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 theref
2、rom, 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 InternationalAll rights reserved. No part of this publi
3、cation 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: +1 724-776-4970 (out
4、side USA)Fax: 724-776-0790Email: CustomerServicesae.orgSAE WEB ADDRESS: http:/www.sae.orgSAE values your input. To provide feedbackon this Technical Report, please visithttp:/www.sae.org/technical/standards/ARP5600AEROSPACERECOMMENDED PRACTICEARP5600Issued 2005-05Reaffirmed 2015-08Disposition of Dam
5、aged WheelsInvolved in Accidents/IncidentsRATIONALEARP5600 has been reaffirmed to comply with the SAE five-year review policy.1. SCOPE: 1.1 This SAE Aerospace Recommended Practice (ARP) establishes a procedure for disposition of aircraft wheels that have been involved in accidents/incidents or have
6、been exposed to overheat conditions or overload conditions from loss of adjacent tire pressure (paired wheels) or wheel tie bolts. 1.2 Recommendations in this document apply to main landing gear (braked) and nose landing gear aircraft wheels, manufactured from aluminum forgings or castings. The most
7、 common wheel material is 2014 or 2214 aluminum but other aluminum alloys are applicable to this document such as 2030, 7049, 7050 and 356 castings. 2. REFERENCES: 2.1 British Civil Aviation Authority Notice 97 (Issue 1, May 10, 1982) Return to Service of Aircraft Items Recovered from Aircraft Invol
8、ved in Accidents/Incidents 2.2 SAE AMS-A-22771, Aluminum Alloy Forgings, Heat treated 2.3 SAE AMS-QQ-A-367, Aluminum Alloy Forgings 2.4 ASTM E 1417, Standard Practice for Fluorescent Penetrant Examination 2.5 ASTM E 1444, Standard Practice for Magnetic Particle Examination 2.6 SAE AMS-S-13165, Shot
9、Peening of Metal Parts 2.7 AIR4403, Tapered Roller Bearings for Wheels 2.8 AIR4777, Nondestructive Inspection for Wheels and Brakes 2.9 T.O. 4W-1-61, Wheel General Maintenance and Overhaul Technical Order 2.10 T.O. 33B-1-1, Nondestructive Inspection Methods Technical Order 2.11 T.O. 44B-1-3, General
10、 Maintenance Instruction for Aircraft Wheel Bearings Technical Order 3. DEFINITIONS: RESIDUAL STRESS: Stress present in a component that is free of external forces or thermal gradients. RESIDUAL STRAIN: Plastic Deformation that remains permanently after removal of the load that caused it. 4. IDENTIF
11、ICATION OF DAMAGE: 4.1 Landing gear wheels involved in accidents/incidents can be classified under four different types as follows: Type I: Severe Mechanical Damage - Wheels with visible severe mechanical damage (gouged, pierced, fractured, etc.). Type II: Abnormal Heat - Wheels involved in abnormal
12、 heat (fire, frictional heat caused by an aborted take-off, extreme landing, dragging brakes), and damage resulting from a failed wheel bearing. Type III: Visual or Dimensional Distortion - Wheels with visual or measureable dimensional distortion. Type IV: No Visual or Measurable Defect - Wheels wit
13、h no visable or measureable defect, but known to have been involved in an accident/incident (no heat damage). These types of damage and their causes may or may not be identified in repair and overhaul manuals. This type of information is pertinent when determining the disposition required, therefore
14、 separate dispositions are provided for each type of damage. A damage assessment is essential to determine the applicable category. It is recommended that the returned wheel include a statement indicating why it is being returned from service. SAE INTERNATIONAL ARP5600 2 OF 75. DISPOSITION: WARNING:
15、 Without a thorough investigation by properly qualified personnel, these wheels should not be returned to service. Retain all subcomponents if deemed relevant to the damage investigation such as bearings, tie bolts, seals, retainers, fuse plugs, inflation valves, etc. CAUTION: Cleaning and handling
16、of damaged components may obscure or discard evidence useful in the follow-on investigation. Reasonable effort should be made to photo document the subject and its adjacent and related parts to record the components condition and location at the time of discovery and at subsequent stages prior to cl
17、eaning, disassembly and further study for investigation of the damage source. 5.1 Type 1 Severe Mechanical Damage: These wheels should be considered scrap unless approved by a detailed evaluation by cognizant engineering office and the airworthiness authorities. However, if the wheels are to be retu
18、rned to service, it is strongly recommended to follow procedures for Types II, III and IV below to ensure removal of harmful residual stresses. 5.2 Type II Abnormal Heat: Type II damage will likely cause a reduction in strength, ductility, fatigue-life and stress corrosion cracking resistance, due t
19、o changes in material properties. The severity of the damage caused by intense heat must be accurately evaluated and approved by engineering personnel and the airworthiness authorities to ensure safe operation of the wheels before they may return to service. It is essential that the initial investig
20、ation of wheels involved in accident/incidents be accomplished before removing any paint, primer or plating and that no chemicals are applied prior to the investigator viewing the wheel, or essential evidence may be lost. Examination of coated surfaces for evidence of blistering and abnormal color c
21、hange to primer and paint, together with accurate testing methods involving conductivity, hardness and non-destructive methods are recommended for proper assessment of wheel damage. Examination of other surfaces such as plated wheel drive keys or torque bars, for abnormal discoloration is essential.
22、 Unless a thorough investigation is performed, these wheels and wheel components should not be returned to service. SAE INTERNATIONAL ARP5600 3 OF 75.2 (Continued): The following are the recommended steps for disposition of Type II wheels: a. The wheel should be thoroughly cleaned using solvent or a
23、queous cleaner in accordance with the applicable maintenance manual. Abrasives or chemicals, which may discolor wheel, should be avoided. b. Prior to stripping paint from the part: 1. Examine primer or painted surfaces for abnormal color changes or blistering. 2. Examine the cadmium-plated surfaces
24、such as tie bolts for blistering. Any cadmium plated steel component that is known to have been exposed to temperatures in excess of 450 F (232 C) shall be replaced. If temperature exposure is unknown the components shall be evaluated per their maintenance manual requirements. 3. Examine the other c
25、oatings (such as chrome on drive keys and torque bars) for evidence of abnormal discoloration. 4. Examine rotor drive keys/torque bars on wheels mated with carbon brakes for evidence of melting or bending due to high temperature exposure. c. Based upon the evidence found during the initial examinati
26、on the following other steps are recommended (complete all steps below if any anomalies are noted from the previous four steps): 1. Remove all components such as drive keys/torque bars, valves, thermal release plugs, bushings and bearing cups. Pay specific attention to thermal release plugs for evid
27、ence of full or partial melting of eutectic material. Discard all component parts of the wheels except for the wheel halves, drive keys/torque bars and heat shields, which will require full dimensional inspection and hardness per the maintenance manual. Without exception replace all elastomeric comp
28、onents, wheel bearings and lubricants 100% with new items. 2. Completely strip wheel halves of all primer, and paint coatings (as required by the maintenance manual). 3. Perform conductivity inspection of wheel surfaces per the applicable maintenance manual to ensure wheels are not heat damaged. Par
29、ticular attention should be given to those wheel areas adjacent to the brake, namely the wheel tubewell and inboard bearing hub wheel features. Confirm any conductivity anomalies using hardness testing in the affected area. Conductivity readings that are slightly in excess of limits should be verifi
30、ed by slight polishing of the affected area with 400 grit emery cloth and retesting. SAE INTERNATIONAL ARP5600 4 OF 75.2 (Continued): 4. Re-shotpeen should be considered if the exposure temperature is known to be less than 450 F but higher than the stress relief temperature of 250 F. Perform other n
31、on-destructive tests such as fluorescent penetrant inspection or eddy current to ensure wheel is defect free. d. Parts requiring hardness testing or local polish to facilitate the non-destructive testing should be reworked in the local rework area to the maintenance manual requirements. If anodize p
32、rotective coating is removed in localized area for clean up or inspection, the reworked area shall be surface protected with brush-on chemical conversion coating prior to primer and paint applications. 5.3 Type III Visual or Dimensional Distortion: Visible distortion indicates that the component has
33、 been subjected to loads in excess of its material yield limits, resulting in residual stresses and strains that may reduce its effective strength even if its function is not affected. In addition, straightening the component is not permitted. Straightening may contribute to an increase of the resid
34、ual stresses/strains and further reduce the components resistance to fatigue cracking. The recommended minimum requirements to reduce harmful residual stresses are: a. From the inspection report on the subject wheel, determine if the part is dimensionally acceptable. 1. If the wheel is dimensionally
35、 unacceptable, it should be scraped. 2. If the wheel is dimensionally acceptable, it should be reworked per steps b through g below and in accordance with the applicable wheel maintenance manual. b. Remove all components such as drive keys/torque bars, valves, thermal release plugs, bushings and bea
36、ring cups. Pay specific attention to thermal release plugs for evidence of full or partial melting of eutectic material. Retain these components if deemed relevant to the damage investigation such as bearings, tie bolts, seals, retainers, fuse plugs, inflation valves, etc. Visually and dimensionally
37、 inspect these components per their applicable wheel maintenance manual specified limits. Harmful residual stresses may be validated using Barkhausen or X-ray diffraction residual stress measurement techniques for maintaining safety of flight. Return to the wheel manufacturer or cognizant engineerin
38、g authority for subsequent analysis and consideration as required. SAE INTERNATIONAL ARP5600 5 OF 75.3 (Continued): c. Discard all component parts of the wheels except the wheel halves and strip wheel halves of the primer and paint. d. Stress relieve the wheel halves with a bake at 225 to 250 F (107
39、 to 121 C) for 24 hours. e. Fluorescent penetrant inspect wheel halves. Verify any indications using eddy current inspection method. f. Conductivity test wheel surfaces identified in the maintenance manual for signs of overheating. Particular attention should be given those wheel areas adjacent to t
40、he brake, namely the wheel tubewell and inboard bearing hub wheel features. Verify any readings out of limits, by lightly polishing affected area with 400 grit emery cloth and retesting. Hardness test all areas which remain out of limit of polishing inspection. g. Shot peen local affected areas or t
41、he entire wheel halves in accordance with applicable maintenance manuals. If anodize protective coating is removed in localized area for clean up or inspection, the reworked area shall be surface protected with brush-on chemical conversion coating prior to primer and paint applications. 5.4 Type IV
42、No Visual or Measurable Defect: Although these components appear to be sound, harmful residual stresses may be present due to localized yielding of the material from an overload condition. These areas may require additional inspection such as Barkhausen or X-ray diffraction. It is therefore importan
43、t to ensure that such residual stresses are minimized prior to returning the wheels to service. Overload conditions adjacent deflated or run-flat tires result in 2X loads on the remaining inflated wheel. Missing tie bolts require wheel inspection and adjacent or complete set of tie bolt hardware rep
44、lacements. To verify wheel halves are free of deformation, dimensional verification of the bead seat area is recommended to check the radial and lateral run-out. The availability of this technical information in the applicable maintenance manual is essential, including all the pertinent dimensional
45、and geometrical tolerances. If the information is not available, contact the wheel manufacturer or the cognizant engineering authority for a comparison between actual dimensions and the drawing dimensions. Any deformation found will result in reclassification to Type III category. In the absence of
46、engineering drawings, it is recommended that the disposition of wheel halves of components with this type of defect be the same as for Type III above. SAE INTERNATIONAL ARP5600 6 OF 76. ADDITIONAL REQUIREMENTS: 6.1 Salvaged aircraft landing gear wheels per this document should have their history ann
47、otated and this paperwork should accompany the wheel after the completion of the repair. 6.2 Any aircraft landing gear wheel that is identified unsound, not having sufficient integrity for continued surface, must be physically mutilated to such a degree that the wheel becomes unusable for its intended purpose. PREPARED UNDER THE JURISDICTION OF SAE COMMITTEE A-5, AEROSPACE LANDING GEAR SYSTEMS SAE INTERNATIONAL ARP5600 7 OF 7
