COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY
SCHEDULE OF AIRWORTHINESS DIRECTIVES
Enstrom F-28 Series Helicopters
AD/ENST 28/2
Amdt 2
Stabilizer Spar Attachment 5/88 DM
Applicability: All models F28, F28A, F28C and F28C-2 helicopters, and all model F28F up to and including S/N 743.
Requirement: 1. Check the security of the attachment of both left and right stabilizers as detailed in section 5.1 of Enstrom Helicopter Corporation Service Directive Bulletin (SDB) 0076 of 15 December 1987.
2. Inspect and measure the stabilizer spars and attachments as detailed in section 5.2 of SDB 0076.
3. Remove from service any stabilizer spar having a nominal wall thickness of .035 inch.
Compliance: For para 1 of the Requirement:
Before each flight.
Note: This inspection may be performed by the pilot in command in which case certification is not required.
For para 2 of the Requirement:
(a) if never previously inspected in accordance with previous issues of this Directive; within the next 10 hours time in service after 22 January 1988.
(b) If previously inspected in accordance with previous issues of this Directive; within 50 hours time in service after the last such inspection or within 10 hours time in service after 22 January 1988, whichever is the later.
(c) Thereafter, repeat the inspections at intervals not exceeding 100 hours component time in service.
For para 3 of the Requirement:
Prior to further flight after detection.
Background: These Requirements follow the November 1987 in-flight failure (overseas) of a spar with .049 inch wall thickness. Amendment 1 which was issued by telex, extended the inspection to additional helicopter models and made the inspection more explicit and more intensive, and effectively placed a 500 hour life on the .039 inch wall thickness spars. Further review has shown this to be unconservative, this amendment therefore requires the thin wall spars, once identified, to be removed before further flight in accordance with SDB 0076.
Overview
The Civil Aviation Regulations 1998, as amended by F2006B09575, introduced specific airworthiness directives to address safety concerns with Enstrom F-28 Series helicopters. Enacted by the Commonwealth of Australia, the Civil Aviation Safety Authority’s directive aims to enhance flight safety by ensuring the structural integrity of the stabilizer spars in these helicopters. This legislation responds to an incident where an in-flight failure of a spar due to inadequate wall thickness was identified, leading to the need for stringent inspection and maintenance protocols. The overarching policy objective is to mitigate the risk of in-flight structural failure, thereby protecting passengers, crew, and the public from potential hazards associated with compromised helicopter components.
Scope and Application
The Civil Aviation Regulations 1998, under Part 39, specifically the Schedule of Airworthiness Directives, applies to all models of Enstrom F-28 Series helicopters, including F28, F28A, F28C, F28C-2, and model F28F up to and including serial number 743. This legislation mandates specific safety checks and inspections to ensure the continued airworthiness of these aircraft. The directive requires pilots or certified personnel to verify the security of the stabilizer spar attachment as detailed in Enstrom Helicopter Corporation Service Directive Bulletin 0076. Additionally, it mandates the inspection and measurement of stabilizer spars, with particular attention to those having a nominal wall thickness of 0.035 inches, which must be removed from service if found to be below safety standards. Compliance with these requirements must occur before each flight and at specified intervals thereafter, with stringent timelines for initial and subsequent inspections post the directive's issuance date of 22 January 1988. The directive was amended to address a previously identified in-flight failure, enhancing the safety measures and ensuring more rigorous inspections to prevent future incidents.
Key Provisions
The Civil Aviation Regulations 1998, specifically in Part 39, Section 105, detail the Airworthiness Directives for Enstrom F-28 Series Helicopters (AD/ENST 28/2 Amendment 2). These directives apply to all models F28, F28A, F28C, F28C-2, and all model F28F up to and including Serial Number 743. The primary requirement (Section 1) mandates that the security of both the left and right stabilizers be checked according to the specifications outlined in Section 5.1 of Enstrom Helicopter Corporation Service Directive Bulletin (SDB) 0076 dated 15 December 1987. Additionally, Section 2 requires an inspection and measurement of the stabilizer spars and their attachments as detailed in Section 5.2 of the same SDB. Section 3 necessitates the removal from service of any stabilizer spar with a nominal wall thickness of 0.035 inches.
The obligations imposed by these directives are quite specific. Section 1 requires that the security check of the stabilizers be performed before each flight, with the flexibility allowing the pilot in command to conduct the check without the need for certification. Section 2 provides different timelines for the inspection and measurement depending on the previous inspection history. If the helicopter has never been inspected under this directive, the inspection must occur within the next 10 hours of time in service after 22 January 1988. If it has been previously inspected, the next inspection must take place within 50 hours of time in service after the last such inspection or within 10 hours of time in service after 22 January 1988, whichever is later. Subsequent inspections must occur at intervals not exceeding 100 hours of component time in service. Section 3 requires that any stabilizer spar identified with a nominal wall thickness of 0.035 inches be removed from service before any further flight.
The consequences for non-compliance with these directives are not explicitly stated in the provided text. However, given the nature of airworthiness directives and the stringent requirements of aviation regulations, non-compliance could lead to severe civil and criminal penalties. These could include fines, grounding of the aircraft, and potential criminal charges for those responsible for the oversight or maintenance of the aircraft. The precise penalties would be determined by the Civil Aviation Safety Authority (CASA) and could vary based on the severity and intent of the non-compliance.