Federal Aviation Administration April 20, 2007 – Federal Register Recent Federal Regulation Documents

The FAA proposes to adopt a new airworthiness directive (AD) for all Airbus Model A310 series airplanes. This proposed AD would require revising the Airworthiness Limitations Section of the Instructions for Continued Airworthiness to incorporate new limitations for fuel tank systems. This proposed AD results from fuel system reviews conducted by the manufacturer. We are proposing this AD to prevent the potential of ignition sources inside fuel tanks, which, in combination with flammable fuel vapors caused by latent failures, alterations, repairs, or maintenance actions, could result in fuel tank explosions and consequent loss of the airplane.

The FAA proposes to supersede an existing airworthiness directive (AD) that applies to all Airbus Model A300 B2 and B4 series airplanes; and Model A300 B4-600, B4-600R, and F4-600R (collectively called A300-600) series airplanes. The existing AD currently requires repetitive inspections to detect cracking of the upper radius of the forward fitting of frame 47, and repair if necessary. This proposed AD would reduce inspection thresholds and repetitive intervals, and add related investigative and corrective actions. This proposed AD also would provide an optional terminating action for the repetitive inspections only for airplanes with cracking that is within certain limits. This proposed AD results from reports of additional cracking in airplanes that were inspected in accordance with the existing AD. We are proposing this AD to detect and correct fatigue cracking of the left and right upper radius at frame 47, which could propagate and result in reduced structural integrity of the airplane.

We are adopting a new airworthiness directive (AD) that supersedes AD 72-22-01, which applies to certain Raytheon Aircraft Company (RAC) (The Beech Aircraft Company and BEECH previously held Type Certificate Nos. 3A15, 3A16, 5A3, and A-777) Models 33, 35, 36, 45, and 95 series airplanes. AD 72-22-01 currently requires you to determine if each uplock roller is of the greasible type (one having a drilled and grooved inner race), replace any nongreasible uplock roller (one having a solid inner race) with the greasible type before further flight, install hollow zerk-ended mounting bolts on the uplock rollers, and repetitively lubricate the uplock mechanism. Since we issued AD 72- 22-01, there was a recent incident involving a RAC Model 95-B55B (T- 42A) airplane where a seizure of the uplock rollers occurred. This malfunction of the uplock rollers is addressed in AD 72-22-01. Thus, the FAA has determined that the actions of AD 72-22-01 should also apply to certain serial numbers of the Model 95-B55B (T-42A) airplanes. Consequently, this AD retains all the actions of AD 72-22-01, adds those Model 95-B55B (T-42A) airplanes to the applicability of this AD, and lists the specific serial numbers. We are issuing this AD to decrease the possibility of gear-up landings caused by seizure of the uplock rollers.

This action aligns the operational and certification safety requirements regarding over-pressurization of airplane extinguishing agent containers or fire bottles to prevent bursting; and it removes an obsolete section reference from part 135. This action eliminates the requirement for an over-pressurized fire bottle to discharge extinguishing agent outside an airplane to prevent bursting, because newer non-corrosive extinguishing agents can now be discharged inside an airplane without degrading an airframe.