AD 84-03-51
Applicability
| Type | Manufacturer | Model | Details |
|---|---|---|---|
| aircraft | Columbia Helicopters, Inc. | 234 | Airworthiness Directives; BOEING VERTOL COMPANY Model 234 Series Helicopters |
Unsafe Condition
Cracking of the main rotor head tie bars, specifically forward and aft tie bars P/N 114R21551 with serial numbers A13207 and below (excluding those with a 'B' suffix), could cause possible hazards in flight.
AI-generated summary from the source AD text. Verify against the official source before acting.
Required Actions
Visually inspect forward tie bars (P/N 114R21551, serial numbers A13207 and below) for cracks within 25 hours time in service from the AD effective date or before 450 hours time in service, whichever is later. Similarly inspect aft tie bars (same part and serial numbers) within 25 hours or before 550 hours. Repeat inspections at intervals not exceeding 450 hours (forward) or 550 hours (aft). Remove and replace cracked tie bars before further flight.
AI-generated summary from the source AD text. Verify against the official source before acting.
Compliance Time
within the next 25 hours time in service from the effective date of this AD or before the accumulation of 450 hours time in service (for forward tie bars) and 550 hours time in service (for aft tie bars), whichever comes later
AI-generated summary from the source AD text. Verify against the official source before acting.
Affected Aircraft
Boeing Vertol Model 234 series helicopters with forward and aft main rotor tie bars P/N 114R21551, serial numbers A13207 and below (excluding those with a 'B' suffix)
AI-generated summary from the source AD text. Verify against the official source before acting.
Federal Register Abstract
Forward Main Rotor Tie Bars
Applicability Source Text
Show captured applicability text from the source AD
AD Final Rules - DRS_84-03-51.html Copy URL Print/Save as PDF Document Versions Feedback Details AD Number: 84-03-51 Document Type: AD Final Rules Docket Number: Unknown Subject Heading: Airworthiness Directives; BOEING VERTOL COMPANY Model 234 Series Helicopters Subject: Forward Main Rotor Tie Bars Status: Current Citation: This information is not available. Citation Publish Date: Effective Date: 03/14/1984 Make: Columbia Helicopters, Inc. Model: 234 Product Type: Aircraft Product Subtype: Rotorcraft Affected AD: Superseded AD: Affected By: Superseded By: Service/Office: Office of Primary Responsibility: CFR Part Reference: Part 39 Comments: AIRWORTHINESS DIRECTIVES FINAL RULES: 84-03-51 CITATION: This information is not available. PAGE NUMBER: DOCKET NUMBER: Unknown AMENDMENT: 39-4823 AD NUMBER: 84-03-51 SUBJECT HEADING: Airworthiness Directives; BOEING VERTOL COMPANY Model 234 Series Helicopters ACTION: SUMMARY: DATES: Effective March 14, 1984. ADDRESSES: FOR FURTHER INFORMATION CONTACT: SUPPLEMENTARY INFORMATION: REGULATORY TEXT: 84-03-51 BOEING VERTOL COMPANY: Amendment 39-4823. Applies to Boeing Vertol Model 234 series helicopters certificated in all categories. Compliance is required as indicated. To prevent possible hazards in flight associated with cracking of the main rotor head tie bars, accomplish the following: (a) Unless already accomplished, within the next 25 hours time in service from the effective date of this AD or before the accumulation of 450 hours time in service, whichever comes later, and thereafter as specified in paragraphs (c) and (d) of this AD, visually inspect for cracks in the forward main rotor tie bars P/N 114R21551 with serial numbers A13207 and below. If the letter "B" is shown after the serial number, this AD does not apply. (b) Unless already accomplished, within the next 25 hours time in service from the effective date of this AD or before the accumulation of 550 hours time in service, whichever comes later, and thereafter as specified in paragraphs (c) and (d) of this AD, visually inspect for cracks in the aft main rotor tie bars P/N 114R21551 with serial numbers A13207 and below. If the letter "B" is shown after the serial number, this AD does not apply. (c) After the initial inspections in paragraphs (a) and (b) or the inspections in paragraph (d), repeat visual inspections of tie bars at intervals not to exceed 450 hours time in service for tie bars in paragraph (a) and 550 hours time in service for paragraph (b). (d) Whenever a main rotor head is disassembled to inspect or replace the hub, horizontal hinge pin, or pitch shaft, conduct the inspection of tie bars specified in paragraph (a) or (b). (e) Remove from service tie bars having a crack and replace with a serviceable part prior to further flight. (f) An equivalent method of compliance with this AD may be used when approved by the Manager, New York Aircraft Certification Office, 181 South Franklin Avenue, Valley Stream, New York 11581. (g) In accordance with FAR 21.197, flight is permitted to a base where the requirements of this AD may be accomplished. This amendment becomes effective March 14, 1984, as to all persons except those persons to whom it was made immediately effective by telegraphic AD No. T84-03-51 issued January 27, 1984, which contained the amendment. FOOTER:
Document Text
Show stored source text (verify against official source)
AD Final Rules - DRS_84-03-51.html Copy URL Print/Save as PDF Document Versions Feedback Details AD Number: 84-03-51 Document Type: AD Final Rules Docket Number: Unknown Subject Heading: Airworthiness Directives; BOEING VERTOL COMPANY Model 234 Series Helicopters Subject: Forward Main Rotor Tie Bars Status: Current Citation: This information is not available. Citation Publish Date: Effective Date: 03/14/1984 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: 84-03-51 CITATION: This information is not available. PAGE NUMBER: DOCKET NUMBER: Unknown AMENDMENT: 39-4823 AD NUMBER: 84-03-51 SUBJECT HEADING: Airworthiness Directives; BOEING VERTOL COMPANY Model 234 Series Helicopters ACTION: SUMMARY: DATES: Effective March 14, 1984. ADDRESSES: FOR FURTHER INFORMATION CONTACT: SUPPLEMENTARY INFORMATION: REGULATORY TEXT: 84-03-51 BOEING VERTOL COMPANY: Amendment 39-4823. Applies to Boeing Vertol Model 234 series helicopters certificated in all categories. Compliance is required as indicated. To prevent possible hazards in flight associated with cracking of the main rotor head tie bars, accomplish the following: (a) Unless already accomplished, within the next 25 hours time in service from the effective date of this AD or before the accumulation of 450 hours time in service, whichever comes later, and thereafter as specified in paragraphs (c) and (d) of this AD, visually inspect for cracks in the forward main rotor tie bars P/N 114R21551 with serial numbers A13207 and below. If the letter "B" is shown after the serial number, this AD does not apply. (b) Unless already accomplished, within the next 25 hours time in service from the effective date of this AD or before the accumulation of 550 hours time in service, whichever comes later, and thereafter as specified in paragraphs (c) and (d) of this AD, visually inspect for cracks in the aft main rotor tie bars P/N 114R21551 with serial numbers A13207 and below. If the letter "B" is shown after the serial number, this AD does not apply. (c) After the initial inspections in paragraphs (a) and (b) or the inspections in paragraph (d), repeat visual inspections of tie bars at intervals not to exceed 450 hours time in service for tie bars in paragraph (a) and 550 hours time in service for paragraph (b). (d) Whenever a main rotor head is disassembled to inspect or replace the hub, horizontal hinge pin, or pitch shaft, conduct the inspection of tie bars specified in paragraph (a) or (b). (e) Remove from service tie bars having a crack and replace with a serviceable part prior to further flight. (f) An equivalent method of compliance with this AD may be used when approved by the Manager, New York Aircraft Certification Office, 181 South Franklin Avenue, Valley Stream, New York 11581. (g) In accordance with FAR 21.197, flight is permitted to a base where the requirements of this AD may be accomplished. This amendment becomes effective March 14, 1984, as to all persons except those persons to whom it was made immediately effective by telegraphic AD No. T84-03-51 issued January 27, 1984, which contained the amendment. FOOTER:
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Retrieved: Apr 8, 2026
Rights: U.S. Government Public Domain
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