请问这损伤标准在哪查？

传说哥

请教大神们一个小问题

请问图中这条回油管的损伤标准在哪里能查到呢？

jamhowson

When tightening hose B-nuts, it is imperative to use two wrenches: one on the B-nut to tighten it and another on the smaller set of wrench flats on the hose body next to the B-nut to prevent the hose from twisting during installation

jamhowson

737NG-FTD-32-17001
        ATA:
3241-00         Last Revised:
17-NOV-2017
Issue Title:
Potential Chafing Between the Left Main Landing Gear Shimmy Damper Hydraulic Return Line and a Brake System Hydraulic Hose         Originated:
18-MAY-2017
Airplane Model:
737NG         Minor Model(s):
  -600, -700, -700C, -800, -900, -900ER, -BBJ         Other Models:
  737MAX         ECD:
27-APR-2018
Attachments/Illustrations: Title(s) in this section are selectable attachments.
Elbow Clearance Requirements, Shimmy Damper Return Tube Chaffing
References:
Fleet Team Economic (FTE) FTE-32-14024, dated 30-NOV-2014
Illustrated Parts Catalog (IPC) 32-41-52-06A, Item 10, dated 15-FEB-2017
Drawing 274A1900
Illustrated Parts Catalog (IPC) 32-41-52-06, Item 55/55J, dated 15-DEC-2015
Aircraft Maintenance Manual (AMM) TASK 20-10-51-300-805, dated 15-FEB-2017
Illustrated Parts Catalog (IPC) 32-41-51-10C, Item 240/240J, dated 15-DEC-2015
Drawing 272A6101
        Issue Status:
Open
Revision Description
Updated STATUS, INTERIM ACTION, and OPERATOR ACTION section.
Applicability
All 737NG aircraft.
Description
In recent years, several 737 operators have reported occurrences of interference between the P/N 272A6101-111/-211 shimmy damper return hydraulic tube and the P/N BACH8A04EE0320B/BACH8A04EE0332K brake No. 2 hydraulic hose common to the left hand main landing gear. This interference may eventually lead to chaffing and subsequent external leakage from the impacted hydraulic tube, as shown in the "Shimmy Damper Return Tube Chaffing" attachment.

NOTE: The right hand main landing gear shimmy damper return tube has a different routing, which precludes it from similar interference/chaffing conditions.
Status
Boeing initiated a design change in early March 2017 to mitigate the potential for future chaffing between the shimmy damper return tube and the brake No. 2 hose common to the left hand main landing gear. A new hydraulic tube (P/N 272A6101-225) has been developed to allow for greater clearance from the brake system hydraulic hose on 737NG aircraft. This tube design improvement has been committed within the 737 production system and Boeing anticipates production incorporation on 737NG L/N 6800 in early 2018. Lastly, we are currently working with the supplier of the main landing gear (UTAS) to manufacture a spares allotment of improved hydraulic tubes for installation on 737NG in-service aircraft (on an attrition basis).

Major milestones for the process are provided in the MILESTONES section, below, recognizing that they may require adjustment as the work progresses.
Interim Action
None, at this time.
Final Action
Boeing intends on incorporating the improved shimmy damper return tube in 737 production in early-February 2018. Furthermore, a Boeing Service Letter will be published that will recommend that operators remove and replace in-service shimmy damper return tubes on an attrition basis.

NOTE: Boeing intends to make the new hydraulic tube the preferred spares component for in-service aircraft
Milestones
Note: Target dates are based upon currently available status and have risk of future revision.

Root Cause Established: 01-MAR-2017 (Complete)
Solution Selected: 14-MAR-2017 (Complete)
Change Committed: 20-APR-2017 (Complete)
Production Incorporation: 01-FEB-2018 (Target)
Service Documents Available: 1Q2018 (Target)
Parts Available: TBD
Operator Action
As an interim measure to prevent tube chaffing and hydraulic fluid leakage, Boeing recommends that operators experiencing interference between the left shimmy damper tube and the brake No. 2 hose perform the following:

1. Inspect the P/N 272A6101-111/-211 hydraulic tube for chaffing damage. If chaffing depth is present, but the damage is within the limits provided below, then the tube may remain in-service.

- Chafed - 0.006 in./Dent - 0.005 in.

If chaffing depth is outside the limits provided above, then the tube must be replaced. NOTE: Boeing will update AMM Task 20-10-51-300-805 to reflect the damage limits provided above in the 15-FEB-2018 revision of the 737NG AMM.

2. Apply spiral wrap in order to protect the left shimmy damper hydraulic tube from chafing damage. Panduit (P/N T25F-C0) weather-resistant polyethylene 0.25 inch diameter spiral wrap is a suitable product; as is Ark-Plas (P/N AP01SW24BK or AP01SW25BK) UV-resistant polyethylene wrap or (P/N AP01NSW25N) nylon wrap.

Panduit Website: www.panduit.com

Ark-Plas Website: www.ark-plas.com

NOTE: Boeing has no objection to the utilization of spiral wrap to protect the left shimmy damper hydraulic tube; however, operators will need to coordinate the incorporation of spiral wrap with their local regulatory agency.

3. Perform an inspection of the hose installation in order to verify that the hoses are not twisted, which could result in the hose making contact with adjacent parts. Boeing also recommends the following: a) When tightening hose B-nuts, it is imperative to use two wrenches: one on the B-nut to tighten it and another on the smaller set of wrench flats on the hose body next to the B-nut to prevent the hose from twisting during installation, b) Verify that the angled elbow fitting at the upper end of the hose are pointed directly forward within plus/minus 5 degrees and that the elbow fitting on the brake is pointed straight forward to 10 degrees away from the wheel (see the "Elbow Clearance Requirements" attachment for additional details).

jamhowson

Elbow Clearance Requirements.pdf (152.05 KB, 下载次数: 11)

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