Federal Aviation Administration August 15, 2008 – Federal Register Recent Federal Regulation Documents

The FAA is amending its proposal to prohibit the filtering of some original flight recorder sensor signals. Comments to the NPRM published in November 2006 and changes in available technology have caused us to reexamine our position on data filtering. We are now proposing that certain critical data parameters may be filtered if a certificate holder can show that the data can be accurately reconstructed. This proposed rule would improve the integrity and quality of the data recorded on digital flight data recorders while giving aircraft designers and operators more flexibility in system design and operation where allowable, including an option to filter data.

We are adopting a new airworthiness directive (AD) for the PZL Swidnik S. A. (PZL) Model W-3A helicopters. This AD results from mandatory continuing airworthiness information (MCAI) issued by the European Aviation Safety Agency (EASA), which is the Technical Agent for the Member States of the European Community. The MCAI states: ``In PZL W-3A helicopter S/N 37.07.05, and previously also in the PZL W-3AS model helicopters, leakage was found in the pipe 37.59.006.00.00 installed in the pressure line of hydraulic system 2, in the part between the hydraulic block and the ground hydraulic unit panel. The hydraulic system in the part between hydraulic blocks and the ground hydraulic unit panel is used only during periodical inspections, for the performance of which it is required to use the hydraulic power unit. This condition, if not corrected, could result in a fire hazard.'' The actions specified in this AD are intended to prevent this unsafe condition.

The FAA is superseding an existing airworthiness directive (AD) that applies to certain Bombardier Model DHC-8-400 series airplanes. The existing AD currently requires revising the Limitations section of the airplane flight manual (AFM) to include procedures for pulling the ``HYD PWR XFER'' circuit breaker in the event of the loss of all hydraulic fluid in the No. 1 or No. 2 hydraulic system. This AD requires a revision to the AFM to include additional procedures for ensuring that the ``PTU CNTRL'' switch is Normal, the ``PTU CNTRL ON'' advisory light is out, and the ``HYD PWR XFER'' circuit breaker is pulled in the event of the illumination of the ``2 HYD ISO VALVE'' caution light. This AD resulted from low No. 2 hydraulic pressure in-flight, which caused the power transfer unit to overspeed, and the fluid flow within the No. 1 hydraulic system to increase. We are issuing this AD to prevent possible loss of both the No. 1 and No. 2 hydraulic systems, resulting in the potential loss of several functions essential for safe flight and landing of the airplane.