AIRWORTHINESS DIRECTIVE
For the reasons set out in the background section, the CASA delegate whose signature appears below revokes Airworthiness Directive (AD) AD/EMB-120/17 and issues the following 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.
Embraer EMB-120 (Brasilia) Series Aeroplanes
AD/EMB-120/17
Amdt 1
Landing Gear - Door Blockage 9/2002
Applicability: Embraer EMB 120 (Brasilia) aircraft serial numbers 120003,120004, and 120006 through 120331 inclusive.
Requirement: 1. Check for the correct installation of check valve P/N CKRC1875005A in landing gear wheel well door closure line as per Embraer Service Bulletin (SB) 120-32- 0077 Revision 3.
2. If the check valve is fitted correctly no further action is required.
3. If the check valve is not fitted, or fitted incorrectly, carry out correct installation as per Embraer Service Bulletin (SB) 120-32-0077 Revision 3.
Note 1: Brazilian AD 97-05-03R3 refers.
Note 2: Aircraft flight manual amendments detailed in AD 97-05-03 are required by CAR 55.
Compliance: Unless previously accomplished; within the next 100 flight hours after the effective date of this Directive.
This amendment becomes effective on 5 September 2002.
Background: The original issue of this Directive was in response to investigation into aircraft incidents has shown that it is possible to lock up the landing gear doors when performing the emergency landing gear extension procedures in the event of the loss of the green hydraulic system. With the landing gear doors locked, the landing gear cannot be extended even by free fall. Installation of the check valve eliminates the possibility of the doors locking up in this situation.
Embraer EMB-120 (Brasilia) Series Aeroplanes
AD/EMB 120/17 Amdt 1 (continued)
Amendment 1 was issued to address the possibility of incorrect installation or the non- installation of the check valve as required by the original version of this
Directive. Revision 3 of Brazilian AD 97-05-03 was issued to address these problems.
The original issue of this Airworthiness Directive became effective on 14 August 1997.
Eugene Paul Holzapfel
Delegate of the Civil Aviation Safety Authority 26 July 2002
The above AD is notified in the Commonwealth of Australia Gazette on 14 August 2002.
Overview
The Civil Aviation (Airworthiness) Regulations 1998 were enacted to ensure that aircraft operated in Australia meet safety standards and are airworthy. This legislative instrument, F2006B09505, revokes Airworthiness Directive AD/EMB-120/17 and issues a new directive to address an identified unsafe condition with Embraer EMB-120 (Brasilia) Series Aeroplanes. The Civil Aviation Safety Authority (CASA) has identified a safety issue with certain Embraer EMB-120 aircraft, specifically serial numbers 120003, 120004, and 120006 through 120331, where the landing gear doors may lock up during emergency procedures due to the incorrect or missing installation of a check valve. This problem could prevent the landing gear from extending even by free fall, posing a significant safety risk. The policy objective of this Airworthiness Directive is to ensure the correct installation of the check valve P/N CKRC1875005A in the landing gear wheel well door closure line, in line with Embraer Service Bulletin SB 120-32-0077 Revision 3. Compliance with the directive is required within the next 100 flight hours after its effective date of 5 September 2002.
Scope and Application
The Airworthiness Directive (AD) AD/EMB-120/17 Amdt 1 pertains specifically to the Embraer EMB 120 (Brasilia) aircraft with serial numbers ranging from 120003 to 120004 and from 120006 to 120331 inclusive. This directive, issued by the Civil Aviation Safety Authority (CASA) delegate, aims to address a safety concern related to the installation of the check valve in the landing gear wheel well door closure line, as outlined in Embraer Service Bulletin (SB) 120-32-0077 Revision 3. The directive is intended to ensure the safe operation of the specified aircraft by preventing the landing gear doors from locking during emergency landing gear extension procedures, which could otherwise render the landing gear unusable even through free fall. Compliance with this directive is mandatory for the specified aircraft, requiring corrective action to be taken within the next 100 flight hours following the directive's effective date of 5 September 2002.
Key Provisions
The main operative sections of this Airworthiness Directive (AD) specify the applicability of the directive to certain Embraer EMB 120 (Brasilia) aircraft (section 1) and the requirement to check and, if necessary, correct the installation of a specific check valve (section 2). Section 3 outlines the compliance timeframe, which is within the next 100 flight hours after the effective date of this directive.
The AD imposes specific obligations on the parties or entities it governs, primarily focusing on ensuring the correct installation of the check valve in the landing gear wheel well door closure line. This obligation is critical to prevent the landing gear doors from locking up during emergency landing gear extension procedures, a risk identified in the background section of the directive. Owners and operators of the affected aircraft must adhere to these requirements by either confirming the correct installation of the check valve or, if it is not installed or is incorrectly installed, carrying out the correct installation as per the specified Embraer Service Bulletin (SB).
Failure to comply with this Airworthiness Directive could lead to safety risks, including the potential for the landing gear doors to lock, which would prevent the landing gear from extending even by free fall. The directive specifically references Brazilian AD 97-05-03R3 and requires aircraft flight manual amendments as per CAR 55. The consequences of non-compliance could be severe, potentially affecting the airworthiness and safety of the aircraft. However, the specific penalties or consequences for non-compliance are not detailed within this AD but would likely be governed by broader aviation safety regulations and civil aviation laws.