Safety Rules & Regs

Air Safety Week, July 14, 2008

Airworthiness Directives; McDonnell Douglas Model DC-9-81 (MD-81), DC-9- 82 (MD-82), DC-9-83 (MD-83), DC-9-87 (MD-87), and MD-88. Final rule. SUMMARY: This AD requires repetitive inspections for cracking of the overwing frames from stations 845 to 905 (MD-87 stations 731 to 791), left and right sides, and corrective actions if necessary. This AD results from reports of cracked overwing frames. We are issuing this AD to detect and correct such cracking, which could sever the frame, increase the loading of adjacent frames, and result in damage to adjacent structure and loss of overall structural integrity of the airplane.

Airworthiness Directive; Viking Air Models DHC-6-1, DHC-6-100, DHC-6-200, and DHC-6-300. Final Rule. SUMMARY: The AD results from mandatory continuing airworthiness information (MCAI) issued by an aviation authority of another country to identify and correct an unsafe condition on an aviation product. There have been reports of inter-rivet cracking on several wing front spar adapter assemblies (P/N C6WM1027-1) on the horizontal and vertical flanges. It was determined that the cracking was caused by stress corrosion in the short transverse grain initiated by local riveting induced stresses.

Airworthiness Directive; Viking Air Models DHC-6-1, DHC-6-100, DHC-6-200, and DHC-6-300. Final Rule. SUMMARY: This AD results from mandatory continuing airworthiness information (MCAI) issued by an aviation authority of another country to identify and correct an unsafe condition on an aviation product. Service experience indicates that as aircraft become older, they are more likely to exhibit indications of corrosion.

Airworthiness Directive; Hawker Beechcraft (Type Certificates No. 3A15, No. 3A16, No. A23CE, and No. A30CE previously held by Raytheon Aircraft) F33 Series and Models G33, V35B, A36, A36TC, B36TC, 95-B55, D55, E55, A56TC, 58, 58P, 58TC, G58 and 77. Final Rule. SUMMARY: This AD requires replacement of certain circuit breaker toggle switches with improved design circuit breaker toggle switches. This AD results from reports of certain circuit breaker toggle switches used in various electrical systems throughout the affected airplanes overheating. We are issuing this AD to prevent failure of the circuit breaker toggle switch, which could result in smoke in the cockpit and the inability to turn off the switch.

Airworthiness Directive; ATR Model ATR42-200, -300, -320, -500 Airplanes; and Model ATR72-101, -201, -102, -202, -211, -212, and -212A. Final Rule. SUMMARY: This AD results from mandatory continuing airworthiness information (MCAI) originated by an aviation authority of another country to identify and correct an unsafe condition on an aviation product. A recent incident evidenced that some failures of the Pitot probe heating resistance may not be seen by the low current detection system on aircraft not equipped with [ATR] modification 05469. In some conditions, an out of tolerance resistance, failing to provide a proper pitot probe de-icing could not be detected. The unsafe condition is that undetected icing of the pitot probe could produce incorrect airspeed readings, which could lead to loss of control of the airplane.

Airworthiness Directive; Boeing Model 747-400, 747-400D, and 747-400F. Final Rule. SUMMARY: This AD requires replacement of an electronic flight instrument system/engine indicating and crew alerting system (EFIS/EICAS) interface unit (EIU) located on the E2-6 shelf of the main equipment center with a new or modified EIU. This AD results from two instances where all six integrated display units (IDUs) on the flight deck panels went blank in flight. We are issuing this AD to prevent loss of the IDUs due to failure of all three EIUs, which could result in the inability of the flight crew to maintain safe flight and landing of the airplane.

Airworthiness Directive; Dornier Model 328-100. Final Rule. SUMMARY: This AD results from mandatory continuing airworthiness information (MCAI) originated by an aviation authority of another country to identify and correct an unsafe condition on an aviation product. During maintenance water has been found in the elevator [assembly]. The unsafe condition is water or ice accumulating in the elevator assembly, which could result in corrosion and consequent reduced structural integrity of the flight control surface, or an unbalanced flight control surface. These conditions could result in reduced controllability of the airplane.

Airworthiness Directive; Eurocopter France Model AS 355 N Helicopters. Final Rule. SUMMARY: This AD results from mandatory continuing airworthiness information (MCAI) originated by an aviation authority of another country to identify and correct an unsafe condition on an aviation product. This AD is issued because it was found that the power drawn by the starter generators from the engines is above the consumption capacity at altitudes above 3,000 meters, declared for the engines of AS 355 N helicopters. Excessive power consumption of the starter generators reduces the engine surge margin, which can result in engine failure.