# Robinson Service Bulletin 89: Revision 44

- Rights: © Robinson. Filed by the FAA in regulations.gov docket FAA-2016-0733, the docket of AD 2016-26-04. Not covered by OpenAirDocs’ CC0 dedication.
- Document: [Robinson Service Bulletin 89](https://openairdocs.org/service-documents/robinson/sb-89.md)
- Title as filed: Robinson SB89 R44 Service Bulletin
- Pages: 6
- PDF: https://openairdocs.org/files/sha256/f7/27/f727eb6b22b27486d5175c42ae7fd640f7d52bce73cecd369d1ee159ba21cce0
- Page: https://openairdocs.org/service-documents/robinson/sb-89/file/f727eb6b22b2

## Text

This text is OCR from a scan. OCR can misread letters and numbers. Each page's text from the PDF; open the PDF at a page with #page=N.

### Page 1

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### Page 2

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### Page 3 (OCR)

R44 SB-89
Page 3 of 6
C016-7 Main Rotor Blade
Using a fine-point marker,
mark trailing edge with a
4.0 - 4.2 inch line.
1.25
inches
• INBOARD
Area to be removed
TRAILING EDGE
OUTBOARD I
Using 10x magnification,
RS 117.0  visually inspect upper and
lower surfaces and trailing
edge in this area. Verify no  RS 124.0
cracks, corrosion, or dam-
age such as nicks which
may initiate a crack.
(VIEW LOOKING DOWN)
FIGURE 1
MS3367-6-0
Ty-Rap
Area to be removed
R7769-6 Slit tube
(VIEW LOOKING DOWN)
FIGURE 2
(OVER)

### Page 4 (OCR)

R44 SB-89
Page 4 of 6
Minimum 0.5 inch -
bare metal  - Correct inside radius (2 inches or greater)
INBOARD
0.25 inch minimum outside radius
TRAILING EDGE
OUTBOARD →
4.0 - 5.0 inch  Incorrect radius (smaller than 2.0 inches)
diameter tube
Gap
(VIEW LOOKING DOWN)
FIGURE 3
Upper skin
Lower skin
(MAGNIFIED VIEW OF TRAILING EDGE)
FIGURE 4

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### Page 6

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