COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY
SCHEDULE OF AIRWORTHINESS DIRECTIVES
Bombardier (Boeing Canada/De Havilland) DHC-8 Series Aeroplanes
AD/DHC-8/61 Rudder Feel Assembly Springs 1/99
Applicability: DHC-8 aircraft, models 102, 103, 106, 201, 202, 301, 311, 314, and 315, serial
numbers 3 through 520, excluding serial numbers 413, 450, 462, 463, 464, 465, 467,
468, 469, 473, 478, 479, 482, 487, 489, 491, 493, 495, 499, and 500.
Requirement: 1. For all aircraft operating under Flight Manual Supplement 54 - Operation from narrow runways:
- Inspect both rudder feel springs in accordance with Part III, Accomplishment Instructions, of Bombardier Inc. Alert Service Bulletin (ASB) A8-27-82.
If either or both rudder feel springs are found to be of a non-conforming single rate configuration, operation from narrow runways in accordance with Flight Manual Supplement 54 is not permitted before accomplishment of Requirement 1.b. below and the following must be added to the LIMITATIONS section of the Flight Manual Supplement 54:
“OPERATION FROM NARROW RUNWAYS IN ACCORDANCE WITH FLIGHT MANUAL SUPPLEMENT 54 IS NOT PERMITTED BEFORE BOTH RUDDER FEEL SPRINGS HAVE BEEN REPLACED IN ACCORDANCE WITH PART III, ACCOMPLISHMENT INSTRUCTIONS, OF ASB A8-27-82”.
This Flight Manual amendment task may be accomplished by inserting a copy of this Directive into the Limitations section of the Flight Manual.
b. Replace both rudder feel springs in accordance with Part III, Accomplishment Instructions, of ASB A8-27-82.
2. For aircraft not operating under Flight Manual Supplement 54:
Inspect both rudder feel springs in accordance with Part III, Accomplishment Instructions, of Bombardier Inc. ASB A8-27-82. If either or both springs are of a single rate configuration, both springs must be replaced.
Note: Transport Canada AD CF-98-39 refers.
Compliance: 1. a. Unless already accomplished, within 100 hours time in service after 28 January 1999.
- b. At the next “C” check, or within 36 months, or prior to operating from narrow runways in accordance with Flight Manual Supplement 54, whichever occurs first after the Requirement 1.a. inspection.
2. Unless already accomplished, at the next “C” check or within 36 months after 28 January 1999, whichever occurs first.
This Airworthiness Directive becomes effective on 28 January 1999.
COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY
SCHEDULE OF AIRWORTHINESS DIRECTIVES
Background: The rudder feel assembly incorporates two dual rate springs. However, a number of single rate springs were inadvertently introduced into some aircraft in production.
Both single and dual rate springs have the same part number but differ in the breakout forces, where single rate springs require heavier than normal rudder pedal forces. A mix of single and dual rate springs produces an asymmetric rudder force condition which is particularly noticeable to the pilot when small rudder control inputs are required in gusty crosswind or single engine failure conditions. It is therefore necessary to restrict aircraft equipped with single rate springs from operating on narrow runways less than 18 metres wide.
Overview
The Civil Aviation Regulations 1998, enacted by the Parliament of the Commonwealth of Australia, address the critical need for stringent safety regulations within the civil aviation sector. This legislative instrument, particularly PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY SCHEDULE OF AIRWORTHINESS DIRECTIVES, was introduced to ensure the airworthiness of aircraft by mandating specific maintenance and operational requirements. The policy objective is to prevent safety hazards that may arise from the inadvertent use of non-conforming components, such as single rate rudder feel springs in Bombardier (Boeing Canada/De Havilland) DHC-8 Series Aeroplanes. This directive specifically targets the replacement or inspection of these springs to prevent operational limitations on narrow runways, thereby enhancing overall flight safety. The directive was necessitated by the identification of single rate springs in aircraft that should only have dual rate springs, which could lead to asymmetric rudder forces and compromise handling characteristics, particularly in challenging weather conditions or engine failure scenarios.
Scope and Application
The Civil Aviation Regulations 1998, specifically Part 39 - 105 under the Civil Aviation Safety Authority's Schedule of Airworthiness Directives, applies to Bombardier (Boeing Canada/De Havilland) DHC-8 series aeroplanes, covering models 102, 103, 106, 201, 202, 301, 311, 314, and 315, with serial numbers ranging from 3 to 520, except for the specified exclusions. This regulation mandates particular inspections and replacements of the rudder feel assembly springs to ensure airworthiness and safety. For aircraft operating under Flight Manual Supplement 54, which pertains to operations from narrow runways, both rudder feel springs must be inspected and, if found to be non-conforming single rate springs, replaced. Additionally, a specific limitation must be added to the LIMITATIONS section of the Flight Manual Supplement 54. For aircraft not operating under this supplement, the springs must still be inspected, and any single rate springs must be replaced. Compliance with these requirements must occur within specified timeframes after 28 January 1999, with the directive becoming effective on that date.
Key Provisions
The Civil Aviation Regulations 1998, specifically under PART 39 - 105, addresses the airworthiness directives for certain Bombardier (Boeing Canada/De Havilland) DHC-8 series aeroplanes. The directive AD/DHC-8/61 concerns the rudder feel assembly springs, which must be inspected and possibly replaced to ensure safe operation. Section 1 outlines the requirement for DHC-8 aircraft models 102, 103, 106, 201, 202, 301, 311, 314, and 315, excluding specific serial numbers, to comply with certain inspection and replacement protocols for the rudder feel springs. For aircraft operating under Flight Manual Supplement 54, the springs must be inspected, and if found non-conforming, they must be replaced to permit operation from narrow runways (Requirement 1). Aircraft not operating under Flight Manual Supplement 54 must also inspect the springs, and if any are non-conforming, they must be replaced (Requirement 2).
The obligations imposed by this directive are stringent and specific. Operators of the specified DHC-8 aircraft must ensure that the rudder feel springs are inspected and, if necessary, replaced within prescribed timeframes. For aircraft operating under Flight Manual Supplement 54, the inspection must occur within 100 hours of time in service after 28 January 1999, or at the next "C" check, or within 36 months, or prior to operating from narrow runways, whichever comes first (section 1.a). For aircraft not operating under this supplement, the inspection must occur at the next "C" check or within 36 months after 28 January 1999, whichever comes first (section 1.b). Additionally, if the springs are found to be non-conforming, they must be replaced according to the instructions provided in Part III, Accomplishment Instructions, of Bombardier Inc. Alert Service Bulletin A8-27-82.
Failure to comply with the requirements set forth in this airworthiness directive may result in serious safety implications, as aircraft equipped with non-conforming single rate springs may exhibit asymmetric rudder force conditions, particularly dangerous during gusty crosswind or single engine failure scenarios. While the regulations do not explicitly state penalties for non-compliance, non-compliance with airworthiness directives can lead to severe consequences, including grounding of the aircraft, enforcement actions by the Civil Aviation Safety Authority (CASA), and potential criminal or civil penalties under other relevant aviation laws. The directive becomes effective on 28 January 1999, and operators must adhere strictly to ensure the safety and airworthiness of the aircraft.