4 Bulge or Blister Criteria . 22_SAE Technical S
5、tandards 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 therefrom, is the sole
6、 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 2014 SAE InternationalAll rights reserved. No part of this publication may be re
7、produced, 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: +1 724-776-4970 (outside USA)Fax: 72
8、4-776-0790Email: CustomerServicesae.orgSAE WEB ADDRESS: http:/www.sae.orgSAE values your input. To provide feedbackon this Technical Report, please visithttp:/www.sae.org/technical/standards/ARP6225 SAE INTERNATIONAL ARP6225 Page 2 of 245.4 Miscellaneous Criteria. 23 5.4.1 Foreign Object Damage 23 5
9、.4.2 Tire Contamination (Hydraulic Fluid, Fuel, Disinfectants, Runway and Airplane De-icers, Hydrocarbons, etc.). 23 5.4.3 Tire Slippage on the Rim. 24 6. NOTES 24 FIGURE 1 RADIAL TIRE COMPONENTS NOMENCLATURE 4 FIGURE 2 BIAS TIRE COMPONENTS NOMENCLATURE 5 FIGURE 3 NORMAL WEAR. 10 FIGURE 4 SHOULDER W
10、EAR 11 FIGURE 5 CENTER WEAR 11 FIGURE 6 TYPICAL TIRE WEAR CHARACTERISTICS. 12 FIGURE 7 FLAT SPOT. 13 FIGURE 8 TREAD RUBBER REVERSION 14 FIGURE 9 SKID THROUGH. 14 FIGURE 10 PEELED RIB . 15 FIGURE 11 THROWN TREAD. 16 FIGURE 12 TREAD CUT 17 FIGURE 13 CHEVRON CUTTING . 18 FIGURE 14 GROOVE CRACKING 18 FI
11、GURE 15 RIB UNDERCUTTING 19 FIGURE 16 OPEN TREAD SPLICE. 19 FIGURE 17 RIB TEARING . 20 FIGURE 18 TREAD CHIPPING AND CHUNKING. 20 FIGURE 19 SIDEWALL CUT 21 FIGURE 20 CIRCUMFERENTIAL CRACK 21 FIGURE 21 SIDEWALL WEATHERING AND CRACKING 22 FIGURE 22 BULGES 22 FIGURE 23 FOREIGN OBJECT DAMAGE 23 FIGURE 24
12、 CONTAMINATION 24TABLE 1 SUMMARY OF REMOVAL CONDITIONS AND ACTIONS 6 SAE INTERNATIONAL ARP6225 Page 3 of 241. SCOPEThis document is for establishing tire removal criteria of on-wing civil aircraft tires only. This document is primarily intended for use with commercial aircraft but may be used on oth
13、er categories of civil aircraft as applicable. The criteria are harmonized with the Care and Service Manuals of the tire manufacturers for both radial and bias tires.2. REFERENCESx Bridgestone: Tire Specification or 2) the flat spot contributes to an unacceptable vibration condition (Figure 7).Tread
14、 Rubber ReversionTread rubber reversion is generally caused by wheel locking on wet or ice covered runways. The affected area is similar in shape to a flat spot (oval), but the rubber appears to be melted (Figure 8).The tire should be removed from the aircraft when: 1) the reversion flat spot damage
15、 exceeds the wear removal criteria of 5.1; or 2) an unacceptable vibration condition is experienced.Skid-Through BurstSkid-through burst results from the locking of the wheel. In this case, the tire experiences either a loss of inflation pressure or an explosive blowout. (Figure 9).Both the failed t
16、ire and axle mate tire should be removed from the aircraft, the burst tire marked as “scrap” and the axle mate tire marked with the removal reason (“Mate to Flat”). The skid through tire can be scrapped locally but the mate to flat tire should be returned to the tire manufacturer or retreader. SAE I
17、NTERNATIONAL ARP6225 Page 7 of 24Peeled RibA peeled rib usually starts with a cut or damage in the tread and results in a circumferential delamination of the tread rib away from the tire casing, typically with no loss of reinforcing plies (Figure 10) or tire pressure.The tire should be removed immed
18、iately from service when the peeled section, regardless of length, is exposing fabric or has fully detached. Pieces from the tread should be requested from airport authorities and returned to the home base for potential analysis by the tire supplier.Thrown TreadA thrown tread on an inflated tire is
19、a partial or complete loss of the tread down to the casing plies or tread reinforcing plies/protector ply (Figure 11).The tire should be removed immediately from service. Pieces from the tread should be requested from airport authorities and returned to the home base for potential analysis by the ti
20、re supplier. If the damaged tire is not inflated due to a loss of inflation pressure, then the axle mate should be removed also. If the tire is still inflated after the aircraft is parked, record the tire pressure after it has cooled down (allow 3 hours). Tread CutsForeign objects that are present o
21、n runways, taxiways and parking areas can cause cuts to the tires (Figure 12).Tire should be removed immediately from the aircraft if: x the cut exposes or penetrates reinforcing ply (bias tire) or protector ply (radial tire), or x the cut or damage severs or extends across a tread rib, or x undercu
22、tting occurs at the base of any tread rib cutChevron CuttingChevron cutting is tread damage (small z-, s-or v-shaped tears) caused by touchdown, running and/or braking on cross-grooved runways (Figure 13). Chevron cutting is a condition of the tread rubber only.Tire should be removed from aircraft i
23、f: x The tread cut criteria are reached, or x The tread reinforcing ply (bias tire) or protector ply (radial tire) is exposed for more than 1.0 square inch (6.45 cm2), or x The cutting involves the full width of any one of the tread ribsGroove CrackingGroove cracking may result from ozone attack of
24、the rubber or excessive flexing of the groove bottoms as a result of insufficient inflation of the tire. These cracks occur along the bottom of tread grooves (Figure 14).The tire should be removed immediately from the aircraft if: x groove cracking exposes the reinforcing ply (bias tire) or the prot
25、ector ply (radial tire) for more than 0.25 inch (6.35 mm) circumferentially in length. x groove cracking has led to undercutting of the adjacent rib by more than 0.25 inch(6.35 mm).Rib UndercuttingRib undercutting can be an extension of groove cracking progressing under a tread rib or develop as a b
26、reak in the groove wall extending under the rib. This can lead to tread chunking, peeled rib, or thrown tread (Figure 15).The tire should be removed immediately from the aircraft if undercutting extends more than 0.25 inch (6.35 mm) under the tread rib.Open Tread SpliceAn open tread splice is a crac
27、k in the tread rubber where the manufacturing joint or splice separates in a radial direction across the tread ribs (Figure 16).The tire having this defect should be removed immediately from the aircraft.Rib TearingRib tearing occurs when the tire is subjected to excessive side force during landing
28、or taxiing (Figure 17).The tire should be removed immediately from the aircraft if cords are exposed for more than 1.0square inch (6.45 cm2) or the damage extends the full width of the tread rib.SAE INTERNATIONAL ARP6225 Page 8 of 24Tread Chipping and ChunkingThis is a condition visible at the edge
29、of the tread rib in which small amounts of rubber begin to separate from the tread surface. Tread chunking can be caused by rib undercutting, tight turning or a high lateral force applied to the tire tread (Figure 18). This can lead to rib undercutting under severe conditions.The tire should be remo
30、ved immediately from the aircraft if the reinforcing ply (bias) or protector ply (radial) is exposed. SIDEWALL DAMAGE CRITERIACONDITION OBSERVATION/DAMAGE ACTIONCuts on the SidewallCuts on the sidewall are caused by damage from FOD (Figure 19).The tire should be removed immediately from the aircraft
31、 if any sidewall cord is visible. Cuts in the rubber which do not reach the cord plies are not detrimental to tire performance but should be monitored at subsequent inspections. The tire can be left in service if the cuts do not reach the ply cords.Circumferential CracksCircumferential cracks can be
32、 caused by a molding condition of the rubber or load shear and stress combined with low tire inflation pressure (Figure 20).The tire should be removed immediately from the aircraft if sidewall cord is visible. If operating underinflated is suspected the operator should investigate and take correctiv
33、e actions.Weathering and CrackingWeathering and cracking occur when tires are exposed to ozone or to direct sunlight for an extended period of time (Figure 21). An insufficient tire inflation pressure accelerates the phenomenon.The tire should be removed immediately from the aircraft if the sidewall
34、 plies are visible. If operating underinflated is suspected the operator should investigate and take corrective actions.Blister or BulgeOperating conditions outside the tire specification can cause bulges or blisters onthe tread or on the sidewalls (Figure 22). They normally indicate a separation of
35、 components. When present, these defects can be observed mainly in the shoulder area of the tire while it is still warm.Any tire showing a bulge or blister should be removed immediately from the aircraft. Mark the affected area with a soft crayon before deflating the tire.MISCELLANEOUS CRITERIACONDI
36、TION OBSERVATION/DAMAGE ACTIONForeign Object Damage (FOD)Foreign object damage (FOD) (Figure 23) occurs when material left on the runway, taxiway or ramp causes damage to tires, engines, or other aircraft structure. It is the most common cause for tires being removed before full wear out. Airport au
37、thorities should be notified when it can be confirmed that tire removals for FOD are prevalent.Remove tires from the aircraft if:x Cuts, embedded objects or other injuries expose or penetrate the reinforcing plies (bias) or protector ply (radial).x Cuts, embedded objects or other injuries that do no
38、t expose or penetrate the reinforcing plies (bias) or protector ply (radial) and extends entirely across a tread rib (any depth).SAE INTERNATIONAL ARP6225 Page 9 of 24Tire Contamination (Hydraulic Fluid, Fuel, Disinfectants, Runway and Airplane De-icers, Hydrocarbons, etc.)In case of contamination,
39、check for rubber condition (Figure 24). The tire has to be cleaned quickly with commercially available denatured alcohol to remove the contaminant and then washed with a soap and water solution.x Ensure that the contaminated rubber surface is not swelled. An easy check is to push your finger nail in
40、to the contaminated surface, and in case of swelling, the nail will leave a permanent imprint. In this case the tire should be returned to the retreader for inspection / possible repair.x If the subject tire needs to be removed and sent to the retreader for inspection, clearly identify the tire by m
41、arking with white chalk “Contaminated Tire”.Tire Slippage on the RimAfter installation of a new tire on the rim, some cycles on the aircraft may be necessary before the tire reaches its final position. During this period of time, a slippage of the tire on the rim may be observed (e.g., the red mark
42、on the tire is no longer aligned with the inflation valve or the wheel heavy point if marked). ARP5507 recommends a maximum slippage of 20 degrees following installation. ARP5507 further recommends that tires which move in excess of 20 degrees should be disassembled and evaluated for appropriate act
43、ion. 5. TIRE REMOVAL CRITERIAWARNING: Aircraft tires should be mounted only with the proper equipment, instructions, and operator training. Serious injury may occur as a result of improper equipment or procedures.WARNING: Always approach a tire/wheel assembly mounted on an aircraft from an oblique a
44、ngle (direction of the tires shoulder). WARNING: Aircraft tire and wheel assemblies should be treated with the same care as any other high pressure vessel. Improper handling may lead to serious injury.WARNING: Aircraft tires should always be inflated with a properly regulated dry nitrogen inflation
45、source. Regulate the supply line to a pressure no greater than 1.5 times the operating inflation pressure. Inflating a tire without a pressure regulator presents a risk of personal injury and/or damage to equipment.CAUTION: Be careful when handling, assembling and disassembling wheel components to a
46、void damage.WARNING: Do not probe cuts or embedded objects while a tire is inflated. Such action could further damage a tire causing it to rupture resulting in personal injury or equipment damage. WARNING: A tire/wheel assembly that has known damage should be allowed to cool to ambient temperature (
47、a minimum of 3 hours) before the tire is deflated.WARNING: Use care when removing the valve core from an inflated tire. Use of a valve core removal tool is recommended. The valve core of an inflated tire can be projected at a high speed and possibly cause injury. NOTE: Tires removed for other than n
48、ormal wear should be investigated for cause with corrective actions taken, if appropriate.NOTE: The regular care and maintenance of aircraft tires while in service is essential to maximizing the number of duty cycles that can be achieved by each tire, and to minimizing the risk of aircraft damage fr
49、om tire failures. It is important that tire condition and pressure are checked daily and underinflated tires should be addressed per the tire pressure maintenance schedule of ARP5265.SAE INTERNATIONAL ARP6225 Page 10 of 245.1 Tread Wear Criteria5.1.1 Normal Wear An even tread wear indicates that the tire has been properly maintained during its service
