AD 88-12-03
final rule
Applicability
| Type | Manufacturer | Model | Details |
|---|---|---|---|
| aircraft | Bell Helicopter Textron, Inc. | 214ST | Airworthiness Directives; BELL HELICOPTER TEXTRON, INC. (BHTI) Model 214ST Helicopters |
Unsafe Condition
Failure of the main rotor (M/R) drag brace assembly due to corrosion pitting, mechanical damage, or cracks in the barrel, clevis, or nuts could result in loss of the helicopter.
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Required Actions
Inspect main rotor drag brace assemblies with 250 or more hours' time in service within the next 10 hours, then every 250 hours. Disassemble, clean, inspect for corrosion pitting and damage, measure length, and replace parts with cracks or excessive corrosion. Reassemble with specified torque and corrosion protection.
AI-generated summary from the source AD text. Verify against the official source before acting.
Compliance Time
Required as indicated, unless already accomplished.
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Affected Aircraft
Bell Model 214ST helicopters, serial numbers 28101 through 28195 and 18402.
AI-generated summary from the source AD text. Verify against the official source before acting.
Federal Register Abstract
Main Rotor Drag Brace Assembly
Applicability Source Text
Show captured applicability text from the source AD
AD Final Rules - DRS_88-12-03.html Copy URL Print/Save as PDF Document Versions Feedback Details AD Number: 88-12-03 Document Type: AD Final Rules Docket Number: 88-ASW-32 Subject Heading: Airworthiness Directives; BELL HELICOPTER TEXTRON, INC. (BHTI) Model 214ST Helicopters Subject: Main Rotor Drag Brace Assembly Status: Current Citation: This information is not available. Citation Publish Date: Effective Date: 04/09/1990 Make: Bell Helicopter Textron, Inc. Model: 214ST Product Type: Aircraft Product Subtype: Rotorcraft Affected AD: Superseded AD: Affected By: Superseded By: Service/Office: Office of Primary Responsibility: CFR Part Reference: Part 39 Comments: AIRWORTHINESS DIRECTIVES FINAL RULES: 88-12-03 CITATION: This information is not available. PAGE NUMBER: DOCKET NUMBER: 88-ASW-32 AMENDMENT: 39-6539 AD NUMBER: 88-12-03 SUBJECT HEADING: Airworthiness Directives; BELL HELICOPTER TEXTRON, INC. (BHTI) Model 214ST Helicopters ACTION: SUMMARY: DATES: Effective April 9, 1990. ADDRESSES: FOR FURTHER INFORMATION CONTACT: SUPPLEMENTARY INFORMATION: REGULATORY TEXT: 88-12-03 BELL HELICOPTER TEXTRON, INC. (BHTI): Amendment 39-6539. Final copy of priority letter AD. Docket No. 88-ASW-32. Applicability: Bell Model 214ST helicopters, serial numbers 28101 through 28195 and 18402, certificated in any category. Compliance: Required as indicated, unless already accomplished. To prevent failure of the main rotor (M/R) drag brace assembly which could result in subsequent loss of the helicopter, accomplish the following: (a) For each M/R drag brace assembly, part number (P/N) 214-010-113-105, with 250 or more hours' time in service, inspect within the next 10 hours' time in service and thereafter at intervals not to exceed 250 hours' time in service as follows: (1) Remove drag brace assembly to the blade attachment bolt, P/N 20-057- 16-68D, and the drag brace to the grip attachment bolt, P/N 20-057-16-92D. (2) Measure length of each drag brace assembly, then disassemble and thoroughly clean all parts. (3) Inspect the barrel, P/N 214-010-120-107; the clevis, P/N 214-010-121- 105; and the nuts, P/N 214-010-198-101, for corrosion pitting and mechanical damage. Remove the part from service if pitting is found in the threads. NOTE: If corrosion pitting or mechanical damage is superficial, it may be polished out. (4) Remove paint and primer for inspection. (5) Inspect each drag brace barrel for cracks using a magnetic particle or fluorescent penetrant method. Pay special attention to the threaded area. (b) If cracks are found, or if corrosion pitting or mechanical damage is found which exceeds a maximum depth of 0.010 inch, replace with serviceable parts. (c) Assemble and install the drag brace as follows: (1) Threads of barrel which have cadmium plating removed during disassembly must be brush cadmium plated or protected. Coat threads of the drag brace barrel, nuts, and the inner surface of clevis with either corrosion preventive compound MIL-C-16173, Grade 2 or Grade 3, or an equivalent. (2) Reassemble and reset the length of the drag brace as measured in the requirements of paragraph (a)(2). Torque inboard nut 375 to 425 foot pounds, while holding outboard nut. (3) Reinstall the drag brace assembly and torque inboard and outboard attachment bolt nuts, 225 to 400 foot pounds. (4) After final drag brace adjustment, if required, clean the exterior of the drag brace assembly. Coat the threads, nuts, and clevis area with MIL-C-16173, Grade 1 (drying), corrosion preventive compound or equivalent. (d) Whenever a new design drag brace assembly, P/N 214-010-191-101, is installed in accordance with BHTI Alert Service Bulletin (ASB) 214ST-88-47, Revision A, dated February 20, 1989, this AD no longer applies. (e) An alternate method of compliance or adjustment of the compliance time, which provides an equivalent level of safety, may be used if approved by the Manager, Rotorcraft Certification Office, FAA, Southwest Region, 4400 Blue Mound Road, Fort Worth, Texas. (f) In accordance with FAR Section 21.197 and 21.199, the helicopter may be flown to a base where the inspection may be accomplished. This amendment becomes effective April 9, 1990, as to all persons except those persons to whom it was made immediately effective by Priority Letter AD 88-12-03, issued on June 3, 1988, which contained this amendment. FOOTER:
Document Text
Show stored source text (verify against official source)
AD Final Rules - DRS_88-12-03.html Copy URL Print/Save as PDF Document Versions Feedback Details AD Number: 88-12-03 Document Type: AD Final Rules Docket Number: 88-ASW-32 Subject Heading: Airworthiness Directives; BELL HELICOPTER TEXTRON, INC. (BHTI) Model 214ST Helicopters Subject: Main Rotor Drag Brace Assembly Status: Current Citation: This information is not available. Citation Publish Date: Effective Date: 04/09/1990 Make: Bell Helicopter Textron, Inc. Model: 214ST 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: 88-12-03 CITATION: This information is not available. PAGE NUMBER: DOCKET NUMBER: 88-ASW-32 AMENDMENT: 39-6539 AD NUMBER: 88-12-03 SUBJECT HEADING: Airworthiness Directives; BELL HELICOPTER TEXTRON, INC. (BHTI) Model 214ST Helicopters ACTION: SUMMARY: DATES: Effective April 9, 1990. ADDRESSES: FOR FURTHER INFORMATION CONTACT: SUPPLEMENTARY INFORMATION: REGULATORY TEXT: 88-12-03 BELL HELICOPTER TEXTRON, INC. (BHTI): Amendment 39-6539. Final copy of priority letter AD. Docket No. 88-ASW-32. Applicability: Bell Model 214ST helicopters, serial numbers 28101 through 28195 and 18402, certificated in any category. Compliance: Required as indicated, unless already accomplished. To prevent failure of the main rotor (M/R) drag brace assembly which could result in subsequent loss of the helicopter, accomplish the following: (a) For each M/R drag brace assembly, part number (P/N) 214-010-113-105, with 250 or more hours' time in service, inspect within the next 10 hours' time in service and thereafter at intervals not to exceed 250 hours' time in service as follows: (1) Remove drag brace assembly to the blade attachment bolt, P/N 20-057- 16-68D, and the drag brace to the grip attachment bolt, P/N 20-057-16-92D. (2) Measure length of each drag brace assembly, then disassemble and thoroughly clean all parts. (3) Inspect the barrel, P/N 214-010-120-107; the clevis, P/N 214-010-121- 105; and the nuts, P/N 214-010-198-101, for corrosion pitting and mechanical damage. Remove the part from service if pitting is found in the threads. NOTE: If corrosion pitting or mechanical damage is superficial, it may be polished out. (4) Remove paint and primer for inspection. (5) Inspect each drag brace barrel for cracks using a magnetic particle or fluorescent penetrant method. Pay special attention to the threaded area. (b) If cracks are found, or if corrosion pitting or mechanical damage is found which exceeds a maximum depth of 0.010 inch, replace with serviceable parts. (c) Assemble and install the drag brace as follows: (1) Threads of barrel which have cadmium plating removed during disassembly must be brush cadmium plated or protected. Coat threads of the drag brace barrel, nuts, and the inner surface of clevis with either corrosion preventive compound MIL-C-16173, Grade 2 or Grade 3, or an equivalent. (2) Reassemble and reset the length of the drag brace as measured in the requirements of paragraph (a)(2). Torque inboard nut 375 to 425 foot pounds, while holding outboard nut. (3) Reinstall the drag brace assembly and torque inboard and outboard attachment bolt nuts, 225 to 400 foot pounds. (4) After final drag brace adjustment, if required, clean the exterior of the drag brace assembly. Coat the threads, nuts, and clevis area with MIL-C-16173, Grade 1 (drying), corrosion preventive compound or equivalent. (d) Whenever a new design drag brace assembly, P/N 214-010-191-101, is installed in accordance with BHTI Alert Service Bulletin (ASB) 214ST-88-47, Revision A, dated February 20, 1989, this AD no longer applies. (e) An alternate method of compliance or adjustment of the compliance time, which provides an equivalent level of safety, may be used if approved by the Manager, Rotorcraft Certification Office, FAA, Southwest Region, 4400 Blue Mound Road, Fort Worth, Texas. (f) In accordance with FAR Section 21.197 and 21.199, the helicopter may be flown to a base where the inspection may be accomplished. This amendment becomes effective April 9, 1990, as to all persons except those persons to whom it was made immediately effective by Priority Letter AD 88-12-03, issued on June 3, 1988, which contained this amendment. FOOTER:
Source: Official FAA Source ↗
Retrieved: Apr 8, 2026
Rights: U.S. Government Public Domain
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