COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY
SCHEDULE OF AIRWORTHINESS DIRECTIVES
Sikorsky S-76 Series Helicopters
AD/S-76/61 AC Generator Interlock System 7/99
TX
Applicability: Model S-76A with Turbomeca Arriel 1S1 engines installed in accordance with Federal Aviation Administration Supplemental Type Certificate SH568NE, including drawing 76070-30601.
Requirement: 1. Determine if the AC generator interlock relays are installed by conducting the following inspection:
- uncover the No 2 relay panel located in the right side of the cockpit overhead (this panel is also referred to as the right-hand panel), and
b. inspect for the presence of the AC generator interlock relays identified as K43 and K44 (two relays) or K46, K47 and K48 (three relays).
Note 1: For S-76A helicopters, Serial Number (S/N) 760001 through 760237 inclusive, the AC generator interlock relays are wired through splice groups to the K31, K32, K11 and K13 relays. For S-76A helicopters, S/N 760238 and higher, the AC generator interlock relays are wired through splice groups to the K11 and K13 relays. Depending on how and when each helicopter was modified, the labels on these relays could be K43 and K44 (two relays) or K46, K47 and K48 (three relays).
2. If, following the Requirement 1 inspection, the AC generator interlock relays are found to be installed, no further action is necessary. However, if the AC generator interlock relays are not installed, fabricate and install, in clear view of the pilot, a placard stating:
“WARNING - AC GENERATOR INTERLOCK SYSTEM NOT INSTALLED SINGLE-ENGINE PERFORMANCE IS REDUCED”
Note 2: Sikorsky Model S-76A Rotorcraft Flight Manual Supplement (RFMS) No 29B, Temporary Revision 1 dated 9 April 1999 is applicable.
3. Remove the placard installed under Requirement 2.
Note 3: RFMS 29B, Temporary Revision 1, need not be complied with following installation of one of the following kits:
- for Model S-76A helicopters S/N 760001 through 760237 inclusive, AC Generator Interlock Kit (Kit) Part Number (P/N) 33776-84790-012, or
b. for Model S-76A helicopters S/N 760238 and higher, Kit P/N 33776-84790-011.
Note 4: FAA Priority Letter AD 99-11-04 and Sikorsky Aircraft Corporation Alert Service Bulletin 76-77-4A, Revision A, dated 6 May 1999 pertain to this Directive.
Compliance: 1. Before further flight after the effective date of this Directive.
2. Before further flight after the Requirement 1 inspection is completed.
COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY
SCHEDULE OF AIRWORTHINESS DIRECTIVES
3. Concurrent with installation of one of the following kits:
- for Model S-76A helicopters S/N 760001 through 760237 inclusive, AC Generator Interlock Kit (Kit) Part Number (P/N) 33776-84790-012, or
b. for Model S-76A helicopters S/N 760238 and higher, Kit P/N 33776-84790- 011.
This Airworthiness Directive becomes effective on 25 May 1999.
Background: The FAA has advised that S-76A helicopters with Turbomeca Arriel 1S1 may fail to achieve the specified single engine performance if the AC generator interlock system is not installed. This Directive requires an inspection to determine if the AC generator interlock system is installed and, if necessary, the installation of a warning placard.
The Directive also provides for an optional terminating action allowing removal of the placard and operation limitation imposed by the temporary RFMS revision.
Overview
The Civil Aviation Regulations 1998, enacted by the Commonwealth of Australia, are a comprehensive set of rules governing aviation safety within the country. One particular legislative instrument within these regulations, F2006B06737, addresses the Sikorsky S-76 Series Helicopters, specifically focusing on the AC generator interlock system. This directive was introduced to address the potential safety risk where S-76A helicopters with Turbomeca Arriel 1S1 engines might not achieve the specified single engine performance without the AC generator interlock system installed. The objective is to ensure that all necessary safety measures are in place to maintain airworthiness and prevent any potential hazards during flight. The Civil Aviation Safety Authority is the enacting body, with a policy objective to mandate inspections and installations as specified to maintain operational safety standards.
Scope and Application
The Civil Aviation Regulations 1998, specifically under Part 39 - 105, mandates the Airworthiness Directive AD/S-76/61 concerning Sikorsky S-76 Series Helicopters, particularly the S-76A model equipped with Turbomeca Arriel 1S1 engines. This directive applies to aircraft that meet the specified criteria of being installed in accordance with the Federal Aviation Administration Supplemental Type Certificate SH568NE, including drawing 76070-30601. The regulation requires an inspection to ascertain whether the AC generator interlock relays are installed and, if not, mandates the installation of a warning placard indicating reduced single-engine performance. Compliance with this directive is required before further flight after the effective date and inspection, with optional removal of the placard following installation of a specific kit. The directive applies nationally, overseen by the Civil Aviation Safety Authority, and provides clear instructions for both the inspection and remedial actions required to maintain compliance with civil aviation safety standards.
Key Provisions
The Civil Aviation Regulations 1998, specifically Part 39 - 105, under the Civil Aviation Safety Authority’s Schedule of Airworthiness Directives, outlines the requirements for Sikorsky S-76 Series Helicopters, with a focus on the AC Generator Interlock System. AD/S-76/61, issued on 7/99, applies to Model S-76A helicopters with Turbomeca Arriel 1S1 engines installed in accordance with FAA Supplemental Type Certificate SH568NE (Section 1). The directive mandates that operators conduct an inspection to determine whether the AC generator interlock relays are installed in the No 2 relay panel in the right side of the cockpit overhead. Specifically, operators must look for relays identified as either K43 and K44 (two relays) or K46, K47, and K48 (three relays) (Section 1(b)). The installation specifics differ depending on the serial number range of the helicopter.
Operators are required to ensure that the AC generator interlock system is installed. If the system is not installed, a placard stating "WARNING - AC GENERATOR INTERLOCK SYSTEM NOT INSTALLED SINGLE-ENGINE PERFORMANCE IS REDUCED" must be fabricated and installed in clear view of the pilot (Section 2). Additionally, operators must comply with Sikorsky Model S-76A Rotorcraft Flight Manual Supplement (RFMS) No 29B, Temporary Revision 1 dated 9 April 1999 (Section 2, Note 2). However, compliance with this flight manual supplement is not necessary if one of the specified AC Generator Interlock Kits is installed (Section 3, Note 3).
Failure to comply with this Airworthiness Directive can lead to serious operational limitations and potential safety hazards. The Federal Aviation Administration has indicated that S-76A helicopters may not achieve the specified single engine performance if the AC generator interlock system is not installed. The Airworthiness Directive becomes effective on 25 May 1999, and compliance is required before further flight after the inspection is completed or after the installation of the specified kit. Non-compliance with these provisions may result in the aircraft being deemed unairworthy, leading to potential grounding and enforcement actions by the Civil Aviation Safety Authority. The specific penalties for non-compliance are not detailed in the directive but could include fines or other regulatory sanctions as stipulated by the Civil Aviation Regulations.