AD 84-15-03

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AD Number:
84-15-03
Document Type:
AD Final Rules
Docket Number:
Unknown
Subject Heading:
Airworthiness Directives; BOEING VERTOL COMPANY Model 234 Helicopters
Subject:
Cylinders -Flight Control System
Status:
Current
Citation:
This information is not available.
Citation Publish Date:
Effective Date:
08/03/1984
Make:
Columbia Helicopters, Inc.
Model:
234
Product Type:
Aircraft
Product Subtype:
Rotorcraft
Affected AD:
Superseded AD:
Affected By:
Superseded By:
Service/Office:
Office of Primary Responsibility:
CFR Part Reference:
Part 39
Comments:
AIRWORTHINESS DIRECTIVES FINAL RULES: 84-15-03
CITATION:   This information is not available.

PAGE NUMBER:  

DOCKET NUMBER:   Unknown

AMENDMENT:   39-4892

AD NUMBER:   84-15-03

SUBJECT HEADING:   Airworthiness Directives; BOEING VERTOL COMPANY Model 234 Helicopters

ACTION:  

SUMMARY:  

DATES:   Effective August 3, 1984.

ADDRESSES:  

FOR FURTHER INFORMATION CONTACT:  

SUPPLEMENTARY INFORMATION:  

REGULATORY TEXT:  
84-15-03 BOEING VERTOL COMPANY: Amendment 39-4892. Applies to Boeing Vertol Model 234 helicopters certified in all categories.

Compliance is required as indicated, unless already accomplished.

To prevent bypassing of the lower boost dual actuating cylinder(s) and to prevent fatigue failures of NAS 1351-3H10P cap screws on lower boost dual actuating cylinders in the flight control system, accomplish the following:

(a) Within the next 25 hours time in service after the effective date of this AD, unless already accomplished, revise Boeing Vertol Rotorcraft Model 234 Flight Manual by inserting Revision 13 dated May 9, 1984.

(b) Within the next 25 hours time in service after the effective date of this AD, unless already accomplished within the last 25 hours time in service, and thereafter at intervals not to exceed 300 hours time in service from the last inspection, inspect for water and total chlorine of the aircraft hydraulic system fluid in accordance with the contamination level test procedure specified in Boeing Process Specification BAC 5820, Revision A, as amended by Process Specification Department Number 8-2. An alternate inspection (including intervals between inspections) may be approved by the Manager, New York Aircraft Certification Office, 181 South Franklin Avenue, Valley Stream, New York 11581.

For aircraft exceeding allowable contamination levels, flush the hydraulic system in accordance with the procedure specified in Boeing Vertol telex No. 8-1420-3-5459 dated May 25, 1984, or an equivalent approved by the Manager, New York Aircraft Certification Office, 181 South Franklin Avenue, Valley Stream, New York 11581. Sample to insure acceptability following flushing. Repeat the contamination level test procedure at intervals not to exceed 300 hours time in service, except that an alternate interval approved by the Manager, New York Aircraft Certification Office, 181 South Franklin Avenue, Valley Stream, New York 11581, may be substituted.

(c) Within the next 200 hours time in service from the effective date of this AD, unless already accomplished within the last 25 hours time in service, and subsequent to accomplishing the work of paragraph (b), remove all lower boost dual actuating cylinders Part Numbers (P/N) 234HS560-1 and -2 and inspect the shutoff valve spools for any visual signs of staining or pitting on the spool lands (shiny, lapped, interface surface). Replace the actuator with a serviceable part if staining or pitting is found, except for staining between lands in the machined clearance areas if no scaling rust or corrosive debris is present. A follow-on spool inspection is not required unless the repetitive fluid contamination level test cited in paragraph (b) shows an increase in chlorine contamination levels. Prior to returning the actuator to service, replace shutoff valve lap assembly P/N 1303-084, Rev. C, with shutoff valve lap assembly P/N 1303-084, Rev. D.

(d) Within the next 25 hours time in service from the effective date of this AD, unless already accomplished within the last 575 hours time in service, and thereafter at intervals not to exceed 600 hours time in service, replace the six NAS 1351-3H1OP cap screws that attach the gland retainers, P/N 1303-044, to the actuator manifold assembly, P/N 1303-010, on all four lower boost dual actuating cylinders, P/N's 234HS560-1 and -2, with zero time screws. Torque the new screws to a value of 30- to 35-inch-pounds (wet).

(e) Within the next 25 hours time in service from the effective date of this AD, unless already accomplished within the last 25 hours time in service, and thereafter at intervals not to exceed 25 hours time in service, conduct the inspections, jam indicator button checks, leakage checks, and safety wire replacement contained in paragraphs 3A, 3B, 3C, 3D, and 3E of Boeing Vertol telex No. 8-1420-3-5455 dated May 25, 1984, or an equivalent approved by the Manager, New York Aircraft Certification Office, 181 South Franklin Avenue, Valley Stream, New York 11581.

(f) Upon submission of substantiating data by an owner or operator through an FAA Maintenance Inspector, the Manager, New York Aircraft Certification Office, New England Region, may adjust the compliance times specified in this AD.

This amendment becomes effective August 3, 1984.

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