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 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 717 Series Aeroplanes
AD/B717/15 Flight Management System 11/2004
Applicability: Model 717-200 series aeroplanes.
Requirement: Amend the Limitations Section of Aircraft Flight Manual (AFM) to include the following statement. This may be accomplished by inserting a copy of this Directive into the AFM.
"Use of PROF mode for descent and/or approach operations is prohibited unless
- The aeroplane is on path and the FMA indicates THRUST | xxx | PROF, or
2. The indicated airspeed is below VMAX for the aeroplane configuration by at least:
- 10 knots at indicated altitudes below 10,000 feet, or
b. 15 knots at indicated altitudes of 10,000 feet or above, or
3. Basic autoflight modes (e.g., LVL CHG V/S, or FPA) are used to recapture the path when the PROF mode is engaged and the aeroplane is:
- Above or below the path and the FMA indicates PITCH | xxx | IDLE, or
b. Below the path and the FMA indicates THRUST | xxx | V/S."
When a statement identical to that above has been included in the general revisions of the AFM and the general revisions have been inserted into the AFM, the copy of this Directive may be removed from the AFM.
Note: FAA AD 2004-18-04 Amdt 39-13782 refers.
Compliance: Within 60 days after the effective date of this Directive
This Airworthiness Directive becomes effective on 28 October 2004.
Boeing 717 Series Aeroplanes
AD/B717/15 (continued)
Background: The United States Federal Aviation Administration (FAA) has received reports of two violations of the selected flight control panel (FCP) altitude during flight management system (FMS) profile (PROF) mode descents on McDonnell Douglas MD-11 aeroplanes. Investigation by the aeroplane and avionics manufacturers revealed that under certain conditions during an FMS PROF descent, the FMS will allow an aeroplane to descend below the selected FCP altitude or FMS-constrained altitude or both. In addition, the FMS will not command the autopilot or flight director to level off at the next altitude constraint, if a specific series of events occur and the airspeed of the aeroplane is within the overspeed detection window during an FMS descent.
As the FMS software on 717-200 aeroplanes is identical to that on the affected MD- 11 aeroplanes, 717-200 aeroplanes may be subject to the same unsafe condition.
This Directive requires a revision to the Limitations Section of the AFM to prohibit use of the FMS PROF mode for descent and/or approach operations unless certain conditions are met. This action is designed to prevent, under certain conditions during the FMS PROF descent, the uncommanded descent of an aeroplane below the selected level-off altitude, which could result in an unacceptable reduction in the separation between the aeroplane and nearby air traffic or terrain.
James Coyne
Delegate of the Civil Aviation Safety Authority 16 September 2004
The above AD is notified in the Commonwealth of Australia Gazette on 6 October 2004.
Overview
The Civil Aviation Safety Authority (CASA) has issued an Airworthiness Directive (AD) AD/B717/15 dated 16 September 2004 under the authority granted by subregulation 39.1(1) of the Civil Aviation Safety Regulations 1998. This AD pertains to Boeing 717-200 series aeroplanes and specifically addresses a safety concern identified with the flight management system (FMS) profile (PROF) mode during descent and approach operations. The directive aims to mitigate the risk of uncommanded descents below the selected altitude, which could potentially lead to unsafe separation from other aircraft or terrain. The AD requires a revision to the Aircraft Flight Manual (AFM) to include a statement prohibiting the use of PROF mode under certain conditions unless specified criteria are met. Compliance with this directive must be achieved within 60 days from its effective date of 28 October 2004.
Scope and Application
The Airworthiness Directive (AD) AD/B717/15 issued under the Civil Aviation Safety Regulations 1998 applies specifically to Boeing 717-200 series aeroplanes. This AD mandates that operators of these aeroplanes must amend the Limitations Section of the Aircraft Flight Manual (AFM) to include specific restrictions on the use of the Flight Management System (FMS) PROF mode during descent and approach operations. This requirement aims to mitigate the risk of an uncommanded descent below the selected altitude, which could result in unsafe separation from other aircraft or terrain. The AD is effective for all aeroplanes of the specified model series, and compliance is required within 60 days of the directive's effective date, which is 28 October 2004. The AD was issued by the Civil Aviation Safety Authority (CASA) delegate and published in the Commonwealth of Australia Gazette on 6 October 2004.
Key Provisions
The Airworthiness Directive (AD) issued under subregulation 39.1 (1) of the Civil Aviation Safety Regulations 1998 (CASR 1998) pertains specifically to Boeing 717-200 series aeroplanes. The directive mandates a revision to the Limitations Section of the Aircraft Flight Manual (AFM) to incorporate a specific statement regarding the use of the Flight Management System (FMS) Profile (PROF) mode during descent and approach operations. This revision is necessary to address an unsafe condition identified during certain descents using the FMS PROF mode. The unsafe condition could potentially allow the aeroplane to descend below the selected altitude, which poses a risk to air traffic separation and terrain clearance. This amendment is detailed in section (a) of the requirement section of the AD.
The AD imposes several obligations on the parties and entities governed by it. Primarily, it requires operators of Boeing 717-200 series aeroplanes to update their AFMs to include the specified statement about the PROF mode. This update must be made within 60 days from the effective date of the AD, which is 28 October 2004. The directive allows for the inclusion of a copy of the AD itself into the AFM as a temporary measure until the general revisions are incorporated into the AFM. Ensuring compliance with this requirement is essential for maintaining the airworthiness of the aircraft and ensuring the safety of flight operations.
Failure to comply with the AD may result in serious consequences. While the specific penalties for non-compliance are not detailed in the text, it is implied that non-compliance with an AD issued under the authority of the Civil Aviation Safety Authority (CASA) can lead to significant legal and operational repercussions. These could include enforcement actions, fines, and potential grounding of the aircraft until compliance is achieved. The severity of these consequences underscores the importance of adhering to the AD to ensure the safety and airworthiness of the Boeing 717-200 series aeroplanes.