COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY
SCHEDULE OF AIRWORTHINESS DIRECTIVES
Fokker F50 (F27 Mk 50) Series Aeroplanes
AD/F50/77 Stabilizer De-Icing Monitoring System 6/98
Applicability: Model F.27 Mk.050 (Fokker 50) aeroplanes with serial numbers 20103 through 20245 inclusive, 20248, 20250 through 20255 inclusive, 20257 through 20269
inclusive, 20272 through 20275 inclusive, 20278, 20280 through 20283 inclusive,
20285, 20287 through 20302 inclusive, 20304, 20305 and 20307 through 20311 inclusive.
Requirement: Install a horizontal and vertical stabilizer de-icing monitoring system in accordance with Fokker Service Bulletin SBF50-30-025 dated 31 October 1997.
Note: RLD AD 1997-113 (A) refers.
Compliance: For aeroplanes without any tail de-icing distributor valve heating system installed - Within the next 10 calendar months after the effective date of this directive.
For aeroplanes that have a tail de-icing distributor valve heating system installed, either in accordance with Fokker Service Bulletin SBF50-30-024 dated 26 March 1997 or Fokker Engineering Report TT95.55175 - Within the next 16 calendar months after the effective date of this directive.
This airworthiness directive becomes effective on 21 May 1998.
Background: The Netherlands airworthiness authority has advised that a number of F.27 Mk.050 operators have experienced problems with the tail de-icing system. After prolonged operation at very low outside air temperatures, one or more sections of the de-icing boots do not inflate when the system is selected ON. Investigation shows that interrupted boot operation may be caused by freezing of one or more distributor valves. Fokker has developed an optional service bulletin (SBF50.30.024), which introduces heater muffs on the affected distributor valves, to decrease the likelihood of the valves freezing. However, on early models, the operation of the de-icing system is not monitored.
This directive introduces a system to monitor the operation status of the horizontal and vertical stabilizer de-icing, and provide a warning in the cockpit when operation is interrupted.
Overview
The Civil Aviation Regulations 1998, specifically Part 39, was enacted to ensure the safety of civil aviation in Australia. One of the airworthiness directives introduced under this Act is AD/F50/77, which was issued to address problems with the tail de-icing system on Fokker F50 (F27 Mk 50) Series Aeroplanes. The directive was introduced in response to issues reported by operators in the Netherlands, where, at very low outside air temperatures, sections of the de-icing boots failed to inflate, potentially due to the freezing of distributor valves. The policy objective of this directive is to ensure the safe operation of the specified aircraft by requiring the installation of a de-icing monitoring system to provide cockpit warnings in the event of interrupted boot operation. This legislation is enacted by the Australian Government and is administered by the Civil Aviation Safety Authority.
Scope and Application
The Civil Aviation Regulations 1998, specifically Part 39 - 105 concerning the Civil Aviation Safety Authority Schedule of Airworthiness Directives, applies to Fokker F50 (F27 Mk 50) series aeroplanes with particular serial numbers. These aircraft must comply with the directive regarding the installation of a horizontal and vertical stabilizer de-icing monitoring system, as stipulated in Fokker Service Bulletin SBF50-30-025 dated 31 October 1997. The directive is a response to reports from the Netherlands airworthiness authority, highlighting issues with the tail de-icing system on these aircraft, which could lead to non-inflation of de-icing boots due to freezing of distributor valves. The directive mandates compliance within specific timeframes depending on whether the aircraft already has a tail de-icing distributor valve heating system installed. This requirement extends across the Commonwealth of Australia and is applicable to the specified Fokker F50 aeroplanes, ensuring their airworthiness and safety in operation.
Key Provisions
The Civil Aviation Regulations 1998, specifically Part 39, Section 105, mandate the installation of a horizontal and vertical stabilizer de-icing monitoring system for Fokker F50 (F27 Mk 50) series aeroplanes with specific serial numbers (AD/F50/77). This requirement is detailed in Airworthiness Directive AD/F50/77, which became effective on 21 May 1998. The directive applies to Fokker F50 aeroplanes with serial numbers ranging from 20103 to 20245, excluding 20246 and 20247, as well as others up to 20311. The installation must adhere to Fokker Service Bulletin SBF50-30-025 dated 31 October 1997. This directive refers to RLD AD 1997-113 (A) for compliance.
Operators of Fokker F50 aeroplanes must ensure that the specified de-icing monitoring system is installed within a defined timeframe. For aeroplanes without a tail de-icing distributor valve heating system, compliance must be achieved within the next 10 calendar months from the directive's effective date. For aeroplanes that have a tail de-icing distributor valve heating system installed, either in accordance with Fokker Service Bulletin SBF50-30-024 dated 26 March 1997 or Fokker Engineering Report TT95.55175, the compliance period is extended to the next 16 calendar months. Failure to comply with these timelines may result in the aeroplane being considered non-airworthy.
Failure to comply with the provisions of this airworthiness directive may result in serious safety risks, including potential malfunction of the tail de-icing system, which could lead to hazardous flight conditions. The Civil Aviation Safety Authority (CASA) has the authority to enforce compliance and may take action against non-compliant operators. The consequences of non-compliance can include civil penalties, which may involve fines, and criminal charges in cases of gross negligence. The severity of penalties can vary, but the directive highlights the importance of adhering to the specified installation timelines to maintain the airworthiness of the aeroplanes.