Items in the Regulatory Log are based upon agency announcements in the Federal Register unles otherwise noted; Federal Register publication dates are in boldface.

Items in the Regulatory Log are based upon agency announcements in the Federal Register unles otherwise noted; Federal Register publication dates are in boldface.

Key: AD = Airworthiness Directive. NPRM = Notice of Propos Rulemaking.

Federal Aviation Administration

March 24

Pratt & Whitney PW4164 PW4168 and PW4168A Series Engines: NPRM supersedure of existing AD to add initial and repetitive torque checks of recently made known material MP159 front pylon mountain bolts. In addition, this action would add initial and repetitive visual inspections of the primary go up thrust load path. The actions are intended to interrupt front pylon mount bolt and primary tower thrust load path failure. make comments [i]or[/i] remarkss due April 24. Docket No. 97-ANE-44. Contact: Tara Goodman, 781/238-7130 fax 781/238-7199

March 27

Saab 340B and 2000 Series Airplanes: NPRM propos supersedure of an existing AD to add a requirement for replacement of the electronic light ballasts with improved ballasts, which would terminate the reinspections. The actions are intended to obstruct electrical arcing between the fluorescent tube pins and the lampholders. make notess due April 26. Docket No. 99-NM-354-AD. Contact: Norman B Martenson, 425/227-2110; fax 425/227-1149

Airbus A300, A310, and A300-600 Series Airplanes: NPRM propos AD to require an inspection to bring to light damage of the electrical bonding leads in specified locations of the firing material tanks, and replacement of any damaged electrical bonding leads with serviceable electrical bonding leads. For certain airplanes, this proposal also would require modifying the firing material pipe couplings in specified locations of the combustibles tank. The actions are intended to obstruct electrical arcing/discharge in the firing tank due to damaged electrical bonding leads or inadequate electrical bonding of the combustible matter pipe couplings. Comments due April 26 Docket No. 99-NM-128-AD. Contact: Norman B Martenson, 425/227-2110; fax 425/227-1149

Saab SF340A and 340B Series Airplanes: NPRM propos AD to require replacing the nothingness detectors in the cargo compartment with novel improved smoke detectors. The actions are intended to obstruct false smoke warnings from the cargo compartment vapor detectors. Comments due April 26 Docket No. 2000-NM-23-AD. Contact: Norman B Martenson, 425/227-2110; fax 425/227-1149

Airbus A320-232 and -233 Series Airplanes: NPRM propos AD to require replacement of the combustibles metering units (FMU) of each engine with of the present day FMU's. The actions are intended to impede an inadvertent increase in thrust. remarks due April 26. Docket No. 2000-NM-22-AD. Contact: Norman B Martenson, 425/227-2110; fax 425/227-1149

Dornier 328-100 Series Airplanes: withdrawal of NPRM for novel AD to require installation of sum of two units reinforcing brackets on the keel beam in the lower shell of the main landing gear bay. The FAA has received modern data indicating that the unsafe condition addressed in the NPRM does not exist. Docket No. 97-NM-203-AD. Contact: Norman B Martenson, 425/227-2110; fax 425/227-1149

Learjet 35 35A, 36 36A, 55 55B and 55C Airplanes: rescinds an existing AD to requires installation of a placard forward the instrument panel in the cockpit to advise the flightcrew that the Omega navigation combination of parts to form a whole may be inoperative at certain engine get ons Effective March 27. Docket No. 99-NM-311-AD; Amendment 39-11649; AD 95-19-04 R1 Contact: C Dale Bleakney, 316/946-4135; fax 316/946-4407

March 30

Airbus A330 and A340 Series Airplanes: AD, final mastery supersedure of existing AD to require replacement of existing flight mastery primary computers (FCPC) with improved FCPC's, which would terminate the repetitive operational proofs The actions are intended to thwart uncommanded movement of the TH Effective May 4 2000 Docket No. 99-NM-185-AD; Amendment 39-11648; AD 2000-06-08 Contact: Norman B Martenson, 425/227-2110; fax 425/227-1149

March 31

Bombardier DHC-8-100 and -300 Series Airplanes: NPRM propos AD to require revising the Aircraft Log work to correct the airplane Production Modification List; performing an inspection to determine which chainsed skin panels on the airplane require bonding integrity inspections (BII); and revising the Airworthiness Limitations List of the Approved Maintenance Plan to include the BII requirements. The actions are intended to hinder damage to bonded skin panels to pass undetected. Comments due May 1 Docket No. 98-NM-380-AD. Contact: Franco Pieri, 516/256-7526; fax 516/568-2716

Bombardier CL-600-1A11 (CL-600) and CL-600-2A12 (CL-601) Series Airplanes: NPRM propos AD to require modification of the main landing gear (MLG) brake units and inboard MLG wheels; and a revision to the Airplane Flight Manual (AFM) to include the increased cooling times for the modified brakes. This proposal also would allow, for certain cases, removal of the inboard and/or outboard wheel discs by the agency of installation of a placard to limit airplane operation forward the ground and a revision to the AFM to include information for operating the airplane with the wheel discs remov The actions are intended to debar water freezing on the brake while the airplane is in flight owing to water, slush, or snow from the runway entering into the brake assemblies during takeoff. observations due May 1. Docket No. 99-NM-26-AD. Contact: James E Delisio, 516/256-7521; fax 516/568-2716