Federal Aviation Administration March 31, 2009 – Federal Register Recent Federal Regulation Documents

We are adopting a new airworthiness directive (AD) to revise AD 2006-08-08, which applies to certain Air Tractor, Inc. (Air Tractor) Models AT-400, AT-401, AT-401B, AT-402, AT-402A, and AT-402B airplanes. AD 2006-08-08 currently requires you to repetitively eddy current inspect the wing lower spar cap in order to reach the safe life and, for certain Models AT-402A and AT-402B airplanes and those that incorporate or have incorporated Marburger Enterprises, Inc. (Marburger) winglets, lowers the safe life for the wing lower spar cap. Since we issued AD 2006-08-08, we have received information to update inspection intervals for the Models AT-401B, AT-402A, and AT-402B airplanes based on a revised damage tolerance analysis. Consequently, this AD would not only retain the actions of AD 2006-08-08, but would reduce the number of repetitive inspections for all affected Model AT- 401B airplanes and certain Models AT-402A and AT-402B airplanes. We are issuing this AD to prevent fatigue cracks from occurring in the wing lower spar cap before the originally established safe life is reached. Fatigue cracks in the wing lower spar cap, if not detected and corrected, could result in wing separation and loss of control of the airplane.

This rule establishes, amends, suspends, or revokes Standard Instrument Approach Procedures (SIAPs) and associated Takeoff Minimums and Obstacle Departure Procedures for operations at certain airports. These regulatory actions are needed because of the adoption of new or revised criteria, or because of changes occurring in the National Airspace System, such as the commissioning of new navigational facilities, adding new obstacles, or changing air traffic requirements. These changes are designed to provide safe and efficient use of the navigable airspace and to promote safe flight operations under instrument flight rules at the affected airports.

We are adopting a new airworthiness directive (AD) for certain Piper Aircraft, Inc. Models PA-46-350P and PA-46R-350T airplanes. This AD requires you to inspect the 35-amp and 250-amp current limiters to verify they are installed in the proper locations and correct the installation if the current limiters are not installed in the proper locations. This AD also limits operation to ``only under day visual flight rules (VFR)'' until the current limiter installation is inspected and corrected. This AD results from three reports of incorrectly installed current limiters. We are issuing this AD to detect and correct incorrect installation of 35-amp and 250-amp current limiters, which could result in failure of the 35-amp current limiter if installed in the 250-amp location. This failure could lead to a total loss of electrical power.

The FAA is adopting a new airworthiness directive (AD) for certain McDonnell Douglas Model MD-90-30 airplanes. This AD requires modifying the auxiliary hydraulic power system (including doing all applicable related investigative and corrective actions). This AD results from fuel system reviews conducted by the manufacturer, as well as reports of shorted wires in the right wheel well and evidence of arcing on the power cables of the auxiliary hydraulic pump. We are issuing this AD to prevent shorted wires or electrical arcing at the auxiliary hydraulic pump, which could result in a fire in the wheel well; and to reduce the potential of an ignition source adjacent to the fuel tanks, which, in combination with flammable fuel vapors, could result in a fuel tank explosion and consequent loss of the airplane.