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 CAR 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.
Aircraft - General
AD/GENERAL/83 Rockwell Collins 621A-3 Transponders 5/2002
Applicability: Transport Category aeroplanes equipped with Rockwell Collins Mode C 621A-3 Air Traffic Control (ATC) transponders, part number (P/N) 522-2703-XXX (where XXX is any series number).
Requirement: 1. Perform a pulse width test to detect malfunctions of any Mode C 621A-3 ATC transponder(s) P/N 522-2703-XXX, where XXX is any part number, in accordance with Rockwell Collins Air Transport Systems Overhaul Manual with Illustrated Parts List, Temporary Revision No. 34-44-00-38, dated 20 April 2000.
Note 1: Pulse width tests done using TIC-49, ATC-601, ATC-601A, or ATC-1400A ramp or bench testers meet the applicable test requirements in Requirement 1 or 2.
Note 2: Previous checks used to perform the test specified in Requirement 1, per Rockwell Collins Air Transport Systems Overhaul Manual with Illustrated Parts List, Temporary Revision No. 34-44-00-38, dated 20 April 2000, are acceptable for compliance with Requirement 1.
2. If the Requirement 1 pulse width test detects malfunction of a transponder, carry out the following, as applicable, in accordance with Rockwell Collins Service Bulletin 621A-3-34-21, Revision 1, dated 14 November 1975:
- For transponders having serial numbers up to and including 7192 - Replace the transmitter tube and resistor with a new tube and resistor and repeat the Requirement 1 pulse width test.
b. For transponders having serial numbers 7193 and subsequent - Replace the transmitter tube with a new tube and repeat the Requirement 1 pulse width test.
Accomplishment, prior to the effective date of this Directive, of the replacement specified in Requirement 2.a. or 2.b, as applicable, in accordance with Rockwell Collins Service Information Letter (SIL) 00-1 dated 25 May 2000 is considered acceptable for compliance with Requirement 2.a. or 2.b.
Aircraft - General
AD/GENERAL/83 (Continued)
3. If the follow-up pulse width test required by Requirement 2 detects malfunction of a transponder, repair the transponder in accordance with the applicable Mode C transponder component maintenance manual and aeroplane maintenance manual.
Note 3: The aeroplane may be operated in accordance with the provisions and limitations specified in the approved Master Minimum Equipment List (MMEL), provided that only one Mode C transponder on the airplane is inoperative.
Note 4: FAA AD 2002-06-05 Amdt 39-12682 refers.
Compliance: For Requirement 1 - Within 6 months after the effective date of this Directive.
For Requirement 2 - Before further flight. For Requirement 3 - Before further flight.
This Airworthiness Directive becomes effective on 16 May 2002.
Background: This Directive requires testing each transponder; replacing certain parts in any transponder that fails the initial test with new parts and performing additional test(s); and making repairs, as necessary, so that the transponder passes the test. The issue of the Directive results from reports that indicate that the equipment used to conduct earlier tests of certain transponders did not detect certain malfunctions.
An aeroplane equipped with such malfunctioning transponders could transmit inaccurate data concerning its altitude to a nearby aeroplane equipped with the traffic alert and collision avoidance system (TCAS II), causing the TCAS II to issue an erroneous resolution advisory to the pilot. The actions required by this Directive are intended to prevent transmission of inaccurate data concerning altitude from one airplane to another, which could cause the pilot receiving the data to change course, either ascending or descending, and possibly lead to a mid-air collision or near mid- air collision.
Eugene Paul Holzapfel
Delegate of the Civil Aviation Safety Authority 4 April 2002
The above AD is notified in the Commonwealth of Australia Gazette on 24 April 2002.
Overview
The Airworthiness Directive (AD) issued by the Civil Aviation Safety Authority (CASA) under subregulation 39.1 (1) of the Civil Aviation Regulations 1998, pertains specifically to Rockwell Collins 621A-3 Transponders with part numbers (P/N) 522-2703-XXX on transport category aeroplanes. This AD, designated AD/GENERAL/83 and dated 5 May 2002, was enacted to address the problem of certain Rockwell Collins Mode C 621A-3 Air Traffic Control (ATC) transponders not being adequately tested, leading to potential inaccuracies in altitude data transmission. This could subsequently result in erroneous resolution advisories issued to pilots by traffic alert and collision avoidance system (TCAS II) equipped aeroplanes, potentially causing mid-air collisions or near mid-air collisions. The policy objective of this directive is to ensure that the transponders are tested, faulty components replaced, and repairs made as necessary, so that accurate altitude data is transmitted.
Scope and Application
The Airworthiness Directive (AD) issued by the Civil Aviation Safety Authority (CASA) under the Civil Aviation Regulations 1998 pertains specifically to the safety of Rockwell Collins Mode C 621A-3 Air Traffic Control (ATC) transponders installed in transport category aeroplanes. This AD applies to all aeroplanes of this category that are equipped with the specified transponders, namely those with part number (P/N) 522-2703-XXX, where XXX is any series number. The directive mandates that the actions outlined in the requirement section be undertaken to address potential unsafe conditions identified in these transponders. These actions include conducting pulse width tests to detect malfunctions, replacing specified parts if malfunctions are detected, and making necessary repairs to ensure the transponders function correctly and transmit accurate altitude data to avoid erroneous traffic alert and collision avoidance system (TCAS II) advisories. The AD is effective from 16 May 2002 and compliance must be achieved within stipulated timeframes as specified in the directive.
Key Provisions
The Airworthiness Directive (AD) AD/GENERAL/83 pertains to transport category aeroplanes equipped with Rockwell Collins Mode C 621A-3 Air Traffic Control (ATC) transponders, specifically those with part number (P/N) 522-2703-XXX (where XXX is any series number). The directive outlines specific requirements to ensure the safe operation of these transponders, which are crucial for accurate altitude reporting to air traffic control and other aircraft equipped with traffic alert and collision avoidance systems (TCAS II). According to the requirement section of the AD, operators must perform a pulse width test to detect any malfunctions in the specified transponders, as outlined in Rockwell Collins Air Transport Systems Overhaul Manual with Illustrated Parts List, Temporary Revision No. 34-44-00-38, dated 20 April 2000 (section 1). This test is to be carried out within 6 months of the directive's effective date (section 1). If a malfunction is detected, the directive mandates that certain parts be replaced and the transponder be retested, as detailed in Rockwell Collins Service Bulletin 621A-3-34-21, Revision 1, dated 14 November 1975 (section 2). If the follow-up test still detects a malfunction, the transponder must be repaired in accordance with the applicable Mode C transponder component maintenance manual and aeroplane maintenance manual (section 3). Operators must adhere to these requirements before further flight.
Operators of the affected aircraft are obligated to ensure that the specified pulse width test is performed on the Rockwell Collins Mode C 621A-3 ATC transponders. This involves using approved testing equipment and following the outlined procedures meticulously. If a malfunction is detected during the initial test, the appropriate parts must be replaced as per the directive, and a follow-up test must be conducted. If the follow-up test still detects a malfunction, the transponder must be repaired according to the relevant maintenance manuals. Operators must also ensure that only one Mode C transponder is inoperative at any time, as specified in the approved Master Minimum Equipment List (MMEL). Failure to comply with these requirements could result in the transmission of inaccurate altitude data, potentially leading to erroneous resolution advisories and compromising flight safety.
Breach of the requirements set out in this Airworthiness Directive can lead to serious safety implications. Although the directive does not explicitly mention specific penalties, non-compliance with ADs is generally taken very seriously under Australian aviation law. Operators who fail to adhere to ADs may face enforcement actions from the Civil Aviation Safety Authority (CASA), which could include fines, suspension of airworthiness certificates, or other regulatory actions. Such non-compliance could also result in civil liability if the failure to adhere to the directive leads to an incident or accident. Additionally, there could be criminal consequences if the non-compliance is deemed to have caused significant harm or endangerment to persons or property.