Inspection Found Structural Damage To, And Separation Of Wing Ribs From Wing Planks
The FAA has issued an emergency airworthiness directive (AD) 2012-13-51 for Gulfstream Aerospace LP (Type Certificate previously held by Israel Aircraft Industries, Ltd.) Model Gulfstream G150 airplanes.
The Civil Aviation Authority of Israel (CAAI), which is the airworthiness authority for Israel, notified the FAA that an unsafe condition may exist on Gulfstream Aerospace LP Model Gulfstream G150 airplanes. The CAAI advises that fasteners protruding from the lower wing surface were discovered during a post-flight inspection. Investigation revealed structural damage to (and separation of) ribs from wing planks. Further inspection showed that the inboard vent tube hole was completely covered with sealant, which blocked airflow through the vent. This condition was also found on some airplanes in production. Under these conditions, the rise of internal pressure during pressure fueling or due to thermal expansion is sufficient to damage the wing. This condition, if not detected and corrected, could compromise the integrity of the wing structure.
This product has been approved by the aviation authority of another country, and is approved for operation in the United States. Pursuant to our bilateral agreement with the State of Design Authority, we have been notified of the unsafe condition described in the MCAI referenced above. The FAA is issuing this AD because we evaluated all pertinent information and determined the unsafe condition exists and is likely to exist or develop on other products of the same type design.
This AD requires a one-time detailed or borescope inspection of the left- and right-hand inboard vent holes for debris or obstructions, and repair if necessary. This AD also requires reporting positive inspection findings to the manufacturer. The inspection is to be done before further flight.