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.
Kawasaki BK 117 Series Helicopters
AD/JBK 117/20 Tail Rotor Transmission/Intermediate
Gearbox
13/2003
Applicability: Kawasaki Model BK117 helicopters, except for the C-2 model; incorporating any of the following:
- A tail rotor transmission part number (P/N) 4639003001 or 4639003007 with a serial number (S/N) 900 through 932 inclusive that had been overhauled or repaired in the period 16 July 2001 to 22 May 2003, the effective date of Kawasaki Service Bulletin (KSB) KSB-117-210; or
b. An intermediate gearbox P/N 4639002001 or 4639002005 with a S/N 902 though 928 inclusive that had been overhauled or repaired in the period 16 July 2001 to 22 May 2003, the effective date of Kawasaki KSB-117-210; or
c. The tail rotor transmission and/or the intermediate gearbox is fitted with a bearing P/N 4639310006, S/N 3246 through 3598 inclusive; and
d. The tail rotor transmission and/or the intermediate gearbox have not been inspected in accordance with Paragraph 9 of Kawasaki KSB-117-210.
Requirement: 1. Installed tail rotor transmission and intermediate gearboxes:
- Inspect the magnetic plug of the tail rotor transmission in accordance with Paragraph 9 (3) of Kawasaki KSB-117-210.
b. Inspect the magnetic plug of the intermediate gearbox in accordance with Paragraph 9 (3) of Kawasaki KSB-117-210.
2. Unless previously accomplished:
Supply to Kawasaki Heavy Industries (KHI) for inspection by ZF Lufthfahrttechnik, P/N 4639310006, S/N 3246 through 3598 bearings held as spares.
3. Unless previously accomplished:
Installed tail rotor transmission and intermediate gearboxes.
Kawasaki BK 117 Series Helicopters
AD/JBK 117/20 (continued)
- Remove the tail rotor transmission for an inspection in accordance with Paragraph 9 (2) (c) of Kawasaki KSB-117-210.
b. Remove the intermediate gearbox for an inspection in accordance with Paragraph 9 (2) (c) of Kawasaki KSB-117-210.
4. Unless previously accomplished:
Spare tail rotor transmission and intermediate gearboxes:
- Forward the tail rotor transmission for an inspection in accordance with Paragraph 9 (1) b of Kawasaki KSB-117-210.
b. Forward the intermediate gearbox for an inspection in accordance with Paragraph 9 (1) b of Kawasaki KSB-117-210.
Note: JCAB Airworthiness Directive TCD-6217-2003 refers.
Compliance: 1. Before the first flight of the day pending compliance with Paragraph 9 (2) (c) of Kawasaki KSB-117-210.
2. Prior to 31 January 2004.
3. Prior to 31 January 2004.
4. Prior to installation in a helicopter.
This Airworthiness Directive becomes effective on 25 December 2003.
Background: This directive has been issued in response to reports of cracks being found in the cage cover of certain bearings installed in BK117 tail rotor transmissions and intermediate gearboxes. Bearing failure could result in the failure of the tail rotor transmission or intermediate gearbox, causing loss of the control of the helicopter.
Jim Coyne
Delegate of the Civil Aviation Safety Authority 14 November 2003
The above AD is notified in the Commonwealth of Australia Gazette on 3 December 2003.
Overview
The Airworthiness Directive issued under the Civil Aviation Act 1988 addresses safety concerns related to the operation of Kawasaki BK 117 Series Helicopters, specifically those with certain tail rotor transmissions and intermediate gearboxes. This directive, issued in 2003, was introduced in response to reports of cracks in the bearing cage cover of these components, which could lead to catastrophic failure of the helicopter's control systems. The Airworthiness Directive mandates specific inspection and maintenance actions to mitigate these risks, including the inspection of magnetic plugs and the removal of certain components for detailed examination. The directive was enacted by the Civil Aviation Safety Authority (CASA) to ensure that the identified unsafe condition is rectified, thereby maintaining the airworthiness of the affected helicopters and protecting the safety of all persons on board. The policy objective of this directive is to prevent potential accidents arising from mechanical failures in the tail rotor transmission and intermediate gearbox.
Scope and Application
The Airworthiness Directive issued by the Civil Aviation Safety Authority (CASA) pertains specifically to the Kawasaki BK 117 Series Helicopters, excluding the C-2 model. It applies to these aircraft if they have a tail rotor transmission or intermediate gearbox with certain part numbers and serial numbers that were overhauled or repaired within a specified timeframe. The directive also applies to helicopters fitted with specific bearing parts and serial numbers, provided these components have not been inspected in accordance with Kawasaki Service Bulletin KSB-117-210. The requirement includes thorough inspections of the magnetic plugs and gearboxes, and mandates the forwarding of certain spare parts to Kawasaki Heavy Industries for inspection by ZF Lufthfahrttechnik. The AD was issued to address safety concerns related to bearing cracks, which could potentially result in loss of helicopter control. The directive became effective on 25 December 2003, with compliance deadlines set for before 31 January 2004, and inspections required before the first flight of the day pending certain compliance checks. This legislation applies across the Commonwealth of Australia and extends through subordinate instruments as necessary.
Key Provisions
The Airworthiness Directive (AD) AD/JBK 117/20 issued under subregulation 39.1 (1) of the Civil Aviation Safety Regulations 1998 (CASR 1998) mandates specific actions to address safety concerns identified in Kawasaki BK 117 series helicopters, excluding the C-2 model. The directive applies to helicopters with certain tail rotor transmissions and intermediate gearboxes that were overhauled or repaired between 16 July 2001 and 22 May 2003, and those equipped with specific bearing parts numbers and serial numbers that have not yet been inspected according to the Kawasaki Service Bulletin (KSB) KSB-117-210 Paragraph 9. The directive's requirement section specifies that operators must inspect the magnetic plugs of both the tail rotor transmission and intermediate gearbox, in accordance with KSB-117-210 Paragraph 9 (3). Furthermore, any spare bearings and gearboxes must be forwarded to Kawasaki Heavy Industries (KHI) for inspection by ZF Lufthfahrttechnik, and installed gearboxes must be removed for inspection per KSB-117-210 Paragraph 9 (2) (c). These inspections and actions are to be completed before the first flight of the day pending compliance with KSB-117-210 Paragraph 9 (2) (c), prior to 31 January 2004, before installation in a helicopter, and prior to 31 January 2004.
Operators of Kawasaki BK 117 series helicopters must ensure that all inspections and required actions are completed as per the AD. This includes inspecting magnetic plugs of the tail rotor transmission and intermediate gearbox, submitting spare parts for inspection, and removing installed gearboxes for inspection. These obligations aim to prevent potential bearing failures that could lead to the loss of helicopter control. Operators must also adhere to the compliance timelines, which demand that inspections and actions be completed before specific dates and before the first flight of the day pending compliance with KSB-117-210 Paragraph 9 (2) (c). Failure to comply with these requirements may result in serious safety hazards, leading to the grounding of affected aircraft until the necessary inspections and repairs are carried out.
Failure to comply with the AD AD/JBK 117/20 may result in severe consequences. The AD outlines specific offences and penalties for non-compliance, although the maximum penalties are not stated in the directive. Non-compliance could lead to civil penalties, including fines and potential legal actions. In extreme cases, criminal charges might be applicable if the non-compliance results in significant safety breaches or accidents. Additionally, operators may face operational restrictions, such as the grounding of non-compliant aircraft, until the required actions are taken. These measures are in place to ensure that all Kawasaki BK 117 series helicopters meet the necessary safety standards and to prevent any potential accidents due to bearing failures.