AD 77-10-07

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AD Number:
77-10-07
Document Type:
AD Final Rules
Docket Number:
Unknown
Subject Heading:
Airworthiness Directives; Bell Model 205A-1 Helicopters
Subject:
Engine-to-Transmission Assembly
Status:
Current
Citation:
This information is not available.
Citation Publish Date:
Effective Date:
05/18/1977
Make:
Bell Helicopter Textron, Inc.
Model:
205A-1
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Superseded AD: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Superseded By: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: 77-10-07
CITATION:   This information is not available.

PAGE NUMBER:  

DOCKET NUMBER:   Unknown

AMENDMENT:   39-2900

AD NUMBER:   77-10-07

SUBJECT HEADING:   Airworthiness Directives; Bell Model 205A-1 Helicopters

ACTION:  

SUMMARY:  

DATES:   Effective May 18, 1977.

ADDRESSES:  

FOR FURTHER INFORMATION CONTACT:  

SUPPLEMENTARY INFORMATION:  

REGULATORY TEXT:  
77-10-07 BELL HELICOPTER TEXTRON: Amendment 39-2900. Applies to Model 205A-1 helicopters, Serial Numbers 30001 through 30232, certificated in all categories.

For helicopters certificated and operated pursuant to Part 133 of the FARs (Class B rotorcraft-load combination or Class C rotorcraft-load combinations as defined by Part 1 of the FARs), compliance is required within the next 100 hours cumulative time in service involving external load combinations as defined above, or 300 hours total time in service, whichever comes first, after the effective date of this Airworthiness Directive (AD), unless previously accomplished.

For standard category helicopters not approved for external load operations as defined above, compliance is required within the next 300 hours time in service after the effective date of this AD, unless previously accomplished.

To prevent failure of the engine-to-transmission drive couplings due to excessive angularity under high loading conditions, adjust the engine-to-transmission alignment as described below:

(a) Remove the engine-to-transmission driveshaft assembly, P/N's 205-040-004-3, - 11, or -17, in accordance with instructions in the appropriate maintenance and overhaul manuals.

(b) Using instructions and special tools prescribed by the maintenance and overhaul manuals, establish the engine-to-transmission alignment prescribed by the manual except as follows:

(1) Index the target plate inner scale to 8.0 (instead of 3.5) and index the target plate outer scale to 35.6 (instead of 1.75).

NOTE: Transmission position must be adjusted and leveled to maintenance manual specifications. Engine position adjustment procedures must follow maintenance manual instructions.

(2) Establish angularity as follows: Install dial indicator in accordance with instructions in the maintenance manual at 2.5 inch radius. Read zero at 12 o'clock position; read +0.030 + 0.004 at 6 o'clock position. Reset dial indicator to zero at the 3 o'clock position; read +0.006 + 0.004 at 9 o'clock position. Plus reading on dial indicator means that flange on transmission is closer to flange on engine.

(c) Shim engine support fittings to obtain required alignment. If total laminated shim thickness (P/N 205-060-137-1 or 205-060-138-1), required under any engine support fitting, exceeds 0.188 inches, fabricate a plate of 2024-T4 aluminum alloy 0.100 thick, same outside dimensions as shim stock, and structurally bond the plate to the engine service deck with EC 934. Total thickness of shims and plate under any engine mount fitting must not exceed 0.288 inches. Verify that the engine support fittings are reinstalled with the same fore and aft orientation as before.

(d) Interference between the engine and the aft upper firewall at the 9 o'clock position (looking forward) may result with this realignment. If this condition occurs, accomplish the following:

Remove the aft upper firewall assembly P/N 205-060-909-27 and disassemble by removing the sixteen (16) screws.

Remove the aft section of the firewall web P/N 204-060-909-13 and enlarge the sixteen (16) holes by drilling to 5/16 inch.

Deburr the drilled holes. Reassemble the firewall assembly using P/N AN970-3 washers over the enlarged holes and under the 16 screw heads.

(e) Check engine deck fittings screws and bolts for proper length and thread engagement.

(f) Check fuel control and governor linkage for proper rigging and cushion.

(g) Reinstall the driveshaft assembly. Reinstall transmission 5th mount assembly. Follow maintenance manual instructions for details of reinstallation of access panels, firewall attachments, and related cleanup, as required.

Equivalent means of compliance with the modifications prescribed by this AD may be approved by the Chief, Engineering and Manufacturing Branch, Flight Standards Division, Southwest Region, Federal Aviation Administration, Post Office Box 1689, Fort Worth, Texas, 76101.

Upon request of the operator, an FAA maintenance inspector, subject to prior approval of the Chief, Engineering and Manufacturing Branch, Flight Standards Division, Southwest Region, Federal Aviation Administration, may adjust the compliance time prescribed by this AD, if the request contains substantiating data to justify the increase for that operator.

This amendment becomes effective May 18, 1977.

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