{"id":"F2010L00706","name":"AD/RAD/91 - Rockwell Collins TDR-94/94D Transponder - Air/Ground Discrete Inputs","slug":"ad-rad-91-rockwell-collins-tdr-94-94d-transponder-air-ground-discrete-inputs","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"repealed","isInForce":false,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":123883,"registerId":"commonwealth-F2010L00706-current","compilationNumber":null,"startDate":"2026-04-03","status":"Repealed","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"Radio Communication and Navigation Equip","sectionType":"division","heading":"Radio Communication and Navigation Equipment","content":"### Radio Communication and Navigation Equipment\n\n| AD/RAD/91 | Rockwell Collins TDR-94/94DTransponder - Air/Ground Discrete Inputs | 6/2010 |\n| --------- | ------------------------------------------------------------------- | ------ |\n\n```html\n

Applicability:

Rockwell Collins Mode S Transponders identified by type and Part Number (P/N) in Table 1.

Table 1

Type

P/N (all serial numbers)

TDR-94

622-9352-004, 622-9352-005, 622-9352-006, 622-9352-007, 622-9352-008, 622-9352-108, 622-9352-207, 622-9352-308 and 622-9352-408

TDR-94D

622-9210-004, 622-9210-005, 622-9210-006, 622-9210-007, 622-9210-008, 622-9210-108, 622-9210-207, 622-9210-308 and 622-9210-408

Note 1: These transponders are known to be installed on, but not limited to, the following aeroplane models:

Manufacturer

Model

Avions de Transport Régional

ATR 42 and ATR 72, all models

Bombardier (formerly Canadair)

CL-600-1A11, CL-600-2A12 (601 Variant), CL-600-2B16 (601-3A, 601-3R and 604 Variants), CL-600-2B19, CL-600-2C10, CL-600-2D15 and CL-600-2D24

Bombardier (formerly de Havilland Canada)

DHC-8, all models

Dassault Aviation

Mystère-Falcon 50 (including EX variant), Mystère-Falcon 900, Falcon 900EX, Falcon 2000 and Falcon 2000EX

Gulfstream

G-IV

Hawker Beechcraft (formerly Raytheon, Beech)

200 and 400 series, all models

SAAB

SF340A and 340B

Requirement:

Verify that the transponder Air/Ground discrete input connections are installed in accordance with Table 1 of Rockwell Collins Service Information Letter TDR-94( ) SIL 07-1 dated 25 May 2007 (document reference 523-0809129-001000). If the wiring installation is not compliant with the information provided in Table 1 of the SIL, modify the aeroplane Air/Ground discrete input connections in accordance with approved aeroplane modification instructions.

Note 2: This Directive is not applicable to aeroplanes that have complied with the following Service Bulletins (SB) or have had the following modifications embodied:

a. ATR aeroplanes modified in accordance with ATR (SB ATR42-34-0164 or SB ATR72-34-1093 (modification n° 05602), as applicable to aeroplane model, including those ATR aeroplanes on which modification n° 05602 was incorporated during production.

b. Bombardier CL-600-2B19 aeroplanes if modified in accordance with Bombardier SB 601R-34-146.

c. Bombardier DHC-8-100/200/300 series aeroplane if modified in accordance with MODSUM IS8Q2450012.

d. Dassault aeroplanes modified in accordance with Dassault Aviation SB
F50-457 (modifications M2966 and M2968), SB F50-469 (modification M2998), SB F900-354 (modification M3896), SB F900-368 (modification M5013), SB F900EX-239 (modification M3896), SB F900EX-270 (modification M5013), F2000-312 (modifications M2624 and M2632),
SB F2000-327 (modification M2468), SB F2000EX-043 (modification M2624) or SB F2000EX-084 (modification M2468).

Note 3: EASA AD 2009-0097 refers.

Compliance:

Within 12 months after the effective date of this Directive.

This Airworthiness Directive becomes effective on 26 March 2010.

Background:

Airservices Australia, the Australian Air Navigation Service Provider (ANSP) together with other national ANSPs, have implemented Advanced Surface Movement Guidance & Control Systems (A-SMGCS) to improve the surveillance and control of on-ground aeroplanes and vehicles, providing conflict detection and alerting on runways.

To ensure proper and effective operation of the A-SMGCS, transponder replies to Air Traffic Control Radar Beacon System (ATCRBS) and All-Call interrogations must be inhibited when the aeroplane is on ground.

\n```\n\n| | Rockwell Collins TDR-94 and TDR-94D Mode S Transponders have two Air/Ground Discrete inputs that may be connected to the aeroplane Weight-On-Wheels system. A connection to the Air/Ground #2 discrete will implement an inhibition of ATCRBS, ATCRBS/Mode-S All-Call and Mode-S Only All-Call replies when the aeroplane is on the ground. No on-ground reply inhibition occurs if the connection is to the Air/Ground #1 discrete. |\n| --- | --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |\n| | An aeroplane with this transponder interface problem, if not corrected, does not meet the specifications of International Civil Aviation Organisation (ICAO) Annex 10 Volume IV Amendment 77 Section 3.1.2.10.3.10 - Inhibition of replies which would lead to degradation of the functioning of the A-SMGCS, could affect the ATC functions in tower, approach and en-route sectors, increase the risk of undetected runway incursions and endangering the aeroplane, its occupants and persons on the ground. |\n| | For these reasons, this Directive requires a check of the transponder Air/Ground discrete input connections and, in case of discrepancies, the accomplishment of corrective action. |\n\n![](image.001.png)\n\nMike Higgins \nDelegate of the Civil Aviation Safety Authority\n\n15 March 2010","sortOrder":0},{"sectionNumber":"AD/RAD/91","sectionType":"part","heading":"AD/RAD/91","content":"## AD/RAD/91","sortOrder":1},{"sectionNumber":"Rockwell Collins TDR-94/94DTransponder -","sectionType":"part","heading":"Rockwell Collins TDR-94/94DTransponder - Air/Ground Discrete Inputs","content":"## Rockwell Collins TDR-94/94D \nTransponder - Air/Ground Discrete Inputs","sortOrder":2},{"sectionNumber":"6/2010","sectionType":"part","heading":"6/2010","content":"## 6/2010","sortOrder":3}],"analysis":{"summary":{"content_quality":"ok","complexity_score":1,"scope_assessment":{"changed":false,"description":"This is a standalone airworthiness directive, not an amendment to a previous instrument."},"complexity_factors":["Narrow applicability (specific transponder part numbers and aircraft models)","Requires reference to an external manufacturer service information letter","Contains exemption conditions based on prior compliance with listed service bulletins"],"plain_english_summary":"This CASA airworthiness directive requires operators of aircraft fitted with certain Rockwell Collins TDR-94/TDR-94D Mode S transponders to verify, within 12 months, that the air/ground discrete input wiring matches the manufacturer’s configuration and to apply approved modifications if it does not. Incorrect wiring can prevent ground-state reply suppression, disrupting A-SMGCS and ATC radar and increasing runway-incursion risk. Aircraft already modified per specified service bulletins are exempt. This AD implements the safety action of EASA AD 2009-0097."}},"importantCases":[],"_links":{"self":"/api/acts/ad-rad-91-rockwell-collins-tdr-94-94d-transponder-air-ground-discrete-inputs","history":"/api/acts/ad-rad-91-rockwell-collins-tdr-94-94d-transponder-air-ground-discrete-inputs/history","analysis":"/api/acts/ad-rad-91-rockwell-collins-tdr-94-94d-transponder-air-ground-discrete-inputs/analysis","conflicts":"/api/acts/ad-rad-91-rockwell-collins-tdr-94-94d-transponder-air-ground-discrete-inputs/conflicts","importantCases":"/api/acts/ad-rad-91-rockwell-collins-tdr-94-94d-transponder-air-ground-discrete-inputs/important-cases","documents":"/api/acts/ad-rad-91-rockwell-collins-tdr-94-94d-transponder-air-ground-discrete-inputs/documents"}}