Airworthiness Directives; Airbus Model A300 B4-600R Series Airplanes, A300 C4-605R Variant F Airplanes, A300 F4-600R Series Airplanes, and Model A310-300 Series Airplanes
The FAA proposes to adopt a new airworthiness directive (AD) for certain Airbus transport category airplanes. This proposed AD would require replacing the existing vent float valve with a new improved vent float valve. This proposed AD results from reports of failure of the vent float valve in the left-hand outboard section of the trimmable horizontal stabilizer. We are proposing this AD to prevent, in the event of a lightning strike to the horizontal stabilizer, sparking of metal parts and debris from detached and damaged float vales, or a buildup of static electricity, which could result in ignition of fuel vapors and consequent fire or explosion.
Airworthiness Directives; Boeing Model 747-100, 747-100B, 747-100B SUD, 747-200B, 747-200C, 747-300, 747-400, 747-400D, and 747SR Series Airplanes
The FAA proposes to supersede an existing airworthiness directive (AD) that applies to certain Boeing Model 747-100 and -200 series airplanes. The existing AD currently requires repetitive inspections for cracking of the station 800 frame assembly, and repair if necessary. This proposed AD would retain the repetitive inspection requirements of the existing AD, but would expand the area to be inspected. This proposed AD also would reduce the initial inspection threshold, remove the adjustment of the compliance threshold and repetitive interval based on cabin differential pressure, and add airplanes to the applicability. This proposed AD results from several reports of cracks of the station 800 frame assembly on airplanes that had accumulated fewer total flight cycles than the initial inspection threshold in the existing AD. We are proposing this AD to detect and correct fatigue cracks that could extend and fully sever the frame, which could result in development of skin cracks that could lead to rapid depressurization of the airplane.
Airworthiness Directives; Sandel Avionics Incorporated Model ST3400 Terrain Awareness Warning System/Radio Magnetic Indicator Approved Under Technical Standard Order(s) C113, C151a, or C151b; Installed on Various Small and Transport Category Airplanes
The FAA proposes to adopt a new airworthiness directive (AD). The new AD is for Sandel Avionics Incorporated Model ST3400 terrain awareness warning systems/radio magnetic indicator (TAWS/RMI) units as described above. This proposed AD would require installing a warning placard on the TAWS/RMI, installing upgraded software in the TAWS/RMI, revising the limitations section of the Airplane Flight Manual (AFM), and removing the placard and AFM revision after installing the software. This proposed AD results from a report that an in-flight bearing error occurred in a Model ST3400 TAWS/RMI, due to a combination of input signal fault and software error. We are proposing this AD to prevent a bearing error, which could lead to an airplane departing from its scheduled flight path, which could result in a reduction in separation from, and a possible collision with, other aircraft or terrain.
Airworthiness Directives; Honeywell International Inc. TPE331 Series Turboprop Engines
The FAA proposes to adopt a new airworthiness directive (AD) for Honeywell International Inc. TPE331 series turboprop engines with certain part numbers of Woodward fuel control assemblies installed. This proposed AD would require initial and repetitive dimensional inspections of the splines between the fuel pump and fuel control, for wear or damage. This proposed AD would also require replacing those fuel control assemblies with serviceable modified fuel control assemblies with improved overspeed protection. This proposed AD results from reports of loss of the drive between the fuel pump and fuel control, leading to engine overspeed, overtorque, overtemperature, uncontained rotor failure, and asymmetric thrust in multi-engine airplanes. We are proposing this AD to prevent rapid, uncommanded, uncontrolled increase in fuel flow to the engine, asymmetric thrust, uncontained rotor failure, and damage to the airplane.