# AD 88-12-03: Main Rotor Drag Brace Assembly - Type: Airworthiness directive - Status: Current - Products: Bell Helicopter Textron 214ST - Effective: April 9, 1990 - Superseded by: Nothing supersedes this AD - Product type: Aircraft, Rotorcraft - Amendment: 39-6539 - Docket: 88-ASW-32 - Registered aircraft: 19 may be affected, by airframe or engine model (OpenAirDocs) - FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/A3EEB1DD77E7A35986256A4E004F3E31.0001 - DRS record last changed: May 30, 2024 - Page: https://openairdocs.org/ad/88-12-03 ## The airworthiness directive 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) Inspectthe 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 orGrade 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. ## Affected data sheets (1) (OpenAirDocs) The type certificate data sheets whose models the AD names. - [TCDS H10SW](https://openairdocs.org/tcds/H10SW): McDermott 214 Holdings, LLC; names 1 of 1 models: 214ST ## Registered aircraft it may apply to (OpenAirDocs) Matched by airframe and engine model; the AD's applicability may narrow it by serial number, part number or equipment. - Aircraft: 19 (19 by airframe model, 0 by engine model) - Makers: Bell 18, Bell Helicopter Textron 1 Models with the most aircraft: - [Bell 214ST](https://openairdocs.org/model/bell-214st): 18 aircraft (airframe model) - [Bell Helicopter Textron 214ST](https://openairdocs.org/model/bell-helicopter-textron-214st): 1 aircraft (airframe model) All 2 models: https://openairdocs.org/ad/88-12-03/models.md Every aircraft: https://openairdocs.org/ad/88-12-03/aircraft.md Its text cites no advisory circulars or STCs. --- OpenAirDocs.org is an independent research project of [Contrail Labs](https://contraillabs.com/). It is not affiliated with the FAA or the NTSB. Source documents are U.S. government works in the public domain.