AIRWORTHINESS DIRECTIVE
For the reasons set out in the background section, the CASA delegate whose signature appears below revokes Airworthiness Directive (AD) AD/B737/180 and issues the following AD under subregulation 39.1 (1) of CASR 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.
Boeing 737 Series Aeroplanes
AD/B737/180
Amdt 1
Speedbrake Operation Limitation - 2 13/2003
Applicability: All Model 737-600, -700, and -700C series aircraft.
Requirement: Revise the Limitations Section of the Aircraft Flight Manual to include the following information:
“Do not operate the aircraft at speeds in excess of 300 KIAS with speedbrakes extended”.
WARNING: Use of speedbrakes in excess of 320 KIAS could result in a severe vibration, which in turn, could cause extreme damage to the horizontal stabiliser.
Note 1: This requirement may be accomplished by inserting a copy of this Directive into the Limitations Section of the Aircraft Flight Manual.
Note 2: Modification or retrofit of the elevator tab assembly in accordance with a method approved by the Manager, Seattle ACO, FAA, constitutes terminating action for the Aircraft Flight Manual revision requirement of this Directive.
Note 3: Emergency FAA AD 2002-08-52 refers.
Compliance: Within 24 hours after 15 April 2002, unless already accomplished. Compliance with AD/B737/210 (FAA AD 2003-03-22) constitutes terminating action for the requirements of this Directive.
The compliance time remains unchanged by this issue. This Amendment becomes effective on 25 December 2003.
Background: The FAA received a report indicating that severe vibration of the horizontal stabiliser occurred on a Model 737-700 aircraft. The high frequency vibration was initiated by deployment of the speebrakes during descent of the aircraft. The FAA and the manufacturer have determined that the vibration was due to a “limit cycle oscillation” of the elevator and elevator tab assembly attached to the horizontal stabiliser. Severe vibration of the elevator and elevator tab assembly following deployment of the speedbrakes, if not corrected, could result in severe damage to the horizontal stabiliser, followed by possible loss of controllability of the aircraft.
Boeing 737 Series Aeroplanes
AD/B737/180 Amdt 1 (continued)
Amendment 1 is issued to introduce terminating action for the requirements of this Directive.
The original issue of this Airworthiness Directive became effective on 15 April 2002.
David Villiers
Delegate of the Civil Aviation Safety Authority 13 November 2003
The above AD is notified in the Commonwealth of Australia Gazette on 3 December 2003.
Overview
The Civil Aviation Safety Authority (CASA) introduced the Airworthiness Directive (AD) AD/B737/180 and its Amendment 1 in 2003 to address a safety issue identified with the Boeing 737 Series aeroplanes, specifically Models 737-600, -700, and -700C. This legislation was enacted to rectify a potentially unsafe condition related to the operation of speedbrakes on these aircraft, which could lead to severe vibration and subsequent damage to the horizontal stabiliser, potentially compromising the aircraft's controllability. The directive was issued under the authority granted by subregulation 39.1 (1) of the Civil Aviation Safety Regulations 1998. The policy objective of this AD is to ensure the continued airworthiness of affected aircraft by mandating specific operational limitations and revisions to the Aircraft Flight Manual to prevent unsafe conditions. Compliance with the directive is mandatory, with an initial timeframe of 24 hours from 15 April 2002, unless already fulfilled.
Scope and Application
This Airworthiness Directive (AD) issued under the Civil Aviation Safety Regulations 1998 (CASR 1998) applies to all Boeing 737-600, -700, and -700C series aircraft operating within Australia. The directive mandates that operators of these aircraft revise their Aircraft Flight Manuals to include a speed limitation prohibiting operation at speeds exceeding 300 knots indicated airspeed (KIAS) with speedbrakes extended, due to the risk of severe horizontal stabiliser vibration and potential damage. Compliance with this directive is required within 24 hours of 15 April 2002, unless already implemented, and it is noted that adherence to FAA AD 2003-03-22 serves as a terminating action for this directive's requirements. The AD was issued in response to reports of severe vibration in the horizontal stabiliser of a 737-700 model due to limit cycle oscillations of the elevator and elevator tab assembly following speedbrake deployment. This directive is enforced by the Civil Aviation Safety Authority (CASA) and is applicable across the Commonwealth of Australia, as notified in the Commonwealth of Australia Gazette on 3 December 2003.
Key Provisions
The Airworthiness Directive (AD) AD/B737/180 Amendment 1 focuses on addressing a specific issue with Boeing 737-600, -700, and -700C series aircraft. The primary requirement (section 1) is to revise the Limitations Section of the Aircraft Flight Manual to include a restriction against operating the aircraft at speeds over 300 knots Indicated Airspeed (KIAS) with the speedbrakes extended (section 1). This is to mitigate the risk of severe vibration and potential damage to the horizontal stabiliser. The directive also includes a warning that operating the speedbrakes above 320 KIAS could lead to severe damage. Compliance must be achieved within 24 hours after 15 April 2002, unless already done.
The obligations imposed by the AD include ensuring that the Aircraft Flight Manual is updated with the specified information (section 1). This can be achieved by either inserting a copy of the directive into the Limitations Section or by modifying the elevator tab assembly in a manner approved by the Manager, Seattle ACO, FAA. Furthermore, compliance with a related AD/B737/210 (FAA AD 2003-03-22) can also satisfy the requirements of this directive.
Failing to adhere to the provisions of this Airworthiness Directive can result in significant safety risks. The AD emphasises the potential for severe vibration and damage to the horizontal stabiliser, which could lead to a loss of controllability of the aircraft. While the AD itself does not explicitly state penalties for non-compliance, failure to adhere to such directives can lead to severe consequences under aviation safety regulations. Non-compliance could potentially result in legal action, fines, or other penalties as stipulated by the Civil Aviation Safety Authority (CASA) regulations. The exact penalties would depend on the specific regulatory framework governing aviation safety in Australia at the time of non-compliance.