AD/INST/32 - Altimeters

Overview

The Civil Aviation Regulations 1998 were enacted by the Parliament of the Commonwealth of Australia to regulate civil aviation activities within Australia. Part 39, specifically addressing Airworthiness Directives, was introduced to ensure that aircraft, components, and parts meet safety standards. One such directive, AD/INST/32, pertains to altimeters manufactured by United Instruments Inc between 1 February 1985 and 28 February 1986, which had reported issues with the barometric scale setting knob causing a disconnection between the millibar scale and the altitude indication pointers. This directive aims to address the safety concerns by requiring compliance with United Instruments Inc Service Bulletin No. 2 and mandates corrective actions to be completed prior to the issue of the next Maintenance Release after 31 May 1986. This ensures that the affected altimeters are appropriately identified and modified by an approved workshop, thereby maintaining the safety standards required under civil aviation regulations.

Scope and Application

The Civil Aviation Safety Authority (CASA) issued the Airworthiness Directive AD/INST/32, which applies to specific United Instruments Inc altimeters of the 5934 series with serial numbers ranging from 6C461 to 2D869, manufactured between 1 February 1985 and 28 February 1986, and not identified as modified by a 6mm yellow dot on the lower half of the rear case and the letter "M" stamped on the data plate. This regulation is part of the Civil Aviation Regulations 1998 under Part 39 - 107 and has a Commonwealth reach, affecting the entire aviation industry within Australia. The directive aims to address a safety issue where a slight outward pull on the barometric scale setting knob may disconnect the millibar scale from the altitude indication pointers. Compliance with this directive is mandatory and requires corrective action to be completed before the next Maintenance Release after 31 May 1986, and corrective action may be carried out by an approved workshop in Australia. The directive does not explicitly mention exclusions, exemptions, or thresholds but specifies that compliance must align with United Instruments Inc Service Bulletin No. 2, referencing FAA AD 86-05-02.

Key Provisions

The Civil Aviation Regulations 1998, specifically Part 39 - 107, outlines the Civil Aviation Safety Authority (CASA) Schedule of Airworthiness Directives, which includes AD/INST/32 concerning United Instruments Inc altimeters. These altimeters, part of the 5934 series, are affected if they were manufactured between 1 February 1985 and 28 February 1986, and bear serial numbers ranging from 6C461 to 6C999, 7C000 to 7C999, 8C000 to 8C999, 9C000 to 9C999, 0D000 to 0D999, and 1D000 to 1D999, up to 2D869. It is important to note that these altimeters must not be identified as modified by a 6mm yellow dot on the lower half of the rear case and the letter "M" stamped on the data plate just before the word "altimeter". The directive mandates that these altimeters must be addressed in accordance with United Instruments Inc Service Bulletin No. 2. The Federal Aviation Administration (FAA) issued a similar directive, FAA AD 86-05-02. Compliance with these requirements is essential and must be achieved before the issuance of the next Maintenance Release after 31 May 1986. Notably, corrective action can be performed in Australia by an approved workshop, provided the altimeter is appropriately identified post-modification. The obligations imposed by this directive are clear: any person or entity that owns, operates, or maintains an affected altimeter must ensure that it is inspected and, if necessary, modified as per the specifications outlined in the directive. This involves either arranging for the altimeter to be serviced by an approved workshop or ensuring the altimeter is marked correctly to indicate it has been modified. Failure to comply with the Airworthiness Directive can result in serious consequences. Although the specific civil or criminal penalties are not detailed in the text, non-compliance with airworthiness directives generally can lead to enforcement actions by CASA. These actions can include fines, suspension or revocation of airworthiness certificates, and potential criminal charges if the non-compliance results in a safety hazard. It is crucial for operators to adhere to these directives to maintain the safety and airworthiness of their aircraft.