AD/PA-28/94 Amdt 1 - Engine Oil Cooler Hoses

Overview

The Civil Aviation Safety Authority (CASA) issued Amendment 1 to the Airworthiness Directive AD/PA-28/94 in 1997, specifically targeting Piper PA-28 Series aeroplanes to address the problem of engine oil cooler hose ruptures. This legislation was introduced to enhance the safety of Piper PA-28 series aircraft by preventing the loss of engine oil due to hose failures. The policy objective is to ensure that oil cooler hoses are properly inspected, maintained, and replaced to avoid potential catastrophic failures mid-flight. Compliance with this directive includes an initial inspection within 25 hours from the effective date of 27 March 1997 and subsequent re-inspections at each re-issue of the maintenance release, with a replacement requirement no later than eight years or 1000 hours of service, whichever comes first. This legislative action was taken in response to numerous reports of oil cooler hose ruptures and failures, thereby aiming to safeguard the integrity and reliability of these aircraft.

Scope and Application

The AD/PA-28/94 Amendment 1 applies to all Piper PA-28-series aircraft that have not integrated oil cooler hoses compliant with Technical Standard Order (TSO) C53a, Type D, standard. The regulation, issued under the Commonwealth of Australia's Civil Aviation Regulations 1998, specifically targets these aircraft to mitigate the risk of engine oil loss due to oil cooler hose ruptures. The requirement encompasses a comprehensive inspection of the oil cooler hoses for signs of heat damage, oil contamination, brittleness, and general condition, alongside ensuring the hoses are properly installed with a minimum clearance of 50mm from any exhaust component for forward-mounted oil coolers. Furthermore, the bend radii of the oil cooler hose assemblies must conform to the aircraft manufacturer's specifications. The directive mandates the replacement of each oil cooler hose assembly, with the incorporation of TSO C53a, Type D, compliant hoses being the terminating action for this directive. Compliance with this directive involves an initial inspection within 25 hours of the effective date of 27 March 1997 or at each re-issue of the maintenance release, and subsequent inspections must occur every eight years or 1000 hours of time in service, whichever comes first. For hose assemblies that have already exceeded 1000 hours since their last replacement or installation, replacement must occur within 200 hours of the directive's effective date. This regulatory measure is designed to ensure the continued airworthiness and safety of the affected aircraft.

Key Provisions

The primary operative sections of this legislation, as indicated by the Civil Aviation Regulations 1998, require that all Piper PA-28 series aircraft that do not already incorporate oil cooler hoses conforming to TSO C53a, Type D, standard, must undergo specific inspections and, if necessary, replacements of their oil cooler hoses. Section (1) mandates that these inspections be conducted to ensure that there are no signs of heat damage, oil contamination, brittleness, or improper installation of the hoses, and that the bend radii of the hose assemblies comply with the manufacturer’s requirements. Moreover, for forward-mounted oil coolers, it is stipulated that there should be a minimum clearance of 50mm (2 inches) between any hose and the nearest exhaust component. Section (2) requires that all oil cooler hose assemblies be replaced. The incorporation of hoses compliant with TSO C53a, Type D, serves as the terminating action for this directive. The obligations imposed by this Act are significant for both aircraft operators and maintenance personnel. Operators must ensure that an initial inspection is conducted within 25 hours of the effective date of 27 March 1997 or at each re-issue of the maintenance release. For hoses that have already exceeded 1000 hours of service or 8 years since the last replacement, a replacement must be made within 200 hours of the effective date. Maintenance personnel are required to follow the inspection and replacement procedures meticulously to ensure compliance with the directive. It is also noted that when installing compliant hoses, the bend radius must be in accordance with the hose manufacturer’s specifications. Failure to comply with the requirements of this directive can result in severe consequences. While the specific penalties or sanctions are not detailed within the text, non-compliance with Civil Aviation Regulations can lead to enforcement actions by the Civil Aviation Safety Authority. These actions can include fines, suspension or revocation of the aircraft's airworthiness certificate, and potential criminal charges if the non-compliance leads to an aviation accident or incident. The seriousness of these potential outcomes underscores the importance of adhering to the stipulated inspection and replacement protocols.