Applicability: Model GIV-X series aeroplanes, serial numbers (S/N) 4001 and subsequent; and Gulfstream Model GV-SP series aeroplanes, S/N 5001 and subsequent; on which Gulfstream Modification ASC-904 or production equivalent has been incorporated.

Requirement: Revise the Limitations Section of the Gulfstream G350, G450, G500 and G550 Aircraft Flight Manuals (AFM) by including the applicable revision listed in Table 1 of this Directive.

Any further revisions to the AFM must contain the identical procedures in the Limitations Section of the AFM revisions as required by this Directive.

Compliance: Within 10 days after the effective date of this Directive.

This Airworthiness Directive becomes effective on 22 March 2006.

Background: The United States Federal Aviation Administration has received a report indicating that all four of the cockpit flight panel display units simultaneously went blank during flight on a Gulfstream Model GV-SP aeroplane. The displays did not recover until the flightcrew pulled circuit breakers associated with the displays; subsequently, three of the four displays returned to normal. Initial investigation revealed discrepancies with the reversion logic of the advanced graphic modules. Similar display failures occurred during ground test operations. Such conditions, if not corrected, could result in a reduction of the flightcrew's situational awareness and possible loss of control of the aeroplane.

This Directive requires the revision of the Limitations section of the AFM by incorporating new procedures to follow in the event that the cockpit displays go blank or malfunction. The amendment of AFM is an interim measure and further rulemaking to correct the discrepancy is anticipated.

FMI: www.casa.gov.au