AIRWORTHINESS DIRECTIVE
For the reasons set out in the background section, the CASA delegate whose signature appears below issues the following Airworthiness Directive (AD) under subregulation 39.1 (1) of CASR 1998. The AD requires that the action set out in the requirement section (being action that the delegate considers necessary to correct the unsafe condition) be taken in relation to the aircraft or aeronautical product mentioned in the applicability section: (a) in the circumstances mentioned in the requirement section; and (b) in accordance with the instructions set out in the requirement section; and (c) at the time mentioned in the compliance section.
Robinson R44 Series Helicopters
AD/R44/20 Main Rotor Swashplate and Tail Rotor Bolts 1/2004
TX
Applicability: Model R44 helicopters.
Requirement: 1. For all R44 and R44 II helicopters except those serial numbers specified in Requirement 2 of this Directive:
- Determine if maintenance has been performed after 7 February 2003 on the areas specified in Figure 1 of this Directive, and determine if any bolt, part number NAS6605-31, shown on Figure 1 has been replaced for any reason.
b. If any bolt has been replaced, or if it is uncertain whether any bolt has been replaced after 7 February 2003, remove the paint from the bolt head to reveal the vendor identification marking. Determine if the bolt vendor identification is 01DO.
(i) If the vendor identification is 01DO, comply with Requirements 3 and 4.
2. The following R44 and R44 II helicopters must comply with Requirements 3 and 4 of this Directive:
- Model R44 helicopters, serial numbers 0210, 0565, 0641, 0987 and 1312 through 1349, except 1345 and 1346; and
b. Model R44 II helicopters, serial numbers 10010, 10062, and 10083 through 10212, except 10092, 10173, 10204, 10207, 10210, and 10211.
3. For the helicopters affected by Requirements 1.b.(i) and 2. of this Directive, accomplish the following:
- Visually inspect each bolt for fretting residue under the bolt head, which indicates a loose, potentially cracked bolt.
b. Apply 10-15 ft-lb (13-20 Nm) torque to each bolt head and verify no rotation. See Figure 1 of this Directive.
c. If residue or rotation of the bolt is found, replace each affected bolt with a serviceable bolt that does not have a vendor identification marking of 01DO.
Figure 1
Note 1: Robinson Helicopter Company Service Bulletin SB-51, dated 24 November 2003, refers.
4. For the helicopters affected by Requirements 1.b.(i) and 2 of this Directive, replace each bolt, part number NAS6605-31, that has vendor identification marking 01DO on the bolt head, with a serviceable bolt, part number NAS6605- 31, that has an alternative vendor identification marking.
Bolt part number NAS6605-31 with vendor identification marking 01DO on the bolt head, is not to be installed on any helicopter.
Note 2: FAA Emergency AD 2003-24-51 refers.
Compliance: 1. Before further flight after 3 December 2003.
2. At the times specified in Compliance 3 and 4.
3. Before further flight after 3 December 2003, and thereafter before first flight of each day of operation.
4. Within 10 hours time in service or before 31 December 2003, whichever occurs first; after determination of vendor identification and/or helicopter applicability.
This Airworthiness Directive becomes effective on 3 December 2003.
Background: The FAA received a report of the failure of the bolt that secures parts of the main rotor swashplate and attaches the tail rotor blade. Investigation revealed that the bolt failed due to hydrogen embrittlement. Hydrogen embrittlement is suspected to have occurred during the cadmium plating process of an entire batch of bolts, which makes the batch suspect.
David Villiers
Delegate of the Civil Aviation Safety Authority 2 December 2003
The above AD is notified in the Commonwealth of Australia Gazette on 3 December 2003.
Overview
The Airworthiness Directive (AD) issued by the Civil Aviation Safety Authority (CASA) under subregulation 39.1(1) of the Civil Aviation Safety Regulations 1998 targets an unsafe condition identified in Robinson R44 Series Helicopters, specifically concerning the main rotor swashplate and tail rotor bolts. This directive was introduced to address the potential failure of bolts due to hydrogen embrittlement, which was found to have occurred during the cadmium plating process. The directive applies to all R44 and R44 II helicopters except those specifically exempted by serial numbers. It mandates actions such as inspecting bolts for fretting residue, applying specified torque, and replacing bolts with certain vendor identification markings to ensure safety. The policy objective is to mitigate the risk of in-flight failure of critical helicopter components, thereby enhancing the overall safety of helicopter operations. This AD became effective on 3 December 2003, following its notification in the Commonwealth of Australia Gazette.
Scope and Application
The Airworthiness Directive (AD) AD/R44/20 applies to all Robinson R44 Series helicopters, specifically targeting the main rotor swashplate and tail rotor bolts. This AD is issued under the authority of the Civil Aviation Safety Authority (CASA) and is applicable to all R44 and R44 II helicopters except those with specific serial numbers outlined in the requirement section. The directive mandates specific actions to ensure the airworthiness of these helicopters, focusing on the replacement of certain bolts to prevent failure due to hydrogen embrittlement, which can lead to catastrophic outcomes during flight. Compliance with this AD is mandatory before further flight after 3 December 2003 and at specified intervals thereafter. The directive also includes a compliance section that mandates inspections and bolt replacements within specific timeframes, ensuring that affected helicopters meet the safety standards set forth by CASA.
Key Provisions
The Airworthiness Directive (AD) issued by the Civil Aviation Safety Authority (CASA) delegate, David Villiers, under subregulation 39.1 (1) of the Civil Aviation Safety Regulations (CASR) 1998, pertains to Robinson R44 Series Helicopters and their main rotor swashplate and tail rotor bolts (AD/R44/20). This AD applies to all R44 and R44 II helicopters except for those specified in Requirement 2. The primary requirements of this AD are to check if maintenance has been performed on specified areas and bolts after 7 February 2003, and to identify and address any issues with bolts of a particular part number and vendor identification. Specifically, if any bolt has been replaced or it is uncertain whether any bolt has been replaced, the paint on the bolt head must be removed to reveal the vendor identification marking. If the marking is 01DO, the affected helicopters must comply with Requirements 3 and 4.
The AD imposes several obligations on the parties and entities it governs. Firstly, it requires a thorough examination of the maintenance records and physical inspection of the bolts in question to ascertain if any replacement has occurred since the specified date. If a replacement is confirmed or suspected, the bolt head's paint must be removed to reveal the vendor identification. If the identification is 01DO, further inspections and actions are mandated. Specifically, each bolt must be visually inspected for fretting residue, torque must be applied to each bolt head to verify no rotation, and any affected bolts must be replaced with ones that do not have a vendor identification marking of 01DO. Additionally, any bolt with the 01DO vendor identification must be replaced with an alternative bolt.
Failure to comply with this AD may result in significant consequences. The AD sets strict timelines for compliance, including immediate action before further flight after 3 December 2003, and periodic checks before each daily flight and within a specific timeframe or by the end of 2003, depending on the circumstances. Non-compliance with these requirements could potentially render the helicopter unsafe, leading to enforcement actions, fines, or other penalties as stipulated by aviation regulations. The specific maximum penalties are not detailed in the AD but typically involve financial penalties or other enforcement actions as prescribed by the Civil Aviation Safety Regulations.