Safety Rules & Regs

Air Safety Week, June 9, 2008

Airworthiness Directives; Rolls-Royce plc (RR) RB211 Trent 500 Series Turbofan Engines Final Rule; Request for Comments. SUMMARY: The FAA is superseding an existing airworthiness directive (AD) for RR RB211 Trent 553-61, 553A2-61, 556-61, 556A2-61, 556B-61, 556B2-61, 560-61, and 560A2-61 turbofan engines. That AD currently requires removing certain serial-numbered intermediate pressure compressor (IPC) drums, part number (P/N) FK30102. This AD requires removing those same IPC drums, and requires a new reduced life limit for all other IPC drums, P/N FK30102. This AD results from an RR engineering assessment that it is necessary to reduce the cyclic lives of the other drums with the same P/N. We are issuing this AD to prevent uncontained loss of IPC stage 1 blades, which could result in damage to the airplane.

Airworthiness Directives; Air Tractor, Inc. AT-200, AT-300, AT-400, AT- 500, AT-600, and AT- 800 Series Airplanes Final Rule. SUMMARY: We are adopting a new airworthiness directive (AD) to supersede AD 2002-25-09, which applies to certain Air Tractor, Inc. (Air Tractor) AT-250, AT-300, AT-400, and AT-500 series airplanes. AD 2002-25-09 currently requires you to install an overturn skid plate in the cockpit area. Since we issued AD 2002-25-09, we received a report of the bolts attaching the forward end of the original design overturn skid plate to the airframe breaking in an overturn accident. This allowed the skid plate to rotate around the rear attach point and the forward end of the plate to enter the cockpit area. Consequently, this AD would require the installation of a modified skid plate kit or modification to skid plate kits that are already installed, including those already installed on AT-402B, AT- 502B, AT-602, and AT-802A series airplanes during production. We are issuing this AD to prevent the front and rear connections of the overturn skid plate to the airplane from breaking, which could allow foreign debris to enter the cockpit during an airplane overturn. This condition, if not corrected, could lead to pilot injury.

Airworthiness Directives; Cirrus Design Corporation Model SR20 Airplanes Final Rule SUMMARY: We are adopting a new airworthiness directive (AD) for certain Cirrus Design Corporation (CDC) Model SR20 airplanes. This AD requires you to perform an inspection and replacement as necessary of the heat exchanger. This AD results from the discovery of engine exhaust fumes in the cabin of CDC Model SR20 airplanes. We are issuing this AD to detect and correct leaks in the exhaust system, which could result in exhaust gases leaking into the cabin heating system. This condition could lead to carbon monoxide in the cabin and incapacitation of the pilot.

Airworthiness Directives; Rolls-Royce plc (RR) Models Trent 768-60, 772- 60, 772B-60, and 772C-60 Turbofan Engines Final Rule; Request for Comments. SUMMARY: We are adopting a new airworthiness directive (AD) for the products listed above. This AD results from mandatory continuing airworthiness information (MCAI) issued by an aviation authority of another country to identify and correct an unsafe condition on an aviation product. The MCAI describes the unsafe condition as: Three Trent 700 IP Turbine discs that exhibited signs of wear at the bore following failure of the bearing chamber sealing sleeve were returned to service. This was based on the fact that Non- Destructive Testing (NDT) did not reveal micro cracking on the affected disc areas. Further engineering investigation considered that, although no micro cracking had been found, the worn disc bore surfaces would have an associated fatigue penalty compared to an unaffected bore. A crack developing from these rubbed surfaces could potentially lead to a disc burst. As the described wear, present at the bores of those three discs, presents a potential unsafe condition, this Airworthiness Directive requires identification of the three affected serial numbers of IP Turbine Discs (P/N FK20795) and removal from service prior to attaining a certain number of cycles, as indicated. We are issuing this AD to prevent a failure of the intermediate pressure (IP) turbine disc that could result in an uncontained failure of the engine and possible damage to the airplane.

Airworthiness Directives; Stemme GmbH & Co. KG Model S10-VT Powered Sailplanes Final Rule; Request for Comments. SUMMARY: We are adopting a new airworthiness directive (AD) for the products listed above that will supersede an existing AD. This AD results from mandatory continuing airworthiness information (MCAI) issued by the aviation authority of another country to identify and correct an unsafe condition on an aviation product. The MCAI describes the unsafe condition as: AD 2007-0315-E was issued to address a possible fuel leakage in the gear compartment in front of the engine and mandated inspections and replacement of fuel plastic-made connectors by connectors made of metal. Since its publication, another fuel leakage has been reported on a S10-VT which had implemented the STEMME Service Bulletin (SB) A31- 10-082 as required by AD 2007-0315-E. It has been determined that the fuel leak may have been caused by the deformation that the originally installed clamps created on the fuel hoses and thus preventing the new clamps from being sufficiently pinched to perform a correct tightening. This AD requires actions that are intended to address the unsafe condition described in the MCAI.