Overview

The Civil Aviation Safety Authority Airworthiness Directive AD/BEECH 36/49 issued on 29 June 2001, addresses the safety concerns associated with the KA-33 cooling blower systems installed in Beechcraft 36 (Bonanza) Series aeroplanes. The directive was introduced in response to reports of blower motors failing, seizing, smoking, and producing a burning odour that enters the cabin and passenger compartment. This was due to the circuit protection being more than one ampere, which does not prevent the blower motor from smoking and creating a burning odour should it fail or seize. The policy objective of this directive is to protect the blower motor circuit and reduce the possibility of emission of smoke or a burning odour into the cockpit or passenger compartment. The directive applies to Beech Model A36 aeroplanes, serial numbers E-2205 through E-3217 inclusive, and Model B36TC aeroplanes, serial numbers EA-443 through EA-628 inclusive. The requirement includes inspecting the aeroplane to verify whether a KA-33 cooling blower system is installed and operating correctly, installing a one ampere circuit breaker in place of the factory installed three ampere or five ampere circuit breakers, and prohibiting the installation of three ampere or five ampere circuit breakers on any aeroplane to protect the KA-33 cooling blower. Compliance with the directive must be achieved within the next 600 hours time-in-service after the effective date of this Directive or the next six calendar months after the effective date of this Directive, whichever occurs first, and before further flight after the Requirement 1 inspection. This Airworthiness Directive becomes effective on 9 August 2001.

Scope and Application

This Airworthiness Directive applies to Beech Model A36 aeroplanes with serial numbers ranging from E-2205 to E-3217 inclusive and Model B36TC aeroplanes with serial numbers from EA-443 to EA-628 inclusive. The AD mandates specific actions to address an unsafe condition identified in the KA-33 avionics cooling blower system. The directive requires an inspection to verify the presence and correct operation of the KA-33 cooling blower system, followed by the installation of a one ampere circuit breaker if the system is found to be operational. Additionally, the AD prohibits the installation of three ampere or five ampere circuit breakers to protect the KA-33 cooling blower. Compliance with these requirements must be achieved within certain timeframes, with inspections to be completed within 600 hours time-in-service or six calendar months from the effective date of the directive, whichever is sooner, and modifications to be made before further flight after the inspection. The AD is issued under subregulation 39.1 (1) of the Civil Aviation Regulations 1998, and its effective date is 9 August 2001. The directive applies nationally within Australia and aligns with the Federal Aviation Administration's AD 2001-11-03 Amdt 39-12244, aiming to mitigate the risk of blower motor failure and associated hazards.

Key Provisions

The Airworthiness Directive (AD) set out in AD/BEECH 36/49 issued by the Civil Aviation Safety Authority (CASA) delegate, applies specifically to Beech Model A36 aeroplanes with serial numbers ranging from E-2205 through E-3217, and Model B36TC aeroplanes with serial numbers from EA-443 through EA-628. The directive mandates the inspection and modification of the KA-33 avionics cooling blower system to mitigate the risk of the blower motor failing, seizing, smoking, or emitting a burning odor. Specifically, the AD requires, as per the requirement section, that the aeroplane be inspected in accordance with Part I of the Accomplishment Instructions of Raytheon Mandatory Service Bulletin SB 34-3267 (section 1). If the inspection confirms the presence of a KA-33 cooling blower, a one ampere circuit breaker, part number 7277-2-1, must be installed in place of any three ampere or five ampere circuit breakers that are factory-installed (section 2). Additionally, the AD prohibits the installation of three ampere or five ampere circuit breakers on any aeroplane to protect the KA-33 cooling blower (section 3). The AD imposes obligations on the owners and operators of the affected aircraft to ensure compliance with the inspection and modification requirements within specified timeframes. For Requirement 1, the inspection must be completed within the next 600 hours of time-in-service after the effective date of the AD, or within six calendar months, whichever comes first. For Requirement 2, any modifications identified during the inspection must be carried out before further flight. Requirement 3, which prohibits the use of three ampere or five ampere circuit breakers, is to be implemented as of the effective date of the AD. Failure to comply with these requirements can result in the aeroplane being deemed non-airworthy, potentially leading to grounding and legal consequences. Under Australian law, non-compliance with an AD can lead to severe penalties. The AD does not explicitly state the maximum penalties for non-compliance, but under the Civil Aviation Act 1988, failure to comply with an AD can result in civil penalties of up to $12,600 for individuals and $63,000 for corporations, as well as potential criminal penalties including fines and imprisonment. Additionally, the AD may be enforced through CASA's regulatory actions, including the issuance of notices, compliance orders, and the potential for legal action to enforce compliance with aviation safety regulations.